基于GIS的山区县域土地生态安全评价

A Study on Land Eco-security Evaluation in Mountainous Area at County Level Based on GIS

研究目的:综合应用数字高程模型(DEM)、TM遥感数据和各种调查数据,在地理信息系统(GIS)支持下,基于栅格对栖霞市土地生态安全状况进行评价与分析,为山区土地生态安全研究探索一种精确的评价方法。研究方法:首先建立栖霞市地形、土壤和土地利用基础数据库;然后结合区域特征选取评价因子,并进行空间量化处理和赋值;最后以地形为主导因子建立评价模型,完成土地生态安全等级划分。研究结果:栖霞市土地生态系统可划分为安全、较安全、预警和中警4个状态级,各级别面积分别占22.62%、49.82%、20.51%和7.05%,土地生态安全级主要分布在西南和东北部的倾斜平地和山间泊地,土地生态较安全级广泛分布于低山丘陵区,西北和东南部的山地区域处于土地生态预警和中警等级。研究结论:栖霞市土地生态状况整体上良好,与实际情况相符合,今后应加强土地利用结构优化和果园集约化管理,提高土壤肥力,减少水土流失,保证土地生态系统健康稳定。

The purpose of this paper is to explore a precise evaluating approach for land eco-security researches in mountainous area via using digital terrain model （DEM）, TM remote sensing data and various survey data, supported by the geographical information system （GIS） and based on the analysis and evaluation of the land eco-security in Qixia City based on the grid data. A basic database was established in this study of the topography, soil and land-use of Qixia, the evaluating factors were selected according to the regional characteristics and they were rasterized and valued. Finally, an appraising model was set up to divide the land eco-security grades, in which the topography is the leading factor . The results show the land eco-system in Qixia City was divided into four grades （safe grade, accounting for 22.62% of total area; relatively safe grade, 49.82%; pre warning grade, 20.51%; intermediate warning grade, 7.05% ）. The safe grade was mainly in northeast and southwest piedmont plains and intermontane plains, relatively safe grade was in hilly land area widely, mountainous regions in the northwest and southeast were pre warning grade and intermediate warning grade. It is concluded the condition of land eco-security in Qixia City was sound as a whole and it is in accordance with the facts. And in the future some measures land use structure and intensify orchard management, to avoid water and soil erosion and health and stability of local land ecosystem.