煤矿采空区特殊下垫面水文模型研究

煤矿采空区的形成改变了传统的水文过程,对洪峰和洪量具有明显的削减作用。以汾河水库控制流域为例,引入裂隙渗漏系数G和渗漏系数k分别表示采空区裂隙位于坡面与河道对产汇流过程的影响,构建了采空区特殊下垫面条件下的水文模型,选取1970～2015年间汾河水库控制流域内采空区先后出现的16场次洪水,对比分析了两种方案的水文模拟精度。结果表明,传统的水文模型在采空区出现前模拟效果较好,7场次洪水模拟合格率为71.43%,而在采空区出现后9场次洪水合格率仅为22.22%,流域中部煤矿采空区对暴雨中心位于中心区域的降雨引起的洪水过程产生较大的影响;对采空区出现后的暴雨中心在采空区附近的7场次洪水采用采空区特殊下垫面条件下的水文模型进行模拟,7场次洪水合格率为71.43%,精度得到了显著提升。

Study on Hydrologic Model of Special Underlying Surface in Goaf of Coal Mine

The formation of goaf in coal mine has changed the traditional hydrologic process, and has obvious reduction effect on flood peak and flood quantity. Taking Fenhe reservoir basin as an example, the fracture seepage coefficient G and leakage coefficient k were introduced to denote the impacts of mined-out area cracks located in the slope and the river on the rainfall-runoff process, respectively. The hydrological model of mined-out area special underlying surface was established. Selecting 16 floods in the mined-out area of Fenhe reservoir from 1970 to 2015, hydrological simulation accuracy of two schemes were compared. The results show that the traditional hydrological model has a good simulation effect before the emergence of goaf, and the qualified rate of 7 floods is 71.43%, while after the emergence of goaf, the qualified rate of 9 floods is only 22.22%. For the 7 floods near the goaf caused by the rainstorm center after the occurrence of the goaf, the hydrological model under the condition of the special underlying surface of the goaf is adopted to simulate, and the qualified rate of the 7 floods is 71.43%, which significantly improves the accuracy.