Abstract: In order to study the hydrogeological characteristics of water source in the karst area of Guizhou Province, we take Taojialongtan water source area in Xiuwen country as study object. In association with investigation methods like hydrological surveying and according to the development law of karst groundwater, we obtain the characteristics such as general geological situation, factors affecting karst development, and boundary conditions. We divide impervious boundary conditions according to three aspects water blocking property of the boundary, development situation of karst along the boundary, and the groundwater emergence location.Moreover on this basis, we study the recharge boundary. Results show that the development area of water source has the characteristics of an independent hydrogeological unit; meanwhile, the development of Taojialongtan hydrogeological unit is mainly influenced by lithology and fissure structures; furthermore, discharges mainly takes the form of karst spring and artificial mining, which ultimately flows into the surface river; finally, the hydrochemistry type of Taojialongtan water source area is of HCO₃·SO₄-Ca·Mg, suitable for drinking water source.

Key words: hydrogeological unit, water source area, karst groundwater, boundary conditions, Taojialongtan