The Characteristic Study of Karst Water at Houzhai Underground Basin in Puding County, Guizhou Province

The hydrography of karst water is specificity and complexity because of the special geomorphological structure and geological structure. As a case study at Houzhai underground river basin in Puding County, Guizhou province, the karst hydrological characteristic and the karst hydrochemistry characteristic are description based on analysis the formation of karst water in this paper. The storage structure and the geomorphological structure or geological structure relationship, the fissure flow and the conduit flow conversion are also description through the pulse test and the precipitation pulse. In the karst peak forest depression, the karst is bare carbinate bedrock and fissure is development. There are sinkholes or infundibulars in the depression and they link the underground river directly. In this area, the storage capacity is low and the hydrography is sharp. The hydrograph is agile response for the precipitation. The base flow in the hydrograph is small. In the peak valley, the karst is covered by topsoil. The collecting area is larger in this area than in the peak forest depression area. The conduit distribution is treelike. The karst storage capacity is high and a mount of fissure flow or conduit flow recharge the outlet after the peak, the hydrograph decay is slow and base flow is high. The storage capacity of covered topsoil and conduit in karst polje is larger than it is in peak valley. With the analyzing the decay curve of the outlet of the underground river basin at Maoshuikeng station, the conduit storage is 3%-10% of the total water storage and fissure storage is 90%-97% of the total storage. The karst hydrochemistry types in the basin are simple. The type is fresh water with low mineral and low hardness. The hydrochemistry characteristic is varying with the hydrograph alteration and the geomorphological structure distribution in the area. This method that using in this paper is useful for karst water research in various storage medium structures. The result is a referential for karst hydrological simulation and karst water resource using.