Integrating Remotely Sensed
and Terristrial Data for Environmental Conservation Management in Tasek
Bera, Pahang, Malaysia Richard F.
Dorall Introduction Associate Professor, Department of Geography, University of Malaya, University of Malaya, 50603, Kuala Lumpur, Malaysia E-mail:f3rich@umcd.um.edu.my Peter Sinniah Geographical Information Systems Data Management Officer, Tasek Bera project, Wetlands International Asia Institute for Post Graduate Studies and Research (IPSR), University of Malaya, 50603 Kuala Lumpur, Malaysia E-mail:speter@tm.net.my Malaysia became a contracting party to the Convention on Wetlands of International Importance Especially as Waterfowl habitat, better know as the Ramsar Convention, in November 1994. The importance Malaysia gives to Wetland conservation and management for sustainable development was emphasized during the International Conference on Wetlands and Development held in Kuala Lumpur in October 1995 when, in the Opening Speech delivered by the Malaysian Prime Minister, YAB Dato Seri' Dr Mahathir Mohamad, acknowledged that, "… wetlands and their resources play a critical role in supporting the lives of millions of people throughout the world. Wetlands not only provide a wide range of valuable products to society, including fish, fodder and timber, but also perform a number of natural biophysical functions such as flow regulation and groundwater recharge. They are therefore relevant for research and understanding to ensure that their contributions to the development of the ecosystems are maintained" (Anon. 1996). The Prime Minister admitted in this speech that " As we meet today, these life -sustaining systems remain under threat. Many wetlands… have been destroyed or degraded through over-exploitation or environmentally unsound development." During the conference, YAB Tan Sri Hj Mohd Khalil bin Yaakob, the Chief Minister of the State of Pahang, announced that his state's Executive Council had agreed to gazette Tasek Bera and its surrounding area of some 26,000 hectares as a reserve for conservation purposes under the Ramsar convention, while an additional 27,500 hectares had been identified as a buffer zone (Anon. 1996a). With financial support from the government of Denmark through the funding agency DANCED, the government of the State of Pahang subsequently contracted Wetlands International Asia-Pacific to implement a three year cooperative project which aims to protect and enhance the biodiversity of Tasek Bera and its catchment area, in order to meets its responsibilities under the Ramsar conventions, and to ensure the long term future, and sustainable development of this wetland site of international importance. The Project Area: Tasek Bera is Peninsular Malaysia's largest natural lake system, and is located in southwest Pahang. It is a lowland (mostly under 80 meters above sea level) dendritic alluvial peat swamp ecosystem measuring some 34km by 35 km, with a wtlands area of 6,150 hectares in a catchment estimated at 61,383 hectares. The lake system drains northwards through the Sungei Bera into the Sungei Phanag. Reversed water flow occurs during the Northeast monsoon (September -January), resulting in fluctuations in water level in the system of between 1 through 5 meters. The system comprises three major habitat types, as reported in the Malaysian Wetland Directory (Anon. 1987): the open water region fringed by submerged Utricularia weeds (approximately 1 per cent of the swamp area); emergent Pandanus and Lepironia reed beds in the littoral zone (32 per cent); and Eugenia swamp forest stands (67 per cent). The catchment was originally lowland dipterocarp forest, but this has over the past two decades been largely replaced with oil palm and rubber plantations developed by the Federal Land Development Authority (FELDA). The site was studied in detail through the International Biological Programme in the 1970s which some 95 species of fish, 200 bird species, large mammals such as elephant (Elephas maximus), tapir (Tapirus indicus), tiger (Panthera tigris) and gaur (Bos gaurus), virtually all the amphibians and reptiles of Malaysian tropical swamps, including the endangered Malayan False Gharial (Tomistoma schlegelii). Tasek Bera is ranked as a wetland site of national and international importance because it is only one of two major natural fresh-water wetlands in Peninsular, and plays an important natural function as a major lake river basin. It supports a diverse biological community unique to Malaysia, "and possibly represented nowhere else in the world" (Anon. 1987). The Malaysian Wetland Directory noted the following threats facing Tasek Bera: shifting cultivation (by indigenous native peoples, the Semelai); possible pollution from tributaries in the system affected by developments taking place upstream; logging operations and associated road construction which alter local drainage patterns and increase siltation in river tributaries which lead to the destruction of the watershed. Project Aims and Objectives The Tasek Bera Project Team set up by the Wetlands International Asia-Pacific, and liaising closely with relevant district and Pahang State government agencies, has described the overall development goal of the project as to protect and enhance the the biodiversity of the Tasek Bera Ramsar Site and its catchment through a series of specific objectives. These objectives include:
