Dinaric karst

8/6/2019 Dinaric karst

1/185


2/185

The designations employed and the presentation

of material throughout the publication do not

imply the expression of any opinion whatsoever

on the part of UNESCO concerning the legal

status of any country, territory, city or area

or of its authorities, or the delineation of its

frontiers or boundaries.

Published in 2010 by the United Nations

Educational, Scientific and Cultural Organization

7, place de Fontenoy, 75352 Paris 07 SP

Printed by UNESCO

UNESCO 2010

IHP-VII/2010/GW-2


3/185

SUSTAINABILITY OF THE KARST ENVIRONMENTDINARIC KARST AND OTHER KARST REGIONS

International Interdisciplinary Scientific Conference

(Plitvice Lakes, Croatia, 23-26 September 2009)Convened and Organised by:Centre for Karst (Gospi, Croatia)

International Scientific CommitteeOgnjen Bonacci (Croatia), ChairmanFranci Gabrovek (Slovenia)Mladen Jurai (Croatia)Boidar Biondi (Croatia)Wolfgang Dreybrodt (Germany)

Arthur Palmer (USA)Derek C. Ford (Canada)David Culver (USA)Andrej Mihevc (Slovenia)Jacques Mudry (France)Daoxian Yuan (China)Nico Goldscheider (Switzerland, Germany)Zoran Stevanovi (Serbia)Mario Parise (Italy)Hans Zojer (Austria)Elery Hamilton - Smith (Australia)

Neven Krei (USA)Bartolom Andreo (Spain)

Local Organizing CommitteeJadranka Pejnovi, Chaireljko upan, SecretaryIvo LuiNeven BoiAleksandar LukiLjudevit TropanDubravka Kljajo

Kreimir ulinoviIvica Tomljenovi


4/185

Foreword

The objective of the international interdisciplinary scientific conference Sustainability ofthe karst environment - Dinaric karst and other karst regions,organized by Centre forKarst, Gospi, Croatia, was to give a theoretical and practical contribution to the concept ofsustainable development in karst regions, with a special emphasis on the experiences achievedin the Dinaric karst region. The exchange of information and findings obtained in other karstregions worldwide allows for an integral approach to this complex issue, and thereby

contribute towards finding reliable solutions. The basic objective of the conference was toapply an interdisciplinary approach to scientifically assess the issues of sustainabledevelopment of all forms of karst.The issue was approached from different perspectives, from those of a technical andbiological nature, to those addressing the social aspects of environmental issues and life onthe karst. The conference itself was held at the Plitvice Lakes (World Heritage Site), one ofthe most fascinating phenomena on Earth. During the conference, one half-day excursion wasorganized to visit National Park Plitvice Lakes. Following the conference, an excursion wasorganised to visit several other significant phenomena of the Dinaric karst in Croatia.

Conference themes were:- Geological aspects- Geomorphological aspects- Hydrological and hydrogeological aspects- Coastal and submerged karst- Biological and ecological aspects of karst- Anthropogenic impacts and protecting karst- Sociological, demographic and social aspects of karst- Dinaric karst and other karst regions (China, Alpine, Caribbean karst, etc.)

The publication will serve as a contribution to the VIIth Phase of the InternationalHydrological Programme (IHP 2008-2013) of UNESCO, which has endeavoured to addressdemands arising from a rapidly changing world.

Chairman of Scientific Committee

Ognjen Bonacci


5/185

International Interdisciplinary Scientific Conference

SUSTAINABILITY OF THE KARST ENVIRONMENTDINARIC KARST AND OTHER KARST REGIONS

(Plitvice Lakes, Croatia, 23-26 September 2009)

TABLE OF CONTENTS

International scientific and local organising committees ......3 Foreword ...................................................................................................................................4Table of contents (authors in alphabetical order) ..5

BONACCI OgnjenSinking, losing and underground karst streamflows ..9

BORDA Daniela, RACOVI Gheorghe, NSTASE-BUCUR Ruxandra,CIUBOTRESCU ChristianEcological reconstruction of bat cave Roost in westernCarpathians .....17

BRINKMANN RobertKarst and sustainability in Florida, U.S.A. ........25

DELLE ROSE Marco, PARISEMarioWater management in the karst of Apulia, southern Italy ...33

DRFLIGER Nathalie, FLEURY Perrine, BAKALOWICZ Michel , EL HAJJ Hahmad,

AL CHARIDEH Abdoul, EKMEKCI MehmetSpecificities of coastal karst aquifers with the hydrogeologicalcharacterisation of submarine springs overview of various examplesin the Mediterranean basin ..41

DRFLIGERNathalie, PLAGNES Valrie, KAVOURI KonstantinaPaPRIKa a multicriteria vulnerability method as a tool for sustainablemanagement of karst aquifers - Example of application on a test site inSW France .49

EFTIMI RomeoInvestigation about recharge sources of Bistrica karst spring, thebiggest spring of Albania, by means of environmental hydrochemicaland isotope tracers ....57


6/185

GANOULIS Jacques, AURELI Alice, KUKURI NenoImportance of transboundary karst aquifer resources in South EasternEurope (SEE) ....67

GUO FANG Jiang Guanghui

The resources, environment and development in Fengshan Geoparkkarst area .......75

HUBINGER Bernhard , REHRL Christoph, BIRK SteffenLinking generic models to site-related models of conduit evolution 83

JAMES Julia M., SPATE Andy

Sustainability in a karst - the Bungonia Caves, New South Wales,Australia ....91

KATSANOU Konstantina, NIKOLAOUEuaggelos, SIAVALAS George, ZAGANA

Eleni, LAMBRAKIS Nikolaos

Hydrogeological conditions and water quality of the karstifiedformations of Louros basin, Epirus, Greece ......97

KNEZ Martin, SLABE TadejKarstology and motorway construction ...107

KNEZ Martin, SLABE TadejShilin - lithological characteristics, form and rock relief of the LunanStone Forests (South China karst) 115

KOVAI Gregor, PETRI MetkaContribution of time series analysis to the study of the Malenicakarst spring, Slovenia .123

MALEKOVI Sanja, TIMA Sanja , FARKA AnamarijaCapacity for managing local development in karst areas ...129

MUDARRA Matas, ANDREO BartolomHydrogeological functioning of the karst aquifer drained by YedraSpring(Southern Spain) from hydrochemical components andorganic naturaltracers ......137


7/185

NAUGHTON Owen, JOHNSTON Paul, GILL LaurenceThe hydrology of turloughs as groundwater dependent terrestrialecosystems ...147

PARISE Mario

Hazards in karst .155

PERNE MatijaModelling of rillenkarren formation 163

RUBINICJosip, KATALINICAna, SVONJAMirjana, GABRICIvana, BUSELIC

Gordana, CUZE Maja, HORVATBojana

Salinization of the Vrana Lake in Dalmatia within the context of

anthropogenic influences and climate changes (situation in 2008) 171

TERZI Josip, PAVII Ante, MARKOVI Tamara, LUKA REBERSKI JasminaProtection of the Miljacka karst spring: an underground connectionbetween the rivers Zrmanja and Krka 179


8/185

9

Sinking, losing and underground karst streamflows

Ognjen BONACCI

Faculty of Civil Engineering and Architecture, Split University, 21000 Split,

Matice hrvatske 15, Croatia, e-mail: [email protected]

Abstract: Sinking, losing and underground streamflows are typical and relatively frequent karstphenomena. A sinking surface streamflow can be defined as a surface river or stream flowing ontoor over karst and which then disappears completely underground through a swallow hole andwhich may or may not rise again and flow as a resurgent surface river or stream. A losingstreamflow can be defined as an open stream or river that loses water as it flows downstream. Thelevel of water in a losing stream is above the water table: in comparison, the level of water in againing stream is below the water table. In a losing stream water infiltrates underground, becausethe water table is below the bottom of the stream channel. Underground or subterranean

streamflows are subsurface karst passages with the main characteristics of open rivers or streams.In underground streamflows water flows through caves, caverns, karst conduits and large galleriesin karst underground. The paper treats some conceptual aspects of sinking, losing and undergroundstreamflows. Some cases of the special hydrological and hydrogeological behaviour of karstsinking, losing and underground streamflows are explained.

Keywords: karst,sinking, losing, underground streamflow

1 IntroductionKarst is defined as a terrain, generally underlain by limestone or dolomite, in which the

topography is chiefly formed by the dissolving of rock, and which is characterised by

sinkholes, sinking streams, closed depressions, subterranean drainage and caves (Field 2002).A wide range of closed surface depressions, a well-developed underground drainage system,and strong interaction the between circulation of surface water and groundwater typify karst.Due to very high infiltration rates, especially in bare karst, overland and surface flow is rare incomparison with non-karst terrains.

Carbonate rocks are more soluble than many other rocks. They are subject to a numberof geomorphological processes. The processes involved in the weathering and erosion ofcarbonate rocks are many and diverse. The varied and often spectacular surface landforms aremerely a guide to the presence of unpredictable conduits, fissures and cavities beneath theground. But at the same time these subsurface features can occur even where surface karsticlandforms are completely absent. Diversity is considered the main feature of karstic systems,

which are known to change over time and in space so that an investigation of each system onits own is required.

