Shalow groundwater dynamic characteristics and response to coal mining in the typical blown-sand region of the Northern Shaanxi Province

Coal mining has great influence on the groundwater dynamic in the blown-sand region of the northern Shaanxi Province. On the basis of long-term monitoring data of groundwater table, the change characteristics of Salawusu group unconfined groundwater table regional dynamic from time and space in Yuyang district of Yulin City were analyzed comprehensively. Dynamic types of shallow groundwater table in the study area were classified into three types by Interactive Self-Organizing Data Analysis Technique (ISODATA):the strong fluctuation area of groundwater table ( Type Ⅰ), the medium fluctuation area of groundwater table ( Type Ⅱ) and the weak fluctuation area of groundwater table (Type Ⅲ). The change laws and main influence factors of groundwater table in different dynamic type areas were analyzed and the correlation analysis between groundwater table dynamic and coal mining and atmos- pheric precipitation was carried out. The conclusion is that the groundwater table dynamic in Type Ⅰ area,which pres- ents a stronger fluctuation,is mainly affected by atmospheric precipitation,while the groundwater table dynamic in Type Ⅱ and Ⅲ is weaker because of the comprehensive influence of atmospheric precipitation and coal mining. Under the present mining conditions,the main influence factor of regional groundwater dynamic in the study area is atmospheric precipitation,followed by coal mining.