Pacific Islands The Newsletter of the GIS&RS news

May, 2007 Pacific GIS&RS NEWS

GIS&RS news

Pa

The Newsletter of theGIS&Remote Sensing

Users in the PacificIssue 1/2007

May, 2007

ISSN 1562-4250

EU Largest Contributor to GIS andRemote Sensing Development inPacific Island CountriesThis issue of the GIS&RSNewsletter reports mainly on theAnnual Regional GIS&RS UserConference, which was held at theend of November in Suva. Again thisconference was the single largestevent of the year, where GIS&RSusers from Pacific Island Countries(PICs) got together to exchangeexperiences and learn about newdevelopments in the areas of GIS,Remote Sensing (RS) and theGlobal Positioning Systems (GPS).The European Union wasconspicuous on manypresentations because of the inputof EU funds. At this point the EU isclearly the largest donor towarddevelopment of GIS and RS inPacific Island Countries and theconference highlighted this. European DevelopmentFund 8 and 9 Euros were used to purchase high-resolution satellite image data; and GIS and imageanalysis software for 14 PICs in the past three yearsand the presentations showcased the applications towhich this input was utilised. Remarkably notable wasthe fact that many GIS&RS methods and toolsdemonstrated had been modified and scaled to PacificIslands standards from those employed in Europe andthe US. Utilities, as the main GIS users, demonstratedcustomisation techniques necessary to scale GIS foruse in small power, water and telecommunication unitstypical in Pacific Island Countries. One such study wasthe utilisation of high-resolution imagery for coconutresource mapping on the island of Rotuma (Fiji). It isexpected, and already underway, that the other PICswill follow suit and make best use of data acquiredthrough EU funding.

Several companies used the opportunity todemonstrate new developments to the wide range ofGIS and RS users as they did at last year’s conference.Intergraph Eagle Technology and ESRI showed new

software developments and Geosytems and Lukeminedemonstrated new GPS technology. MDA as mainsatellite data provider was not present but providedpresentations explaining the latest image data.

On the final day, users discussed further areas thatwould benefit from the application of these versatiletechniques in the sustainable development of PacificIsland Countries. The subject matter of that discussionis reported in this newsletter; and is also featured onthe PICISOC web site. Developments will bemonitored there and also reported in the newsletter. Aspecial interest group was also formed within thePacific Chapter of the Internet Society (PICISOC), tomonitor developments regarding the areas discussedThis newsletter can also be downloaded from thePICISOC web site.

The Regional GIS&RS User Conference, with more than 250participants it is the largest conference of Pacific Islands' GIS andRS users.

Pacific Islands

2 Pacific GIS&RS NEWS March, 2006

Content

2006 Pacific Island Countries GIS & RS User Conference 3

Discussions on Development in Needs for Pacific Island Countries in GIS and Remote Sensing 4

Leica Geosystems Geospatial Imaging (ERDAS Imagine) Acquires ER Mapper 6

The Guam Coastal Atlas: Creating Bethic Habitat data and a Printed, CD-ROM, and web based

atlas with limited Resources 8

Hydrodynamic Model of Tarawa 13

Town Planning Projects and Modelling Tools 15

Coral reef, Tuamotu Archipelago:This comparison of Landsat 7 ETM+ and Digitalphotography from the ISS illustrates how astronautphotography can be an important source ofsupplemental data to studies using satellite imagery.In this set of images the key fishery habitat to bemapped is the reticulated reef lagoon. At Landsat’s 30m spatial resolution there is not enough informationabout the lagoon structure — the most important reefstructures are too small to be seen on Landsat images.By combining astronaut photography from ISS that has5-m resolution, scientists were able to get a map ofthe area that meets the needs of local resourcemanagers.

Detailed photographs of reefs taken from the ISS arebeing used around the world to serve as base mapsfor field cartography during surveys of thegeomorphological and ecological zones of the reefs.The high spatial resolution of the images (about 5 m/pixel) make them highly suited for comparison to whatis seen by divers in the water.

Digital photographs from the Space Station are morethan just pretty pictures, they contain 3 bands ofremote sensing data. NOAA scientists recentlyreported success in measuring shallow bathymetry(the depth of the water around the reefs) from ISSreef photographs.

Article copied from http://earthobservatory.nasa.gov/

March, 2006 Pacific GIS&RS NEWS 3

2006 Pacific Island Countries GIS and RS User Conference

!continuation page 4

2006 Pacific Island Countries GIS & RS UserConference

“GIS and Remote Sensing: PacificDevelopments”

Craig Clouet

ESRI, Honolulu, Hawaii

Political tensions in Fiji were unable to stop thegathering of GIS and Remote Sensing professionals

from meeting toexchange ideasand report on realprogress in thePacific IslandsRegion. Thevenue was thesame as theconference lastyear, the lowercampus of theUniversity of theSouth pacific. Anideal place that isjust far enough outof downtownSuva, yet close tohotels andrestaurants. While

it was hot and humid, the impending governmenttakeover by the military was the unofficial topic ofconversation. The coup did not occur during the

conference, and it actually had little effect on the dailyproceedings, except that a few foreign presenters wereunable to travel to Fiji due to the political situation.

The conference itself was a day longer than last year.It covered a wide range of GIS and remote Sensingtopics. The conference organizers did an excellent jobof putting the tracks together and keeping thepresentations moving smoothly. The sessions weregrouped into compatible topics. There was also aposter session and vender displays in the exhibit room.

As there was a wide range of topics, everyone got achance to learn somethingnew, and see what othersare doing across the Pacific.While many of the issuesraised were related to thecost of technology, bothhardware and software,there was also many greatpresentations highlightingsolutions and the progressmade due to the efforts andhard work of the GIS andRemote Sensingcommunity. Severalstudents were also invited topresent their work. Ofcourse they were probablynervous having to present ata professional conference,but the experience is at leastas valuable for them as anycourse work .

The social events were bothfun and engaging. The people of Fiji and other Pacific

Figure 01: The EU as the mainsupporter of GIS and RSdevelopment in PIC's wasrepresented by Flor van de Veldeexplaining the potential ofincreased development underEDF10 funding.

Figure 02: companies presented their serviceand products. Martin Hewitt from GeosystemsNew Zealand explaining latest developments ofGPS receivers from Trimble.

Figure 03: This year the media reported detailedabout the conference. The picture shows WolfForstreuter (SOPAC) interviewed by the TV stationFiji One.

