Research On Response Relationship Between Tailings Reservoir’s Slope Vegetations Of Jin Shandian Mine And Their Capactities Of Water And Soil Conservation

Water and soil erosion has become the heart of matter which can restrict human survival and development. Mining development is an important economic activity, and tailings reservoir is a key link of mining, which is the largest environmental protection engineering of mining. Now, water and soil erosion of the tailings reservoir slope for the rainfall and environmental problem and consequence that it will cause are more and more serious. The general treatments mainly focus on engineering measures with a great quantity of engineering and investment. While biological measures can resolve the problem ultimately with less investment and forever benefit.Therefore, in the angle of vegetation promoting soil and water conservation for tailings reservoirs and based on the present situation of Jin Shandian tailings reservoir we have investigated, the author make an analysis of impact factors of water and soil erosion of Jin Shandian tailings reservoir slope, probe into the principle of water and soil conservation of slope vegetation, set up the outdoor simulative runoff plots for water and soil conservation test, make a comparative analysis and quantitative study on five vegetations’water and soil conservation abilities by artificial rainfall simulative and washout tests, which gains the proper vegetation of the highest ability of water and soil conservation of tailings reservoir slope. It will provide theoretical foundation for tailings reservoir’s expansion and slope safety ecological protection.The main results are as follows:(1) Under different rainfall intensity by artificial simulative rainfall, the time of runoff produced of test plots:For the rainfall intensity of 53 mm/h, the bare soil is the fastest, only 1.55 minute, while for the rainfall intensity of 53 mm/h, Festuca elata Keng needs 28.36 minute, which is the slowest. Time of runoff produced (T), vegetation coverage rate (C), original soil moisture content (M) and the rainfall intensity (R) tie up with each other closely.(2) Under different rainfall intensity by artificial simulative rainfall, the quantities of runoff and sediment of the bare earth produced are the highest; Sowing plots:Festuca elata Keng with the lowest quantities of runoff and sediment has the highest benefit, water benefit is 86.78% and soil benefit is 98.83%(rainfall intensity of 53 mm/h), water benefit is 66.67% and soil benefit is 97.78%(rainfall intensity of 76 mm/h); Remove-planted plots:Plantago asiatica Linn. with the lowest quantities of runoff and sediment has the highest benefit, water benefit is 86.25% and soil benefit is 98.44% (rainfall intensity of 53 mm/h), water benefit is 65.67% and soil benefit is 78.42% (rainfall intensity of 76 mm/h).(3) For the twice washout tests, all the experimental plots’first time of outflow are smaller than the second, the speeds for the second are larger than the first, the time of outflow for the bare soil plot is the smallest and the speed is the largest; Overall, compared with the bare soil plot, the vegetation coverage of the sowing and remove-planted plots has the function of delaying time of runoff produced and reducing speed of runoff.(4) In washout conditions, the distinction of quantities of runoff and sediment of the sowing and remove-planted plots is huge. The rate of soil is 41.699% of the bare soil plot with lower washing resistance; Sowing plots:The rate of soil is 0.138% of Festuca elata Keng; Remove-planted plots:Plantago asiatica Linn. is 1.219%; Festuca elata Keng is the smallest with the highest washing resistance.(5) In washout conditions, Sowing plots:Festuca elata Keng with the highest benefit of water and soil conservation are 84.824% and 99.950%; Remove-planted plots:Plantago asiatica Linn. are 86.982% and 99.619%.(6) By artificial simulative rainfall and washout tests, the result shows that Festuca elata Keng has the highest ability of water and soil conservation for Jin Shandian tailings reservoir slope. What’s more, Plantago asiatica Linn. and Remex japonicus Houtt. can adapt the soil of tailings reservoir slope and grow well, and Plantago asiatica Linn. (mixed growing with Cynodon dactylon Pers.) has the higher ability of water and soil conservation.