Interactions between the surface and subsurface in karst are very strong (Bonacci 1987).Groundwater and surface water are hydraulically connected through numerous karst featuresthat facilitate the exchange of water between the surface and subsurface (Katz et al 1997).High and fast oscillations of groundwater levels in karst control the hydrogeological andhydrological regimes of influent and underground streams. An important issue in studyingthese streams is that subsurface water is highly heterogeneous in terms of the location ofconduits, the location of vertically moving water, and flow velocities. Due to the previouslymentioned reasons, the occurrence of losing, sinking and underground streamflows is morethe rule than an exception.
mailto:[email protected]:[email protected]


9/185

10

A great problem regarding the explanation of the hydrological and hydrogeological behavior of such streamflows is connected with the particularities of karst undergroundfeatures and especially with karst aquifers. Karst aquifers are some of the most complex anddifficult systems to decipher. The highly heterogeneous nature of karst aquifers leads to aninability to predict groundwater flow direction and travel times. The circulation ofgroundwater in karst aquifers is quite different from water circulation in other non-karstic

type aquifers. The hydraulic permeability of karst aquifers is essentially created by flowingwater and has an anisotropic character.

In karst terrains groundwater and surface water constitute a single dynamic system. Dueto this reason one of the almost unavoidable characteristics of open streams, creeks and riversin karst regions is that they either have partial water loss along their course or completely sinkinto the underground (Bonacci 1987). Sinking, losing and underground streamflows are moretypical, significant and relatively frequent karst phenomena than is reflected in their treatmentin the karst literature. A synonym for a sinking and losing stream is an influent stream. Suchstreams have an integral function in karst hydrology and hydrogeology.

Influent and underground streams develop when they cross soluble rocks along theirtransfer route to base-level rivers or seas (Ray 2005). Challenges to the investigation of

influent and underground streams include the concurrent existence of fast turbulent flowthrough large karst conduits and slow, diffuse laminar flow through small karst fissures, joints,cracks and bedding plains (the karst matrix). Numerous and extremely varied surface andunderground karst forms make unexpected water connections possible in karst medium space,which changes over time. Changes of the underground flow path over the time are caused by:1) Different recharges from different surface areas, mainly due to the by variable distributionof areal precipitation; 2) Different groundwater levels and their rapid changes in time andspace; 3) Anthropogenic influence; and 4) Exogenic and endogenic forces (Bonacci 2004).

The objective of this paper is to discuss the hydrological aspects of losing, sinking andunderground streams that are closely connected with the hydrogeological characteristics of theregions through which they circulate. One of the key issues for the better understanding,

protection and management of karst systems is the determination of the influent andunderground stream catchment area. Due to very special and complex underground andsurface karst forms, there are a wide variety of cases of karst sinking, losing and undergroundstreamflows. An attempt at their conceptualisation is provided in the paper. The main issue inthe classification of these kinds of karst rivers is that they can be losing, sinking andunderground, all at the same time. A description of specific cases of the special hydrologicalbehaviour of sinking, losing and underground streamflows is given.

2 Losing streamflowA losing streamflow can be defined as an open stream or river that loses water as it

flows downstream. A losing streamflow is a surface stream that contributes water to the karst

groundwater system in localized areas. Ithas cracks in its bed that allow water to seep into thegroundwater. These losses can be massive in particular river sections, whereas in others theyare small and difficult or even impossible to observe without performing especially precisemeasurements. A direct way surface water becomes groundwater is through the capture ofsurface streams into subsurface voids through swallets. These features swallow the surfacestream and represent a rapid and direct way for groundwater recharge. Losing streamssegments are important groundwater recharge zones for underlying karst aquifers.

A losing streamflow is one having a bed that allows water to flow directly into thegroundwater system. The water level in a losing stream is higher than the water table, asopposed to the water level in a gaining stream which is lower than the water table. The waterthan infiltrates underground as the water table is lower than the bottom of the stream channel.


10/185

11

Losing streamflows are often used in relation to karst aquifers. Aquifers gain the water lost bythe losing stream. Due to very rapid rise and fall of groundwater levels in karst terrains, somelosing rivers or their losing stretches can intermittently act as gaining streams.

Figure 1 presents an attempt at the conceptualisation of losing streamflows.Occasionally, permanent water courses flow beyond the groundwater level, even for 50 m ormore. Bonacci (1987, 1999) called these river sections suspended or perched. Water

infiltrated from these sections can either flow in another catchment or can reappear in thedownstream reaches of same river (at the spring B in Figure 1b).

a)

b)B

c)B

river section without losses

river flow direction

sinkhole (swallow hole, ponor)

flow direction of infiltrated water through thelarge karst conduits in the same river catchment

Legend:

spring

suspended river section

flow direction of infiltrated water through the

karst matrix in the same river catchment

flow direction of infiltrated water through the

large karst conduits in an other river catchment

flow direction of infiltrated water through thekarst matrix in an other river catchment

B spring can bepermanentor intermittent

Figure 1 Conceptualisation of losing streamflows

For example suspended or perched stretches exist on two neighbouring karst riversZrmanja and Krka (Dinaric karst of Croatia). While the Zrmanja River dries out, the KrkaRiver never dries out in these sections. The reason why there are no water losses on the Krkasuspended section of the Krka is in the fact that its riverbed is comprised of fine-grainedsediments, which make infiltration impossible.

Dye-tracing methods are commonly used to determine groundwater flow paths,relations between surface water and groundwater, and groundwater travel times through thekarst underground. It should be stressed that flow paths, connections between certain sinksand springs, very often vary in time and space, mainly due to the varying groundwaterconditions in the underground. Complexity of the precise determination of the water lossesalong open streamflows in karst is discussed by Bonacci (1987).

3 Sinking streamflowA sinking surface streamflow can be defined as a surface river or stream flowing onto or

over karst that then disappears completely underground through a swallow-hole (ponor orsinkhole) and which may or may not rise again and flow as a resurgent surface river or stream.Infiltration from sinking streams into the karst groundwater system is the most rapid form ofrecharge for carbonate aquifers (Hess et al 1989).

Sinking streams represent the most direct access to the sensitive and highly vulnerablekarst groundwater system. The unique nature of sinking rivers is their development andevolution of conduit flow routes and caves through soluble rocks. The evolution of most ofthe worlds largest and most significant karst caves and springs are formed as a consequenceof large volumes of concentrated recharge from sinking rivers (Ray 2005).


11/185

12

Figure 2 presents an attempt at the conceptualisation of sinking streamflows. Sinkingstream can reappear at the surface through a typically large karst spring (Figure 2a), thoughthere are some cases when it reappears through many permanent and intermittent karst springsdissipated over a large area.

a)

b)

intermittent (temporary) spring

river flow direction

sinkhole (swallow hole, ponor)

flow direction of sinking water

through large conduits

Legend:permanent spring

flow direction of sinking water

through karst matrix

Figure 2 Conceptualisation of sinking streamflows

Hess et al (1989) explains that the south-Central Kentucky karst aquifer is fed by manysinking streams. Their catchments are made up of an aggregate of many small surfacecatchments ranging over an area of a few square kilometres. Some of these streams haveseveral surface tributaries, but most of the sinking creeks are short, first order streams.

The Lika and Gacka Rivers (Dinaric karst of Croatia) are typical sinking streamflows.These rivers are located in the central part of the Dinaric karst region of Croatia (Figure 3) between 4417 and 4458N and 1507 and 1548E. Their precise hydrologicalcatchment areas and boundaries are not known (Bonacci and Andri 2008). The Velebit

Mountain (max. altitude 1758 m a. s. l.) separates their catchments from the Adriatic Sea.Water from the both rivers sinks at altitudes between 400 and 450 m a. s. l. and reappears atmany permanent and intermittent coastal and submarine karst springs of the Adriatic Sea(Figure 3).

4 Underground streamflowUnderground or subterranean streamflows are subsurface karst passages that have the

main characteristics of open rivers or streams. In an underground streamflow, water flowsthrough caves, caverns, karst conduits and large galleries in the karst underground. The karstunderground system provides access to fragments of the abandoned conduit system, whichhave hydraulic geometries comparable, though not identical, to those of surface rivers or

streams.The Port Miou system (Cassis, France) is a two kilometre long submarine gallery that

extends in the limestone series of Calanques (Marseille, France). The two largest karstsubmarine springs, Port Miou and Bestouan, represent the mouths of two underground karstrivers into the Mediterranean Sea. The average discharge of brackish water flowing from thePort Miou spring is between 2 to 5 m3/s (Poti et al. 2005; Cavalera and Gilli 2009). The roofof the entirely submerged Port Miou gallery lies between 10 and 20 m below sea level toabout 800 m from the spring exit. It then goes between 10 to 30 m deeper. At about 2200 mfrom the entrance, the primarily horizontal karst conduit suddenly drops into a deep verticalshaft. Cave divers were able to explore the conduit to a depth of 179 m below sea level. At


12/185

13

that depth, the water is still brackish. The system extends further and deeper, howeverexploration is limited by the present diving technology.

Figure 3 The Lika and Gacka Rivers (Dinaric karst of Croatia), typical sinking streamflows

The Cassidaigne canyon cuts the continental shelf where bathymetric studies haveshown the presence of dolines. Caves and speleothems have been observed during submarineexplorations on the walls of the canyon. Its presence is related to the several stages of the

lowering of the Mediterranean Sea during the Messinian salinity crisis. Cavalera and Gilli(2009) suggest that during the important drop of sea level of the Mediterranean, theunderground river of Port-Miou, flowed several hundreds meters below its current position,and excavated the canyon. At the end of the Messinian crisis, the system was flooded by seawater. Karst water now flows through an upper gallery, however the presence of a paleo-drainfilled by sea water makes deep marine intrusion into the karst system possible. In order toprevent intrusion of sea water, two submarine dams were constructed in the horizontal conduit,about 500 m from the spring exit. However, the issue of contamination with sea water was notresolved by their construction. Cavalera and Gilli (2009) consider that the salinecontamination of Port Miou could be carried out by a sea water inflow through a deep karsticconduit connected to the canyon of Cassidaigne.