Figure 04: ISPRSwas representedthrough poster andprospective materialin the exhibition room.


GIS & RS Pacific Development

Island nations could not be more genuinely friendly.They offered the tradition Yaqona (kava drinkingceremony), a cocktail social, a dinner, and for thosewho could stay an extra day, a boat trip and picnic ona small island off shore. The social events were a greattime to experience local culture and customs, plus todiscuss in greater detail topics presented at theconference.

There are many people to thank for making thisconference a success. Certainly the staff and studentsat USP Geography, SOPAC, and many governmentagencies of Fiji are the ones that deserve high praise.Anyone interested in doing work in the Pacific Islandsregion that has any geospatial aspect should stronglyconsider coming to next years conference.

About the author; Craig Clouet works for ESRI in theHonolulu, Hawaii, USA office as a technical marketingrepresentative. He has been to the GIS & RSconference in Fiji twice now. He can be contacted [email protected].

Figure 06: Like last year a social program providedavenues to contact colleagues of other Pacific IslandCountries. The picture shows the Yagona ceremonya Fijian traditional protocol for welcoming guests

Figure 05: The president of the Pacific IslandsChapter of the Internet Society (PICISOC), RajneshSingh explained the potential of the internet for thedevelopment of GIS and RS in the Pacific.

Discussions on Development Needs fo PacificIsland countries in GIS and RS

Wolf Forstreuter

SOPAC

Like previous GIS and Remote Sensing User Conference, adiscussion was held on the last day. This discussion arosefrom a conversation on GIS-PacNet e-mail distributing list andall points were published on the PISOC web site. Thediscussion highlighted that development is required to transfertechniques and methods in the areas of GIS, GPS andRemote Sensing (RS) applied outside the Pacific tailored tofit the conditions and needs of Pacific Island Countries. About100 technicians attended the discussion and the discussionwas much livelier than that of 2005.

This forum proved to be bigger than the rest, with many peopleinvolved in the actual application of GIS, GPS and RSexpressing their needs and voicing their opinions aboutpossible solutions.

The discussion reflected the needs and possible solutionsfor 15 different subjects outlined below. The discussion hasbeen shortened due to the word limit for this article. A moredetailed article is available on the PICISOC’s web sitewww.picisoc.org

1 Creation of Digital Terrain Models (DTMs) at 1:10,000scale with sub-meter Contour LinesSand or beach movements on atoll islands have the potentialto cause significant problems for housing and infrastructure.It is important to monitor where the sand drifts away and wherebeach is building up. The reasons for these shorelinemovements are still not known. More understanding wouldallow a forecast to reduce negative impact. Contour lines ofsub-metre accuracy are required to map the shape of thebeach. The technique could also be used to create detailedDTM’s for wind farms allowing the optimisation of windmilllocations. Another application would be the ortho-correctionof high-resolution image data, which so far does not work inPacific Island Countries due to the missing DTMs.LiDAR (Light Detection and Ranging) theoretical could beutilised. Examples have demonstrated that mapping ofbeaches as well as change detection is possible with highaccuracy. However, high costs are involved to base systemin the Pacific or even to bring a system on demand fromoutside. In addition, it only works on cloud free days, whichwill add to the running costs. The LiDAR data analysis requiresnew software packages or add-on modules.

DTM production through Kinematic GPS was highlighted bya presentation on the GIS&RS User Conference 2005. Thisapplication has high capacity although the results were notfully convincing in the trial in 2005 because of old equipmentand successive failure. DTM can be created with software


GIS & RS Pacific Development

available in Pacific Island Countries. The requirementsinclude a base station in the 15 km radius and surveyof a 3 member team by walking along the contour linesin 1 to 4m distances. Real time differential KinematicGPS would enhance such a survey as the teamimmediately would see inappropriate receiving andslow down the survey in such cases. New receiversavailable at Geosystems/Trimble (GLONASS) at anestimated cost $100,000 FJD. Currently the KinematicGPS was tested in the Suva reef to create a DTMfrom the Sand bank; the result seemed to be positivewhich will be outlined in the next newsletter.

360 degree laser scanners mounted on vehicles suchas trucks or even balloons would be cheaper thanLiDAR because plane, pilot, navigator etc. does nothave to be transported to an island. It would be alsopossible to mount the system on a tripod and moveafter scanning to the next position in about 50mdistance and scan again. The system could be broughtas normal airfreight and be reassembled on the island.So far this application has not been tested in PacificIsland conditions.

A DTM creation is also possible using conventionalsurvey by total stations. Low-level islands would besurveyed by kinematic GPS to establish a network ofmarks around the island with 200 to 300m intervals.The marks will be permanent (stainless steel). Fromthere a team (two to three) will survey the surface withconventional total stations and convert the survey datainto DTM where sub decimeter accuracy can beachieved. These total stations are available for aboutAUD 20,000 and the teams can be built from staff ofthe islands. This application could easily be introducedinto the Pacific Islands, as the systems are relativelyinexpensive, and easily transported. (See articlewritten by Mike Poidevin).

2 Satellite Image Bathymetry of Shallow WaterSOPAC has two swath mapper systems, which arealmost permanently in use. However, the boatscarrying the swath mapper cannot drive in shallowwaters, which leave a gap between the contour lineson land and in deeper water.LIDAR airborne would be able to create the requiredinformation; however, it is very expensive to capturedata between contour lines on land and for deeperwaters would be impossible at this stage. Satelliteimage data could be utilised, data is available andtechnique is available. So far, the technique is notimplemented in Pacific Island Countries.

The SOPAC-EU Project will finance a master thesis,which will adapt existing techniques to Pacific IslandConditions. Part of the terms of reference is the writeup of a “cooking book”, which will enable GIS&RS units

in Pacific Island Countries to perform such a task withavailable satellite image data.

3 More Frequent Space Borne Image Data (MobilGround Receiving Station)With the exception of PNG all Pacific Island Countriesare outside the footprint of any ground receiving station.For every image recording on-board tape space hasto be booked. Last minute decision related to cloudcover is impossible in the Pacific. A mobile groundreceiving station would provide faster and more cloudfree image data.

John Trinder, Vice President of ISPRS mentioned theissue at the Regional Cartographic Conference for Asiain the Pacific, in Bangkok. The response was that noorganisations are currently willing to provide a mobileground receiving station because more satellites willbe available with onboard tape facilities capable tocapture data from Pacific Island Countries. Since thelast conference it was not possible for GIS&RS usersto activate the responsible regional organisations andauditorium decided to drop a further discussion abouta mobile ground receiving station.

