基于GIS的关中-天水经济区地形起伏度与人口分布研究

The Relief Degree of Land Surface and Population Distribution in Guanzhong-Tianshui Economic Region Using GIS

地形起伏度作为影响人口分布的重要因素之一,是人居环境自然评价的一个重要指标,在小尺度人居环境自然评价方面也具有较高的准确性和实际应用价值。基于关中-天水经济区栅格数字高程模型,采用窗口分析等方法,利用ArcGIS软件空间分析模块中的邻域分析,提取了基于栅格尺度的关中-天水经济区地形起伏度,并从比例结构、空间分布和高度特征3个方面系统分析了关中-天水经济区地形起伏度的分布规律及其与人口分布的相关性。研究结果为:①关中-天水经济区的地形起伏度以中低值为主,地形起伏度小于2.4的区域占总面积的96.66%,其中平地比例占总体的32.4%;地形起伏度越高的地区,平地比例越低,反之亦然。②关中-天水经济区的地形起伏度呈现南北高中间低的空间格局,最高值为宝鸡市太白县,最低值为关中平原;经度上的变化规律不是很明显,纬度上的地形起伏度无论从南到北还是从北到南都是先下降后增高的。③随着海拔高度的增加,地形起伏度呈现逐渐升高趋势,但变化幅度不大。④地形起伏度对区域人口分布有较强的影响,关中-天水经济区近90%的人口居住在地形起伏度小于1.5的地区,人口密度与地形起伏度的曲线拟合度非常高。

With the degeneration of environment and acceleration of urbanization, human environment has attracted great attention worldwide. As one of the key factors, the relief degree of land surface is an important in- dicator for natural evaluation, and it also has high accuracy and practical application in small scale residential environmental evaluation. Based on lattice digital elevation model of scale 1 ; 25 0000 in Guangzhong-Tianshui economic region, using the window analysis and spatial analysis model of ARCGIS software, this article ex- tracts the relief degree of land surface and population distribution in Guanzhong-Tianshui economic region.From the characteristics of proportion, spatial distribution and height, it also systematically analyzes the disci- pline of the relief degree of land surface .and its relationship with the distribution of population in Guan- zhong-Tianshui economic region. The study has shown that： 1） The relief degree of land surface in Guan- zhong-Tianshui economic region is dominated by middle and low value, and its topographic area is less than 2.4 occupying 96.66% of the total area, and the average proportion occupying 32.4% of the whole area. The higher is the relief degree of land surface, the lower is the proportion of plains, and vice versa; 2） The relief de- gree of land surface in Guanzhong-Tianshui economic region presents such spatial patterns that the south and north are higher and the middle is lower, and there is the maximum value in Taibai Country in Baoji City and the minimum value in Guanzhong plains. The variation is not apparent on the longitude, and the degree of lati- tude increases after the first drop no matter from South to North or from North to South;3）As the altitude in- creased, the degree presents a rising trend but has not much change; 4） The relief degree of land surface has a strong impact on the regional distribution, nearly 90% residents in Guanzhong-Tianshui economic region lived in the area where less than 1.5 degree, the curved fitting of population density and topographic is very high; 5） The relational area of topographic and population distribution have significant difference, the topographic has obvious relation with population distribution, but the relationship of the topographic is smaller in four coun- tries in Shangluo and Tianshui cities. To sum up, the relief degree of land surface can better reflect the topo- graphic feature and reveal its regularities of space in Guanzhong-Tianshui economic region. Empirical research shows that, as one of the key factors, the relief degree of land surface is an important indicator for natural eval- uation; it also has high accuracy and practical application in small scale residential environmental evaluation. In summary, the RDLS model established in this paper can not only reflect the natural environment suitability for human settlements in Guanzhong-Tianshui economic region, but also can illustrate the spatial distribution rules of it very well.