Groundwater Vulnerability Assessment And Wellhead Protection Area Delineation In Huangshuihe River Basin

Coastal area is the economic center of Shandong Province. The groundwater environmental problem is more and more series with the rapid development of economic and human activities. The main measures of groundwater protection are groundwater vulnerability assessment and wellhead protection area delineation. The Huangshuihe River basin was chosen as the typical study area to assess groundwater vulnerability and delineate the groundwater protection area in this paper.The new definition of groundwater vulnerability was brought forward combined with the local conditions of coastal area in north China on the basis of research experiences of groundwater vulnerability at home and abroad. It considered that the groundwater vulnerability is the intrinsic attribute of groundwater system and the result of natural factor and human activities.The DRAMTICH groundwater vulnerability assessment method was established in this paper. It contains 8 indexes which are: depth to groundwater table, aquifer net recharge module, aquifer media, groundwater mineral hardness, slope, impact of vadose zone media, aquifer integrated conductivity, human activities and land use. The groundwater vulnerability in middle and lower course area of Huangshuihe River basin was assessed by using the above DRAMTICH index model. It gets a very good result.The groundwater vulnerability assessment system (GW_VAS), whose basic framework, main function, component parts, characteristics and usage was put forward on this paper, was set up on the basis of geographic information system MapGIS which was made in China. The other methods of groundwater vulnerability assessment, such as DRASTIC, GOD and so on, were also used in the GW_VAS system. The assessment system becomes more objective, scientific and practical because it contains many other current-use groundwater vulnerability assessment methods.The groundwater vulnerability of study area was assessed by using parametric system method and entropic weight fuzzy optimization method based on GIS. The results of the two assessment methods were basically coincident. The entropic weight fuzzy optimization method can reflect the difference between different samples because it can take the continuously change of every assessment index into consideration. It determined the index weight by using entropic method instead of artificial designation. The parametric system method is simply, easy to operate and has more popular future.The hydrogeological condition of Dabao and Mojia well fields in middle and lower course of Huangshuihe River basin was detailed analyzed on the basis of groundwater vulnerability assessment. The 60d, 10a and 25a groundwater capture zone isolines were determined by using analytical element method software WhAEM2000 which was developed by USEPA. The three-grade groundwater protection zones were delineated and the corresponding groundwater protection safeguard was put forward.