Research On The Early-warning Of Cultivated Land Ecological Security In West Liaohe Plain

The West liaohe Plain is located in the east of the West liaohe Basin and the west of the Songliao Plain.The plain is fertile and is known as the "Inner Mongolia Granary" and is an important grain production base in China.In recent years,with the continuous development of urbanization and industrialization,there are many problems in the region,such as population,resources,environment and so on.These problems have caused certain damage to the ecological environment of cultivated land in this region.Therefore,in order to avoid the further deterioration of cultivated land ecological environment,it is particularly important to carry out the early-warning research of regional cultivated land ecological security.In this paper,Tongliao City of Inner Mongolia,a typical agricultural area in the West Liaohe plain,is selected as the research area to build an early-warning index system of cultivated land ecological security based on PSR model.Entropy method is used to determine the proportion of early-warning index data,and comprehensive index method is used to quantitatively evaluate the level of cultivated land ecological security in Tongliao City from 2002 to 2017 to determine the level of warning.On this basis,combining with the evaluation results,analyzes the temporal and spatial evolution changing trend of cultivated land ecological security,and introduce the diagnosis model of obstacle degree to find the main obstacle factors that restrict the ecological security level of cultivated land.And finally uses GM(1.1)model to predict the evolution trend of cultivated land ecological security warning situation in Tongliao City from 2018 to2022.The main results are as follows:(1)On the time scale,from 2002 to 2017,the early-warning level of cultivated land ecological security in Tongliao City decreased from "heavywarning" to "light warning";the warning index fluctuated and increased from 0.3823 in 2002 to 0.6346 in 2017 and 16 years A total of 0.2523 increased,of which the index of cultivated land ecological security pressure system declined,and the state and response system index increased year by year.On the spatial scale,the ecological security situation of cultivated land in each County of Tongliao City increased significantly from 2002 to2017.The early-warning degree of cultivated land ecological security gradually decreased from the central region to the surrounding areas,and the cultivated land ecosystem was continuously improved.In general,the warning index of cultivated land ecological security in Tongliao City is rising,but the cultivated land ecological environment still faces certain threats,and it is necessary to further increase the ecological protection of cultivated land.(2)The main obstacles that restricted the ecological security of cultivated land in Tongliao City from 2002 to 2017 were the unit farmland fertilizer load,unit farmland pesticide load,per capita water resources,irrigation guarantee rate for cultivated land,soil erosion control area,and the proportion of primary industry employees.From 2002 to 2017,there was a clear difference in the change trend of the each subsystem obstacles degree of cultivated land ecological security in Tongliao City.Among them,the pressure subsystem obstacles degree was the highest overall and the fluctuation increased.In 2017,pressure subsystems obstacles degree accounted for more than 50% of the total system obstacles;The second is the state subsystem obstacle degree,showing a downward trend of fluctuations;the response subsystem obstacle degree index is the smallest and the fluctuation is decreasing.(3)From 2018 to 2022,the early-warning degree of cultivated land ecological security in Tongliao City has gradually declined,and the warning index has steadily increased.The pressure subsystem index decreased from 0.1152 in 2017 to 0.0852 in 2022;the status subsystem and response subsystem indexes increased from 0.2345 and 0.2850 in 2017 to0.2683 and 0.5032 in 2022.(4)Based on the analysis of the evolution trend of cultivated land ecological security in Tongliao City from 2002 to 2017,combined with the current situation of cultivated land,the following countermeasures and suggestions are proposed: scientific use of chemical fertilizers and pesticides,raising awareness of cultivated land protection,increasing investment in cultivated land,strengthening cultivated land ecological construction,Coordinate social and economic development with cultivated land protection,establish a dynamic monitoring and early-warning system for cultivated land ecological security.