The Settlement Pattern And Its Quality Evaluation Of Desertification Areas

Human settlement, permanent community where people live, consisting of buildings, structures, roads, greenbelts and waterhead areas, is usually the shortened form of rural human settlement. In the world, studies of settlements mainly focus on Historic Geography, the ecological construction and Energy Ecology, while domestic researches usually study on cities with architecture, sociology, ecology and geography. Compared with urban human settlements, rural human settlements are not received much attention. But in China, rural area is the majority. Study on rural human settlements is very important, especially in the sandy area where ecosystem is fragile. This paper analyses the type and pattern of settlements in sandy area, based on evaluation of every type, aimed to choose a suitable land-use pattern of settlement for improving the construction of settlements in sandy area. In this paper, sandy area in the north of Yanchi county in Ningxia province is selected as a case. Based on TM images (in 1989,1995,2000,2007) and SPOT5 image in the year of 2005, land use maps are obtained by interpretation. The results are as follows:(1) Settlements'area doesn't change greatly during the year of 1989 to 1995. It begins to descend since the year of 1995, exchanging with areas of farmland, grassland and woodland.(2) According to land use map, spatial and temporal variation characteristics are summed up, and settlements'type is divided into eleven types considering its spatial relationship with neighboring land and land use pattern. Then settlements'pattern is concluded into three kinds (radial, annular, radial-annular).(3) The typical settlements of each type were surveyed with thirty indicators attached to three systems about the quality of human settlements environment in April of 2009, and then data was made an evaluation with the method of mean square error. The result shows that the quality of pattern B (annular) is the best, which has a isolation belt with sandy area (the ring-shaped area); pattern A (radial) is the worst, which mostly exposed to sandy area directly; type B2 is the finest type with a ring-shaped area, belonging to pattern two; the second is type C3, complex radial-annular type belonging to pattern three; worst type is type A2, radial shape with arable land.In the evaluation, type B2 is the highest one, but it cannot be the most recommended type. Due to the local rainfall is rare in recent years, water for life mainly rely on water from underground, which is not enough for irrigating all around area. Type B2 is a new socialist countryside which has many preferential policies, so it has enough water to make around area to be irrigable land with the project YangHuang. After analyzing the procedure of the construction of each settlement pattern, type C3 is chosen to be the most suitable type in this paper. In its isolation belt, hedgerows are planted in the upwind direction of the farmland and settlement, which is relatively easy to realize in sandy area.