The Santa Fe River (Florida, USA) flows from an impervious catchment onto karstifiedEocene limestones. At the OLeno Sink, it sinks underground for 5 km before resurfacing atthe Santa Fe River Rise. Hisert (1994) conducted a geochemical tracer study to determinewhich of the numerous karst features occurring between the OLeno Sink and the Santa FeRiver Rise are connected to the underground river. In addition, water temperaturemeasurements were made to distinguish the relative proportions of groundwater and surfacewater in each water filled karst feature. The results showed that the Santa Fe River Rise is a point of resurgence for a portion of the Santa Fe River flow diverted underground at theOLeno Sink. The underground river course is singular and sinuous. The flow is conduit andrapid with a velocity of 2.5 km/day (Hisert 1994). The upstream half of the underground riveris fairly well delineated, due to the great number of surface sink features. In the downstream


13/185

14

section, the underground course is questionable due to the lack of surface karst features thatcan be used as windows to the karst underground.

Figure 4 presents the map of the Disu underground stream system (Yuan 1991), whichhas a catchment area of 1004 km2. The system has a total length of 241.1 km, and includes amain conduit that is 57.2 km long and 12 tributaries. The Disu underground system is thelongest identified subterranean stream in China. In the upstream section, it is about 100 m in

depth, with karst conduits usually in a simple fissure-shape, from several meters to 30 m wide,and ten to tens of meters high. The average hydraulic gradient is about 12%. At the middleand lower reaches, it is 30 to 50 m below the bottom of the valleys. The cross-section of theconduit here varies between 145 and 184 m2, and the average hydraulic gradient is 1%.Discharges at the exit of the Disu underground river vary from the minimum 4.03 m3/s in dryseason to the maximum 544.9 m3/s (Yuan 1991).

Figure 4 The Disu underground stream system in China (Yuan 1991)

5 DiscusionTrue cases of karst losing, sinking and underground rivers are much more complex than

any concept can imagine. In reality, very different combinations exist. Some streams can, atthe same time, be losing, sinking and underground.

The Dobra River (Dinaric karst of Croatia) serves as a good example. Figure 5represents the longitudinal cross-section of the entire Dobra River, divided into three parts.The first one is a losing and sinking river called Upper Dobra, with a length from the spring tothe ula sink-hole of 51.2 km. The second part is an underground karst river flowing from theula sink-hole to the karst spring zone near the village Gojak. The shortest aerial distancebetween the ula sink-hole and the Lower Dobra River karst springs zone is 4.6 km. In orderto reappear at the karst springs zone, the Lower Dobra River flows through karst caves andconduit system that is 16,296 km long. The longitude of the Lower Dobra River is 52.1 km.There are huge water losses along some sections of the open watercourse of the Upper DobraRiver through small karst sinks located at the bottom of its channel. These have changed over


14/185

15

time as a function of the groundwater level. During periods with high groundwater levelslosing stretches become gaining stretches.

The importance of sinking, losing and underground streamflows in karst systemfunctioning is very significant. Their hydrological, hydrogeological and other characteristicsare extremely complex. Due to these reasons, it is necessary to apply interdisciplinaryapproaches, methods and concepts in their investigation. It is obvious that efforts aimed at to

their better understanding should be intensified.

0.0

110.0

11.1

110.0

34.8

140.0

40.1

147.4

48.0

175.0

51.7

200.0

56.3

320.0

60.7

322.5

62.6

323.0

65.6

335.0

350.0

420.0

107.9

840.0

94.7

77.9

110.0

175.0

320.0

840.0

"MORAVICE"GAUGINGSTATION

"LUKE"GAUGING

STATION

"HRELJIN"GAUGING

STATION

"TURKOVICI"GAUGING

STATION

"SV.PETAR"GAUGING

STATION

"DANI"GAUGING

STATION

"LECE"GAUGING

STATION

"STATIVE"GAUGING

STATION

HEPPGOJAK

ULASINKHOLE

"TROMARIJA"GAUGING

STATION

RIVERMOUTH

RIVERSPRING

ALTITUDE[m

a.s.l.]

100

200

300

400

500

600

700

800

900

1000

ALTITUDE

[m a.s.l.]

L [km]

0 km 20 km 40 km 60 km 80 km 100 km 107.9km

39.0

147.0

HEPPLECE

~

Figure 5 Longitudinal cross-section of the Dobra River (Dinaric karst of Croatia)

ReferencesBonacci O (1987) Karst hydrology with special references to the Dinaric karst. Springer

Verlag, Berlin, 184 ppBonacci O (1999) Water circulation in karst and determination of catchment areas:

example of the River Zrmanja. Hydrological Sciences Journal 44(3):373-386Bonacci O (2004) Hazards caused by natural and anthropogenic changes of catchment

area in karst. Natural Hazards and Earth System Sciences 4:655-661Bonacci O, Andri I (2008) Sinking karst rivers hydrology: case of the Lika and Gacka

(Croatia). Acta Carsologica 37(2-3):185-196

Cavalera T, Gilli E (2009) The submarine river of Port Miou (France), A karstic systeminherited from the Messinian deep stage. Geophysical Research Abstracts Vol. 11, EGU2009-5591

Katz BG, DeHan RS, Hirten JJ, Catches JS (2007) Interactions between ground waterand surface water in the Suwannee river basin, Florida. Journal of the American ResourcesAssociation 33(6):1237-1254

Field MS (2002) A lexicon of cave and karst terminology with special reference toenvironmental karst hydrology. USEPA, Washington, DC, 214 pp

Hess JW, Wells SG, Quinlan JF, White WB (1989) Hydrogeology of the South-CentralKentucky karst. In: WB White, EL White (eds) Karst hydrology concepts from the Mammothcave area. Van Nostrand Reinhold, New York, pp 15-63


15/185

16

Hisert RA (1994) A multiple tracer approach to determine the ground water and surfacewater relationships in the Western Santa Fe River, Columbia County, Florida. Ph.D.Dissertation, Department of Geology, University of Florida, Gainesville, FL 32601.

Poti L, Ricour J, Tardieu B (2005) Port-Mioux and Bestouan freshwater submarinesprings (Cassis-France) investigations and works (1964-1978). Proceedings of InternationalConference Water resources & environmental problems in karst, Belgrade and Kotor, pp

266-274Ray JA (2005) Sinking streams and losing streams. In: DC Culver, WB White (eds)

Encyclopedia of Caves. Elsevier, Amsterdam, pp 509-514Yuan D (1991) Karst of China. Geological Publishing House, Beijing, 232 pp


16/185

17

Ecological reconstruction of bat cave Roost in westernCarpathians

Daniela BORDA1, Gheorghe RACOVI1, Ruxandra NSTASE-BUCUR1, Christian

CIUBOTRESCU

2

1 Emil Racovitza Institute of Speleology, Clinicilor St., no 5, 400006 Cluj-Napoca,Romania, e-mail: [email protected]

2 Speleological Association for Environmental Protection and Karst "Sfinx" Grda, Romaniae-mail: [email protected]

Abstract: The underground environment represents an extreme and, at the same time, fragileenvironment because of the particularities of biotic and abiotic factors and of its trophicdependence on surface ecosystems. The high constancy of cave factors makes it one of the mostvulnerable environments on Earth. Because of the increased human pressure, in the last decadeswe witnessed a strong degradation of the underground environment in areas exposed to pollution,as a consequence of restraining, retreating or even extinction of specific fauna. In this context wemonitor a show cave where the cave electrification and the wood staircase, which facilitated thetourists passage in the upper level, were removed. Also, the artificial entrance to the upper levelwas reversibly obstructed. Our research focused on analyzing the microclimatic conditions, as wellas on the airborne microorganisms from the cave, and on the bat dynamics, after the obstruction ofthe artificial entrance in the upper level of the cave. The results show a direct relation betweencave climate, bats, airborne microorganisms, and the cave visitors. From the climatic perspectivePoarta lui Ionel Cave is characterized by a permanent bidirectional thermal circulation and theexistence of a convection cell exclusively at the level of the lower gallery. The bat monitoringshowed that a nursery colony ofMiniopterus schreibersii re-inhabited the cave in a very short time

after the show paths were removed. The success of the ecological reconstruction was confirmed bythe return of the colony next summer. Bats contribute significantly to the generation, spreadingand maintaining of a rich and diversified air microflora. Also, the morphology of the cave and itsventilation system contribute to conducting and concentrating airborne microbial communitiestoward the upper level of the cave. In the evolution of the cave air microflora a seasonal tendencyis evident, according to which a quantitative and qualitative maximum is recorded in spring-summer and a minimum in autumn-winter. To conclude, our results reveal important implicationsfor cave and bat management.

