Characteristics and influencing factors of rainfall runoff in Huaibei Region

In order to study the runoff and influencing factors of natural rainfall in Huaibei Region,Xinmaqiao Experimental Zone in Bengbu was taken as a representative.Based on the statistical analysis of historical rainfall data and the natural rainfall-runoff experiments on typical areas with different land uses, the loss rules of surface runoff in farmland under different crop vegetation types were investigated.The results of four times of runoff generation experiments show that when the previous rainfall is large,the rainfall intensity for the generation of runoff is small.Due to the impact of crop vegetation types,under the four kinds of land use patterns,the depth of cumulative amount during the runoff generation process is different.The variation of the difference(δ) of the cumulative amount of surface runoff in farmland with different types of crops with time is gradually obvious.It is significant at the interim period of crop growth,and the descending order is as follows: δbare,δcorn,δcot and δsoybean.The planting of crops with large leaves such as soybean during the flood season can effectively reduce the runoff,soil erosion and nutrition loss induced by rainfall so as to mitigate the eutrophication effects of farmland on the nearby water.