| Based on the Project of Solving the Drinking Water Problem in SouthernMountainous Region of the City of Tong Liao, Inner Mongolia, and this paperadopted the EH-4continuous conductivity profiler to find water. EH4geophysicalwater exploration took the principle of magnetotelluric sounding method which wasalso known as EH4continuous conductivity measurement due to the simultaneousmeasurement the four components of electric and magnetic fields in both directions.The resistivity of the formation was calculated by the observation of surfaceelectromagnetic field, the distribution of underground rock resistivity, thesimultaneous measurement of the electric and magnetic fields of the natural fieldsources and human factory source excitation method. The EH-4continuousconductivity profiler possessed the characteristics of stability, strong anti-jammingcapability, short acquisition time and it is easy to carry. Wild-collected data can beprocessed and conducted a two-dimensional analysis by IMAGEM.The survey area is located in the town of Feng Shuishan, Kou Hezi village,Kulun country, the city of Tongliao. It belongs to the north temperate continentalclimate which means it is windy and dry for most of the time during the whole year.The annual precipitation is about350-400mm, and the evaporation is1886.1mmwhich is about five times the precipitation. The coordinates is E:121°46’12.9"N:42°45’36.7". When the EH-4continuous conductivity profiler is used, two east-west direction parallel profiles which are north section line and south section line areadopted with a total length of98.5km and a total of measured points of199. Thegeological conditions, here are complex and the areas are covered bymulti-Quaternaryn which is mainly fine sand with low resistivity of about20Μ.Cretaceous is mainly sandstone, interbedded of sandstone and mudstone. As for thephysical character, the relatively high resistivity of the sandstone is25~40Μ andthe sandy conglomerate is40~60Μ. There are less obvious differences betweenthe Cretaceous rock groups. Based on available information, Jurassic is mainlyinterbedded of mudstone and sandstone which is hard and complete with highresistivity that are greater than80Μ.According to the analysis of the data, the western area is richer in water than theeastern district due to the presence of sandstone and mudstone lenses. The quaternarypore water is mainly holocene alluvial sand and gravel layer pore water and isdistributed in the valley. North section of Cretaceous strata of sandstone and mudstone,sandstone and mudstone of the boundaries is not obvious, reflect on the electricalmudstone, sandstone interbedded, the average thickness of the Cretaceous about600m. The most shallow point on the1st, the thickness of about850m, the thickest in theNo.99point, the thickness of1050m or so. Cretaceous strata of the south section ofsandstone and mudstone, sandstone and mudstone of the boundary is not very obvious,a reflection of the electrical mudstone, sandstone interbedded. Average thickness ofthe Cretaceous about600m, of which the maximum thickness of around43points,reaching600~800m,, the most shallow near the point of the1st, about700m.Theapparent resistivity data inversion shows that the well can be built at No.45point inthe north section line, and No.58point in the south section line. The recommendeddepth is70m, and the theoretical water inflow of a single well is10t/h. The water exploration by using EH-4continuous conductivity profiler achievedreliable and satisfactory results which also provided a scientific basis for theexploitation of groundwater resources. However, due to the lack of hydrogeologicaldata and deep drilling data, the deep geological conditions can be further studied. |
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