4 Ocean Colour MonitoringThe situation since last year has remained unchanged.Not a single fishery department in the Pacific isequipped with the technique and skills to analysesatellite image data to visualise possible fishconcentration within their EEZ, which is not onlynecessary to guide the own fishing fleet but also toprotect the EEZ from illegal operating fishing vessels.Data is available from satellites such as OrbView-2or ENVISAT detect ocean colour, sea surfacetemperature or wave height. Last year, SOPAC hostedone person financed by the Pacific Islands GlobalOcean Observing System; however, the person leftand there was no visible output transferring know-howto Pacific Island Countries. It is assumed the most ofthe expensive purse seine fishing vessels are equippedwith required technique and know-how to analysespace borne RS data and it is essential to equiptPacific Island fishery departments with necessaryskills and technique.

5 Vessel Monitoring and Vessel DetectionSystemsDuring the discussion it was mentioned that PacificCountries need a faster display of detected vesselswithin their EEZ. The Vessel Detection System wastested in Fiji’s EEZ during early 2006. Space borneradar image data was purchased by the JointResearch Centre of the EU Commission for thenorthern part of Fiji’s EEZ, where normally aconcentration is expected during that time of the year.The data had to be ordered two weeks before therecording and during the over flight all fishing vessels


were concentrated on the east boundary of the EEZ.There was no way to revise the target area and theimage data did not provide the help expected. Therewill be an article providing an overview of the status oftechnique by Kyle Hurst, the manager of the VesselMonitoring System at FFA in Honiara in the nextnewsletter.

6 Open Source SoftwareMore Pacific Islands Countries are signing thecopyright laws and software investment andmaintenance will be a critical factor for GIS&RSdevelopment, as many users will not be able to paythe costs.

MySQL as relational database software is tested byUSP and SOPAC, while it has geographic data types;so far it does not allow linking to GIS and databasefront end software in the way SOPAC trains PacificIsland Countries. Other open source databaseproducts are also under test, but there is nothingavailable yet allowing the switch over from MicrosoftAccess.

Participants from USP mentioned free and powerfulremote sensing software, but during the discussion itwas clarified that not all basic functions of ERDASImagine were covered.

The same applied to open source GIS software, whereSOPAC tested Quantum GIS. The Pacific users havestill to wait until open source software in these areaswill provide a minimum standard for commonapplications.

7 Monitoring BiodiversityBiodiversity is one of the targets within the EDF10funding, but there were no important activities or Pacificinteresting developments mentioned in the discussion.8 Monitoring Coconut Palm CoverThe SOPAC activities presented during the conferencedemonstrated that delineation of palm densities ispossible at 1:5,000 scale when applying pan-sharpened QuickBird image data. Also the analysis ofpalms per hectare utilising this image data provideaccurate results in adult plantations. There is a growinginterest in applying the techniques for coconutresource inventories before planning bio dieselproduction.9 Data Sharing and MapServerMap server acts as the central location of data sets incountries, which are readily available thereforeencouraging data sharing. Regional organisationsshould participate to this effort and ensure that theirdata sets are not duplicated but standardised for alluses.

Commercial license of high-resolution satellite imagesare for SOPAC, PDC and the respective country. Adownload possibility would be in conflict with the

copyright agreement and therefore cannot bepermitted. In many countries the Internet connectionis still a problem and there are more overseas usersthan Pacific Islanders.

SOPAC participants suggested that if WMS and WFSservers are enabled, data can be published on otherclients.

10 Early Detection of LandslidesLike last year a discussion was planned, but nobodywas available to contribute. In many Pacific IslandCountries land slides are a serious problem and RS/GIS are tools which could help in early warning.

11 Ground Control Point Identification in ReefAreasUtilising Landsat TM data it was possible to identifyreefs and map them geometrically correct. Thecorresponding Landsat scene was geometricallycorrected with ground control points of islands alsoshown on the same scene. For reefs far away fromany island this technique does not work. Such mappingis also limited to 1:50,000 scale. High-resolutionsatellite images allow a mapping at 1:10,000 scale,however, in the Pacific such georeferenced imageshave to be shifted and it is necessary to identify pointson the reefs and do a DGPS data recording. Therewas no ongoing project mentioned testing theidentification of GCPs on reefs.

12 Ground Control Point Identification in CoastalAreasHigh-resolution, georeferenced satellite images canbe utilised to rectify historical aerial photographs. Thisenables change detection of coastal areas. However,problems exist in identifying GCPs in near shore areasto rectify the satellite image. A method should bedeveloped to identify more GCPs (imageenhancement, GPS). In addition, a method needs tobe developed to identify more possible features usableto rectify the historical aerial photographs towards therectified satellite image. The possibility was mentionedthat multi-beam data could be utilised to identifyadditional GCPs.

13 GCP 1:5,000Pan-sharpened QuickBird image data can be utilisedfor thematic mapping such as roof areas estimationfor rainwater harvesting. In such case they have to begeometrically checked and possibly corrected at1:5,000 scale levels. This requires a different DGPSsetup than utilised for 1:10,000 scale mapping. A trialof SOPAC in Rotuma failed due to equipmentproblems, but a new test will be repeated beginning ofnext year and reported in the newsletter.


The University of Guam Marine Laboratory, incollaboration with the U.S. National Oceanographicand Atmospheric Administration Pacific ServicesCenter and the Guam Coastal Management Program,recently released the Guam Coastal Atlas, a productthat provides benthic habitat data and other coastalinformation to Guam’s coastal resource managers,researchers, students, fishermen, recreational users,and the general public. The atlas, which is availablein print, as an interactive CD-ROM, and as a website,contains a series of maps that provide pan-sharpenedIKONOS satellite imagery and benthic habitat data forthe length of Guam’s coastline. Additional maps thatuse a larger map scale and contain more detailedbenthic habitat data for four of Guam’s marinepreserves and three “focus areas” are also provided.The atlas also contains a “Spatial Data Library” section,which contains descriptions and sample images forseveral of the spatial data sets available for the island.The benthic habitat data and the atlas products weredeveloped using relatively limited resources by buildingupon existing data sets and process steps, utilizingGIS software for creating the atlas layout instead ofprofessional graphic design software, and takingadvantage of free, customized scripts to enhanceproductivity.

