CONTROLLING ROLE OF ROCK PERMEABLE SPACE TO THE SHAPE OF GROUNDWATER TABLE NEAR A RIVER: A CASE STUDY

he shape of the groundwater table is a sign of the characters of the flow field. Its cause of formation is very important to the seepage and feasibility of project. The rock permeability is not uniform in space even in the small district of one project. It has the characters of strong anisotropy and notable zoned phenomenon in those mountain-canyon regions, especially in southwest China. This leads to the result that the profile shapes of groundwater table may be of gentle U shape, gradient W shape or W shape. Such result means a possible occurrence of a special phenomenon that there are strips of lower water table in the bank areas near the river. Moreover, the actual conditions in the district of Jiudianxia hydro-project give an example that the characters of strong anisotropy and notable zone of rock permeability may fully arouse strips of lower water table in the bank though without strong vadose zones, which dispels the worry about the seepage and provides good reference to other hydro-projects.