Wetlands are very complex structures, ". each wetland is specific in terms of management potential and it is impossible to draw up a detailed management plans which can be applied to all wetlands" (Roggeri 1995), and, therefore, broad regional and national level wetland management plans are of little practical value on the ground that specific stands of forest and their related exosystems have unique characteristics. Wetland management for sustainable development is in practice, therefore, an exercise in site-specific area management which take into account unique combinations of human, animal, vegetation, water and socio-economic processes which interact to shape particular wetland forest areas. The senior author has shown in an earlier paper that: "Only a modem geographical information system (GIS), with its ability to standardize multiple layers of map information, both human and physical, in both the vector and raster formats, import and geo- reference imagery (satellite, aerial photographs, etc.), link geographical objects and locations to relational database which can organize and store practically unlimited number of objects and site characteristics in the from of numerical data, text, photogre\aphs, hyperlinks, sound and animation which are today the standard technologies of multimedia information system, meets the needs of modem management system, and offer to are management techniques of analysis, of visualization , and of presentation, which no other management system can presently offer. Such a GIS litraally provides a virtual environmental for area management which is second only actually going to the site itself' (Dorall 1997). The Tasek Bera Integrated Managements Project on which the two authors are currently working seeks to develop a GIS-based Area management Plan for the Ramsar site which incorporate map, terrestrial and remotely sensed data, past, present as well as data collected in "real-time" to facilitate area monitoring, into a geo-referenced multimedia information management system which will canble the Tasek Bera area managers to base their decisions on virtual geographical environmental models which are a quantum leap forwards from the paper-based maps currently used by Malaysian environmental managers. The principal activities (b),(c), and (e) above will be met by the proposed GIS-based area management plan for tesek Bera which will from the basis of achieving the major project objectives of the delineation of the project area (2), and scientific area management (1). Enriching the Geographical Data Sets: The geographical data sets for the Tesek Bera Area Management are multi-parameter. The discussion below focuses on low the spatial data are being enriched by digital- based field mapping as well as data from remote sensing, both aerial and satellite imagery. Topographical Data: Contour lines of 20 meter interval derived from the peninsular Malaysia's most recently published topographical map series L8028 (Edition 1-PPNM), map scale 1:25,000. are being used to develop the basic elevation database. These data have a major shortcoming. Contour line elevations in the project area range from 40 meter to 120 meters, but many of the peaks of the low, rounded forested hill tops in the area are not marked by spot heights or trigonometrical stations. Processing such map derived contour line data in a digital terrain model without hill-top elevation points esults in plateau zones emering on many hill top where in the real world slopes exit. Likewise, the water-level of Tasek Bera as depicted on the topographical map is somewhere below the 40 meter contour line, and above the 20 meters line. For accurate digital terrain modeling, therefore, the heights of hill-tops in the area, as well as the water-level of the lake had to be measured in the field. Adventures from the Raiegh International who used Tasek Bera as a base for their exploration activities in June- August and October- November 1997 undertook field altimetry measurements of hil tops as wellas lake's water level using differentially corrected digital altimeters and global positioning system (GIS) devices to achive elevations of within 2-3 meter when compared to the few map bench mark and spot heights in the area. Lake Morphometric Data: Measuring the morphometry of the land's surface benesth the lake's water-surface in essential if modeling water-level rise and fall, as well as calculating water volumes etc. in the course oh hydrological modeling of the Tasek Bera catchment area is to the undertaken with relative accuracy. Since there are no sub-surface data available, the same Raleigh International explorers were used to measure water depths along cross-sections of the Tasek Bera lake. The location of each site was