163 / 2015-08-30 21:33:24

Distribution of Groundwater Quality in Nakhon Ratchasima Province, Northeastern Thailand by Using GIS

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Distribution of saline water and groundwater contamination are a major issue of the groundwater quality in Nakhon Ratchasima province, Northeastern Thailand. Major factor comes from a man-make and geology in this area due to the most extensive area of this province is underlain by a thick sequence of Mesozoic rocks which contain considerable quantities of rock salts in the Maha Sarakham Formation. The occurrence of this Formation leads to the problems of saline water throughout the regions. Therefore, the purpose of this study is to mapping the distribution of groundwater quality by using the ArcGIS program. The groundwater quality studies from a previous data of the Department of Groundwater Resources base by comparison with the standards for consumption of the Ministry of National Resources and Environment. The groundwater quality map consist the data of iron, total hardness, total dissolved solids and chloride contents from 1,239 groundwater wells of Nakhon Ratchasima using the ArcGIS program. The result of iron content shows a high content as more than 0.6 mg/l, especially in Khon Buri, Soeng Sang, Pak Chong, Dan Khun Thot, Non Sung, Non Daeng, Khong, Huai Thalaeng, Kham Sakaesaeng, Phimai, Prathai, Chakkarat, Pak Thong Chai, Sung Noen and Chaloem Phra Kiat districts (Fig. 1). This high iron content involves the total hardness in the groundwater (Fig. 2) due to the aquifer in these areas located in Khok Kruat Formation that majority consisting of red sandstone bed. The total dissolved solids content is high in the northern part of the province (Fig.3). This content usually refers to the mineral content of water, including common salts such as sodium, chloride, calcium, magnesium, potassium, nitrate, sulfates and bicarbonates. The saline water distribution was mainly diffused from the north to the middle and eastern part of the province (Fig. 4), especially in Mueang, Dan Khun Thot, Non Thai, Kham Thale So, Non Sung, Phimai, Chum Phuang, Prathai, Non Daeng, Khong, Kham Sakaesaeng, Bua Yai, Sida, Kaeng Sanam Nang, Ban Lueam, Phra Thong Kham and Mueang Yang districts. This the high content of saline water relates to the chloride content as more than 200 mg/l (Fig. 5) due to the aquifer in these areas located in Maha Sarakham Formation, which generally consists of sandstone and siltstone interbedded with rock salt beds. These results have caused the groundwater in these areas were brackish to saline.