Ecosystem Based Adaptation in the Magdalena Basin – AID-514-A-13-00004

The project utilizes the WEAP (Water Evaluation and Planning) model to simulate the effects of different scenarios on water regimes, including population growth, sectoral development, and climate change. The project's methodology involves the development of an integrated model of water supply and demand using the WEAP21 tool. This model estimates the regional effects of different scenarios on water regimes and contributes to the formulation of guidelines for regional water environmental flows within the ELOHA (Environmental Flow Assessment of Human Allocations) framework. The project's third report presents the results of the implementation of the WEAP model in the Magdalena River Basin, with a focus on simulating and selecting measures of adaptation to climate variability and change in floodplains. The report includes the following products: * Product D: Adjustments made to the WEAP model of the Magdalena River Basin in relation to the representation of meteorological input series and vegetation cover, based on land cover mapping and the hydrological effects of changes in cover. * Product F: Description of new WEAP routines for simulating hydrological responses in floodplains, considering environmental flows, climate variability, and climate change. * Product G: Application of WEAP to the Magdalena River Basin with the implemented improvements and a document analyzing the implementation of this model. * Product H: Application of the WEAP floodplain submodel that includes routines for floodplain management. The WEAP model with the implemented improvements is included in Annex 2, and specific results obtained from the model are presented and discussed in sections 1.3, 1.4, and 2.3 of the report. The project also includes a proposal from the Stockholm Environment Institute (SEI) for dynamic integration between applications with different spatial scales using the WEAP model of the Magdalena River Basin and its sub-basins (Product C). The report presents the methodology for generating climate series implemented in this study, including the number of observations of flow and precipitation in the Magdalena-Cauca River Basin, and the comparison of the performance of precipitation interpolation methods. The report also includes maps of vegetation cover and units of the model, as well as series of time of specific runoff observed and modeled. The project's results show that the WEAP model can be used to simulate the effects of different scenarios on water regimes in the Magdalena River Basin, and that the model can be used to select measures of adaptation to climate variability and change in floodplains. The project's findings have implications for the formulation of guidelines for regional water environmental flows within the ELOHA framework. The Magdalena River Basin is a critical region for water resources management in Colombia, and the project's results have important implications for the development of water management policies and strategies in the region. The project's methodology and results can be used as a basis for future studies and projects aimed at addressing the impacts of climate change and variability in the Magdalena River Basin. The project's results also highlight the importance of considering environmental flows and climate variability in water resources management, and the need for dynamic integration between applications with different spatial scales. The project's findings have implications for the development of water management policies and strategies that take into account the complex interactions between water resources, climate, and human activities in the Magdalena River Basin.