Keywords: cave, ecological reconstruction, climate, bats, airborne microorganisms

1 IntroductionThe subterranean habitat represents an extreme environment with unique characteristicslike its trophic dependence on surface ecosystems, and to the particularities of biotic andabiotic factors (Biswas 2009). The high constancy of these factors makes cave and theirassociated faunas one of the most vulnerable environments on Earth (Juberthie 2000).Because of the increased human pressure in the last decades we witnessed a strongdegradation of the underground environment followed by the retreating or even extinction ofspecific fauna (Elliot 2000). Bats are particularly sensible to a persistent human disturbance inmaternity sites and hibernacula (Kurta et al. 1993). Disturbances of these roosts are the majorcause for the bat depopulation and may induce bats mortality and caves abandonment (Martinet al. 2000). Poarta lui Ionel Cave is an example for the bat depopulation due to improper

show exploitation in the last 20 years. A recent effort was realized by the Speleological
mailto:[email protected]:[email protected]:[email protected]:[email protected]


17/185

18

Association Sfinx Grda who tried to recover the bat colonies from this cave. Theconservation measures, which intended to reduce the human pressure in the bat roost, wereaccomplished by a climatic study that is still in progress, as well as a mesophilic airbornemicroorganisms screening. The airborne microbial communities are well represented in thesubterranean environment, but not all of them are resident in cave, being carried in fromoutside by human and animals (Borda and Borda 2006, Borda et al. 2009). Additional work

has shown that bats are responsible by an increase of the airborne microorganisms in the caveatmosphere (Borda et al. 2004). Our researches focus on: (i) the analysis of the climate ofPoarta lui Ionel Cave after the ecological reconstruction, (ii) determination of the airbornebat-related microorganisms, and (iii) monitoring the seasonal presence of bats in the cave.

2 Materials and methods

2.1 Climatic DataThe temperature and relative humidity were measured by Tinytag Dataloggers Plus 2

(-25 + 85oC and 0 100% RH) registering. The data loggers were set to take themeasurements at 1-hour intervals. In order to detect the meroclimatic structure of the cave

(Racovi 1984), we established 5 sample sites (samples 1-5), located from entrance to theterminal passage of the cave (Fig. 1).The climatic study is still in progress, the records beingcarried out for at least one year.Therefore, our results are partial, covering the time periodfrom 15 November 2008 to 11 June 2009.

2.2 Air microflora Samples CollectingAirborne microorganisms samples were collected by gravitational sedimentation

(Kochs sedimentation method) in two sample sites: in the visiting passage (samples I) fromthe lower level of cave, and in the passage not open to public access from the upper level ofthe cave (samples II) (Fig. 1). Investigations were performed seasonally.The specific mediawere exposed to the cave air for 30 min. After that, the Petri dishes were stored and

transported to the laboratory at 50C, where they were incubated in specific conditions.

2.3 Culture MediumsWe used sterile media for the growth of the following groups of air microorganisms:x Beef-extract agar medium - for the total count of aerobic bacteria growth (TAG);x Levine medium - for gram-negative bacteria growth (GNB);x Chapmann medium - for staphylococci growth (SPH);x Holmes medium - for streptococci growth (STP);x The Sabouraud medium for fungi growth (FUN).The media for the aerobic mesophilic bacteria (TAG, GNB, STP, and SPH) were

incubated at 37C for 24 hours and the media for fungi was incubated for 3-5 days at 20 0C, indarkness conditions. The total count of the colony-forming units was calculated using theOmelianskis formula. The results were expressed per m3 of air (cfu/m3) (Popescu and Borda2008).

3 Results and discussions

3.1 Cave reconstructionPoarta lui Ionel Cave located near the village Garda de Sus (Bihorului Mountains,

Western Carpathians) is easily accessible, being known by natives from very old times. Thecave was first mentioned by J. Vass in 1857 (Bleahu 1976) and described by Jeannel andRacovi (1929). The entrance is represented by a portal impressive by its dimensions (20m


18/185

19

height and 15m width) open in the background of a rocky amphitheatre. Thus, the name ofPoarta (Gate), given to this cave by natives, is very proper. Beyond this portal an activegallery opens, wide of 5-7m and long of 130m that turns twice toward left in right angle (Fig.1). Except of some fragments on the limestone floor and a big stalagmite flow of 6m height,this sector of the cavity lacks any concretion. In its extremity, on the clayey floor is anexcavation in form of a funnel with a diameter of 5m that fills up with water in periods with

abundant precipitations. Usually, the subterranean stream appears only at the base of theportal, from a spring situated at the base of the left wall. At high flood the waters appear in thefirst turn of the gallery among the alluvium accumulated beside the right wall.

Figure 1 Map of Poarta lui Ionel Cave and the samples sites. M I - M II, AirborneMicroorganisms sample sites; C 1 C 5, Climate sample sites

During an international expedition in 1988 an upper level of the cave was discovered,fact that determined the inclusion of the entrance of Poarta lui Ionel Cave in a more ampletouristic circuit, together with the Scrioara Glacier Cave. The galleries that form the upperlevel of the cavity are ordered on two levels, inter-connected by a couple of not very deepwells. The terminal part is totally closed by a compact wall of limestone, in which animpenetrable fissure can be seen.

The first arrangements consisted in installing the wood access stairs toward the upperlevel and digging an opening of about 150/40cm at the base of the stalagmite wall that blocked the access to the new discovered sector. Starting with 1992, the SpeleologicalAssociation for Environmental Protection and Karst "Sfinx" from Grda restored thearrangements, and in 2003, together with the mayoralty of Grda de Sus village, they realisedthe electric illumination of the cave.

Based on the evidences of chiropterit spots on the ceiling of the cave, and also on thenatives token, the Speleological Association Sfinx Grda restored the old maternity shelter.


19/185

20

The ecological reconstruction of the cave started in April 2008 and lasted a few days. Thework consisted in the elimination of the cave electrification and of the wood staircase,restricting thus the tourists passage to the upper level. Also, the artificial entrance to theupper level was reversibly obstructed with resident stones from the cave and walled in.

3.2 Cave climate

The climatic particularities of the cave are mainly determined by the air currents thatmove between the exterior and the subterranean void (Racovi 1975). Their origin relies inthe thermo-circulation, determined by temperature difference between the subterranean andthe surface atmosphere and, implicitly, the air density difference that moves (Andrieux 1970).Because Poarta lui Ionel Cave has a single communication way with the surface, representedby the big entrance (20m/15m), the air changes with the exterior are permanently bidirectional,with moderate external perturbation. In winter time the cold air enters the cave at the floorlevel and the warm air from inside out at the ceiling level. In summer time the air thermo-circulation is inverted. Because the lower gallery is huge and slightly ascendant, the air flowis very weak, functioning as cell convection. Besides, the effects of hibernal thermo-circulation upon the subterranean atmosphere materializes by the emergence of an important

number of ice formations (stalagmites, stalagmitic domes and parietal crusts), but only in thevicinity of the cave entrance.

The temperature values registered in the lower level of the cave (Fig. 2) show followingwinter averages (15 November 31 March): -0.3960C (St. Dev. = 2.346) at the entrance of thecave (sample 1), 1.6510C (St. Dev. = 2.215) at the basal level (sample 2), 3.0190C (St. Dev. =1.546) in the lake gallery (sample 3).

Lower Level - Sample Site 1

-10. C

-5. C

0. C

5. C

10. C

15. C

20. C

Nov-08 Dec-08 Jan-09 Jan-09 Feb-09 Mar-09 Apr-09 May-09Jun-090.0 %RH

20.0 %RH

40.0 %RH

60.0 %RH

80.0 %RH

100.0 %RH

Temperature

Humidity

Lower Level - Sample Site 2

-10. C

-5. C

0. C

5. C

10. C

15. C

20. C

Nov-08 Dec-08 Jan-09 Jan-09 Feb-09 Mar-09 Apr-09 May-09 Jun-090.0 %RH

20.0 %RH

40.0 %RH

60.0 %RH

80.0 %RH

100.0 %RH

Temperature

Humidity

Lower Level- Sample Site 3

-10. C

-5. C

0. C

5. C

10. C

15. C

20. C

Nov-08 Dec-08 Jan-09 Jan-09 Feb-09Mar-09 Apr-09 May-09 Jun-09

0.0 %RH

20.0 %RH

40.0 %RH

60.0 %RH

80.0 %RH

100.0 %RH

Temperature

Humidity

Figure 2 The air temperature and relative humidity (RH %) trend in the lower part of thePoarta lui Ionel Cave from November 2008 to June 2009

In upper part of the cave, behind the walled gate, the air temperature is constantly higherthen in the basal passages (Fig. 3). Theoretically, the upper level can function as a warm airtrap and the temperature should rise to about 20C (i.e. Wonders Room from Huda lui PaparCave, Trascu Mountains). Before digging the artificial opening, the access to the upper level


20/185

21

was made only through the natural window that has a lower section. Therefore, the existenceof considerable temperature differences between the two levels can be excluded. Besides, thenatural window that opens close to the ceiling remains inaccessible to any cold air current thatmove at the level of the floor. As a result, the upper gallery shows a more constanttemperature slightly higher than the lower level, 7.6850C (St. Dev. = 0.832) behind of thewalled gate (sample 4), and 7.4540C (St. Dev. = 0,123) at the end of the cave (sample 5).

Due to the huge entrance that is the subject to high temperature fluctuations dependentto the external climate and in accordance with the climatic data, the basal level of the cave isrepresented by a perturbation meroclimate. The relative humidity ranged 67% near theentrance to constantly 100%, above the temporary lake (Fig. 1).

Upper Level - Sample Site 4

-10. C

-5. C

0. C

5. C

10. C

15. C

20. C

Nov-08 Dec-08 Jan-09 Jan-09 Feb-09 Mar-09 Apr-09 May-09 Jun-09

0.0 %RH

20.0 %RH

40.0 %RH

60.0 %RH

80.0 %RH

100.0 %RH

Temperature

HumidityUpper Level - Sample Site 5

-10. C

-5. C

0. C

5. C

10. C

15. C

20. C

Nov-08 Dec-08 Jan-09 Jan-09 Feb-09 Mar-09 Apr-09 May-09 Jun-090.0 %RH

20.0 %RH

40.0 %RH

60.0 %RH

80.0 %RH

100.0 %RH

Temperature

Humidity

Figure 3 The air temperature and relative humidity (RH%) trend in the upper part of thePoarta lui Ionel Cave from November 2008 to June 2009

The upper level is represented by a stability meroclimate, where the temperature isconstant all year long and the relative humidity was also constantly saturated (Fig.2).

