摘要
基于1977、1999、2007年三期生长季的Landsat遥感影像,利用RS、GIS及景观生态学方法,对青海省贵南县1977—2007年的土地利用/覆被进行监测,并计算土地利用转移矩阵和景观格局指数;在此基础上对研究区土地利用与景观格局动态变化进行分析。结果表明:1977-2007年间贵南县的土地利用/覆被状况发生了显著变化,草场面积总体呈现退化趋势,其中东南部芒曲镇和森多乡地区的高覆盖度草场持续退化,而木格滩地区的中覆盖度草场则经历了被开垦为耕地后又退耕还草的过程;耕地先增后减,总体呈减少趋势;另外研究区东部和南部山地地带的疏木灌林有所增加,龙羊峡水库的修建淹没了周围一些裸岩和低覆盖度草场,而2000年后政府实施的退耕还草工程也逐步见效,木格滩沙地面积被控制。30年间贵南县景观总体发生破碎化,前期破碎化程度剧烈,优势斑块呈分散趋势,景观异质性上升;后期因退耕还草等保护措施,破碎化程度有所缓和,优势斑块倾向聚集,景观内部聚合度增加。研究区景观变化是自然因素与人为因素共同作用的结果,但近几十年来人口和牲畜数量急剧增加、人类对草场乱采滥伐、不合理发展畜牧业等人为干扰因素还是占主导。
Based on Landsat satellite remote sensing data in growth season of 1977,1999 and 2007, we had monitored LUCC in Guinan County from 1977 to 2007 by RS, GIS and landscape ecology. Then, we calculated land use transform matrix and a set of landscape indices to analyse changes. The results show that from 1977 to 2007, noticeable changes in land use and land cover change （LUCC） occurred in Guinan County. There was a decreasing tendency in grassland, especially for high coverage grassland near Mangqu and Senduo, the degradation persisted throughout the 30 years; however the middle coverage grassland was reclaimed to farmland in prophase, then some farmland was returned to middle coverage grassland again in anaphase because of implementation of the national project for returning farmland to rangeland. So, the area of farmland was ascended in prophase and was descended in anaphase, but it kept a decreasing tendency in the mass. Meanwhile, woodland on east and south mountain of Guinan was increased, and the construction of the Longyangxia reservoir led to flooding of some low coverage grassland and rocks. After 2000, the area of sandy land was controlled along with the implementation of the national project. Between 1977 and 1999, the landscape fragmentation and landscape heterogeneity of the study area were increased, and the dominant patch was scattered. After 1999, the trend of landscape fragmentation was slow and the dominant patch was gathered again because of implementation of the project. Those changes in Guinan County were caused by nature and human activity. However, the human＇s contributions are great, such as the increase of population for human and livestock, such as the unreasonable exploitation of grassland and the excessive grazing.
出处
《地理科学进展》
CSCD
北大核心
2009年第2期207-215,共9页
Progress in Geography
基金
国家自然科学基金项目(40871057)
关键词
贵南县
遥感
土地利用/覆被
景观格局
斑块
Guinan County
RS
land use and land cover change （LUCC）
landscape pattern
patch
