摘要
利用遥感和GIS技术对四川省20世纪90年代后半期林地的动态变化特征进行了研究。利用遥感和GIS技术获取20世纪90年代中期和2000年的土地利用数字数据以及土壤侵蚀数字数据。利用GIS技术获取坡度分级数据、环境质量等级数据、地貌分区数据和地市州行政单元数据。将所有数据转化和重采样为100m分辨率的栅格数据。再次,将所有数据投影到同一投影同一坐标系上。利用GIS的提取、叠加和统计分析功能对林地动态变化特征及其背景特征和空间分布特征进行了分析。分析表明,林地净增面积主要来源于草地和其它用地,而林地净减少部分的主要去向是耕地和建设居民用地,总体上,林地净减少7972hm2;净增林地的区域主要是广元市、绵阳市和达州市或盆周山地和丘陵地区。净增林地的区域主要位于生态环境质量较好,坡度等级较低,土壤侵蚀为强度和中度的区域。净减少林地的区域主要位于生态环境质量中等、水土流失较轻、坡度较大的区域。就林地的生态功能而言,局部区域改进,总体下降;退耕还林的效果在20世纪90年代后半期还未能显现。建议加大对川西北高原和川西南山区的森林保护力度,特别是加大对甘孜藏族自治州、乐山市、雅安市和阿坝藏族羌族自治州等处的森林保护力度,加大对脆弱生态和陡坡环境的森林保护力度。
Here we report the dynamic change of forestland in the late 1990＇s in Sichuan Province. With the technologies of remote sensing and/or GIS, we obtained the land-use digital data of 1995 and 2000, the soil erosion data of 1995 and the data of slope grade, environment quality grade, geomorphic region, and administration districts. All of these data were further sampled into the raster data with a resolution of 100 meters and projected into the same coordination system with the same resolution. After extraction, overlay and statistical analyses, we characterized the dynamic forestland change in the late 1990＇s. Our data indicate that the net increase of forestland was mainly resulted from the transformation of grassland and other land types ; while most of the net decrease of forestland was attributed to cultivation, construction and residential land-uses. The net reduced forestland that totally amounts to 7972 hectares occurred in the regions with slight soil erosion, higher slope grade and mild environment quality, which were mainly located in the cities of Guangyuan, Mianyang and Dashou, as well as other mountainous regions around the Sichuan basin. In contrast, the net increased forestland was mainly distributed in the regions with considerable to moderate soil erosion and the regions with lower slope grade and better environmental quality. Although partially improved, the general ecological function of the forestland was deleterious since the effect of the project of converting cultivated land into forestland was not functionally obvious until the late 1990＇ s. Based on our result, we suggest that the forest protection should be further reinforced in the northwestern plateau and southwestern mountainous regions of Sichuan province, especially the regions with higher slope and unstable ecological environment, which include Ganzi Tibetan Autonomous prefecture, Leshan city, Yaan city and Abe Jiang ＆Tibetan Autonomous prefecture.
出处
《生态学报》
CAS
CSCD
北大核心
2006年第12期4113-4119,共7页
Acta Ecologica Sinica
基金
四川省青年基金资助项目(03ZQ026-032)
四川省教育厅重点资助项目(2002A081)
中国科学院知识创新资助项目(CX10G-E01-02-03)
四川省软件重点实验室资助项目~~
关键词
地理信息系统
林地
动态变化分析
geographic information system
foresfland
dynamic change analysis
