Unit 4 (6 Hrs.) Renewable Natural Resources - :: …ku.edu.np/aec/sharmaPDF/MA/4 Water.pdf · ·...

Subodh Sharma Dr.nat.tech.; Aquatic Ecology Centre, P.O. Box: 6250, [email protected]. 1

Unit 4 (6 Hrs.) Renewable Natural Resources4.1 Water as a vital resource

4.1.1 Hydrologic cycle4.1.2 Water pollution and its prevention

4.2 Soil as a foundation for land ecosystems4.2.1 Soil characteristics4.2.2 Conserving the soil

4.3 Subsistence Agriculture in the Developing World4.4 Sustaining Biodiversity

4.4.1 Biodiversity and its decline4.4.2 Protecting biodiversity

Post Graduate Diploma in Environment Education


Unit 4 4.1 Water as a vital resource 2Hrs.

4.1.1 Hydrologic cycle4.1.2 Water pollution and its prevention




4.1.1 Hydrologic cycle




“Water is the driver of nature”

The main processes in Hydrologic cycle or Water cycle are:

1.Evaporation2.Transpiration3.Condensation4.Precipitation5.Infiltration6.Percolation7.Runoff




1.EvaporationThe water cycle is powered by energy from the sun and by

gravity converting liquid water into water vapor, this process is called evaporation.

The amount of water vapor in the air is the humidity.

Absolute humidity is the amount of water vapor found in a certain mass of air and is usually expressed as grams of water per kilogram of air.

Relative humidity is a measure (expressed in percentage) of the amount of water vapor in a certain mass of air compared with the maximum amount it could hold at that temperature.




2. Condensation

It is the opposite of evaporation i.e., conversion of water vapor into droplets of liquid water.

The result of condensation is fog and clouds.

If the droplets form on the cool surfaces of vegetation, the result is dew.

Condensation is greatly facilitated by aerosols.




3. PrecipitationAs air rises, it cools,

condensation occurs, and precipitation results as rain, sleet, hail or snow.

Factors affecting Precipitation:Convection current and the rain shadow


Convention Current and the rain-shadow (in pictures)






4.1.2 Water pollution and its prevention(Miller page 478)

TYPES OF WATER POLLUTION

1. disease causing agents (pathogens)

2. oxygen demanding wastes

3. water soluble inorganic chemicals

4. inorganic plant nutrients

5. organic chemicals

6. sediments or suspended matter

7. water soluble radioactive isotopes

8. thermal pollution

9. genetic pollution


1. Disease Causing AgentsType of organism

Disease Effects

Bacteria Typhoid fever Diarrhea, severe vomiting, enlarged spleen, inflamed intestine: often fatal if untreated

Cholera Diarrhea, severe vomiting, dehydration: often fatal if untreated.

Bacterial dysentery Diarrhea, rarely fatal except in infants without proper treatment.

Enteritis Severe stomach pain, nausea, vomiting: rarely fatal

Viruses Infectious hepatitis Fever, severe headache, loss of appetite, abdominal pain, jaundice, enlarged liver: rarely fatal but may cause permanent liver damage.

Parasitic protozoa

Amoebic dysentary Severe diarrhea, headache, abdominal pain, chills, fever: if not treated can cause liver abscess, bowel perforation, and health.

Giardiasis Diarrhea, abdominal cramps, flatulence, belching, fatigue.

Parasitic worms

Schistosomiasis Abdominal pain, skin rash, anemia, chronic fatigue, and chronic general ill health.


2. Oxygen demanding wastes


3. Water soluble inorganic chemicals

1.Acids

2.Salts, and

3.Compounds of toxic metals such as mercury and lead.

High levels of these can make water unfit for drinking, harm fish and other aquatic life, depress crop yields, and accelerate corrosion of equipments that uses the water.


4. Inorganic plant nutrients

1.Water soluble nitrates, and

2.phosphatesThey cause excessive growth of algae and other

aquatic plants, which then die and decay, depleting water of dissolved oxygen and killing fish.

Among people who drink water with excessive levels of nitrates, the oxygen carrying capacity of their blood can be reduced; this can kill unborn children and infants, especially those under one year old.


5. Organic chemicals

1.Oil

2.Gasoline

3.Plastics

4.Pesticides

5.Cleaning solvents

6.Detergents, and

7.Many other chemicalsThey threaten human health and harm fish and

other aquatic life.


6. Sediment, or suspended matter

1.Insoluble particles of soil and other solids that become suspended in water, mostly when soil is eroded from the land.

• Sediment clouds water and reduces photosynthesis.

