Ecological Evolution And Impact Tracking Assessment Of The Coal-buried Villages In The Hilly Region

A watershed is a terrestrial river catchment,and the watershed is a relatively independent ecosystem unit.Under natural conditions,the watershed ecosystem is relatively stable,and its ecological evolution is also slow,but under the influence of human beings,such as hydropower,over-exploitation of resources,deforestation,land reclamation and other economic activities,which produce strong ecological change in a short time,the ecological evolution of the watershed is obvious.Especially in the watershed with rich coal resources,coal resources are abundant.Extensive exploitation of coal resources and land subsidence,which not only damage the land resources but also damage the watershed water resources,resulting in land and water resources caused by uncoordinated land use and having a huge impact on vegetation cover and landscape,thus changing the watershed ecosystem.Therefore,a systematic and comprehensive research on the ecological evolution of watershed under the influence of coal mining,and scientifically assess the impact of coal mining on the ecological environment of the watershed,and comprehensively develop the watershed 's coal resources,and protect the ecological balance of the watershed and realize the balance of water and soil resources and the social economy sustainable development,which is of great significance.This paper mainly carries out the following research:(1)Summarize and review the domestic and foreign relevant research on the evolution of the watershed,discuss the focus of different factors,and clarify the starting point of this paper;(2)analyze the characteristics of land use change and coal mining driving force under the influence of coal mining;(3)Based on landscape index,the evolution rules of landscape pattern under the influence of coal mining is analyzed,and the paper points out the situation of the overall watershed;(4)select the key factors of the ecological impact of coal mining,construct the ecological impact assessment index for small watershed in the coal hilly area,and further propose the ecological impact assessment process of small watershed;(5)Using the improved set pair analysis method to evaluate the level of Ecological Changhe watershed,and introduce the Markov chain theory to forecast the ecological evolution of the watershed in 2020,and follow the time series to track and evaluate.Through the above research,the following conclusions are drawn:(1)The coal mining on the basin scale of cultivated land change is the strongest driving force,followed by the land use change of the construction land,grassland,forest land and water and the coal mining index driving force is gradually increasing.(2)On the scale of landscape,the landscape pattern of the Changhe watershed from 2005 to 2010 developed rapidly from fragmentation and developed to heterogeneity and low connectivity.From 2010 to 2015,the landscape pattern developed rapidly and continuously,and the connectivity of the formation of patches in the watershed is greater than that of other plaque types.(3)The results of the evaluation of the Changhe watershed show that the ecological environment of the watershed response index level from grade III in 2005 to 2010,grade II in 2015;In the time series,during the period 2005-2010,ecological environment of the watershed decreased;the ecological conditions of the Changhe watershed during 2010-2015 years gradually improved and stabilized,and the trend of the whole was fluctuating;From the sub-index,the vegetation coverage index and the water body density index decreased gradually in the river basin from 2005 to 2015,the land degradation index and the biological abundance index increased,coal mining subsidence damage index and mining disturbance index increased,leading to the ecological response index dynamic fluctuations,coal mining caused a decrease of vegetation,water density and other negative effects should also be taken seriously.(4)Based on the Markovian prediction of improved set pair analysis,the ecological impact level of coal mining in 2020 remained unchanged,and the ecological quality evolution was on the rise.This paper only provides a reference for the study of the ecological evolution of small watersheds,which can provide reference for comprehensive land remediation in the northern hilly villages of the Changhe watershed.