陕西省生态安全及空间差异定量分析

利用生态足迹的理论与方法,提出了生态压力指数的概念,建立了生态压力指数测算模型和生态安全等级划分体系,以及不同地区生态足迹、生态承载力、生态盈余及生态安全度变化预测模型。据此对1986~2002年陕西省三大自然区 (陕北黄土高原、关中渭河盆地、陕南秦巴山区) 的生态足迹、生态承载力、生态盈余/亏损进行了测算和分析。研究结果：① 各地区生态承载力均呈减少趋势,减少幅度差异明显,陕北黄土高原最快,陕南秦巴山区最慢,关中渭河盆地居中;② 各地区生态足迹均呈现增加趋势,增加幅度大小不一,由小到大依次为陕北黄土高原、关中渭河盆地、陕南秦巴山区;③ 1986~2002年生态压力指数：陕北黄土高原从0.44增加到0.91,增加幅度0.47;关中渭河盆地从0.75增长为1.20,增长幅度为0.45;陕南秦巴山区从0.19增长为0.22,增长幅度为0.03。年平均压力指数关中渭河盆地最大,是陕南秦巴山区的5.37倍,是陕北黄土高原的1.30倍;④ 各区生态安全状况：陕南秦巴山区处安全状态;关中渭河盆地已严重超载,处于不安全状态;陕北黄土高原处于临界状态,压力指数增长最快。

Quantitative Analysis of Dynamic Change and Spatial Difference of the Ecological Safety: The Case of Shaanxi Province

Using the theory and method of the ecological footprint, combining the change of regional land use, resource environment, population, social and economics, this paper calculated the ecological footprint, ecological carrying capacity and ecological surplus / loss in 1986-2002 in the three major regions of Shaanxi Province, namely, the Loess Plateau, the Weihe basin in Guanzhong and Qinling-Daba Mountains. What is more, this paper has put forward the concept of ecological pressure index, set up ecological pressure index models, ecological safety grading systems, and the prediction models of different ecological footprints, ecological carrying capacity, ecological surplus and ecological safety change, also has tested and assessed the ecological footprint demands of 10,000 yuan of GDP. Results show that: (1) The ecological carrying capacity in each region shows a decreasing tendency, the difference of reducing range is obvious, the northern part of Shaanxi is the fastest, the southern part is the slowest, Guanzhong is in the middle. (2) The ecological footprint in each region shows an increasing trend with varying degrees, from small to big, the three regions are successively the Loess Plateau of northern Shaanxi, Weihe basin of Guanzhong, Qinling-Daba Mountains of southern Shaanxi. (3) The ecological pressure index of the period 1986-2004: increasing from 0.44 to 0.91 in the Loess Plateau of northern Shaanxi, an increase of 0.47; from 0.75 to 1.20 in the Weihe basin, an increase of 0.45; from 0.19 to 0.22 in the Qinling-Daba Mountains of southern Shaanxi, an increase of 0.03. Annual average pressure index in the Weihe basin is the greatest, 5.37 times that of Qinling-Daba Mountains, and 1.30 times of the Loess Plateau. (4) The ecological safety in each region: Qinling-Daba Mountains are in a safety state; Weihe basin overloading seriously and in an unsafety state; the Loess Plateau of northern Shaanxi in a critical state with pressure index increasing the fastest.