• It also disrupts aquatic food webs and carries pesticides, bacteria, and other harmful substances.

• Sediments that settles out destroys feeding and spawning grounds of fish, and it clogs and fills lakes, artificial reservoirs, stream channels, and harbors.


7. Water soluble radioactive isotopes

1.Which are capable of being concentrated in various tissues and organs as they pass through food chains and webs.

• Ionizing radiation from such isotopes can cause birth defects, cancer, and genetic damage.


8. Thermal pollution

1.Heat absorbed by water used to cool industrial and power plants can lower water quality.

• Lowers dissolved oxygen and makes aquatic organisms more vulnerable to disease, parasites, and toxic chemicals.


9. Genetic pollution

1.Occurs when aquatic systems are disrupted by the deliberate or accidental introduction of nonnative species.

• Reduce biodiversity, and cause economic losses.


4.1.2 Water Pollution and its prevention

SOURCES OF POLLUTION: Point Sources of Pollution

Factories,

Sewage treatment plants,

Active and abandon underground mines,

Offshore oils wells, and

Oil tankers



SOURCES OF POLLUTION: NON Point Sources of Pollution

Runoff of chemicals into surface water,

Seepage into the ground from cropland,

livestock feedlots, logged forests,

Streets, lawns, septic tanks,

construction sites, parking lots,

and roadways.


Water Quality Problemsin Rivers and Streams


•River is a source of water and transportation.•Rivers have been the site of urban development from ancient times.•Rivers served as a receptacle for the large quantities•of waste generated by urban populations.


Water Quality Problemsin Rivers and Streams

Classical Wastewater Problems

WTP

CITY

WWTPWaste removed

Waste loading

Critical concentration (CC)(decomposition = rearation)

CCDO (mg/L)

River

saturationDiurnalrange

Recovery zone

distance

Fig. 1: An urban water-wastewater system

Fig. 2: The DO ‘sag’ below sewage discharges into stream.


Types of Problems

Water Quality Problemsof Rivers and Streams

NitrificationNitrate pollutionAmmonia ToxicityEutrophicationSediment Oxygen DemandOrganic Toxicants & MetalsParticulate & Dissolved SolidsTemperature


Water Quality Problems in lakes


Water Quality Status in Nepal

Case Studies

Subodh Sharma Dr.nat.tech.; Aquatic Ecology Centre, P.O. Box: 6250,

[email protected].

27

One major, overwhelming reason why we are running out of water is that we are killing the water we have.

William Ashworth, Nor Any Drop to Drink, 1982


Water Quality Facts

1 in 3 children in Nepal die before the age of 3 of diarrhea and other waterborne illnesses (44,000 childhood deaths/year).

67% of children are stunted on account of waterborne diseases.

Because of their responsibility caring for sick children and carrying water from dirty or scarce sources, women miss the chance for education and economic opportunities.

Source: Susan Murcott October 1, 1999


Water Supply Facts

61% of Nepalis have water supply coverage but 70% lack access to clean, safe suppliesUrban areas have piped water supplies, but these supplies are intermittent on account of scarcity -pressure drops in storage tanks, and intermittent power supplyGenerally, there is no water treatment, except chlorine addition in some rare instances



Sources of Water Supply Facts

The majority of Nepalis obtain their water from wells, springs, watertaps, and streamsTerai: rivers are highly polluted, so drinking water comes from hand-dug, shallow wellsMiddle hills and high Himalayas: Water supply is typically from springs and streams which supply gravity collection systems and water taps.



Indus Brahmaputra

Ganges

Mekong

Yangtse

Huangho

Pearl river

River Systems – Himalaya


River Systems – Nepal

Saptakosi

Saptagandaki

Karnali

Mahakali

Bagmati

West Rapti

Tinau

Babai


Surface Water Quality

Water Quality of Streams & Rivers(n = 315)

05

101520253035404550

Kosi ( n =71)

Gandaki (n =91)

Karnali (n = 9)

Mahakali(n = 5)

Bagmati ( n = 115)

Tinau ( n = 11)

Rapati (n = 4)

Babai ( n = 9)

II-II

II

II-III

III

III-IV

IV


Water Quality of Bagmati River System

I

I-II

II

II-III

III

0

5

10

15

20

25

30

Bagmati ( n = 115)


Study Area


Findings on the status ofSurface water quality in Midhills Nepal

Physico-chemical aspects

1. Ph values were usually higher.2. The problem of nitrate in drinking

water supply is negligible.3. Calcium removal methods must

be considered in advance beforelaunching any drinking watersupply projects.

