Southeast Asia

Southeast Asia provides interesting contrasts to the Amazon, with different geologies, weather patterns, and especially human pressure. The extraordinary pace of development and population growth   in the region has placed dramatically increasing pressure on river basins and their downstream coastal ecosystems. The impact on river systems occurs through erosion of the land surface, changes in the nature of the sediment and its associated organic matter, and nutrient content from agricultural and urban sources. Changes in hydrology are immediate consequences of dam construction and large-scale water diversion for irrigation. Longer-term changes in regional weather patterns and climate will result in altered flow regimes and thus impact downstream ecosystems including the coastal zone. Coastal ecosystem production relies very strongly on material inputs from the land. Deterioration of water quality, due to natural causes such as salt and acidity, and anthropogenic causes such as domestic, agriculture and industry, is problematic in most if not all countries in this region. These changes have major consequences for economic opportunities and hence are risks for investments.

To extend and test our understanding of basin-scale dynamics derived from the Amazon in tropical basins where human impacts were greater, we initiated the SEA-BASINS project, as a joint endeavor of the UW (School of Oceanography and Department of Civil Engineering) and SEA START (Chulalongkorn University, Bangkok, responsible for networking multiple institutions for training and information throughout Southeast Asia , http://www.start.or.th). SEA/BASINS began with a series of information exchange and technical training workshops, starting in July of 1998. The First Partners Workshop, in Chiang Rai, November 1998, involved 40 scientists and engineers from across Southeast Asia, including universities, NGOs, government agencies, and UNESCO. Between workshops, development work continues at the UW and SEA START. Initial funding was  provided by START, the U.S. National Science Foundation, the NASA Earth Observing System program, Asia -Pacific Network (APN), START, UNOPS/GEF program, the World Resources Institute (WRI), and the Association Liaison Office (ALO) For University Cooperation in Development of AID. With a grant from NSF, we began more in-depth sampling and model development, to examine the magnitude and dynamics of CO2 outgassing, as a test on our Amazon observations.

Our current project is Connectivity of the Landscape of Southeast Asia with the South China Sea: Scaling of Hydrologic and Biogeochemical Processes (NASA IDS). The focus of this work is to examine regional-scale landscape dynamics in river basins of Southeast Asia, relative to their connectivity to the sea. By focusing on how transient forcing of the atmosphere combines with land-use change at multiple space and scales time- to impact the land surface and mobilize water and carbon to the sea, we are examining the critical and poorly understood interfaces between the atmosphere, land surface and sea function.  The focal questions for the work are:

· How do composite processes of land-water interactions scale up to generate regional
patterns?

· What do these regional patterns in carbon transport and transformation indicate about
the overall relation among water movement, landscape structure (topography, soils),

and vegetation structure and productivity across the region?

· What are the implications of land use and climate change?

The individual components of this work, utilizing modeling, remote sensing, and field measurements, are summarized under Current Research.

Virtual Mekong Basin