Symeonakis Elias, Calvo-Cases Adolfo, Arnau-Rosalen Eva
CSIRO Mathematical and Information Sciences, Private Bag 5, Wembley 6913, Australia.
Environ Manage. 2007 Jul;40(1):80-94. doi: 10.1007/s00267-004-0059-0. Epub 2007 May 24.
The magnitude of the environmental and social consequences of soil erosion and land degradation in semiarid areas of the Mediterranean region has long been recognized and studied. This paper investigates the interrelationship between land use/cover (LULC) changes and land degradation using remotely sensed and ancillary data for southeastern Spain. The area of study, the Xaló River catchment situated in the north of the Alicante Province, has been subjected to a number of LULC changes during the second half of the 20th century such as agricultural abandonment, forest fires, and tourist development. Aerial photographs dating back to 1956 were used for the delineation of historic LULC types; Landsat ETM+ data were used for the analysis and mapping of current conditions. Two important indicators of land degradation, namely, susceptibility to surface runoff and soil erosion, were estimated for the two dates using easily parametrizable models. The comparison of 1956 to 2000 conditions shows an overall "recuperating" trend over the catchment and increased susceptibility to soil erosion only in 3% of the catchment area. The results also identify potential degradation hot-spots where mitigation measures should be taken to prevent further degradation. The readily implemented methodology, based on modest data requirements demonstrated by this study, is a useful tool for catchment to regional scale land use change and land degradation studies and strategic planning for environmental management.
地中海地区半干旱地区土壤侵蚀和土地退化所造成的环境和社会影响的严重程度早已得到认识和研究。本文利用西班牙东南部的遥感数据和辅助数据，调查土地利用/覆盖（LULC）变化与土地退化之间的相互关系。研究区域是位于阿利坎特省北部的哈洛河流域，在20世纪下半叶经历了一系列土地利用/覆盖变化，如农业废弃、森林火灾和旅游业发展。利用可追溯到1956年的航空照片来划定历史土地利用/覆盖类型；利用陆地卫星增强型专题制图仪（ETM+）数据来分析和绘制当前状况。利用易于参数化的模型，对这两个时期的两个重要土地退化指标，即地表径流敏感性和土壤侵蚀敏感性进行了估算。1956年与2000年状况的对比表明，整个流域呈现出总体“恢复”趋势，只有3%的流域面积土壤侵蚀敏感性增加。研究结果还确定了潜在的退化热点地区，应在这些地区采取缓解措施以防止进一步退化。基于本研究所示适度数据要求的易于实施的方法，是流域到区域尺度土地利用变化和土地退化研究以及环境管理战略规划的有用工具。