IntroductionThe University of Guam Marine Laboratory, incollaboration with the U.S. National Oceanographicand Atmospheric Administration (NOAA) PacificServices Center (PSC) and the Guam CoastalManagement Program (GCMP), recently released theGuam Coastal Atlas, a product that provides satelliteimagery, benthic habitat data, marine preserveboundaries, and other coastal information to Guam’scoastal resource managers, researchers, students,fishermen, recreational users, and the general public.The Guam Coastal Atlas is available in print, as aninteractive CD-ROM, and as a website. The GuamCoastal Atlas is an updated version of the Universityof Guam Marine Laboratory’s Atlas of the Reefs andBeaches of Guam, created by R. H. Randall and L. G.Eldredge in 1976. The Atlas of the Reefs and Beachesof Guam provides hand-drawn sketches of thecoastline derived from aerial photographs. With theproliferation of Geographic Information Systems (GIS)

The Guam Coastal Atlas: Creating BethicHabitat data and a Printed, CD-ROM, and web

based atlas with limited Resources

David R BurdickGuam

On 21 May 2007,Leica Geosystems(ERDAS Imagine)announced that ithas acquired allassets of EarthResource MappingLtd (ER Mapper), a geospatial software companyheadquartered in Australia. ER Mapper was the maincompetitor.

ER Mapper isthe first tomarket indelivering anew, highper fo rmances e r v e ra p p l i c a t i o n ,Image Web

Server (IWS), specifically made for the enterpriseenvironment. Designed to manage and distribute largeimage datasets, IWS provides users access toimagery with unprecedented speed, which is key toutilizing geospatial intelligence within the enterprise.Additionally, as a leader in the development of imagecompression techniques, ER Mapper brings thispatented technology to enhance existing products andfuture development of geospatial solutions. Movingforward, the ER Mapper and Leica Geosystemsproduct portfolios will be maintained and new solutionswill be developed using existing technologies of bothcompanies.Leica Geosystems is part of the Hexagon Group,Sweden. For more information about LeicaGeosystems or its products and services, call +1 770776 3400, toll free +1 866 534 2286, or visit gi.leica-geosystems.com.

Leica Geosystems Geospatial Imaging (ERDASImagine) Acquires ER Mapper

This DVD (left)contains allpresentations andsome video clipsof the RegionalGIS&RS UserConference inSuva, 2006. TheDVD is availableat SOPAC.


The Guam Coastal Atlasin recent years and the acquisition of high-resolutionsatellite imagery, a new generation of coastal resourceinformation had become available. The Guam CoastalAtlas was developed using these technologies andincludes benthic habitat maps derived from satelliteimagery, marine preserve boundaries mapped usingthe Global Positioning System (GPS), and the mappingof other important coastal features. The Guam CoastalAtlas is not intended to replace the previous atlas, butrather updates and supplements the informationpresented in the original publication.

This paper presents the methodology used to developthe benthic habitat data set that is the centerpiece ofthe Guam Coastal Atlas product, as well as themethodology used to create the printed, CD-ROM, andweb-based versions of the atlas. An emphasis is madeon how this product was developed with relativelylimited resources. Utilizing existing equipment andsoftware, building upon existing data sets andmethodologies, relying on a network of professionalswilling to contribute their expertise, and using freely-available software and customized ArcGIS scripts toimprove productivity, are some of the strategiesemployed to overcome the limitations of staff size andexpertise, hardware and software availability, andfunding.

Methods and ResultsOverviewThe production of the Guam Coastal Atlas involvedthe development of a benthic habitat data set for thenearshore waters of Guam as well as the developmentof printed, CD-ROM, and web-based versions of anatlas product to deliver the benthic habitat data, satelliteimagery, and other spatial data to users. These taskswere carried out by the NOAA Pacific Islands Assistantfor Guam over the course of approximately 18 months,with expert advice provided by individuals from variouslocal and federal agencies at various stages of atlasproduction. The development of the benthic habitatdata, even though based upon an existing data set,still comprised the bulk of the time required to completethe atlas. ESRI’s ArcGIS v8.3 and ArcGIS v9.0 softwareapplications were used to digitize benthic habitat unitsfrom pan-sharpened IKONOS satellite imagery. ATrimble GeoXT GPS receiver was used to collectground validation data, which was in turn used to helpinterpret the satellite imagery. Maps containing thebenthic habitat data, satellite imagery, and marinepreserve boundaries were then produced usingArcGIS, with the freely-available DSMapbook andLegend Limiter scripts used to improve productivityduring map development. The layout of atlas pagesthat did not contain maps was also developed withArcGIS, with figures, graphics, and tables producedusing Adobe Photoshop and Microsoft Excel. An

interactive CD-ROM product containing the benthichabitat maps as well as several spatial data sets wasproduced using Macromedia Dreamweaver andFireworks software. The contents of the CD-ROMproduct were then slightly modified and copied to aweb server in order to disseminate the data throughthe internet. Details for each of these steps areprovided below. Funding for atlas production wasprovided through a U.S. Department of Interior andNOAA Coral Reef Initiative grant, while the salary ofthe NOAA Pacific Islands Assistantship Program wasprovided through the NOAA Pacific Services Center.

The NOAA Pacific Islands Assistantship ProgramThe Guam Coastal Atlas was developed by DavidBurdick, the 2004-2006 NOAA Pacific Islands Assistantfor Guam, under the supervision of Dr. TerryDonaldson, the Principle Investigator, and Barry D.Smith, Director of the University of Guam MarineLaboratory. Since 2001, the NOAA Pacific IslandsAssistantship (PIA) program has provided the coastalmanagement communities of Hawai’i, Guam, theCommonwealth of the Northern Marianas Islands, andAmerican Samoa with hardware, software, satelliteimagery, and highly trained technical assistants.Through the PIA program, each jurisdiction receivesa technical assistant every two years; each assistantpossesses an advanced degree in natural resourcemanagement, environmental studies, marine science,geography, or related field, as well as significantexperience with spatial information technologies. Byintegrating emerging geospatial technologies, such asGIS, into each jurisdiction’s coastal managementprograms, the assistantship program aims to help theislands better manage and protect their coastal andmarine resources. In addition to providing support foreach jurisdiction, the assistantship program alsofosters each assistant’s professional developmentthrough guidance by one or more mentors and withfunding for attending conferences, workshops, andother training opportunities. The 2004-2006 NOAA Pacific Islands Assistant forGuam provides support to the Guam CoastalManagement Program, the University of Guam (UOG)Marine Laboratory, and other Government of Guamagencies, in integrating quality spatial data into newand existing applications, while also supporting grantprojects involving spatial data and providing trainingto agency staff and UOG students utilizing spatial dataand GIS. The Pacific Islands Assistant worked on theGuam Coastal Atlas project over a period of about 18months, with approximately 50% of his time devotedto this particular project and the rest devoted to variousother projects.

