Annual and seasonal streamflow responses to climate and land-cover changes in the Poyang Lake basin, China

Repeated severe floods and damages in the Poyang Lake basin in China during the 1990s have raised the concern of how the floods have been affected by regional climate variations and by human induced changes in landscape (e.g., draining wetlands around the lake) and land-use in the basin. To address this concern and related issues it is important to know how the climate, land-use and land-cover changes in the region affect the annual and seasonal variations of basin hydrology and streamflow. This knowledge is essential for long-term planning for land-use to protect water resources and to effectively manage floods in the Poyang Lake basin as well as the lower reaches of the Yangtze River. It also has important ecological and socioeconomic implications for the region. This study used the SWAT model to examine the climate and land-use and land-cover effects on hydrology and streamflow in the Xinjiang River basin of the Poyang Lake. A major finding of this study is that the climate effect is dominant in annual streamflow. While land-cover change may have a moderate impact on annual streamflow it strongly influences seasonal streamflow and alters the annual hydrograph of the basin. Because of the vegetation and associated seasonal variations of its impact on evapotranspiration, increase of forest cover after returning agricultural lands to forest reduces wet season streamflow and raises it in dry season, thus reducing flood potentials in the wet season and drought severity in the dry season. On the other hand, losing forests increases flood potential and also enhances drought impacts. Results of this study improve our understanding of hydrological consequences of land-use and climate changes, and provide needed knowledge for effectively developing and managing land-use for sustainability and productivity in the Poyang Lake basin.

[1]  J. Palutikof,et al.  Climate change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Summary for Policymakers. , 2007 .

[2]  J. Nash,et al.  River flow forecasting through conceptual models part I — A discussion of principles☆ , 1970 .

[3]  Peter Krause,et al.  Quantifying the impact of land use changes on the water balance of large catchments using the J2000 model , 2002 .

[4]  R. Scott,et al.  ECOHYDROLOGICAL IMPLICATIONS OF WOODY PLANT ENCROACHMENT , 2005 .

[5]  Tracy E. Twine,et al.  Effects of Land Cover Change on the Energy and Water Balance of the Mississippi River Basin , 2004 .

[6]  R. E. Rallison,et al.  Past, present, and future SCS runoff procedure , 1982 .

[7]  F. Gasse,et al.  Hydrological response of a catchment to climate and land use changes in Tropical Africa: case study South Central Ethiopia , 2003 .

[8]  Jie Song,et al.  Flood frequency in China's Poyang Lake region: trends and teleconnections , 2006 .

[9]  N. Arnell,et al.  Freshwater resources and their management , 2007 .

[10]  E. Lin,et al.  Future climate change, the agricultural water cycle, and agricultural production in China , 2003 .

[11]  D. Lee,et al.  Centennial-scale dry-wet variations in East Asia , 2003 .

[12]  Rae Mackay,et al.  Spatial variation in evapotranspiration and the influence of land use on catchment hydrology , 1995 .

[13]  Xi Chen,et al.  Effects of climate and landcover change on stream discharge in the Ozark Highlands, USA , 2005 .

[14]  Saralees Nadarajah,et al.  Modeling Annual Extreme Precipitation in China Using the Generalized Extreme Value Distribution , 2007 .

[15]  Vijay P. Singh,et al.  Rainfall-runoff modeling , 1988 .

[16]  J. Palutikof,et al.  Climate change 2007 : impacts, adaptation and vulnerability , 2001 .

[17]  Joe T. Ritchie,et al.  Model for predicting evaporation from a row crop with incomplete cover , 1972 .

[18]  Q. Hu,et al.  A Southward Migration of Centennial-Scale Variations of Drought/Flood in Eastern China and the Western United States , 2001 .

[19]  Vijay P. Singh,et al.  Rainfall-runoff relationship , 1982 .

[20]  Marcos Heil Costa,et al.  Water balance of the Amazon Basin: Dependence on vegetation cover and canopy conductance , 1997 .

[21]  Ü. Mander,et al.  Impact of climatic fluctuations and land use change on runoff and nutrient losses in rural landscapes , 1998 .

[22]  Wei Zhang,et al.  Impacts of human activity on river runoff in the northern area of China , 2002 .

[23]  E. Baltas,et al.  Human implication of changes in the hydrological regime due to climate change in Northern Greece , 1999 .

[24]  A. Becker,et al.  Assessment of land use and climate change impacts on the mesoscale , 2001 .

[25]  Tong Jiang,et al.  Interactions of the Yangtze river flow and hydrologic processes of the Poyang Lake, China , 2007 .

[26]  V. Singh,et al.  Computer Models of Watershed Hydrology , 1995 .