STUDY ON LAND QUALITY MONITORING SAMPLING IN OPENCAST COALMINING AREA – TAKING PINGSHUO OPENCAST MINING AREA AS AN EXAMPLE

Land quality monitoring is one of necessary means to grasp land use in mining area, which could guide land reclamation. In order to obtain the land quality changes, control the workload and improve efficiency in a certain extent, it is required to monitor land quality in mining area. This paper developed a series of principles should be followed, such as representative, controllability, randomness and variability. It selected land pollution, ground slope, effective soil thickness, soil texture, soil bulk density, pH, organic matter, nitrogen, phosphorous and potassium as quality monitoring indicators, and described the choice of monitoring plots and sampling method on profile and hybrid soil. In this paper, Pingshuo opencast coal mine on the Loess Plateau was taken as an example, and 18 plots were selected under different situations. Among the plots, soil sampling was implemented by 10cm intervals. In the end, it is collected a total of 204 copies, including profile and hybrid soil samples. The result showed that the monitoring plots selected could basically cover the land quality situation, including the original, damaged without reclamation, and reclaimed land. The quality indicators could meet the dynamic monitoring requirements of land quality, which helped accumulate experience for the full implementation of land quality monitoring and sampling in the mining area in the future.