Characteristics of Slope Runoff and Sediment of Different Vegetation Types under Individual Rainfall Events in Loess Hilly and Gully Region北大核心CSCD

The runoff plots of Anjiagou watershed were selected as the research object in Dingxi City,Gansu Province,and the characteristics of rainfall infiltration, runoff and sediment of different vegetation types were studied using the observed data of runoff and sediment under natural rainfall conditions. The results showed that: the infiltration rate of soil under different vegetation types increased linearly with the increase of rain intensity, while the relation between the infiltration rate and the rainfall duration was a power function. The runoff coefficient of pine forest (15.97%~19.88%) was the largest, the wheat field (10.91%~17.32%) and sea buckthorn forest (9.51%~17.47%) the second,the wheatgrass meadow (4.62%~8.30%) and the alfalfa land (6.82%~10.66%)were the smallest. In the meanwhile,the relation between runoff coefficient (1%~28%) and rainfall presented a power function (P<0.05). The order of average sediment concentration was as follow: wheat field (16.49~22.71 g·L-1) > alfalfa land (12.66~16.91 g·L-1) > sea buckthorn forest (7.04~11.8 g·L-1) > pine forest (6.95~7.78 g·L-1) > wheatgrass meadow(5.53~7.71 g·L-1). There was a positive correlation between sediment concentration and soil erosion rate and rainfall erosivity (P<0.01),which can be quantified separately by linear function and quadratic function. The results can provide references for optimizing configuration of water and soil conservation in Loess hilly and gully region. © 2019 China Agricultural University. All rights reserved.