3.2 Bats

Although Jeannel and Racovi (1927) did not cite the bat colony occurrence when theyvisited the cave, the spots of chiropterit on the ceiling and parietal leaking, as well as thetestimony of natives prove that Poarta lui Ionel Cave sheltered in the past significant batnurseries. In the period of tourist management during our research we did not record any batcolonies. We recorded a few specimens of Myotis spp., Rhinolophus spp, Barbastellabarbastellus,Plecotus spp. only in the lower level, at the beginning of the winter.

After the pressure induced by tourists was eliminated and the cave was brought back tothe natural state, the bat colonies immediately installed in the old summer roost. In May 2008a nursery colony ofMiniopterus schreibersii of more than 150 individualswas found in theupper part of the lower level of the cave (about 20 m high). The bats re-inhabited the cave in afew weeks after the ecological reconstruction of the cave was implemented. The success of

the ecological cave reconstruction was proved by the maternity colony ofM. schreibersii thatreturned to the cave in May 2009.Pursuant to the climatic traits, the lower level of the cave is not suitable for bats

hibernation. But in the upper level the climate is more constant, with higher temperatures.Therefore, Rhinolophidae prefer that part of the cave for the hibernation period. During thewinter 2008-2009 in this part of the cave were recordedRhinolophus ferrumequinum (13 ind.),R. hipposideros (1 ind.), R. euryale (1 ind.), Myotis myotis/M. oxygnathus (2 ind.), Myotis spp.(1 ind), Miniopterus schreibersi (5 ind). All species encountered in the cave are strictly protected (Annex II, 13/1993 Law), migratory species (Annex II, 13/1998 Law) and alsospecies of European Community interest whose exploitation may be subject to managementmeasures (Annex 3, 57/2007 OU).


21/185

22

We consider that the main perturbation factor that contributed to bat colonies extinctionin the Poarta lui Ionel Cave was represented by human disturbance in the vulnerable periodsof their biological cycle. To this, we can add the system of electric illumination of the caveand the gate with vertical bars, placed at the artificially digging opening from the base of theupper level.

3.3 Airborne microorganismsThe results concerning the airborne microorganisms diversity and concentrations in

Poarta lui Ionel Cave are showed in Fig. 4. Total aerobic germs showed the highest values,corresponding with the beginning of the bats maternity season. The morphology of the caveimprints a stability climate at this level, with higher temperatures than in the lower level,favourable to the development of a mesophilic air microflora. Besides, the air circulationfavours the airborne microorganisms to remain captive in the upper level.

The presence of bats and guano, corroborated with morphological particularities of thecave (Borda et al. 2004) explains the high incidence of the five groups of microorganismswith hygienic significance and the high number of colony forming units in the upper levelcompared with the lower level. The presence of fungi is less significant, compared with that

of other microorganisms, their occurrence being in an increased number in the lower level,close to the entrance. Usually the fungi originate from the exterior (Caumartin 1966, Koilrajet al. 1999), their number decreasing from the entrance to the profound areas of the cave(Borda and Borda 2006).

0 1000 2000 3000 4000 5000 6000 7000

UFC/m3

Autumn

Winter

Spring

Summer

Airborne Microorganisms in the Upper Level TAG

STP

SPH

GRN

FUN

0 1000 2000 3000 4000 5000 6000 7000

UFC/m3

Autumn

Winter

Spring

Summer

Airborne Microorganisms in the Lower Level TAG

STP

SPH

GRN

FUN

Figure 4 Seasonal variationsof airborne microorganisms in Poarta lui Ionel Cave


22/185

23

The seasonal tendency of air microflora indicates a maximum of the mesophilicbacteria in the warm season, during the summer for the lower level and during the spring forthe upper level. The absence of fungi in the spring can be explained by their biological cycle.

All these data are important for the future cave management plans that should takeinto account the needs of the bats, the effects of human disturbance upon the bat populationsand also the airborne microorganism biohazards.

3 ConclusionsAfter the ecological reconstruction, the Poarta lui Ionel Cave was re-populated by a

maternity colony ofMiniopterus schreibersii. The climatic particularities of the cave supportthe bats colonies. This is characterised by a permanent bidirectional thermo-circulation and bythe existence of a cell convection that closes at the extremity of the lower gallery, withoutaffecting the upper level of the cave. Bats significantly contribute to the spreading andmaintaining of a rich and diversified air microflora. The morphology and ventilation of thecave contributes to the directing and concentrating the airborne microbial communities towardthe upper level. A seasonal tendency of airborne microorganisms is evident, being assured bythe temperature of the external environment and by the presence of tourists. Therefore, we

consider these investigations relevant for cave conservation and for the protection of varioustypes of bat colonies that inhabit these caves, even in the conditions of tourist exploitation.

AcknowledgmentsWe thank the staff of the Apuseni Natural Park Administration, who helped us and

contributed with logistics in the field. We are particularly thankful to Negrea Avram for fieldassistance.

This study was supported by The ID_2325 Grant from CNCSIS.

ReferencesAndrieux C (1970) Contribution a ltude du climat des cavits naturelles des massifs

karstiques. II. Arodiynamique souterraine. Ann. Splol. XXV(2):491-529Bleahu M, Decu V, Negrea S, Plea C, Povar I, Viehmann I (1976) Caves from

Romania, Ed. tiin. Enc. 415 ppBorda D, Borda C, Tma T (2004) Bats, climat, and air microorganisms in a Romanian

Cave. Mammalia 68(4):337-343Borda C and Borda D (2006) Airborne microorganisms in show caves from Romania.

Trav. Inst. Spol. mile Racovitza 43-44: 65-74Borda D, Bucur-Nstase R, Borda C, Gorban I (2009) The assessment of the airborne

microorganismes in subterranean environment, Bulletin UASVM, Veterinary Medicine 66 (1)(in press)

Caumartin V (1966) Principes de repartition des associations dorganismes

microscopiques en caverns. Bull. Sci. Bourgone 24:39-56Elliot W R (2000) Conservation of the North American cave and karst biota. In:

Wilkens H, Culver D C, Humphreys W (Eds.) Ecosystems of the World - SubterraneanEcosystems, Elsevier. pp 665-689

Jayant B (2009) The biodiversity of Krem Mawkhyrdop of Meghalaya, India, on theverge of extinction, Current Science 96(7):904-910

Jeannel R, Racovi E G (1927) Enumration des Grottes visites, 1918-1927 (VII -e

srie). Archives de Zoologie Exprimentale et Gnrale 68(2):293-608Juberthie C (2000) Conservation of subterranean habitats and species. In: Wilkens H,

Culver D C, Humphreys W (Eds.) Ecosystems of the World - Subterranean Ecosystems,Elsevier, pp 691-700


23/185

24

Koilraj A J, Marimuthu G, Natarajan K, Saravanan S, Maran P., Hsu M J (1999) Fungaldiversity inside caves of Southern India. Current Science Bangalore 77(8):1081-1083

Kurta A, King D, Teramino J A, Stribley, J M, Williams K J (1993) Summer roosts ofthe endangered Indiana bat (Myotis sodalis) on the northern edge of its range. Am Mid Nat,129:132-138

Martin K V, Puckette W L, Hensley S L, Leslie D M (2000) Internal Cave Gating as a

Means of Protecting Cave-Dwelling Bat Populations in Eastern Oklahoma. Proc. Okla. Acad.Sci. 80:133-137

Popescu S, Borda C (2008) Igiena Animalelor i Protecia Mediului. Lucrri Practice.Editura Napoca Star Cluj-Napoca, 167 pp

Racovi G (1975) La classification topoclimatique des cavits souterraines. Trav. Inst.Spol. E. Racovitza 14:197-216.

Racovi G (1984) Sur la structure mroclimatique des cavits souterraines. Theor. Appl.Karstol. 1:123-130


24/185

25

Karst and sustainability in Florida, U.S.A.

Robert BRINKMANN

Karst Research Group, Department of Geography,

University of South Florida, Tampa, FL 33620, USA, e-mail: [email protected]

Abstract: The State of Florida, which consists of one of the most extensive karst regions in theAmericas, is also one of the fastest growing regions in the United Starts. The population increases,which are driven by both migrations into Florida from within the United States and from manyareas of the world, particularly Latin America, put significant pressure on the karst systems withinFloridas fragile subtropical environment. Within this cultural and environmental context, variousstakeholders are attempting to address a variety of sustainability issues unique to Floridassubtropical environment. It is evident that karst systems impact in some way key sustainabilitysectors such as water, food and agriculture, building, energy, and greenhouse gas management.

Floridas karst waters are continually under thread due to over pumping and pollution.Improvements in the systematic management of water eliminated some of these problems.Agricultural production in the state often impacts the states karst systems through water extraction,irrigation, and associated fertilizer pollution of the aquifer. Local limestone and marine sand isused in the construction of concrete block building materials. Offshore oil and gas reserves, oftenfound in limestone, are not utilized and the state relies on external sources for energy.

