Journal of Geoscience and Environment Protection, 2014, 2, 68-78 Published Online December 2014 in SciRes. http://www.scirp.org/journal/gep http://dx.doi.org/10.4236/gep.2014.25010 How to cite this paper: Shi, P., Wu, M., Ma, X. X., Qu, S. M., & Qiao, X. Y. (2014). Stream-Flow Response to Climate Change and Human Activities in an Upstream Catchment of Huai River. Journal of Geoscience and Environment Protection, 2, 68-78. http://dx.doi.org/10.4236/gep.2014.25010 Stream-Flow Response to Climate Change and Human Activities in an Upstream Catchment of Huai River Peng Shi 1,2* , Miao Wu 2 , Xinxin Ma 2 , Simin Qu 2 , Xueyuan Qiao 2 1 State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, China 2 College of Water Resources and Hydrology, Hohai University, Nanjing, China Email: * ship@hhu.edu.cn Received November 2014 Abstract Climate change and human activities have great implications for hydrological process and water projects planning. In order to evaluate the impacts on stream-flow, statistical methods and SWAT model are applied to this research. The results indicate that the abrupt change year (1965) of an- nual stream-flow is chosen as the split point of natural and human influenced (particularly reser- voirs) periods. The calibrated SWAT model is proved to be applicable in this catchment and is used to simulate the monthly runoff which can be regarded as the natural runoff induced by cli- mate change. A major finding of this study is that the reservoir regulations have apparently al- tered the monthly and seasonal stream-flow regimes. By quantifying the impacts of climate varia- tion and human activities, the decreasing trend of annual stream-flow is found, and human activi- ties are proved to be the dominant role in the catchment. This research improves our knowledge of hydrological responses to natural and artificial factors, and provides a better understanding for the future reservoir regulations. Keywords Trend and Saltation Analysis, SWAT Model, Climate Change, Human Activities, Stream-Flow 1. Introduction The scientific knowledge of hydrological processes and their responses to climate change and human activities is of great importance in both theoretical and practical meaning, attracting numerous researches around the world (Wu & Johnston, 2007). Climate change caused by increasing atmospheric concentration of carbon dio- xide and other micro gases has altered the magnitude and timing of runoff to some extend. In addition to climate oriented variations, human activities such as land use changes (Guo et al., 2008; Shi et al., 2013b), constructions of water conservancy projects, interbasin water diversions and industrial and agricultural needs have taken pro- * Corresponding author.