| Volumes and Issues Contents of Issue 2 |
www.hydrol-earth-syst-sci.net/11/1035/2007/
© Author(s) 2007. This work is licensed
under a Creative Commons License.
Hydrologic effects of land and water management in North America and Asia: 1700–1992
1Department of Geosciences, University of Oslo, Oslo, Norway
2Norwegian Water Resources and Energy Directorate, Oslo, Norway
3Department of Civil and Environmental Engineering, University of Washington, Seattle, USA
Abstract. The hydrologic effects of land use changes, dams, and irrigation in North America and Asia over the past 300 years are studied using a macroscale hydrologic model. The simulation results indicate that the expansion of croplands over the last three centuries has resulted in 2.5 and 6 percent increases in annual runoff volumes for North America and Asia, respectively, and that these increases in runoff to some extent have been compensated by increased evapotranspiration caused by irrigation practices. Averaged over the year and the continental scale, the accumulated anthropogenic impacts on surface water fluxes are hence relatively minor. However, for some regions within the continents human activities have altered hydrologic regimes profoundly. Reservoir operations and irrigation practices in the western part of USA and Mexico have resulted in a 25 percent decrease in runoff in June, and a 9 percent decrease in annual runoff volumes reaching the Pacific Ocean. In the area in South East Asia draining to the Pacific Ocean, land use changes have caused an increase in runoff volumes throughout the year, and the average annual increase in runoff is 12 percent.
Final Revised Paper (PDF, 1046 KB) Discussion Paper (HESSD)
Citation: Haddeland, I., Skaugen, T., and Lettenmaier, D. P.: Hydrologic effects of land and water management in North America and Asia: 1700–1992, Hydrol. Earth Syst. Sci., 11, 1035-1045, 2007. Bibtex EndNote Reference Manager
