The circulatory system of underground water in the Karst valley area of the Zhongliang Mountains in Chongqing consists of three distinct layers: The circulatory zone of the upper stratum underground water, the circulatory zone of the middle stratum underground water and the diffusion layer of the deep underground water.

Due to limited understanding of the groundwater circulation, groundwater development lacks solid basis.

When it is applied to the analysis of groundwater environmental system(GES), we can select the most important one in many variances, so that to attain "the optimum of variance structure", to simplify system, and the same time, don't loss the principal information which has direct and indirect relation to the GES.

Standing column well ground heat exchange system and its application prospects;

The heat source wells of standing column well ground heat exchange system(SCWGHES) have three types now: standing column well(SCW),pumping & recharging well(PRW) and gravel-backfill PRW(GB-PRW).