Through field measurements and computer modeling this project attempted to understand how headwater streams in mainland SE Asia would be affected by plausible changes in both climate and land-cover/land-use. Fieldwork was conducted for several years in Thailand; two years in China. Analyses performed at these sites are some of the most comprehensive ever performed in the region. In collaboration with other international projects, the modeling component involved the prediction of land-cover/land-use change and climate change for the entire SE Asia region. Advances were also made on developing a model for simulating sediment and nutrient dynamics in headwater catchments; however, the end goal of predicting changes in sediment with a changing climate was not fully achieved. Collectively, the various phases of the project have led to nearly 30 publications in international journals. In addition, follow-on work has already been started on a few important issues in the region, for example (1) studying the the impact of uncontrolled expansion of rubber plantations in mainland SE Asia; and (2) determining the anthropogenic and natural controls on stream chemistry.