Impacts of Global Climate Change and Regional Land-use Alteration on Water Resources in the Dongjiang (East River) Basin

Principal Investigator:
Chen, Yongqin

Co-investigator(s):
Xia, Jun
Fung, Tung
Lam, Kin Che
Leung, Yee
Chen, Junhe

Summary:
Water resources of the Dongjiang (East River) basin have provided tremendous benefits to the economic success and prosperity of regions including Hong Kong. Over two-thirds of the water supply in Hong Kong is now imported from Dongjiang by cross-basin water transfer. Rapid economic and population growth have caused serious concerns over the adequacy of Dongjiang water in the next several decades. Therefore, hydrologic modeling and assessment studies on the impact of global climate change and regional land-use alteration are urgently needed.

The proposed research will investigate the potential changes in surface runoff and soil moisture in the Dongjiang basin, on various temporal scales (daily, monthly, seasonal and annual), due to atmospheric CO2-induced global warming and typical regional land-use alteration resulting from urbanization and reforestation.

Watershed hydrologic modeling and climate water budget calculation are the two approaches used to evaluate hydrologic regimes under the current and future climatic and land-use conditions. The Hydrologic Simulation Program-FORTRAN (HSPF) and the Thornthwaite water balance will be tested and applied for major tributary basins and two selected small watersheds in the Dongjiang basin. A range of climate-change scenarios will be prescribed hypothetically and derived from state-of-the-art general circulation models (GCMs). Spatial analysis techniques such as satellite image processing and geographic information systems (GIS) will be employed for watershed characterization and segmentation in support of hydrologic modeling and assessment. Modeling results of various hydrologic variables will be statistically evaluated to demonstrate the capabilities and limitations of the combined use of climate and hydrologic models, as well as to highlight the regional vulnerabilities.

This study will not only contribute to our knowledge about hydrologic response of a subtropical basin to global warming, but also has enormous significance for planning, allocation, and management of Dongjiang water resources.