Natural and Built Infrastructure: ecosystems and flow
By affecting transpiration and evaporation and influencing how water is routed and stored in a basin, forests, wetlands and floodplains play a crucial role in the hydrological cycle. Although a major role is widely attributed to them in regulating flows (i.e., both attenuating floods and maintaining flow during dry periods) these services are seldom, if ever, explicitly factored into the planning and management of water resources. One reason for the failure to include them is lack of understanding of the hydrological functions occurring, their dynamic nature, and the interaction of these functions with the catchments in which the ecosystems are located. Very often, it is unclear exactly which functions are performed and how these functions change over time (i.e., between seasons and between years). Furthermore, both the lack of quantitative information and a recognized method to incorporate them into decision-making processes, make it very difficult to integrate natural hydrological functions into the planning and management of water resources. The objective of this study is to develop a pragmatic approach for quantifying the flow regulating functions of natural ecosystems in the Volta and Mekong Rivers and to determine how these might be incorporated into IWRM.