水土流失风险扰动下区域人地系统适应性研究——以榆林市为例

适应性概念为可持续性科学领域提供了新的研究思维。论文在总结、梳理适应性内涵,整合相关适应性理论与方法的基础上,提出了基于风险扰动的适应性分析框架,采用风险-适应能力指数评估区域人地系统适应性,将系统适应性分解为风险干扰和适应能力（包括生态、经济、社会能力3个参数）两个维度,从研究区水土流失风险出发,构建系统适应性评价指标体系。通过美国通用土壤流失方程（USLE）与适应性函数模型,分析榆林市水土流失风险以及人地系统适应能力时空演化特征,在系统适应性水平评估基础上,揭示榆林市不同时期人地系统适应性演化的驱动因素。研究结果表明：1）2000—2011年榆林市水土流失风险显著下降,但时空演化明显,到2011年高流失区转移分布于西南部、长城沿线等县域;2）12 a间榆林市系统适应性水平整体呈增高趋势,但空间上出现两极分化,呈现“西北高、东南低”的格局,其中北部县区（根据榆林市当地分区,北部县区包括府谷、神木、榆阳、横山、靖边、定边6县区;南部县域包括佳县、米脂、吴堡、子洲、绥德、清涧6县。）在生态、经济和社会子系统能力上明显高于南部,但南部县域适应性水平提升较北部更为明显;3）人地系统适应性演化驱动力由社会经济发展转化为生态环境修复、经济能力增强和社会保障提升的共同作用。

The Adaptation of Regional Human-environmentalSystem under the Risk of Soil Erosion: A Case Study of Yulin City

The concept of adaptation provides a new research thought in the field of sustainable science. On the basis of summarizing and combing the definition of adaptation and integrating the theories and methods related to adaptation, this paper proposes an analytical framework of the adaptation based on the risk disturbance. In this research, risk-adaptive capacity index is used to quantify the adaptation of regional human-environmental system, and adaptation of system is divided into two dimensions: risk interference and adaptive capacity (including three parameters: ecological capacity, economic capacity and social capacity). From the perspective of the risks of soil erosion in the study area, the adaptation evaluation index system is constructed. By using USA Universal Soil Loss Equation (USLE) and adaptive function model, the risk of soil erosion and the spatial-temporal evolution characteristics of adaptive capacity of human-environmental system in Yulin City were analyzed. On the foundation of the evaluation of adaptive level of system, this paper reveals the driving factors of the adaptive evolution of human-environmental system in different periods in Yulin City. The results are shown as follows: 1) In Yulin City, the risk of soil erosion significantly decreased during 2000-2011, but the spatial and temporal evolution was obvious. In 2011, the high loss areas were transferred to the southwest region and region along the Great Wall. 2) During 2000-2011, the adaptive level of system showed an overall increasing trend in Yulin City, however it was polarized in space showing a pattern of “high in northwest Yulin and low in southeast Yulin”. The northern counties were significantly higher than the southern part in ecological capacity, economic capacity and social capacity, but the advancement of adaptive level of the southern counties was more obvious than the northern part. 3) The driving force of the adaptive evolution of human-environmental system transformed from the social and economic development to the combined action of ecological environment restoration, economic capacity enhancement and social security promotion.