4. A proper selection of GI pipes isrecommended when used inpublic drinking water systems.

5. The use of HDP pipes in pipelinesin the presence of corrosivewaters has resulted in higherlead concentrations at the tap insome of the areas studied.

Microbiological aspects

1. Microbiological contamination in particular is of great concern.

2. Faecal coliform counts are slightly higher during the monsoon season than during the pre-monsoon season.

Source type

Number of

sources surveye

d

Bacterial countFaecal coliform (colony/100mL)

Rainy season Dry season

*A *F *A *F

Kuwa 13 2-150 0- TNC 0-15 0-TNC

Spring 13 8-TNC 0-TNC 0-0 0-231

Tap 10 NA 0-TNC NA 0-55

Tank 6 NA 56-TNC NA 0-

TNCBiological Quality ?


Groundwater Quality of Nepal : An Overview

1. Out of the total population of Nepal, only 34% have access to safe groundwater (NepalNet, 2001).

2. Shallow groundwaters are at risk from contamination: pathogenic bacteria, pesticides, nitrate and industrial effluents.

3. In the deep aquifers, concentrations of nitrate and nitrite are low (<1mg/l as NO3 and <0.01 mg/l as N02respectively).

4. Deep aquifers in the Kathmandu Valley has high ammonium Nitrogen (up to 35mg/L).

5. Iron, manganese and methane concentration is also high in deep aquifers.

6. Iron and manganese concentration is low in the shallow aquifers.

7. In the deep aquifers of Terai and Kathmandu Valley, a high concentration of Iron (<0.5 – 9 mg/l) and manganese (<0.1 –0.7 mg/l) have been found.


Groundwater Quality of Nepal : State of Arsenic

Arsenic in the terai is a newly emerging problem.

High concentration of arsenic was found in tubewells at a depth ranging between 20 feet to 150 feet.

Most of the arsenic contaminated tube wells were found to be constructed within last ten years. Source: The State of Arsenic

in Nepal – 2003; NASC, ENPHO.


Groundwater Quality of Kathmandu Valley: Microbial Aspects

Well type

Number of wells

Monsoon*

Dry Season*

Dugwells 12 4404 132

Shallow tubewells

43 88 136

Deep tubewells

20 (18) (< 1)

Table: Kathmandu Valley groundwaters: relative levels of faecal contamination

(Source: Jha et al., 1996)

* Faecal coliforms / 100 mL


1. The art of rainwater collection has been in practice in Nepal since ancient times.

2. Evidence of traditional water collection ponds especially in the hilly region are available.

3. The technology of rainwater collection from rooftops in ferro-cement made jars for domestic purposes is becoming more and more popular in the water scarce districts of Nepal.

4. Rainwater harvesting appears to be one of the most promising alternatives for supplying freshwater in the face of increasing water scarcity and escalating demand.

Rainwater Quality


Rainwater QualityThanapati(Gulmi)

Chhapani (Palpa)

Total jars 87 36Not contaminated

13 (15%)

10 (28%)

Contaminated 73 (84%)

26 (72%)

Doubtful 1


Summary

1. Inner-Himalaya & Fore Himalaya:Study showed a vulnerability of water resources due to faecal pollution in this region added by touristic influence.

2. Midhills: Study showed that the agricultural intensification, urbanisation, and industrialisationhas caused an increase in fertilizer and pesticide contents in the rivers of rural areas and untreated domestic and industrial pollution has increased in cities.

3. Terai: Shallow groundwaters are also at risk due to pathogenic bacteria, pesticides, nitrate and industrial effluents. Deep groundwaters in Kathmandu and Terai are largely anaerobic and hence vulnerable to increased concentrations of iron, manganese, and ammonium. Arsenic is becoming a problem in some parts of Terai.


Conclusions

Inconvenient access to water, which is mainly affecting womens workload;Inadequate water quality, leading to poor health and affecting infants and the old in particular;Lack of sufficient water in places also contributes to poor health, because people use inadequate amounts of water for washing and hygiene and herewith potential contamination through cooking and eating;Seasonal water shortage for domestic water supply;Inadequate water resources management, which leads to high water losses and inefficient use of available resources.


RecommendationsProviding water for domestic use in the vicinity of the settlements and close to the single households;Appropriate approaches and technologies for water purification to treat microbiological contamination;Appropriate approaches for water distribution;Appropriate approaches for water source and catchment protection to avoid contamination;Adequate water supply in areas with dispersed settlements without access to springs such as the ridge tops and valley flats.