Nevertheless, there is a growing interest in developing local policies to address greenhouse gasemissions, some of which involve carbon sequestration within karst systems. A policy review ofthese five themes reveals that Florida provides strong examples how sustainability can bethematically approached within a subtropical karst environment. The United States Government,until recently, has not provided guidance on a variety of sustainability issues. But at the local level,a number of government and non-government organizations are addressing these important topics.The development of local approaches to enhancing environmental sustainability in karst

environments requires examination of regional environmental settings and how human activityimpacts them.

Keywords: karst, sustainability, Florida

1 IntroductionThe state of Florida has undergone tremendous population growth in the last 100 years

as its population doubles approximately every 20-30 years (U.S. Census 2009). However, itis also one of the most fragile karst systems on the planet with regional interconnected groundwater systems, dozens of high-flow springs, hundreds of caves, and unique sinkholes and

wetlands (Brinkmann et al. 2007, Brinkmann and Reeder 1994, Fleury, Carson, andBrinkmann 2008, Florea 2006, Scott et al 2004, Screaton et al. 2004, Tiahnsky 1999). Thehigh growth coupled with the natural vulnerability of karst landscapes (North, van Beynen,and Parise 2009), provides challenges for environmental managers. In the last several years,indices that measure community-scale sustainability were developed to benchmarksustainability efforts at the county and local levels in Florida (Florida Green BuildingCoalition 2009, Myfloridaclimate 2009, Upadhyay 2009). These matrices evolved, in part,due to the complex political landscape of the state that encourages economic developmentwhile preserving natural resources. Within this context, the Governor of Florida, CharlieCrist, challenged local governments and state agencies to develop strategies to reducegreenhouse gases and improve the overall environmental sustainability of their organizations
mailto:[email protected]:[email protected]


25/185

26

through Executive Orders 126, 127, and 128 (Crist 2007a-c). Due to this challenge, dozens ofcommunities adopted specific policies to enhance sustainability in their operations. Whilemany of these approaches are still evolving, several strategies directly impact karst systems.The new policies can be grouped into strategies for water, food, building, energy, andgreenhouse gas management.

Prior to discussing each of these in detail, it is worth reviewing the nature of the karst

systems in Florida. To many, Florida is a flat, featureless plain. Throughout its approximate150,000 square kilometers in area, the maximum elevation is 105 meters and the local relief inmany portions of the state is difficult to discern. However, upon closer examination, Floridais home to a diverse karst landscape. Its carbonate platform underwent a series of marinetransgressive cycles that modified existing carbonate and created new carbonate and sandymarine sediments and rocks. As a result, the state contains older carbonate ridges that wereexposed for longer periods than the surrounding lowlands. In addition, in many areas, marinesands blanket the limestone, thereby creating a covered karst landscape. The landforms in thelowlands are what one would expect to see in recently emerged karst plains. Circular dolinesdominate the landscape and streams are uncommon. Most of the drainage is to the subsurfacewere hundreds of kilometers of flooded underground caves are found. In addition, springs are

commonly found in these lowland areas. Many form spring runs that lead directly to the coast.In contrast, the karst landscapes on the older ridgelands are more complex. Here, karstdepressions are extensive and their forms are complicated. These uvalas are often sites of air-filled cave entrances.

The karst landscape is continually forming in Florida. It is evident through thecomposition of spring water exiting karst aquifers that solution of limestone is occurring at arapid rate (Scott et al. 2004). There are hundreds of homeowners insurance claims in the stateeach year due to sinkhole damage (Eastman et al. 1995). In addition, human activity, such asover pumping of aquifers, enhances depression formation. The karst plain in Florida, due toits active nature is quite vulnerable because of the 18 million residents that live on top of it.Nevertheless, there are some interesting approaches that have been taken in recent years that

improve the overall environmental sustainability in Floridas karst systems

2 Approaches to environmental sustainabilityThe approaches to environmental sustainability will be discussed within five major

themes: water, food and agriculture, building, energy, and greenhouse gas management.Certainly there are others that could be explored, such as population sustainability anddisaster resilience. Nevertheless, karst systems have the greatest impact within these fivesustainability themes in Florida.

2.1 WaterFlorida experiences high variation in monthly precipitation. During the summer and

early fall, rainfall is quite high due to sea-breeze induced convectional thunderstorms, andoccasional tropical storms and hurricanes. Precipitation can exceed several centimeters dailyand depressions are filled with storm water runoff via overland flow. Ephemeral rivers beginto flow and the discharge in perennial streams and springs increases. In dry months, manysprings and streams either dry out or decrease their discharge significantly. Karst wetlands,lakes, and pond may dry. Within this environment, water managers must provide drinkingwater to millions of people. Unfortunately, the production of water in Florida in the late 20thcentury caused a reduction of the regional groundwater table and concomitant drying ofwetlands, lakes, and rivers. Collapses of the land surface into underground voids increased.This occurred largely due to the decision to manage water in the state within local watermanagement districts. Thus, a region like Miami must find water within their local region and


26/185

27

cannot import it from wetter areas of the state. They must use whatever sources they canwithin their region. While all efforts are made to protect the environment, withdrawals occurduring extreme drought periods in late winter and early spring.

Thus, there have been significant impacts to the karst systems in Miami, Tampa, andOrlando due to ground water withdrawal (Rand 2003). However, this sustainability tenet ofusing local water supplies has let to innovative approaches to water management. For

example, several governments in the Tampa Bay area formed Tampa Bay Water, anorganization charged with providing drinking water to the region. Because the region cannotwithdraw more from the aquifer without further damaging the karst systems, Tampa BayWater developed a 25 million gallons of water per day desalination facility and built a 15billion gallon reservoir that supplements surface and groundwater sources. While one mayquestion the carbon footprint of the desalination plant and reservoir within a sustainabilitycontext, there is no doubt that these innovative projects prevented further damage to theregions karst environment as the regions water demand increased.

2.2 Food and agricultureFlorida is one of the most productive agricultural states in the U.S (USDA 2008). It is a

major beef and dairy producer, although it is probably best known for its citrus groves,strawberry fields, and fresh produce farms. It is also home to niche agricultural markets suchas caladium bulbs, orchids, and tropical fish production. Farms and food processing use thegreatest amount of water than any sector in Florida (USGS 2009). Water withdrawals insome agricultural areas trigger sinkhole collapses and local well failure (Tehansky 1999). Forexample, in 1997, strawberry farmers induced sinkholes in rural Polk County Florida whenthey sprayed millions of liters of water on their crops to prevent them from freezing. Ofspecial concern in the state is nitrogen and other fertilizers and pesticides that enter thegroundwater system and rapidly disperse within the interconnected karst aquifers. Nitrogenpollution has steadily increased in springs in the state (Katz 2004, Scott et al. 2004) as a resultof increased fertilizer use not only on agricultural lands but also on lawns and golf courses

that are ubiquitous on the Florida landscape.New approaches to organic farming, community sponsored agriculture, and community

gardening can reduce the impact in some settings. In the last few years, there has been a rapidincrease in these efforts in the state. In the Tampa Bay area, for example, several hydroponicsand soil-based community gardens started, several organic farms began operation on the edgeof the urbanized area, and there is great interest in local governments in encouragingcommunity sponsored agriculture. In addition, many golf courses are using green golfcourse management protocols that reduce fertilizer runoff and officials are encouragingreplacement of lawns with native vegetation and trees. However, Floridas unique growingseason makes it a significant fresh food source for many parts of the world and the impacts ofagribusiness cannot be discounted.

These large food-producing organizations are also trying to do their part to enhance theregions sustainability. For example, many farms are developing drip irrigation or aretransforming fields to hydroponic operations. Others are using hi-tech irrigation schemes thatreduce their overall groundwater use. In addition, many agricultural fields take the solidwastes from sewage treatment plants in urban areas, thereby reducing their need for fertilizers.There is also great interest in Florida in developing biodiesel fuels from agricultural crops thatneed little to no fertilization. The state has invested in research into a variety of crops andthere are some biodiesel plants currently in operation. Associated with this is the emergingarea of using vegetation in Florida for carbon capture. Large landholders are examining theprofitability of transforming pasture or croplands into forested land within the carbon tradingmarket. With the new administration within the executive branch of the U.S. government and


27/185

28

with the associated congressional movement on climate change, it is likely Florida will be ahigh-interest area in the carbon market due to its long growing season. While many have theimage of Florida as a highly urbanized region, there are large areas of the state with lowpopulation densities where vast agricultural regions are found.

2.3 Building

One of the key tenets of modern urban sustainability is green building. In Florida, thereare special challenges compared to the rest of the United States due to its unique subtropicalclimate and maritime setting. While much of U.S. green building policy focuses on heating,in Florida, a larger focus is on cooling and water storage. In fact, green building on the karstlandscape in Florida provides special challenges for land stability, cooling, and deriving local building materials. Because the setting is so unique, an organization evolved, the FloridaGreen Building Coalition (FGBC), which certifies green building and design using matricesdeveloped for Florida.

The certification process is similar to the well-known LEED (Leadership in Energy andEnvironmental Design) process, but focuses on the particularities of Florida (Florida GreenBuilding Coalition 2009). Commercial buildings, developments, high rises, homes and local

governments can be certified. For homes, the FGBC, in similar fashion to LEED, willdesignate a home as a certified green home at the Bronze, Silver, Gold, or Platinum levelsdepending upon how many points one earned on a matrix. The points can be earned in eightcategories: energy, water, lot choice, health, materials, disaster mitigation, and other. Thereare many ways to earn points within each category. However, within the matrix, there is astrong emphasis on the use of technology and design in reducing energy and water use. Asignificant aspect of the matrix is the focus on local conditions, particularly the high rainfalland coolant needs of homes. Within a karst context, this is significant as the karstenvironment is highly reactive to surface conditions. For example, if a home is using non-native vegetation that requires fertilization and extensive irrigation, it is likely that thefertilizer will drain into the aquifer at the same time the aquifer is being depleted. Therefore,

points can be gained in the FGBC system for using native vegetation in landscaping and forreducing or eliminating the need for lawn irrigation.

