Lakes: The Mirrors of the Earth
Lakes contain large volumes of freshwater readily accessible for human uses. As such, lakes, whether natural or artificial (reservoirs) are dramatic and highly-visible features of the global landscape. They also provide a wide range of life-supporting and economically-important ecosystem goods and services. Our planet contains an estimated 27 million natural lakes with surface areas greater than 1 ha, with the 17 largest natural lakes covering an area of about 100 million ha (1 million km2). There are an additional half million artificial lakes (reservoirs) with surface areas exceeding 1 ha. These water bodies collectively contain more than 90% of the liquid freshwater on the surface of our planet at any given instant. Being major lentic water systems easily accessible to human exploitation, lakes are used for a wider range of human purposes than any other type of freshwater system, which also makes them more susceptible to water use conflicts. Lakes exhibit several defining characteristics, including: (1) a long water residence time; (2) an integrating nature for all inflowing water and material inputs; and (3) non-linear responses to human interventions (so-called hysteresis property), all of which complicate their accurate assessment and effective management. In fact, being integrating ‘sinks’ for inflowing waters and the materials carried in them, lakes represent valuable barometers of the impacts of human activities within their drainage basins, with their degradation often being a trigger for freshwater management interventions.
The overall objective of the lakes component of the TWAP project is to provide a comparative global assessment of the state of transboundary lakes and reservoirs through a systematic review of existing data and information, the application of relevant indicators, and the utilization of both expert opinion and lake basin-specific questionnaires. The anticipated outputs, all of which will contribute to an improved understanding of transboundary lakes and reservoirs for both scientific and management purposes, include a systematic assessment of the relative ranking of transboundary lakes and reservoirs, based on a logical analytical assessment methodology, as well as a framework for sustainable periodic assessments of lakes, their basins and their resources.
The International Lake Environment Committee (ILEC), in cooperation with national, regional and international partners, is responsible for carrying out the TWAP-related assessment of transboundary lakes and reservoirs, based on a methodology originally developed during the TWAP MSP project, and subsequently revised to facilitate a more accurate and management-relevant ranking of these water bodies. The transboundary water bodies being analyzed include 159 lakes and reservoirs in countries eligible for GEF-funding, with surface areas ranging from approximately 13 ha (0.13 km2
) to nearly 40 million ha (400,000 km2
). It also includes another 47 lakes and reservoirs in countries not eligible for GEF-funding, mainly in North America and Europe. This represents a total of 206 transboundary lakes and reservoirs being analyzed in this component of the overall TWAP project.
Because of the lack of systematized data on a global scale, as previously noted, this work includes GIS-based
analyses, lake basin-specific stakeholder questionnaires, and regional expert group meetings. Additional resources being utilized in the lakes component of TWAP include ILEC’s (i) Integrated Lake Basin Management (ILBM) Platform, (ii) LAKES (Learning Acceleration and Knowledge Enhancement System) relational data search and mining engine; and (iii) expert opinion provided by its regionally-representative Scientific Committee. The experiences and lessons learned from these applications, as well as other relevant lake basin studies, will be captured within the transboundary lakes analyses. No strictly sequential process is undertaken for the lakes component of TWAP, but rather a step-by-step approach will be utilized where necessary in regard to specific project elements. The chosen assessment indicators, which highlight both scientific/technical and socioeconomic/governance issues, are meant to provide a simplified means of conveying a sense of their current status, as well as to facilitate comparisons between transboundary lakes and reservoirs.
ILEC has been developing and refining its Integrated Lake Basin Management (ILBM) Platform over multiple years. This Platform comprises major assessment components, involving both the biophysical and governance elements of lake assessment and management. Based on experiences regarding its application to a wide range of lake and reservoir basins in numerous countries throughout the world, the ILBM Platform will be utilized to the maximum extent in the lake assessment. The ILBM Platform, designed to consider not only a lake itself, but also its upstream, downstream and sub-surface hydrological connections, will also be useful to the GEF as a supplement to its traditional TDA/SAP approach to river basin management. ILEC also is exploring the use of multicriteria analysis techniques, such as Analytic Hierarchy Process, which will allow consideration of both quantitative and qualitative indicators for ranking the transboundary lakes and reservoirs in the TWAP project.
Against these project goals, it is noted the required data and information to adequately characterize a transboundary lake and its basin will differ significantly between countries and regions. Where it exists, such needed inputs (data, case studies, lessons learned, etc.) are often scattered among different governmental, academic, research, private sector, and other sources. This will involve utilizing existing data, information and assessment and management experiences, and formalizing relevant partnerships with these diverse data and expertise sources. The above-noted LAKES data and information mining engine will be used to integrate and consider the linkages and relationships between these various data. appropriate partner buy-in, it is anticipated the lakes component of this project will facilitate a sustainable global process for transboundary lake assessments, as well as providing guidance regarding the cost-effective allocation of funds directed to the assessment, management and sustainable use of transboundary lakes and reservoirs, their basins and their resources.
Further information on this component of the TWAP project is available through the project website (http://www.geftwap.org/