福建土地利用/覆被人为影响指数及其变化的地统计学分析

Geostatistical Analysis of Human Impact Indexes for Land Use/Cover Change in Fujian

土地利用/覆盖变化（LUCC）是全球变化研究的重要内容,LUCC驱动力的研究是探索LUCC驱动机制的核心问题。本研究以地统计为研究方法,构建土地利用/覆被人为影响指数,以福建省1985年TM和2002年ASTER遥感影像解译结果为数据源,编制土地利用/覆被人为影响指数图层和土地利用/覆被人为影响指数变化图层,分别计算其时空变异特征。结果表明：2002年福建土地利用/覆被人为影响指数具有方向性,5个一级地类和整个区域所有地类的椭圆长轴都大致呈北北东-南南西走向,分布方向与地形和海岸线较为一致。结构方差所占比例为88.92%,空间相关性较强,结构性因子以地形等自然要素为主,在土地利用/覆被空间分布格局中起主导作用;1985年-2002年土地利用/覆被人为影响指数变化的分布趋势与地形和海岸线有偏差,结构方差所占比例为18.07%,空间相关性较弱,随机性因子占主导地位,表明地形等自然要素对人为影响指数变化不起决定性作用,人为活动成为主导因素。

Land use/cover change （LUCC） is an important component of global change research, and the driving forces of LUCC are one of the main topics of research, including both biophysical and socioeconomic factors. Because of the widespread occurrence of spatial autocorrelation, applying linear spatial information statistics to analysis of settings with randomness and unknown structures will lead to significant errors. Geostatistics are an important tool for spatial analysis, and have been applied to many fields of natural science such as geography, ecology, and soil science. This study uses data from TM images from 1985 and ASTER images from 2002 of Fujian. We then constructed human impact indexes, compiled the land use/cover human impact index maps for 1985 and 2002 and the land use/cover human impact index change map from 1985 to 2002, and calculated the temporal and spatial variability. The results show that the human impact indexes for 2002 have directionality which is consistent with the topography and the coastline, and trends of the five general land use/cover types and all of the regional land use types are approximately NNW-SSW using Standard Deviational Ellipse. The structural factors are mainly natural ones, with terrain roughly in the shape of a staircase, declining from the northwest to the southeast in strips of mountains, hilly lands, terraces and plains. In total, 87.5 % of the province is covered with mountains and hilly land. The mountain areas are mainly in the Daiyunshan mountain range and Wuyishang mountain range, which are more or less parallel to the coastline. The terrain affects the properties and development of soil and vegetation. The proportion of structural variance is 88.92 % and the proportion of nugget variance is 11.08 % with strong spatial correlation, and the structural factors are the dominant component of the LUCC spatial distribution pattern. The change in human impact index from 1985 to 2002 deviates with the topography and the coastline, which means there are other relevant factors besides terrain. The proportion of structural variance is 18.07% and the proportion of nugget variance is 81.93 % with weak spatial correlation, which means the natural factors don＇t play a decisive role in the human impact index change the way that human factors do. Commonly, the structural factors are the dominant cause of spatial variability while the human factors are the dominant influence on temporal variability.