Research on comprehensive hydrogeological exploration technology insurface-underground combined mining area of river basin

The Huhewusu Mine is located at the intersection of Ulan Moron River and Huhewusu Ditch. There are open-pit mining backfill areas and underground mining old goafs in the upper coal seams of the basin. Aquifers, backfilled water-rich areas, and water-collected areas have complex hydraulic links with rivers, which have a greater impact on lower coal seam mining. In order to find out the aquifer, backfill area, and goaf area rich in water and hydraulic connections, it made full use of the technical advantages of drilling to accurately obtain local hydrogeological parameters, geochemical analysis of water sources and hydraulic connections, and large-scale and fast detection of geophysical prospecting totarget point (drilling)-line (chemical prospecting)-surface (physical prospecting) integrated hydrogeological investigation.Not only the water-rich characteristics of the target aquifer in the study area were ascertained, the hydraulic connection between the river and the target aquifer was more finely screened out, and the water inflow area prediction was carried out in the study area.The results show that the unit water inflow of the target aquifer has changed by experimental orders of magnitude, and the unit water inflow of the boreholes near the Ulan Moron River open-pit backfill area was much larger than that in the underground mining area through drilling and pumping tests;It was found that the water quality types of the Ulan Moron River and Huhewusu ditch were obviously different after analyzing the hydrochemical characteristics. The borehole water samples near the Ulan Moron River belonged to the Quaternary alluvial water, and the borehole water samples near the Huhewusu Ditch belonged to sandstone aquifer water. There was an obvious replenishment relationship between the accumulated water in the open-pit backfill area and the Ulan Moron River;The results of transient electromagnetic detection showed that the apparent resistivity value gradually increased in the underground mining area from west to east far away from the river, and the overall resistance value was higher than that of the open-pit mining area, indicating that the water content of the underground mining goaf was weak (or not water content), and less affected by the river. The apparent resistivity value was reduced overall in the open-pit mining backfill area which was close to the river confluence from west to east, the abnormal intensity and range of low resistance were relatively large, indicating that the open-pit mining backfill area had strong or strong water richness and more obvious replenishment by the river.In addition, based on the transient electromagnetic method and pumping test results, a preliminary attempt was made to establish the functional relationship between apparent resistivity and unit water inflow, and to draw a regional single-point unit water inflow plan to provide a basis for obtaining regional hydrogeological parameters and reduce exploration costs.