西藏一江两河地区耕地垦殖强度影响因子及其临界值确定  

Identification and determination of its critical values for influencing factors of cultivated land reclamation strength in region of Brahmaputra River and its two tributaries in Tibet

作　　者：陶娟平 王宇坤[1] 刘峰贵[1,2] 张镱锂[2,3] 陈琼[1] 吴林[1] 

机构地区：[1]青海师范大学生命与地理科学学院,西宁810008 [2]中国科学院地理科学与资源研究所陆地表层格局与模拟院重点实验室,北京100101 [3]中国科学院青藏高原地球科学卓越创新中心,北京100101

出　　处：《农业工程学报》2016年第15期239-246,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(41271123;41261010);中国科学院战略性先导科技专项(XDB03030500)

摘　　要：西藏"一江两河"地区耕地分布的空间面积狭小,限制性因素突出,识别和测度其耕地分布的影响因子,对今后区域农业发展和耕地利用具有现实意义。根据西藏"一江两河"耕地数据,应用GIS对其不同地貌类型、海拔高程的垦殖强度进行分析,在此基础上选择代表地形、气候、土壤、水文、可达性等12个因子作为自变量,1 km×1 km网格内耕地垦殖强度为因变量,运用偏最小二乘回归方法构建回归模型,并用变量投影重要性指标衡量各因子对变量的解释能力。测度结果表明:坡度是最重要的影响因子;太阳辐射、最暖月气温、海拔高度和降水等对耕地分布有重要影响,说明西藏"一江两河"地区耕地分布主要受地形、气候两大因素控制。The region of Brahmaputra River and its two tributaries is one of the important typical agricultural area in Tibet Plateau. The development of agriculture depends on natural environment strongly which makes the cultivated land area is narrow. The arable land is only distributed in valley and its restrictive factors are prominent. To identify and measure the influence factors of cultivated land distribution has a realistic significance for the agricultural development and cultivated land reconstruction. According to this, the paper used the existing data in the region of Brahmaputra River and its two tributaries to analyze the regularity distribution and its reclamation strength in different altitude and geomorphic unit. We found that the proportion of grids whose reclamation ratio was 10%-30% was the biggest and it accounted for 29.39% of total grids with cultivated land. The cultivated land was mainly distributed on the diluvial plain in wide river valley with the altitude of 3700-4100 m. The proportion of its arable land was up to 59.85%. Partial least squares regression （PLS） is a method of multivariate statistical data analysis with the characteristics of multiple linear regression analysis, canonical correlation analysis and principal component analysis method. To explore the relationship between cultivated land and natural, social and economic influencing factors, we took the proportion of cultivated land in each 1 km × 1 km grid as the dependent variable, and 12 impacting factors of cultivated land as the independent variable, which consisted of elevation, slope, aspect, precipitation, accumulated temperature of higher than 0 ℃, average July temperature, average January temperature, solar radiation, soil organic matter content, soil thickness, distance from the nearest town and distance from the nearest river, and established the PLS regression model, using the variable projection importance index to measure the interpretation capacity of various factors on the variable. The results showed that the

关 键 词：土地利用 回归分析 地形 一江两河 耕地 影响因子 偏最小二乘回归 

分 类 号：P966[天文地球—自然地理学] F301.21[经济管理—产业经济]