Evaluation And Early Warning Of Land Ecological Security In Coal Mining Area Of Datong City

Ecological security is the foundation of regional sustainable utilization and has attracted high attention from the world.Land ecological security is an important component of ecological security and an important guarantee for the sustainable land resources utilization.However,in coal mining areas,large-scale and high-intensity exploitation and utilization of coal resources have caused varying degrees of damage or even destruction to land resources,and have become one of the areas where the contradiction between human and land is relatively prominent.Datong,as one of the important coal production bases,has a long history of mining and continues to expand its scale.Since the reform and opening up,it has produced 3.619 billion tons of raw coal for the country,providing reliable energy security for the healthy and stable development of the national economy.However,the land ecological security issues in mining areas have become increasingly prominent,seriously restricting the sustainable development of mining areas.Therefore,systematic research on land ecological security in coal mining areas of Datong City is of great significance for ensuring highquality regional development.This thesis takes Datong coal mine area as the research area.Firstly,based on the scale effect and TWINSPAN model,the best evaluation scale was determined.On this basis,the evolution mechanism of land ecological security in mining areas was analyzed,and based on the "pressure-state-response" model,the evaluation index system of land ecological security in Datong coal mine area was established to evaluate and analyze the land ecological security in coal mine area.Then,the mutation series model and grey prediction model are constructed to dynamically predict the evolution trend of land ecological security at the township level,and early warning analysis was conducted on the future land ecological security of each township.Finally,the obstacle degree model is introduced to calculate and analyze the main obstacle factors affecting the land ecological security,and the regulation suggestions are proposed to ensure land ecological security in mining areas.The main conclusions of this thesis are as follows:(1)Taking grid units as the spatial scale,based on the consistency within grid units and heterogeneity between grid units under different grid scale sizes,the optimal evaluation scale for land ecological security evaluation is determined to be 1200 m *1200m.(2)The spatial pattern of land ecological security in the research area was high in the northwest and low in the central area,and the security state was deteriorating first and then improving.From 2002 to 2020,the area proportionn of land ecological security grade deterioration was smaller than that of improvement area in Datong,showi ng a strong autocorrelation.The high-high aggregation areas were concentrated in the western and northern regions,while the low-low aggregation areas were concentrated in the central region.(3)There are differences in the development trends of land ecological security among different townships in the research area.Early warning analysis found that the land ecological security warning situation level of 15 administrative units in Datong coal mine area were mainly in the range of "medium warning situation " and "heavy warning situation".In 2020,due to the environmental pressure caused by coal mining and the economic pressure caused by urbanization,the land ecological security w arning situation level in Majunying Township,Gaoshan Township,Kouquan Township,Pingwang Township,Jiaoerya Township and Yungang Township has been significa ntly reduced,and the land ecological security alert level in Kouquan Township has be en reduced to "heavy warning situation ".The prediction results show that by 2029 and 2038,the development of land ecological security warning situation level in the western and northern towns of Datong coal mine area presents a trend of improvement,while the township warning situation level in the central and eastern regions presents a trend of deterioration.(4)The obstacle degree of the three criteria layers varies in different states,and the obstacle degree of the main factors in the indicator layer varies in size.From 2002 to 2-020,the obstacle degree of pressure layer and state layer is increasing,while the obsta cle degree of response layer is decreasing.Among them,the proportion of tertiary ind ustry,grain yield per unit area,land reclamation rate,landscape fragmentation,per ca pita cultivated land area,industrial and mining waste discharge intensity,mine land da maged area,raw coal output,industrial and mining land interference degree and const ruction land development and utilization intensity are the main obstacle factors for the improvement of land ecological security warning situation in Datong coal mine area.Therefore,the main measures to improve land ecological security in Datong City are put forward.The thesis has 29 figures,25 tables and 151 references.