Water and Matter Flows in Mountainous Watersheds of Southeast Asia: Processes and Implications for Management

Abstract

The mountainous ecosystems of Southeast Asia have experienced a tremendous increase in human activity over the last few decades. An integral part of land use change and land use intensification in the area is the changes in water and matter cycling that have taken place, a situation which calls for increased attention to be paid to resource management, particularly given the environmental vulnerability of the region. Building on four case studies that describe the consequences of such change and provide implications for resource management with regard to flooding, nutrient stocks and fluxes, and the fate of pesticides, we develop a general perspective on current matter and water related issues. This perspective will require us to integrate (1) knowledge on water and matter related processes, (2) the spatial and temporal scales on which they are active and through which they connect inside a watershed, and (3) their physiographic (site and land use specific) domains.