岩溶森林区地下河流域水文地球化学特征研究-以贵州荔波板寨地下河为例

通过对板寨地下河流域内岩溶泉、地表水体和地下河水各测站的水化学资料的分析,讨论了流域内各点的水化学类型、空间分布及成因。由于森林植被覆盖，计算得岩溶泉水的PCO2很高，实测得拉桥泉域内土层20cm深处CO2浓度高，达38000ppm，是退耕田地中土壤CO2浓度的30倍；森林中地表覆被形成林中滞留水含水层，它与岩溶含水岩层组形成多层水文地质含水空间结构，增加了调蓄量，延缓了水的释放，这极大改善了区内因降雨分布不均匀而引起的干旱面貌。虽然茂兰处在原始森林区，但是土壤较少，根据实验结果，森林区岩溶作用强度并不比非森林岩溶区强。自然保护区缓冲区有少量村民居住，农业活动，如施肥和生活污水排放等，造成了地下水污染。岩溶表层带泉,受地表环境、降雨量影响大,水化学动态变化较大。地下河水的水化学变化特征明显受降雨的稀释作用影响。

Study on Hydrogeochemical Features in Karst Forest Underground River Catchment Of Banzhai, Libo, Guizhou

The hydrochemistry type,spatial distribution and the cause of formation about the river were discussed by analyzed the hydrochemistry data which from the karst springs,the surface water and the underground water monitoring stations in Banzhai.The results showed that the PCO 2 of the karst spring was high which was 457.8 Pa,and the concentration of the CO 2 in 20 cm depth was 3800 Pa in the area of Laqiao,which was 30 times the area of returning farmland.The surface retained water which was formed by the land cover in the forest and karst aquifer made up a multilayer hydrogeology space structure,which increased discharge storage largely and decreased the water release.Then the arid landform caused by an unequal distribution of rainfall was improved greatly.The process of karst in the forest area was not strong in dry season.The dynamical change of hydrochemistry in epikarst spring water was influenced by surface environment and rainfall greatly.The hydrochemistry of underground water was affected by the diluting processes of rainfall obviously.