Coal Mining Subsidence Impact on Soil Physical and Chemical Properties in Windy Desert Area

Abstract

The temporal impact characteristics of soil physical and chemical properties and plants characteristic had been revealed by investigation and sampling of multi-phase soil and plants sample in subsidence area and control area. Through the research, it could study the effect of surface ecological environment caused by coal mining, and further propose the corresponding countermeasures of management and restoration. Evolution characteristic of soil physical properties is that soil water content, bulk density and porosity made a response to mining subsidence, and soil moisture content variation was much more obvious and affected by seasonal weather. Evolution characteristic of soil chemical properties is that soil nitrogen and available phosphorus had decreased due to coal mining subsidence, expect pH, organic matter and available potassium. However, the impact degree of subsidence was relative slight and had “partition” feature, showing a trend ofDSR>CUSR&RUSR. Moreover, the response time node of subsidence was different from physical properties with a certain lag, which usually occurred in alternating hot and humid periods. All the affected indexes of chemical properties did not recover to initial level before mining in one year. Based on above studies, a new “partition” differentiated ecological restoration model had been proposed for the first time. For theCUSRandRUSRshould followed “natural closure” model, conversely, theDSRshould selected “marginal fissures filling & vegetation optimization & rhizosphere environment improvement” of artificial induction model, which giving priority to ecological self-healing with supplementing appropriate human interventions.