Benthic Habitat Data Development


The Guam Coastal AtlasThe benthic habitat data set used in the Guam CoastalAtlas was not created entirely from scratch, but ratherwas based on data developed by the NOAA NationalCenters for Coastal Ocean Science (NCCOS)Biogeography team for their February 2005publication, Atlas of the Shallow-Water BenthicHabitats of American Samoa, Guam, and theCommonwealth of the Northern Mariana Islands. TheNOAA Biogeography Team’s benthic habitat data setwas created by visual interpretation of IKONOSsatellite imagery captured between 2001 and 2003 andvalidated by in situ surveys. The NOAA BiogeographyTeam’s benthic habitat data utilized an averageminimum mapping unit of approximately 1 acre(4,046.86m2), however, and did not fully take advantageof the high level of detail that the IKONOS imageryallowed.

In order to update the benthic habitat data developedby the NOAA Biogeography Team and improve thedata’s level of detail, the most recently available (2004)multispectral IKONOS image mosaic and asignificantly smaller minimum map unit was used. Anaverage minimum map unit of approximately 1/8 acrewas used for the mapping of benthic habitats in fourof Guam’s marine preserves and other “focus areas.”Benthic habitat maps for someof the area beyond the marinepreserve boundaries and thefocus areas utilized the originalNOAA Biogeography Teambenthic habitat data, withalterations (e.g., polygonboundary adjustments,classification corrections/updates) performed on the datain other areas. Additionalground truthing data were alsocollected to allow more detailedmapping without compromisingthe accuracy of the original dataset. In order to obtain the bestpossible spatial resolution, themultispectral IKONOS imagerywas pan-sharpened usingERDAS Imagine imageprocessing software. Theheads-up digitizing functions ofArcGIS v8.3/v9.0 were thenused to adjust the boundaries of the existing benthichabitat data, create new features, and update featureattribute information. A hierarchical classificationscheme similar to that used by the NOAABiogeography Team was adopted for the data used inthe Guam Coastal Atlas (see below for moreinformation about the classification scheme).

While the availability of an existing benthic habitat dataset certainly reduced the amount of time and effortrequired to develop a more detailed benthic habitatdata set, the lack of a pre-existing data set would nothave required a substantial amount of additional work.Much time was spent modifying the boundaries andattributes of existing polygons, for example, requiringnearly as much effort as creating polygons fromscratch. The existing polygons in some areas wereeven deleted entirely as a result of their apparentinaccuracy and their potential to add confusion to theinterpretation and digitization process of the new dataset. It is also important to note the significant benefitof utilizing local knowledge in both the digitizing andvalidating of the benthic habitat data.

Classification SchemeA hierarchical classification scheme similar to thatused by the NOAA Biogeography team was adoptedfor the benthic habitat data used in the Guam CoastalAtlas (Figure 1). Using this classification scheme,benthic habitats were described from the broadestlevel of classification to a very detailed level ofclassification. The major structure (unconsolidatedsediment or coral reef/hard bottom), the detailedstructure (e.g. aggregated reef, pavement, patch reef,

etc.), the major cover type (e.g. coral, macroalgae,turf algae, uncolonized, etc.), and the percent coverof the major cover type (e.g. 0%, 1%-<10%,10%<50%, etc.) were also recorded for each habitatfeature. The use of an existing classification schemedesigned specifically by NOAA for the reefs of the U.S.Pacific trust territories provided a significant head-startfor the development of the benthic habitat data set

Figure 01: Hierarchical classification scheme used in thedevelopment of the benthic habitat data.

1 0 Pacific GIS&RS NEWS March, 2006

The Guam Coastal Atlasused in the Guam Coastal Atlas. Adopting andmodifying existing classification schemes eliminatesthe effort required to develop an relevant system fromscratch. This process, which usually involvesconsulting with numerous experts, can be timeconsuming and potentially costly.

Ground Validation SurveysA series of ground validation surveys were performedduring the development of the benthic habitat data setin order to assist in the interpretation of the satelliteimagery. A Trimble GeoXT handheld GPS receiverwas used to collect benthic habitat information in situ.During the ground validation surveys, benthic habitatwas described at each of the numerous data pointscollected throughout the study area. Data points werecollected along haphazard transects, with the locationof the points purposefully chosen in order to representa variety of distinct, neighboring habitat types. Thebenthic habitat within a 1m2 area at each point wasdescribed using the hierarchical classification schemedescribed above. Many survey points also containthis same information for the area surrounding eachpoint (10m radius) in order to account for the highdegree of heterogeneity in benthic habits that existsat even the smallest scales and to account for thelimitations of the satellite imagery. Once the data weretransferred to a desktop computer, they were post-processed using Trimble Pathfinder Office 3.00software. A total of 846 ground validation points werecollected at various sites around the island. The 203ground validation points and the 241 accuracyassessment points collected by the NOAABiogeography team were also used to help interpretthe satellite imagery.

Because of environmental conditions, field surveyswere limited mostly to the shallow reef flat areasaround Guam. A much wider cross-section of coastalarea, including many fore reef areas, was observedand documented using a digital still camera and byhand-drawn sketches during snorkeling and scubadiving excursions. These in situ observations allowedfor a general assessment of an area’s benthic habitatcomposition, assisted with the interpretation of thesatellite imagery, and improved the accuracy of thebenthic habitat classification in areas not surveyedusing the GPS receiver.

An accuracy assessment had not been performedprior to the production of the printed and CD-ROMversions of the Guam Coastal Atlas, so the accuracyof any changes made to the original NOAABiogeography Team’s benthic habitat data during thedevelopment of the Guam Coastal Atlas have not beenassessed. An accuracy assessment will likely beperformed at a later date. This information will beavailable on the website.

