The Study Of Land-use Pattern On Guan Zuo-ling Small Watershed

Land is the most important physical basis of existence and development of human being. At present, under the theme of global sustainable development, the study on land use has become a significant study task with epoch-making significance. Unreasonable land use is the main cause of soil and water loss and slow economic development. Small watershed is the fundamental landform unit in mountain areas, It is an efficient route to improve land quality and promote economy development and strengthen entironment contruct in mountain areas taking a small watershed as a fundamental unit.This study selects Guan Zuo-ling small watershed in Liang Ge-zhuang town in Yi country of He Bei province as research object. By the field investigation, experimental measurement and image processing, with the support of ArcView, GIS mapping software and SPSS statistical software, this study analysed land use spatial distribution of small Watershed and land use influences on soil nutrients, provided the problems in land use, described the influences factors of land use and soil nutrient distribution. Finally, terrain, lithology and water supply situation were used to making small watershed land-use division, according to the principles of land-use pattern design, this study adopts reasonable biological measures, engineering measures, agricultural measures and comprehensive measures, designs the land-use pattern of small watershed. The main conclusions as the following:(1)Through the spatial distribution analysis of small watershed land, put forward the problem of small watershed in the land-use issues. From the land-use analysis of the structure, unused land area is the largest in whole watershed, it accounts for the total land area of 65.1%, followed by woodland and farmland, with respective shares of the total land area of 15.9 % and 13.8 %, garden area is a smaller size and no pasture exist. From the distribution of land space, with the increase of the slope, small watershed land area increased, <15°,15-25°,>25°and their proportion occupyed the total land area was 19.65%, 30.34% and 50.01% respectively; elevation grades were:<150m,150-400m,>400m and their proportion occupyed the total land area was 24.25%, 46% and 29.75% respectively. From the spatial distribution analyse of land-use types, the farmland mainly in the low altitude on the gentle slope, the forests are mainly distributed on the >15°slope land, grassland are distributed in various altitudes and slopes.(2) This study analysed the influence of land use fashion, land-use combination and after natural soil reclamation for agriculture soil to soil nutrients. It evaluated the land degradation in different land-use fashion and analysed the influence factors on the land-use and soil nutrients. The result of land use fashion influence soil nutrients: soil organic matter content is shrub grass land>shaw forest>sparse forest>sloping land>orchard, soil available nitrogen content is shaw forest>shrub grass land>sloping land>orchard>sparse forest, there were significant differences between the both land use patterns, orchards and sloping land as fertilizer reasons, soil available phosphorus is significantly higher, soil available potassium does not change significantly; From the analysis of different land-use combination, shrub grass land-shaw forest-sloping land and orchard-shaw forest-sparse forest were the more reasonable land-use combination; From the compare between natural soil and agriculture soil, the results show that the natural soil organic matter, available nitrogen content were higher than that of agriculture soil, agriculture soil available phosphorus content was significantly higher than that of natural soil, soil available potassium greater impact on the parent material, its content is changed by the difference of the parent material. In different locations on the slope, in the influence of rainfall and terrain, soil nutrients had a downward collection trend. Soil degradation evaluation results show that shrub grass land had no degradation, shaw forest had the degradation trend, the degradation of sloping land and orchards were more serious.(3) According to land use spatial distribution and the field survey results, this study pointed out that land-use problem such as the structure is irrational, the system of planting is unreasonable, cultivation had no large-scale, land-use efficiency is low, taking into account the terrain, lithology, water supply etc are the restricting factor in small watershed land-use, with the result of land-use impact on soil nutrient analysis, the study area is divided into four areas: deep limestone mountain area—solid plantting pattern with arbor-shurb-grass and mainly using biological measures; low limestone mountain area—coordination land-use pattern with forest-fruit-pasture for the purpose of water-storage; low- granite gneiss mountain area—complex land-use pattern with economy fotest- pasture for the purpose of soil and water conservation; gentle hilly area—comprehensive development of agricultural industrialization pattern.