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| Effect of land cover change on runoff and sediment yield of small watershed in Loess Hilly-gully region |
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Abstract To explore the impacts of land cover change on runoff and sediment yield in Loess Hilly-gully region, Lvergou watershed, Luoyugou watershed and her son basins of Qiaozigou in the study region were selected as the research objects. Mathematical statistics method and paired catchments approach were applied to analyze the effect of land cover change on runoff and sediment yield. Brief conclusions can be drawn as follows: The rapid increase of forest land at the rate of 1.07% per year was the most obvious features of the land cover changes in Lvergou watershed during the period of 1982-2004. Moreover, under the influence of terracing sloping fields, about 73% of sloping farmland was converted to terraces in Luoyugou watershed during the period of 1986-2004. Combined with the paired catchments approach, land cover change was the strongest contributor to the reduction in annual runoff and sediment yield of watersheds, and the average reduction rate reached 43.76% and 35.23% under the same rainfall condition, respectively. Annual runoff modulus and precipitation and forest cover rate were significantly correlated, and showed an exponential relationship for each watershed during the study period. When the forest cover rate increased by 5%, the runoff modulus decreased by 18.43% to 37.58%.
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Received: 22 November 2013
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