4.2 Soil as a foundation for land ecosystems – 2 hrs

4.2.1 Soil characteristics4.2.2 Conserving the soil

4.2.1 Soil Characteristics

1.Soil layers, components, and types

2.Soil texture and porosity

3.Soil acidity



4.2 Soil as a foundation for land ecosystems

4.2.1 Soil characteristics4.2.2 Conserving the soil

1. Soil layers, components, and types









acid litter and humuslight colored and acidic

humus and iron andaluminum compounds




2. Soil texture and porosity




3. Soil acidity (pH):

The acidity or alkalinity of a soil determines the types of plants it can support.

Acidity or alkalinity of substances in water solution are commonly expressed in terms of pH.




4.2.2 Conserving the SoilFactors that lead to erosion and desertification:

1. overgrazing2. deforestation, and3. over cultivation

Soil conservation:1. individual landholder

1. FARM2. Farmer Field Schools

2. public policysubsidiessustainable agricultureconservation reserve programfarm bills



4.3 Subsistence Agriculture in the Developing World

• In Subsistence agriculture traditional agricultural methods are used.

• Subsistence farmers live on small parcels of land that provide them with the food for their households and, it is hoped, a small cash crops.

• Such farmers are very poor.

Subodh Sharma Dr.nat.tech.; Aquatic Ecology Centre, P.O. Box: 6250,

[email protected].

53

Effects of agricultural intensification on the quality of riversin rural watersheds of Nepal

4.3 Agricultural Intensification in the Developing World


Cropping Pattern Cropping Season

January to March April to June July to September

October to December

1. Bari landi. Mustard*i. Vegetables*i. Wheat i. Potatoi. Maize and

Millet2. Khet landi. Vegetables*i. Rice variety 1*i. Maize i. Rice variety 2* When irrigation availableData Source: Baseline survey of the watersheds during 2004.


What is a Bariland ?


What is a Bariland ?


What is a Khetland ?

Irrigated khetland Rainfed khetland


Indicators of Agricultural Intensification


Indicators of Agricultural Intensification


Objectives of the study1) observe the relationships between agricultural intensification and water quality from streams to public distribution systems; 2) document the temporal and spatial variations in water quality;3) understand the role of river biota as biological indicatorsin assessing the impact of increasing extent of agricultural development; and 4) document the influence of in-stream habitat conditions and the influence of land use on stream integrity.


Study Area


Site SelectionAsikhola Catchment

5 sites selectedA reference site (ARf) is defined as being representative of a group of minimally disturbed sites organized by selected physical, chemical and biological characteristics (Reynoldson, 2000). Disturbed site (AD1, AD2) is one where impact is clearly visible.Recovery sites (ARc1, CRc) are beyond the impacted areas with conditions similar to reference status.


Site SelectionChakhola Catchment2 sites selected

Parameters considered in the selection of Reference sites:

1. Ecoregion2. Physical structure3. Local Knowledge4. Use of historical data


Reference Sites

ARf1

ARf2

CRf


AD1

AD2 CRc?

CD1

Disturbed Sites


What, How and When to sample?

Physico-chemical ParametersTemperature, pH, Conductivity, Ammonia,Nitrate,OrthophosphatePb, Cu, Zn,Na, andK.

BiologicalIn case of biological analysis, both qualitative and quantitative composition of biological indicators (Macroinvertebrates) were considered.

Obj.1) observe the relationships between agricultural intensificationand water quality from streams to public distribution systems;

MicrobiologicalIn case of microbiological analysis, Faecal coliform were analysed.


When to sample?

Temporal variations: Seasonal samples of water were collected in Mid Winter 2004 and Mid Summer 2004Spatial variations:

River water were sampled from varying altitudes, Spring water were sampled from different land use

Obj. 2) document the temporal and spatial variations in water quality.


Obj. 3) To understand the role of river biota as biological indicators in assessing the impact of increasing extent of agricultural development, biologically based index NEPBIOS (Nepalese Biotic Score) was applied.

Obj 4) To document the influence of in-stream habitat conditions and the influence of land use on stream integrity, a field protocol was developed and used with at least 37 attributes describing habitat of streams.

What to sample, How and When?


Biological Indicators of AIGOOD RIVER

QUALITY

MODERATE RIVER QUALITY

BAD RIVER QUALITY


Conclusions

The influence of agricultural intensification can be demonstrated by taking an example of NO3 concentrations.

The highest concentration of PO4 (0.4mg/L) is measured in the disturbed section (CD) of Chakhola in rainy season, whereas in Ansikhola the observed concentrations are higher in the dry season suggesting fertilizer application as the single most source of PO4

Microbial contamination of water sources is less in Agricultural land compared to forest land.

Biomass and abundance of river communities increased rapidly with the increase in agricultural intensification.

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