The Trimble GeoXT GPS receiver used for the groundvalidation surveys was in the possession of the GuamCoastal Management Program prior to the project’sinception, and thus it was not necessary to includethe cost of a GPS receiver into the grant proposal.While the sub-meter accuracy of the Trimble GeoXTGPS receiver and its ability to utilize a data dictionaryimproved the quality of the ground validation data andenhanced the efficiency of data collection, neither ofthese features are required when collecting groundvalidation data. This is especially true when thebenthic habitat data are derived from satellite imagerywith limited resolution. Using an expensive GPSreceiver with sub-meter accuracy when derivingbenthic habitat data from multispectral IKONOSsatellite imagery (4m2 resolution), for example, wouldproduce no significant advantage over a GPS receiverwith 1-3 meter accuracy. Post-processing of theground-validation data also improves the accuracy ofthe data, but this too is not vital. If differential correctionis possible through a local base station, butcommercial software such as Trimble’s GPSPathfinder Office is not available, low cost (free - $99)alternatives are available.

While carrying out ground validation surveys by asingle person can be dangerous and comes withcertain limitations, valuable ground truthing data canstill be collected with a GPS receiver in shallow,protected waters. If carried out by a local residentfamiliar with the area’s reefs, ground validation surveyscan be much more flexible than off-island teams andcan take advantage of favorable weather conditionsat a moment’s notice. Utilizing qualitative sketches ofan area’s benthic landscape while scuba diving orsnorkeling (both during work hours and recreationally)also provides the benthic habitat data developer(s) withvaluable information for the interpretation of the satelliteimagery in areas that are inaccessible by a singleperson using a GPS receiver.

Creating a printed, CD-ROM, and web-basedatlas productA printed version of the atlas was developed in orderto deliver the benthic habitat data and other coastal-associated data to the island’s coastal resourcemanagement agencies, researchers, teachers, andothers potential users in an attractive, user-friendlyformat. The final printed version of the Guam CoastalAtlas is a full-color, 11 x 17-inch, 149-page publication.The printed atlas is comprised primarily of a series ofmaps that provide satellite imagery and benthic habitatdata for the length of Guam’s coastline. Two 1:15,000-scale maps are provided for each of 35 contiguoussections along Guam’s coastline – one map providesthe pan-sharpened IKONOS satellite imagery and themarine preserve boundaries while the other providesthe satellite imagery, the marine preserve boundaries,


The Guam Coastal Atlas

!continuation page 12

as well as the benthic habitat data. Each mapcontains a detailed legend containing symbols for onlythe classes visible in that particular section of thecoastline. A digital photo of a beach, rocky shoreline,reef, seagrass bed or other notable feature is providedwith most maps. These photos are intended to providethe users – many of whom may be unfamiliar withmuch of the island’s coastline – with at least someidea of the appearance of the landscape or seascapedepicted in the map. Other information, including anoverview of the methodology, a description of thehierarchical classification scheme and the groundvalidation process, and underwater photos ofexamples of the various structural and biologicalclasses used in the classification scheme are alsoprovided. The atlas also contains a Spatial DataLibrary section, which provides an overview of someof the digital spatial data available through the GuamBureau of Statistics and Plans and from other sources.The data sets described in the Spatial Data Librarywere selected for their potential application to coastal-related management, research, and educationendeavors. Brief descriptions of the data as well aspreviews of the data sets are provided. The digitalspatial data layers covered in the Spatial Data Libraryinclude IKONOS satellite imagery mosaics, digitalbathymetry, digital elevation, land cover, marineprotected area boundaries, coastal features, soils,geology, and watershed data. Approximately 300hundred copies of the printed atlas were producedduring the first round of printing at a cost ofapproximately US$55 per copy. One hundredadditional copies were printed by the U.S. NavyEnvironmental Office, with 30 of those copies providedto the Guam Coastal Management Program.

In continuing with the theme of “using what you haveto the best of your ability,” the maps and the layout forpages that did not contain maps (e.g., table ofcontents, methods, etc.) were developed using ArcGISsoftware instead of professional graphic designsoftware. The content of the atlas pages wasenhanced with figures and graphics created in AdobePhotoshop and with tables created in Microsoft Excel.These software applications were already availableand the Pacific Islands Assistant was familiar with thefairly easy-to-use tools provided with these softwarepackages. The photographs of Guam’s reefs,beaches, and other features included with most of themaps were taken using the author’s personal digitalpoint-and-shoot camera (and an underwater housingwhen necessary).

In order to produce the maps presented in the atlas, afree script for ArcGIS called DSMapBook (availableat http://arcscripts.esri.com) was used to generate amap index based on a customized grid system. Adifferent customized grid system was created for the

1:15000-scale maps used for the entire coastline ofGuam, the 1:4000-scale maps for the marinepreserves and most of the focus areas, and the 1:8000-scale maps used for the remaining focus area. Thegrids were created by creating rectangular graphicsin ArcMap and manually placing them contiguouslyalong Guam’s coastline. Another script downloadedfreely from http://arcscripts.esri.com was used toconvert the graphics to a polygon shapefile format,which was the format required by the DSMapBookscript to generate the map index. The resulting mapindex allowed the use of a map template to generatethe maps, with the extent of each map defined by theindividual, contiguous cells. While the use of the mapindex and the map template greatly reduced theamount of time required to generate the 132 separatemaps, there was some degree of customizationrequired for each of the maps. In order to do this, aseparate ArcMap Document (MXD) was used for eachmap. Perhaps one of the more major customizationsfor each map was the map legend. Because of thelarge number of possible benthic habitat classes inthe data set, the display of all of them on each mapwould consume an unacceptably large area of the mapor would have to be presented using a small, difficult-to-read font size. To address this issue, yet anotherscript was obtained from http://arcscripts.esri.com.This script, called the Legend Limiter, provides for thedisplay of only those classes present in a given mapextent. In most cases, the number of classesdisplayed in the legend was reduced from 68 to lessthan 10. While not absolutely necessary, the legendand other map elements can also be converted tographics and the individual elements ungrouped inorder to achieve a greater degree of aesthetic freedom.

Concomitant with the development of the printed atlaswas the development of an interactive CD-ROMproduct. The CD-ROM product, which wassignificantly cheaper to produce than the printedversion, was designed to deliver the informationpresented in the printed version to a larger audienceand in an interactive format. While the developmentof the CD-ROM product is completed, the 300-500copies have not yet been produced. The CD-ROMversion of the atlas contains the same maps providedwith the printed atlas, but these maps are accessedthrough a Javascript-based interactive map selectionpage and are stored and viewed as Adobe PDF files(Figure 2). The CD-ROM also contains the SpatialData Library and the same project overview andmethodology information, as well as spatial datalayers, including the benthic habitat data, the marinepreserve boundary data, coastal features data, andground validation data in ESRI shapefile format. AnESRI Layer file, which is a companion file format to


The Guam Coastal Atlasthe shapefile that contains symbology information, isalso provided for the benthic habitat data in order toallow users to create their own maps using the samesymbology presented in the atlas. U.S. FederalGeographic Data Committee-compliant metadata isalso provided for each dataset.