There are some particular areas of green building and design that impact karst systemsmore directly. Some certified green buildings in the state use air-cooled in subsurface karstvoids for cooling interiors. This geothermal cooling approach has not seen widespreadapplication to date, but there is high potential for reducing energy use in cooling Floridahomes through this innovative technology. Another important aspect associated withsustainable building is the use of local products in construction. In Florida, most of the homesand buildings are constructed out of concrete blocks on a poured cement foundation. In mostcases, the cement and concrete are derived from local sources. Local limestone is crushed andprocessed and mixed with the local marine sands to produce these products. However, the

limestone itself is rarely used as a building material. It is an extremely soft, vuggy stone thatis not practicable for building except as a decorative element. Instead, the local limestone issometimes used as decorative landscape features.

2.4 EnergyUnlike many karstic areas of the world, Florida is not exploiting its known oil and gas

reserves. Due to the importance of tourism to the states economy, the majority of thepopulation in Florida does not want oil and gas producing rigs and platforms within view ofits popular beaches. Instead, Florida relies on imported energy sources for the vast majorityof its power. While Floridians spend less than any other state on energy (USDE, 2009), thestate is a one of the countrys top three energy users. The reasons that energy costs are so low


28/185

29

in the state are because of the proximity to major energy sources, importance of regionalpipelines, and the extensive energy port and distribution system in major urban areas. Most ofthe energy sources in the state are petroleum, natural gas, and coal (see Figure 1).

Figure 1 Energy sources in Florida (USDOE 2009)

However, the state is trying to develop nuclear, wind, solar, and biofuel energy sourcesto try to reduce the need for fossil fuels and to meet ambitious goals set forward by FloridasGovernor, Charlie Crist. He has challenged the state to reduce greenhouse gas emissions toyear 2000 levels (Crist 2007a-c).

Regardless, there has been tremendous pressure from a variety of stakeholders to try todevelop more locally-derived petroleum-based energy sources in Florida through offshoredrilling (Manheim 2004). However, many state leaders resist this effort due to the concernsover the impact to tourism in the state. With Venezuelan and Gulf of Mexico petroleum products cheap and accessible through one of the states several petroleum ports, it seemsunlikely that offshore drilling will commence any time soon. While petroleum exploitationwould enhance the understanding of Floridas karst systems, it is more likely that greateremphasis will be placed on conservation measures such as fuel economy and mass transitbefore these reserves will be tapped.

It must be noted that coal use in the area has received a great deal of attention in recentyears due to power plant emissions and mountain top mining. Much of the coal that is used inthe region comes to Florida from the Appalachian Mountain landscape where mountain topremoval coal mining is sometimes employed. Mountain top removal is a process where anentire mountain is removed from the landscape in the mining process. Coal is separated fromother rocks. The tailings remain where the mountain once stood. Environmental activists arecritical of this mining technique because it destroys ecosystems, viewsheds, and anyassociated Appalachian karst systems in the process. Floridas insistence in not developing itsown energy resources therefore deleteriously impacts distant karst systems.

2.5 Greenhouse gas managementIn recent years, Floridians have become more and more concerned with sea level rise

due to global warming. Many scientists forecast sea level increases in the coming decadesthat would decimate beaches, some urban areas, and many low-lying areas including theFlorida Everglades. The United States Government, until recently, did not aggressivelyapproach this problem, leaving states and local governments to figure out how to try to protect


29/185

30

their lands. Unfortunately, this created a somewhat scattered approach with states likeCalifornia adopting strong regulations to reduce greenhouse gases while others remainuncommitted to adopting regulatory guidelines. Fortunately, there are several organizationshelping state and local governments develop guidelines and benchmarks. The U.S.Conference of Mayors, for example, developed a Climate Commitment that emphasizesmeeting or beating the Kyoto Protocols within their own city (U.S. Conference of Mayors

2009). To date, over 900 mayors have signed the agreement. There are similar agreements in place for American universities (American College and University Presidents ClimateCommitment 2009) and other private and public organizations. While the Federalgovernment has been relatively absent in policy development at the national level, the gap inleadership has been filled at the grassroots.

One key aspect of local sustainability approaches is greenhouse gas inventories andmanagement. There are two aspects to conducting a greenhouse gas inventory for anyorganization: measuring greenhouse gas outputs and greenhouse gas credits that mitigate theoutput. The outputs are in the form of energy used in transportation and electricity production,as well as gases emitted through cooling, agricultural practices, and waste. Greenhouse gascredits vary considerably. They could be in the form of alternative energy production,

development of biostorage of carbon through significant landscape conversion, or throughother carbon storage practices. In karst landscapes, there is the potential for mitigating thegreenhouse gases emitted through carbon storage in karst voids and through enhancing theformation of carbonate deposits. There is ongoing research on storing carbon in deep aquifersin the state. The idea is to take carbon dioxide and pump it deep within the earth into karstvoids or other host rocks. Another approach is to enhance carbon storage in forest or othervegetative reserves and by constructing offshore artificial reef systems. However, the coastalzone in many urbanized areas in Florida is polluted (Fink and Charlier 2003), thereby limitingthe capacity of offshore ecosystems to produce carbonate reef materials. In addition, theenhanced carbon dioxide in the atmosphere has caused ocean acidification in some coastalareas of the United States thereby inhibiting the growth of some reef-building animals (Feely

et al. 2008). It is unclear how effective the oceans ecosystems will be at sequestering carbonas the acidification process advances.

3 ConclusionsIn summary, Floridas sustainability policies provide examples of how intricate social

and environmental interactions can be modified to enhance environmental sustainability. Thekarst system is part of the global carbon cycle and it is important to evaluate its role in avariety of emerging sustainability practices. It is evident that Floridas approaches to water,food, building, and greenhouse gas management can be employed in other karst settings. TheUnited States may be a unique test case for examining sustainability in that most measurable progress was initiated at the local and state level and not within the national government.

This bottom-up approach may have assisted the expansion of sustainability efforts since theU.S. Federal Government has been known to develop standard rules that make it difficult toaddress local complex problems. Therefore, the sustainability efforts in Florida firmly includekarst systems in many of the policies, plans, and activities. In this way, Florida may serve asa testing ground for developing and assessing sustainable management on karst terrains, particularly in the areas of water, food and agriculture, and greenhouse gas management.Florida does not provide particularly helpful guidance on energy. While it is admirable thatresidents have resisted local oil exploration, Florida continues to rely on external sources forits energy and has not developed significant alternatives to traditional energy production todate.


30/185

31

ReferencesAmerican College and University Presidents Climate Commitment (2009) American

college and university presidents climate commitment. July, 2009.http://www.presidentsclimatecommitment.org/html/commitment.php

Brinkmann R, Reeder P (1994) The influence of sea-level change and geologicstructure on cave development in west-central Florida. Physical Geography 15:52-61

Brinkmann R, Wilson K, Elko N, Seale LD, Florea L, Vacher HL (2007) Sinkholedistribution based on pre-development mapping in urbanized Pinellas County, Florida. In:Parise M and Gunn J (eds) Natural and anthropologic hazards in karst areas: Recognition,Analysis, Mitigation, Geological Society of London Special Publications 279:5-11

Crist C (2007a) State of Florida Office of the Governor Executive Order Number 07-126. http://www.flgov.com/pdfs/orders/07-126-actions.pdf

Crist C (2007b) State of Florida Office of the Governor Executive Order Number 07-127. http://www.flgov.com/pdfs/orders/07-127-emissions.pdf

Crist C (2007c) State of Florida Office of the Governor Executive Order Number 07-128. http://www.flgov.com/pdfs/orders/07-128-actionteam.pdf

Eastman KL, Butler AM, Lilly III CC (1995) The effect of mandating sinkhole

coverage in Florida homeowners insurance policies. CPCU Journal 9:165-176Feely RA, Sabine CL, Hernandez-Ayon, JM, Ianson D, Hales B (2008) Evidence for

upwelling corrosive acidified water onto the continental shelf. Science 320(5882):1490-1492

Fink CW, Charlier RH (2003) Sustainability of subtropical coastal zones in southeasterFlorida: Challenges for urbanized coastal environments threatened by development, pollution,water supply, and storm hazards. Journal of Coastal Research 19(4):934-943

Fleury S, Carson S, Brinkmann R (2008) Testing reporting bias in the Florida sinkholedatabase: An analysis of sinkhole occurrences in the Tampa Metropolitan Statistical Area.Southeastern Geographer 48(1):38-52

Florea LJ (2006) The Karst of West-Central Florida. PhD. Diss., Department of

Geology, University of South Florida.Florida Green Building Coalition (2009) Standards. July, 2009.

http://www.floridagreenbuilding.org/db/?q=node/5357Katz BG (2004) Sources of nitrate contamination and age of water in large karstic

springs of Florida. Environmental Geology 46:689-706Manheim FT (2004) US offshore oil industry: New perspectives on an old conflict.

