基于改进蒙特卡洛模拟的耕地生态安全时空特征研究——以齐齐哈尔市为例

Temporal and spatial characteristics of cultivated land ecological security based on improved Monte Carlo simulation——Taking Qiqihar as an example

为解决耕地生态安全评价中高维指标权重赋值难,及由此导致的评价结果不确定性的问题,以齐齐哈尔市为例,通过引入蒙特卡洛模拟,采用三角分布模型对蒙特卡洛模拟中权重值域不合理问题进行了改进,构建了基于PSR(压力-状态-响应)模型的耕地生态安全评价指标体系,利用Python语言编程实现了模拟计算过程,从时空角度分析了区域耕地生态安全状况.结果表明:(1)近15年齐齐哈尔市耕地生态安全值从0.333增长至0.641,呈现“缓和下降—快速增长—平稳上升”的阶段性发展特点,耕地生态安全状态呈逐渐改善趋势;(2)依据各区县耕地生态安全值时空变化特征可以将齐齐哈尔市划分为耕地生态安全良好区、缓和区与风险区三类,其分布具有一定的空间聚集特征;(3)改进的蒙特卡洛模拟优化了权重值域分布,可以量化因权重差异导致的最终评价结果的不确定性,使得评价结果更客观、可靠.运用改进的蒙特卡洛模拟可以客观真实地反映齐齐哈尔市耕地生态安全状况,对齐齐哈尔市耕地资源利用、因地制宜地兼顾生态文明建设与经济发展需求具有重要意义.

Introducing Monte Carlo simulation to solve the difficulty of weighting high-dimensional indicators in the current evaluation of cultivated land ecological security and the uncertainty of the evaluation results.At the same time,the triangular distribution of indicator weights was attempted to improve weight range of Monte Carlo for more reasonable.The evaluation index system of cultivated land ecological security based on the PSR model was constructed to analyze the spatial and temporal ecological security of cultivated land in Qiqihar City,and the calculation process was realized by Python programming.The results show that:(1)In the past 15 years,the ecological security value of cultivated land in Qiqihar City has increased from 0.333 to 0.641,showing a phased development situation of“gentle declining—rapid growth—steadily rising”.The state of cultivated land ecological security has gradually improved.(2)According to the temporal and spatial features of cultivated land ecological security values in each district and county,Qiqihar City can be divided into three categories:well-developed arable land ecological security area,moderate arable land ecological security area and risk arable land ecological security area,with certain spatial aggregation characteristics.(3)Improved Monte Carlo simulation optimizes weight distribution,can quantify the uncertainty that is transmitted to the final evaluation result due to the weight difference,making the evaluation result more objective and reliable.It concluded that the improved Monte Carlo simulation can objectively and truly reflect the ecological security status of cultivated land in Qiqihar City.It is of great significance to align the utilization of cultivated land resources in Qiqihar City and take into account the needs of ecological civilization construction and economic development.