Macromedia’s Dreamweaver software was used tocreate the CD-ROM’s HTML-based framework andcontent. Macromedia Fireworks and Adobe Photoshopwere used to develop the Javascript-based interactiveimages used in the interactive map selection sectionof the CD-ROM. The CD-ROM product was designedto be compatible with several internet browsers,including Internet Explorer, Mozilla Firefox, andNetscape.

A website, perhaps the most cost-effective andefficient method of disseminating the atlas to thegeneral public, was also developed. The website,available at http://www.uog.edu/marinelab/coastal.atlas/ is simply a slightly modified version ofthe CD-ROM product, with the contents of the CD-ROM copied to a web server after only minormodifications. Further modifications will be made tothe website to make it more compatible with internetuse, including reducing the file size of the maps andimages to improve downloading and page loading time.

ConclusionWhile the Guam Coastal Atlas was produced withlimited resources, especially compared to similar

products developed by teams of individuals with fargreater resources, it would be difficult to produce sucha product without satellite imagery, GIS software, andweb-design and graphic-design software. However,with the increased accessibility and decreasing costsof high-resolution satellite imagery and GIS software,and the availability of free or inexpensive web-design

and graphics design software, a high quality atlas canbe produced at minimal cost and effort. A relativelylow-cost atlas, such as the Guam Coastal Atlas, thatprovides remotely sensed imagery, benthic habitatdata, and other coastal-related information to resourcemanagers, resource users, educators, and others, cancontribute signficantly to more effective and efficientmanagement of these resources.

ReferencesNOAA National Centers for Coastal Ocean Science(NCCOS). 2005. Atlas of the Shallow-Water BenthicHabitats of American Samoa, Guam, and theCommonwealth of the Northern Marianas Islands.NOAA Technical Memorandum NOS NCCOS 8,Biogeography Team. Silver Spring, MD. 126 pp.

NOAA Biogeography Program website: http://biogeo.nos.noaa.gov

Randall, R. H. and L.G. Eldredge. 1976. Atlas of theReefs and Beaches of Guam. University of GuamMarine Laboratory, Mangilao, Guam, 191 pp.

AcknowledgementsA debt of gratitude should be extended to the variousagencies, organizations, and individuals whocontributed to the development of the Guam CoastalAtlas. I would like to thank Dr.Terry J. Donaldson, thePrincipal Investigator, and Barry D. Smith, Director ofthe University of Guam Marine Laboratory as well asEvangeline Lujan, the Administrator of the GuamCoastal Management Program, Victor Torres, theBureau of Statistics and Plans GIS Manager. I wouldalso like to thank Darcee Killpack, Nancy Cofer-Shabica, and the rest of the staff at the NOAA PacificServices Center and the NOAA Coastal ServicesCenter who provided their valuable advice duringseveral stages of this project. Support andcontributions for the Guam Coastal Atlas project wereprovided by several other organizations and individuals,including:

- University of Guam Marine Laboratory

- Guam Coastal Management Program

- NOAA National Centers for Coastal Ocean ScienceBiogeography Team

- NOAA Coastal Services Center

- NOAA Pacific Services Center

- Department of Aquatic and Wildlife Resources,Guam Department of

Agriculture

- Guam Environmental Protection Agency

Contact the authur - Email: [email protected]

Figure 02: The Javascript-based interactive mapselection page of the Guam Coastal Atlas CD-ROMproduct.

March, 2006 Pacific GIS&RS NEWS 13!continuation page 14

Hydrodynamic Model of Tarawa


Herve Damlamian

SOPAC

Because of a population increase in South Tarawa,Kiribati, of 5.2 % per year, it has become crucial toimprove our understanding of thelagoon marine environment in orderto better manage potentialimpacts This has been partlyachieved by the SOPAC/EU project‘Reducing the Vulnerability ofPacific ACP States’, which initiateda baseline hydrodynamic modelusing MIKE 21 software. Thiscomputer-generated watercirculation model utilised high-resolution bathymetric data(collected by SOPAC with amultibeam echosounder), which were merged withwater depths derived from a Landsat satellite imageof Tarawa.

The water circulation can be simulated by acombination of the tidal flow, wind forcing, and incidentwaves. However, due to the large area (~400 squarekilometres) and shallow water (<25 metres)environment of this lagoon, a crucial role is expectedto be played by the tide on the overall water motion.

Used as a management tool, the water circulationmodel can deliver much useful information relating towater quality, the dispersion of the sediment plumefollowing a dredging operation, and sediment transportpatterns.

Set UpThe semi diurnal tidesand dominant easterlywinds recorded at theBetio tide gauge wereused as an input to thehydrodynamic model.The tide gauge isinstalled as part of theSouth Pacific Sea Leveland Climate MonitoringP r o j e c t(www.bom.gov.au).

We collected water flow in three eastern channels, inorder to simulate the effect of the incident ocean swellwaves on the water circulation inside Tarawa lagoon.

This data collection was undertaken during neap andspring tides, and the data was used to obtain anunderstanding of the variation of water flow with thetide in every eastern channel. The description andresults of this survey are published in the SOPAC/EUtechnical report “Inter-Tidal Channel Flow in NorthTarawa” (Webb and Damlamian, 2006).

These data were integrated into the model by addingadditional sources in each of the channels on theeastern reef, helped to simplify the bathymetry, andreduced the computation time (see Figures illustratingthe model set up).

CalibrationThe validation of the model was done by comparingmodel outputs against measured surface elevations(tidal levels) and current data (water velocities). Thesurface elevations were available from the tide gauge,and velocities were obtained by four ADP (AcousticDoppler Profilers) deployed in the lagoon to measurecurrent speed and direction.

