采空区特殊下垫面径流模拟研究

Study on simulation of special underlying surface runoff in goaf area

由于长期大规模地开采煤炭资源导致山西省许多地区形成了煤矿采空区,改变了传统的水文过程。以上静游水文站控制流域为研究区域,通过6组室内试验,探讨了采空区裂隙发育对产汇流过程的影响机制并进行参数化,引入到传统双超模型,选取研究区大规模煤矿开采前后25场洪水分两种方案进行了水文模拟。结果表明:在采空区特殊下垫面进行水文模拟时,可引入4个参数来表示采空区对流域坡面产汇流过程的影响,可引入2个参数来表示采空区对河道汇流过程的影响。大规模煤矿开采前的14场洪水模拟结果中,模拟合格率为85.71%,大规模煤矿开采后的洪水11场洪水模拟结果较差。考虑采空区特殊下垫面对产汇流过程的影响,引入概化的参数重新计算上静游水文站控制流域大规模煤矿开采后的11场洪水过程,得到重新模拟的11场洪水模拟结果总体合格率由0提升为了81.82%,大规模采煤后采空区参数的引入有效提高了上静游水文站控制流域内场次洪水模拟精度。

Due to large scale long-term mining of coal resources, goaf areas are formed in many regions in Shanxi Province, and then the conventional hydrological processes therein are changed as well. By taking the watershed controlled by Shangjinyou Hydrological Station as the study area, the mechanism of the influence from the fracture development of the goaf area on the runoff yield and confluence process therein is discussed and parameterized through 6 groups of indoor experiments, from which the parameters are introduced into the conventional double-excess model, while 25 floods before and after large scale coal mining are selected to carry out the relevant hydrological simulations with two schemes. The results show that during the hydrological simulation of the special underlying surface runoff in the goaf area, four parameters can be introduced to express the influence from the goaf area on the slope runoff yield and confluence process in the watershed, while two parameters can be introduced to represent the influence from the goaf area on the river channel confluence process. For the results from the simulations made on the 14 floods occurred before the large scale coal mining, the simulation qualification rate is 85.71%, while the simulation results of the 11 floods occurred after the large scale coal mining are relatively poor. Under the consideration of the influence from the special underlying surface in the goaf area on the runoff yield and confluence process in the watershed, the flood processes of the 11 floods after the large scale coal mining occurred within the watershed controlled by Shangjinyou Hydrological Station are recalculated through introducing the relevant generalized parameters into the recalculation, and then the overall qualified rate of the re-simulation results of the 11 floods is enhanced from 0 to 81.71%, which indicates that the simulation accuracy of the flood event within the watershed controlled by Shangjinyou Hydrological Station is effectively enhanced by means of introducing the parameters of the goaf area after the large scale coal mining into the simulation concerned.