叶尔羌河平原绿洲耕地生态安全评价及预警分析

目的]为了明确叶尔羌河平原绿洲耕地生态环境现状,分析耕地生态安全当前面临的主要影响因素,探索耕地生态安全预警问题及协调人地关系。方法]文章运用DPSIR概念模型构建预警指标体系,在此基础上,运用DPSIR概念模型与障碍度模型对1991—2016年叶尔羌河平原绿洲的耕地生态安全警情格局进行评估和主要障碍因子分析,最后采用灰色GM(1, 1)预测模型对其2018—2025年的警情演变趋势进行预测。结果](1)总体上, 1991—2016年叶尔羌河平原绿洲耕地生态安全预警值从0.149 1增加到0.691 8,呈波动上升趋势,安全警情经历了"巨警—重警—中警—轻警"的发展历程。(2)就各子系统的变化趋势而言, 1991—2016年压力系统的预警值整体上呈现下降态势,驱动力、状态、影响和响应系统的预警值总体上呈现递增趋势。(3)长期来看,系统压力是影响耕地生态安全的主要因素,是今后调控的重点。1991—2016年系统压力的障碍度以年均7.57%的速度增加,而系统驱动力、状态、影响和响应的障碍度分别以年均0.34%,1.01%,100%和4.65%的速度下降。(4)影响耕地生态安全的主要障碍因子包括农作物受灾面积、农药使用强度、灾害指数、地膜使用强度、化肥使用强度和人口密度等。(5)按现状发展态势,灰色预测分析得出2018—2025年耕地生态安全预警值分别为0.697 0,0.730 1,0.765 3,0.802 8,0.842 5,0.884 6,0.929 2,0.976 3。结论]叶尔羌河平原绿洲耕地生态安全在向较好的态势发展。

STUDY ON EARLY WARNING OF CULTIVATED LAND ECOLOGICAL SECURITY IN YARKANT RIVER PLAIN OASIS

In order to clarify the present situation of cultivated land ecological environment in Yarkant River plain oasis, this research analyzes the main influencing factors of cultivated land ecological security, explores the early warning problem of cultivated land ecological security and coordinates the human land relationship. DPSIR conceptual model was used to construct the early warning index system. On this basis, DPSIR conceptual model and obstacle degree model were used to evaluate and analyze the warning pattern of cultivated land ecological security in the Yarkant River plain oasis from 1991 to 2016, and the main obstacle factors were analyzed. Finally, gray GM(1,1) prediction model was used to predict the warning evolution trend from 2018 to 2025. The results were showed as follows. Firstly, In general, from 1991 to 2016, the early warning value of cultivated land ecological security in Yarkant River Plain oasis increased from 0.149 1 to 0.691 8, showing a fluctuating upward trend. The security warning had experienced the development process of "huge alarm heavy alarm medium alarm light alarm". Secondly, in terms of the change trend of each subsystem, the early warning value of the pressure system presented a downward trend on the whole from 1991 to 2016, and the early warning value of the driving force, state, influence and response system presented an increasing trend on the whole. Thirdly, in the long run, system pressure was the main factor affecting the cultivated land ecological security, and it was the key point of future regulation. From 1991 to 2016, the obstacle degree of system pressure increased at an average annual rate of 7.57%, while the obstacle degree of system driving force, state, influence and response decreased at an average annual rate of 0.34%, 1.01%, 100% and 4.65%, respectively. Fourthly, the main obstacle factors affecting the ecological security of cultivated land included the affected area of crops, the intensity of pesticide use, the disaster index, the intensity of plastic film use, the intensity of fertilizer use and the population density, etc. Finally, according to the current development situation, the early warning values of cultivated land ecological security from 2018 to 2025 obtained by gray prediction analysis were 0.697 0, 0.730 1, 0.765 3, 0.802 8, 0.842 5, 0.884 6, 0.929 2, and 0.976 3, respectively. The ecological security of cultivated land in Yarkant River Plain oasis is developing to a better situation.