土地资源生态安全动态评价研究--以西安市长安区为例

A Research on the Appraisal on Ecological Security Dynamic of Land Resource——A Case Study on Chang'an District,Xi'an City

基于PSR模型,以主成分分析法为基础,建立相应的评价指标体系,确定了17项指标在总体水平和子系统生态水平中的权重系数,对西安市长安区近10年来的土地资源生态安全状态进行了动态评价分析,并进行了相关分析与时间序列预测。研究结果表明1996-2005年长安区的土地资源生态安全呈现逐渐恶化趋势,目前已经处于极不安全状态。相关性分析显示,造成土地资源压力加大的主要因子为人均耕地面积、人口密度、耕地面积占地区比例、城镇化水平、人均水资源量、每公顷耕地化肥负荷等。通过时间序列预测,在2005年后5年内该区域状态值与响应值呈上升趋势,但由于土地资源所受压力继续加大,土地资源生态环境继续恶化,政府必须及时采取适当措施,保障当地土地资源生态环境安全,促进土地资源的可持续利用。

Based on the PSR model, this article establishes the corresponding target system taking the principal components analysis as the foundation, determines the evaluation weights of 17 targets under the overall ecology level and the subsystem ecology, makes a dynamic state evaluation analysis on land re- source ecological security around 10 years in Changan district, and makes correlation analysis and time series estimating. The result indicates that the ecological security of land resource from 1996 to 2005 years is becoming worse and is in the extremely insecurity state at present. Correlation analysis shows that the main factors that causes the land resource pressure increased are farmland area, population density, the ratio of the farmland to the whole area, the urbanization level, per capita water resources, average fertilizer load of farmland. According to time series estimating, the appearance value and responding value are uptrend in 5 years after 2005, the land ecological security of resource is continuingly worsen because the pressure is continuingly enlarging. The government has to adopt appropriate measure in time to make land resources eco- system environment safe, and to keep the land resources on exploitation.