重庆市地下河的空间分布及水资源

Spatial distribution of underground river streams and water resource in the Chongqing Municipality

文章利用ArcGIS软件提取重庆市1∶20万水文地质图信息,统计出重庆市地下河约380条,总长度约为1 898.43km,多年平均流量约144.20m3/s,水资源量约45.47×108m3/a。总的来说,重庆市地下河主要分布在渝东北、东南地区,其分布范围和重庆市碳酸盐岩分布范围一致。同时利用地下河发育密度和多年平均径流模数,结合各地区多年平均降水量,对重庆市地下河水资源的分布规律进行了分析,得出地下河发育密集地区并不一定就是水资源量大的地区;降水量高的地区也不一定是地下河水资源量大的地区,二者在重庆市存在较大差异。这主要是和各地下河的地质背景、构造条件、岩性、汇水面积、降雨特征等因素的相匹配情况有关。

Karst rocks in the Chongqing Municipality in southwestern China for approximately 36.49% of the total area of Chongqing. The 1/200 000 hy covers about 3.0 × 10^4m^3 , accounting drogeological map of Chongqing and the relevant reports show that there are approximately 380 underground streams with a total length of about 1 898.43km, with a total mean discharge of more than 144.20m^3/s and water resources of more than 4.547 × 10^9m^3/a. The underground streams, in general, exist mostly in the southeast and northeast of Chongqing. The distribution of the underground rivers is consistent with the occurrence of the carbonate rocks in Chongqing. Three indicators, i.e., the development density, runoff modulus and multi-year average precipitation, are used to judge distribution of the underground streams in Chongqing. The coefficient of development density of the underground streams varies between 12.25m/km^2 and 263.37m/km^2 , and the coefficient of runoff modulus of the underground streams, between 0.10L1 （s· km^2 ） and 22.89L/（s·km^2 ）. It appears that variation exists from region to region. The high development zones occur in the west and southeast of Chongqing. The high runoff modulus zones concentrate in the northeast, southeast and west of Chongqing. In Chongqing, it is also found that the high-density zone of underground streams is not necessarily the high runoff modulus zone, and the high rainfall zone is not necessarily the high runoff modulus zone.