Geotimes 2004:26Myfloridaclimate (2009) Executive Orders and Partnership Agreements. July, 2009.

http://www.myfloridaclimate.com/2007_climate_summit/executive_orders_partnership_agreements

North LA, van Beynen, PE, Parise M (2009) Interregional comparison of karst

disturbance: West-central Florida and southeast Italy. Journal of EnvironmentalManagement 90(5):1770-1781

Rand H (2003) Water Wars: A story of people, politics, and power. Exlibris, 282 p.Scott TM, Means GH, Meegan RP, Means RC, Upchurch SB, Copeland RE, Jones J,

Roberts T, Willet A (2004) Springs of Florida. Florida Geological Survey Bulletin 66.Florida Geological Survey, Tallahassee, Florida, 377 pp

Screaton E, Martin JB, Ginn B, Smith L (2004) Conduit properties and karstification inthe unconfined Floridan Aquifer. Ground Water 42:338-346

Tihansky AB (1999) Sinkholes, West-Central Florida. In: Galloway D, Jones DR, andIngebritsen, SE Land Subsidence in the United States. Reston, Virginia: USGS
http://www.presidentsclimatecommitment.org/html/commitment.phphttp://www.flgov.com/pdfs/orders/07-126-actions.pdfhttp://www.flgov.com/pdfs/orders/07-127-emissions.pdfhttp://www.flgov.com/pdfs/orders/07-128-actionteam.pdfhttp://www.floridagreenbuilding.org/db/?q=node/5357http://www.myfloridaclimate.com/2007_climate_summit/executive_orders_partnership_agreehttp://www.myfloridaclimate.com/2007_climate_summit/executive_orders_partnership_agreehttp://www.floridagreenbuilding.org/db/?q=node/5357http://www.flgov.com/pdfs/orders/07-128-actionteam.pdfhttp://www.flgov.com/pdfs/orders/07-127-emissions.pdfhttp://www.flgov.com/pdfs/orders/07-126-actions.pdfhttp://www.presidentsclimatecommitment.org/html/commitment.php


31/185

32

Upadhyay, NS (2009) Green local governments in Florida: An analysis of sustainabilityand green building policies. Unpublished masters thesis. Department of Geography.University of South Florida.

U.S. Census (2008) U.S. Census Data July, 2009 http://www.census.govU.S. Conference of Mayors (2009) Mayors leading the way on climate protection. July

2009. http://www.usmayors.org/climateprotection/revised/

USDA (2008) 2008 State agricultural overview. July 2009.http://www.nass.usda.gov/Statistics_by_State/Ag_Overview/AgOverview_FL.pdf

USDE (2009) Florida. July 2009. http://www.energy.gov/florida.htmUSGS (2009) Historical water use in Florida. July 2009.

http://fl.water.usgs.gov/WaterUse/hwu_FL.htm
http://www.census.gov/http://www.usmayors.org/climateprotection/revisedhttp://www.nass.usda.gov/Statistics_by_State/Ag_Overview/AgOverview_FL.pdfhttp://www.energy.gov/florida.htmhttp://fl.water.usgs.gov/WaterUse/hwu_FL.htmhttp://fl.water.usgs.gov/WaterUse/hwu_FL.htmhttp://www.energy.gov/florida.htmhttp://www.nass.usda.gov/Statistics_by_State/Ag_Overview/AgOverview_FL.pdfhttp://www.usmayors.org/climateprotection/revisedhttp://www.census.gov/


32/185

33

Water management in the karst of Apulia, southern Italy

Marco DELLE ROSE, Mario PARISE

National Research Council, IRPI, Bari, via Amendola 122-I, Bari, Italy,

e-mails: [email protected]; [email protected]

Abstract: Among the peculiarities of karst environment, distinguishing it from any other naturalsettings, the very limited surface runoff and the slightly defined surface watersheds play asignificant role. Notwithstanding such features, even in flat karst areas as is the case for most ofApulia (south-east Italy), the surface hydrographic lines were a very important element in the karstlandscape, that greatly controlled location and spreading of the first human settlements in theregion. In the centuries, the many interventions carried out by man have caused heavy changes inthe original hydrographic network: swallets have been covered and/or clogged, water linesdiverted, and a complex network of artificial channels progressively took the place of the original

surface runoff. The artificial channels are still today used to discharge the urban and industrialwastewaters in many areas of the region. All these situations on the occasion of extreme rainfalldetermine floods, extending over wide areas, and, as indirect consequence, spreading of pollutantsin the fields. Water management in the karst environment of Apulia is discussed in this paper. Twoexamples are used to describe both history of the anthropogenic actions, and the main effects theycaused: Castellana-Grotte, in the Murge plateau, and Nard, in the Salento Peninsula.

Keywords: flood, water management, karst

1 IntroductionIn karst environments water rapidly infiltrates within the epikarst through the network

of fissures and conduits, and the swallow holes. This feature, combined with the slightlydefined surface watersheds, distinguishes clearly karst from any other natural setting.Nevertheless, even in flat karst areas as is the case for most of Apulia (south-east Italy), thesurface hydrographic lines were a very important element in the landscape, and greatlycontrolled location and spreading of the first human settlements in the region (Lopez et al.2009, Parise 2009). In the centuries, the many interventions carried out by man caused heavychanges in the original hydrographic network: swallets were covered and/or clogged, waterlines diverted, and a complex network of artificial channels took progressively the place of theoriginal surface runoff. The artificial channels are still today used to discharge the urban andindustrial wastewaters in many areas of the region.

Due to geological and morphological settings, Apulia is frequently affected by flooding

(Carrozzo et al. 2003, Parise and Pascali 2003). Although generally non destructive incharacter, these events cause serious economic losses. During the last centuries, flood eventshave been prevented or mitigated by a methodical maintenance of karst sinkholes anddrainage canals. The last decades, however, have been characterized by several anthropogenicmodifications, often realized illegally, that resulted in the partial or total destruction of manynatural karst features, of great importance for the hydrologic regime. These changes are at theorigin, on the occasion of heavy to extreme rainfalls, of a two-fold hazard: floods, extendingover wide areas; and, as indirect consequence of the flood events, spreading of pollutants intothe fields and underground. Once the artificial channels are not able to transport the unusualamount of water, and the swallow holes become clogged, in fact, the consequence is floodingover wide areas, locally involving also the built-up environment, especially when the urban
mailto:[email protected]:[email protected]:[email protected]:[email protected]


33/185

34

areas are located at the lowest part of endorheic basins, a situation which is quite common inApulia. In the next years it has been estimated that, due to global warming, the soil erosionwill greatly increase in semi-arid regions as Apulia, whereas the extreme meteoric events arepredicted to be more frequent and strong (IPCC 2007). As regards management of Apulianendorheic catchments, this should result in higher risks of sinkhole clogging and floodproblems (Delle Rose 2007).

Water management in the karst environment of Apulia is discussed in this paper. Twoexamples are used to describe both history of the anthropogenic actions, and the main effectsthey caused: Castellana-Grotte, in the Murge plateau, and Nard, in the Salento peninsula.

2 Geological settingApulia (Fig. 1) approximately coincides with a block of the Adria Microplate built up

by Mesozoic platform carbonates overlain by Tertiary-Quaternary bioclastic deposits. Salentoforms the structurally less elevated sector and is bounded to the N by the Murge plateau alongan E-W tectonical deformation strip. Horst and graben structures characterize both Murge andSalento, as a result of mainly distensive stresses that dislocated the carbonate bedrock startingfrom the Upper Cretaceous (Ciaranfi et al. 1988). The Mesozoic platform carbonates had been

intensively shaped by sub-aerial conditions during large part of the Paleogene. Salento hostscontinental, transitional and marine Oligocene to Miocene deposits (Fig. 1). These calcareousterrains form a second order sequence which lies on the Mesozoic carbonates, locally with theinterposition of continental and residual deposits.

Figure 1 Geologic sketch of Apulia and location of case studies. Explanation: 1) Mesozoic

platform carbonates; 2) Oligocene-Miocene deposits; 3) Pliocene and Quaternary depositsDuring the Messinian Salinity Crisis, Apulia formed a chain subject to intensive

dismantling and karst processes. The subsequent Lower Pliocene carbonates locally passesinto Middle Pliocene marlstones that are overlain by Upper Pliocene-Lower Pleistocenecalcarenite deposits. The latter are bounded by a disconformity from a glauconiticfossiliferous deposit that is overlain by clayey marls, capped in turn by sandy deposits formeduntil the Middle Pleistocene. The whole marine Cretaceous-Middle Pleistocene Murge andSalento succession is overlain by a series of discontinuous terraces, formed because of theinteraction between regional tectonic raising and the glacio-eustatic sea level changes.

Karst processes have produced a dense network of cavities and conduits which

characterize large portions of Apulia. Many karst caves and sinkholes act to collect and


34/185

35

transport underground the surface waters; these doline-type landforms have different names,according to the different parts of the region:pulo, gurgo, vora, viso, etc. (Parise et al. 2003).

3 Case study no. 1 Castellana-GrotteThe oldest part of Castellana-Grotte lies at the bottom of a karst valley (Fig. 2), which

main morphological features are represented by flat bottom valleys filled with alluvial and

residual deposits.

Figure 2 The karst valley of Castellana-Grotte (after Parise 2003). Explanation: 1) watersheddivide; 2) morphological saddle; 3) water lines; 4) lame (karst valleys); 5) urban area

Low permeability of infilling materials determines high surface runoff on the occasion ofintense rainstorms. Location of the historical part of town in the lowest sector of the valley(indicated in ancient maps with the name ofLago, meaning lake; Colamonico 1917), and

progressive clogging and/or closure of the main swallow holes there present, due to urbanexpansion, are at the

Date post:	07-Apr-2018
Category:	Documents
Upload:	jmvictoria6870
View:	228 times
Download:	0 times

Dinaric karst

Documents