Study On Ecological Security Evaluation Of Cultivated Land In Qiqihar City

Cultivated land ecological security has great impact on the basic production materials of agricultural production and human survival and the cultivated land of natural resources,which in turn affects the stability of the national society and the sustained development of the national economy,is a strong guarantee and basic component of China's food security and ecological civilization construction.With the rapid urbanization and industrialization of China,the cultivated land resources continue to flow to the non-agricultural direction,and the industrial and agricultural wastes cause serious pollution to the cultivated land,which makes the ecological security of cultivated land face a severe test.In order to understand the basic situation and evolution of cultivated land ecology,ensure the sustainable use of cultivated land resources,promote economic development,and ensure national food security,it is imperative to carry out research on the evaluation of cultivated land ecological security.This paper summarizes the research results of arable land ecological security evaluation at home and abroad,based on the theory of human-land relationship coordination,sustainable development theory,system theory and ecosystem balance theory,taking Qiqihar City as the research area,twenty-two index factors were selected to construct the PSR cultivated land ecological security evaluation index system in the study area,and the Monte Carlo simulation was introduced and optimized by the analytic hierarchy process,entropy method,coefficient of variation method and dispersion maximization method.Calculate and evaluate the ecological security status of cultivated land in Qiqihar City from 2001 to 2015,and the calculation process is implemented in Python 3.6;Using the obstacle model to diagnose the obstacles in the ecological security of cultivated land in the study area;Using Matlab R2014 a to build a grayscale model to predict the development trend of cultivated land ecological security in the research area in the next10 years.And propose countermeasures to improve the ecological security of cultivated land in the study area.The main results are as follows:(1)On the time scale,from 2001 to 2015,the ecological security level of cultivated land in Qiqihar City gradually improved during the fluctuation,from 0.333 in 2001 to 0.641 in 2015.And in 2003 and 2012 as the time node,it shows the characteristics of the phased development of“mitigating and decreasing – rapid growth – steady rise”;On the spatial scale,according to the time series characteristics selected in 2003,2009 and 2015,the ecological security evaluation and analysis of the cultivated land in 10 counties under the jurisdiction of Qiqihar City,according to the rate of change of the ecological security level of each county and the distribution of safety levels,Qiqihar City can be divided into three types of cultivated land ecological security good area,mitigation area and risk area,and each type of area has obvious spatial accumulation characteristics;The Monte Carlo simulation improved by the triangulation function optimization eliminates the uncertainty caused by the weight difference to some extent and can quantify the uncertainty passed by the index weight difference to the evaluation result.It is better used in the field of arable land ecological safety assessment.(2)The main obstacle factors restricting the ecological security of cultivated land in Qiqihar City from 2001 to 2015 are the total agricultural output value of cultivated land,Per capital net income of farmers,proportion of fiscal expenditure on agriculture and environmental protection,Soil erosion area ratio,forest coverage,the pesticide load per unit of cultivated land,the fertilizer load per unit of cultivated land,and the agricultural film load per unit of cultivated land.The order relationship of each major obstacle factor shows a significant alternating relationship with time;The stress degree of the stress criterion layer shows an upward trend,the degree of disorder of the state criterion layer fluctuates within a certain range,and the response criterion layer shows a downward trend.Since 2009,the pressure gauge layer and the response criteria layer have a significant trend and reverse synchronization.(3)In 2016-2025,the ecological security pressure value of cultivated land in Qiqihar City decreased from 0.149 in 2015 to 0.130 in 2025,the state value and response value rose from 0.220 and 0.272 in 2015 to 0.273 and 0.409 in 2025,respectively.The comprehensive evaluation value rose from 0.641 in 2015 to 0.812 in 2025,with an average annual change of 0.0171,the ecological security of cultivated land in the study area is generally on a slow upward trend.(4)In order to improve the ecological security level of cultivated land in the study area,promote the construction of ecological civilization,ensure food security,and improve the quality of life of residents in Qiqihar City,measures and countermeasures can proposed from cultivated land use,agricultural production,environmental protection,policy orientation,the public awareness and other aspects to guarantee and improve the ecological security status of cultivated land in the study area and prevent possible problems.