Parameters such as wind friction and bottomroughness were adjusted until the model outputsclosely matched the real world measurements, and asatisfactorily calibration of the hydrodynamic modelwas achieved. This is illustrated in Figure 2

Results

The model was used to simulate water circulation overa two-week period, from the 15th to the 30th of October

Figure 01: Illustration of the set up model

Figure 02: Bathymetry and bottom roughness map ofTarawa lagoon



2005. The results show that the water motion in thelagoon is controlled by tides. Effects of waves are seenlocally on the eastern side, but only during the springand high tide when the ocean water is high enough toovertop the eastern reef (~ 1.6 m). Three Circulationpatterns were extracted from the simulation for eachtide phase (Flood & Ebb) at neap and spring tide.

ApplicationsUsing the calibrated hydrodynamic model as abaseline, a numerous number of applications can beexamined.

Environmental impact assessment from proposeddredging operationA dispersion sediment plume model was carried outusing the hydrodynamic baseline, aimed to addressProject works in relation to the Kiribati AggregatesCompany Proposal being jointly developed by the

SOPAC-EU Project’s CoastalProcesses component, theKiribati, EU Office and theMinistry of Fisheries andMarine ResourceDevelopment, Kiribati. Theimpacted zone from dredgingoperation in two resourceareas was studied.

The dispersion plume beingcarried out by a 3D currentand as MIKE 21 produces 2D

hydrodynamic baseline, the output of the dispersionmodel was only used as a guide.

Figure 3: Comperative diagrams of surface elevation and current speed callibration result


Town Planning Projects and Modelling ToolsComparison of Olden day and Now day waterquality of the lagoonThe water quality depends a lot on the capacity of thelagoon to clean itself, which is leaded by its flushing.The maps below show how many days a particle ofwater could stay in the lagoon before being flushedout.

Since the second half of the 20th century, causewayswere built in south Tarawa to link the islets. Noenvironmental impact assessments were done andwe realise today as population is growing and pollutionbecoming more and more worrying the aftermath ofsuch a project.

Town Planning Projects and Modelling Tools

Myriam Gallois

Empreintes, New Caledonia

IntroductionThe urbanisation of the administrative districts locatedat the outskirt of Nouméa form an out-off-townsettlement. Indeed till now, the essential of the urbandevelopment has been realised by the juxtaposition ofhousing subdivisions.

An urban development which was an answer to animportant need of housing. Because of the closenessof Nouméa - administrative, economic, socio culturalcentre of the “Grand Nouméa” Agglomeration1 - andbecause of the light demographic weight of theadministrative districts of Dumbéa and Mont Dore, therewas politic to build up centres able to federate thesemagmas of subdivisions of individual housings.

Among the administrative districts of the “grandNouméa”, Dumbéa is distinguished by its particular

status of welcoming. Welcoming of populationscoming from the other administrative districts of the

“ G r a n dNouméa”. Thesemigrations plusthe naturalgrowth rate putthe global growthrate of Dumbéato a levelsuperior to theones of the other

administrative districts.

The population of Dumbéa would increase from 18 600to 60 000 inhabitants in the next 20 years. Indeed,taking in consideration all the projects of developmentin progress or planned on the territory of Dumbéa, itwould welcome, as early as 2015, between 40 and45 000 inhabitants.

An exceptional growth followed by a “return to normal”of its rate of growth, would bring the population ofDumbéa to a weight set between 60 and 65 000inhabitants towards 2026.

The welcoming if these populations can anymore besupported by an urban sprawling, ant Dumbéa is leadto organize its territory and especially to build its ownCentre / Down Town.

So, Dumbéa has thrown itself in the build up of a downtown, from an area free from urbanisation. But thisevolution from a low rise urban patterns to a compacturban patterns is very sudden and the constraints notnecessarily mastered by the local councillors.

Indeed, create a Down Town, it’s doing the oppositeof what has been done till now. It means to concentrateand organize housing, services and activities in a smallscaled area, which induce compact urban patternscontrolled by complex rules.

Help to the design of complex projectsThe area chosen by Dumbéa to realise its project ofdown town is located between educational facilities, abig shopping centre and areas of low rise housing.

So, in thesurroundingof thef u t u r ed o w nt o w n ,there wasno urbanpatternswhich canbe usedas a germfor thep r o j e c t .

Figure 02: volumetry representing the maximumconstructible envelopvolumetry representing themaximum constructible envelop

For more information contact: Herve [email protected]


T h ebuilding upof thisdown townis planedin an areathat can bequalified of“no man’sl a n d ”which leadto use the3 Dmodellingat specificstages ofthe study.

At first, the3 Dmodelling

is used to make clear the project in its guidingprincipals, in other words, in the expected volumetry(figure 2). That means the maximum envelop in whichthe future buildings would have to slip into. Thevolumetry also enables to display the surfacededicated to the public areas like roads that the projecthas planned with imposed alignment or not for theconstructions implantation regarding to the public /private limits.

In a second time, the 3D modelling inserted in a digitalelevation model, allows to check the integration of theproject in its natural or urban environment (figure 3).

Tool for landscape analysisAt the time of the carrying out of a project ofdevelopment, the impact on the environment and onthe landscape must not be overlooked.

Figure 03: Integration of the future down townin its environment

The use of digital elevation models allows to realise aquick analysis of several elements which can becomelimits to urbanisation :

- slopes,-landscapes markers that would haveto be preserved or high-light.

The slopes represent technical and financialconstraints and to urbanize lands with a slope superiorto 25-30 % can have irreparable impacts on thelandscape. (Figure 4) So DEM is a tool to fix theboundaries of the area of severe slopes. (the precisiondepends of the accuracy of the topographic data)

The landscape makers are most of the time maintopographic elements, as a crest line easy to identify.

But when the topography is complex and can be readonly by the eyes, it is interesting to analyse the visibilityyou can have from a specific point. (Figure 5)

This analysis of visibility would have an direct impacton the development chosen. Indeed, in town planning

visibility and readability of a territory arefundamentals. So the choices of urbanplanning must take in considerationthese markers to use them tostrengthen the urban frame.

Tool of communicationAll the previous illustrations help to thestudies progress, but also to explainthe evolutions and the choices of urbanplanning retained.

Foot Notes1 The Grand Nouméa is the name given to theagglomeration constituted by 4 administrativedistricts (Dumbéa, Nouméa, Mont Dore and Païta)

Figure 05: Map of « visibility » (the area hatched is visiblefrom the magenta square)

Figure 04: Slopes map (in orange and red the slopes superior to 25 %)

Date post:	01-Dec-2021
Category:	Documents
Upload:	others
View:	2 times
Download:	0 times

Pacific Islands The Newsletter of the GIS&RS news

Documents