新开河流域土地利用格局变化图谱分析

The TUPU Analysis of Land Use Pattern in Xinkai River Basin

基于地学信息图谱分析方法,运用ARC/INFO软件,以马尔柯夫空间概率模型为基础,利用新开河流域33年(1969-2001年)土地利用格局4期的空间数据(1969年、1979年、1992年、2001年),合成了一系列土地利用格局变化图谱,通过图谱分析来了解新开河流域的土地利用格局变化规律。结果表明:在过去33年期间该流域土地利用格局发生了显著变化。耕地大幅度增加,其净增面积1357.2km2,占流域总面积超过32%,其主要来源于草地、沙地、沼泽地、林地;沙地变化有所起伏,占流域总面积不低于23%,虽然总体呈减少趋势,但流域的草地沙化、耕地沙化还比较严重;草地大幅度减少,其净减面积1582.6km2,占流域总面积由36.2%缩减为18.5%,其主要来源于开垦草地为耕地、草地退化成沙地、沼泽地、盐碱地以及草地改造种植林地;居民地、盐碱地呈增加趋势,湿地、林地呈减少趋势。

In this paper,the research is conducted based on the geographic information TUPU analytic methods and Markov model of space probability.With the support of ARC/INFO software,this paper has compounded a series of varying TUPU of the land-use pattern by using spatial data covering four periods（1969,1979,1992 and 2001） in the Xinkai River basin.We can comprehend the changes of land-use pattern in the Xinkai River basin through the TUPU.The result shows that great changes have taken place on the land-use pattern in this basin during the past 33 years.The farmland has a net increase of 1357.2 km2（exceeding 32% of the total basin）,and most ofit was converted from grassland,sandy soil,marsh and woodland.The changes of sandy soil somewhat oscillated.The area of sandy soil accounted for less than 23% of the total basin area.Although the sandy soil tended to decrease on the whole,the desertification of grassland and farmland is still serious in this basin.The grassland has decreased greatly.It has a net reduction of 1582.6 km2 from 36.2% to 18.5% of the total basin area.The main reasons are summarized in three respects：first,grassland has been cultivated into farmland;second,grassland has degenerated into sandy soil,marsh and saline land;third,grassland has been transformed into plantable woodland.The residential land and saline land show a decreasing trend while the wetland and woodland present an increasing trend.