Experimental Study On The Newly Increased Soil And Water Loss Caused By The Mining Exploitation In The Shenfu-Dongsheng Coal Mining Area

According to the severe newly increased soil and water loss caused by the mining exploitation in the Shenfu-Dongsheng coal mining area, the newly increased soil and water loss on several land surface slopes in the Shenfu-Dongsheng coal mining area, including undisturbed soil, disturbed soil, dirt road, spoil and rubble heaps with different accumulation times, under different design rainstorms with several rainfall patterns and design frequencies, were studied by using a combination of field simulated rainfall infiltration experiments and field runoff scouring experiments. In the paper, based on the observed data of the field simulated rainfall infiltration experiments, the Horton infiltration models, which were suitable for describing rationally the rainfall infiltration processes on the several land surface slopes mentioned above, were fitted. Secondly, according to the fitted infiltration models and the data of the design rainstorms and antecedent soil moisure, etc., the excess rainfall hyetographs and the discharge hydrographs on every land surface slope mentioned above, under the design rainstorms with several rainfall patterns and design frequencies, were analyzed and calculated by using the method of accumulated infiltration curver without rainfall loss and the method of travel time isochrones respectively. Thirdly, on basis of analyzing systematically the processes of runoff erosion and sediment yield of field runoff scouring experiments that conducted on the mentioned land-surface slopes, a correlativerelations between the mean runoff and mean sediment yield per unit time interval in the runoff scouring experiments was established for every land surface slope. Finally, with the obtained discharge hydrographs under different design rainstorm and the obtained correlative relationships, the sediment yield amount of the several man-made disturbed land surfaces including disturbed soil, dirt road, discard soil heaped in 1994,discard soil heaped in 1997 and discard rubble in 1997, under the design rainstorms with different rainfall patterns and design frequencies, were calculated. And in comparison to the sediment yield on the undisturbed soil slope under the same conditions, their newly increased soil and water loss caused by the mining exploitation in Shenfu-Dongsheng coal mining area were analyzed.