measured using GPS. Depths were converted into meter above sea level elevations, and entered as point data into the GIS topographical database where they were processed together with map contour line data as well a map field-measure spot height data into digital terrain models. Stream Profile Data: The hydrological modeling of the Tasek Bera system requires elevation and slope data which are available on the 20 meter contour topographical maps. Rivers and streams flowing into the lake often extend for many kilometers between 40 meter contour lines without crossing the next contour line, and this marks three- dimensional locational coordinates are also required to enrich the elevation data set before hydrological modeling can be undertaken. Land Cover Mapping: Land cover mapping in Malaysia has been undertaken for many years using aerial photography from topographical maps, as well as form the present landuse maps produced by the Malaysian Department of Agriculture provide information on land-cover change in the Tasek Bera district. These data classes, however, are insufficient for forestry management in the area, and so black-and-white aeral photography flown at 1:40,000 scale are being interpreted by the Forest Research Institute of Malaysia (FRIM) to delineate vegetation zones within the broad forest classes presented in published maps. Landsat Thematic Mapper (TM) imagery with 30-meter spatial resolution flown in June 1995 has also been analysed. The satellite imagery shows a wealth of information on the water and vegetation classes which when checked on the e ground can be related to variations in the evolution of peat soils and associated vegetation types. Area of disturbed forest caused by shiftin cultivation by the local Semelai communities, logged tracts in various staqges of regeneration, and location of illegal timber felling clearly stand out in the satellite imagery. Sample Site Selection for Detailed Field Study: The variations in the water-logged soil under various stages of peat formation identified in the satellite imagery are of particular interest. These sites have been targeted for field visitation for soil and vegetation mapping, as well as for sampling for aquatic macrophytes and phytoplankton, and for water quality testing. The same methodology is used for selecting field locations for field test site which will scientifically monitored over time, and compared with other field sites over space. Monitoring Site and Area-based Change: Satellite-based data taken initially at yearly intervals overTasek Bera will be incorporated into the project's spatial database to enable changes in the forest cover, quality of vegetation, impact of continued shifting cultivation, and the rate of regeneration of disturbed areas, including legal and illegal logging tracts, to be mapped and measured in the most be collected during the course of day-to-day management of the site, and which will also be incorporated into the overall spatial database. Socio-Economic and Cultural Mapping: The indigenous communities living within the Tasek Bera Ramsar site are uniquely associated with the resource base of the area. These spatial associations, many of which are dynamic and not static as is the case of the more sedentarised communities living outside the area, will be mapped to better understand the patterns and processes involved, and to take these into account in managing the area for sustainable development. Developing an Integrated Spatial Decision Support System (SDSS) for the Management of Tasek Bera: The Tasek Bera project is generating a large number of geo-referenced database, including: map data, aerial photography and satellite imagery data, field point and area data inculuding text, numerical and image (both still and animation data). These range from biological and environmental to socio-economic and administrative data, and all these need to be integrated into a decision support system which can be used not only for scientific research, but also area management and administration. Following Turban & Meredith (1991), a Spatial Decision Support System (SDSS) has been designed with an architecture consiting of (1) a Decision Support Model Base, consisting of a range of models including area management software (Countryside Management System partnership 1996), the Wetland Database (Wetland Data Base 1997), a GIS viewer and analysis software (Mapinfo Professional), a remote sensing package (probably Clark University's IDRISI for Windows), as well as statistical and other analysis toold;and finally(3) a Programmed Graphical User Interface (GUI) which enable data and model base management inquiry, data input and information output wetland management sites nationally as wella s worldwide through the Internet's World Wide Web, and this same medium will link the Tasek Bera Area Management Information System to researchers and other throughout the world who are interested in the development of Tasek Bera as a Wetland if International Importance Reference Cited:
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