Patterns of karst geomorphologic combinations in areas with rich groundwater

Only in rock masses with strong karstification and active karst development, it is possible to form areas with rich karst groundwater or zones with concentrated flows. Karst landform with particular surficial appearance is the result of geological activities controlled by many geological factors such as geological conditions, endogenic and exogenic geological dynamic processes, and neotectonic movements as well. The karst geomorphologic patterns, with the combination of various geomorphologic units, are usually the ground manifestations of underground features and processes such as the formation and evolution of underground karsts and associated groundwater flow and storage. These geomorphologic patterns can accordingly be used as important indicators for identifying the areas that enrich in groundwater resources. In this article, eight karst geomorphologic patterns are presented through the analysis of the information of regional hydrogeological survey and relevant database. For groundwater prospecting and borehole siting purpose, these geomorphologic combination forms that reflect areas of good aquifers are of great value and can provide a great amount of effective information in the hydrogeological survey and drilling. These eight karst geomorphologic combination forms include the sedimentary plain in the karst fault basin or valley, the paleochannel in karst valley and lower land, the isolated karst hill at the valley mouth, the junction of karst valleys, the long belt under the karst fault escarpment, the area of the opposite concave bank in karst valley, the zone with gentle slope and shallow depression, and the karst shallow hill and roomy ridge. In the article, the morphological characters of each karst geomorphologic patterns are also described in detail. Via typical case study, the formation mechanisms of groundwater dynamics in these areas are further analyzed.