摘要
以5m分辨率DEM为信息源，借助样方分析思想，运用数字地形分析方法和克里格插值模型，获得黄土高原全区的沟谷密度分布图。在此基础上，探讨黄土高原沟谷的空间分异特征及影响因素。实验结果表明，黄土高原沟谷密度空间分异明显，沟谷密度在陕北的绥德一米脂一带达到高峰，由北向南递减。以六盘山和吕梁山为界，沟谷密度有三种变化特征，六盘山以西地区，沟谷密度较低且变化平稳，六盘山以东吕梁山以西地区的沟谷密度由北向南呈现梯度显著下降变化，吕梁山以东地区，沟谷密度呈现起伏变化，沟谷密度值分布在1．7~6．4km／km^2范围内。在宏观上，由陇西盆地、鄂尔多斯地台和汾渭裂谷等地质构造控制沟谷空间分布态势；降雨强度因素对沟谷侵蚀作用显著，加剧了沟谷密度空间分异特征；植被条件和地面组成物质呈现由西北向东南变化制约着沟谷发育。土壤侵蚀方面，沟谷密度与输沙模数空间耦合性较强，存在明显的正相关。
Gully density is used to describe the intensity of regional soil erosion and landform development, which is significant to understand the spatial pattern and formation mechanism of loess landforms by analyzing the spatial distribution. According to the principal of quadrat analysis, this article represent a series of maps revealing the spatial distribution of gully density in the Loess Plateau through digital terrain analysis method and Kriging interpolation model, as well as 5 m x 5 m DEM data sets. The spatial variation characteristics of gully in the Loess Plateau were investigated. Moreover, some controlling factors on gully development were explored, and relationship between gully density and soil erosion was revealed. Results showed that the spatial variation feature of gully density was obvious, and gully density reached the peak in region of Suide-Mizhi in northem Shaanxi, then, it decreased from north to south in the Loess Plateau. On the macroscopic, the distribu- tion trend of gully was eontroUed by geological structure so that it was classified into three parts. To the west of the Liupan Mountains as the first part, its value was low with smooth changes. The second part located in the middle and southern parts of the Loess Plateau to the east of the Liupan Mountains, the west of the Luliang Mountains, and its value decreased in gradient from north to south. To the east of the Luliang Mountains as the third part, its value ranged from 1.7 to 6.4 km/km^2 with fluctuant change. Rainfall intensity was rather significant for spatial variability of gully erosion, which was coupled with the diversification of gully density in space. In addition, vegetation condition and composition of ground material in the Loess Plateau varied from northwest to southeast, which influenced gully development. Gully density was positively and strongly correlated with the sediment transport modulus in the soil erosion in spatial, especially for regions of the middle Loess Plateau, indicating it is an important factor reflecting the capacity of gully erosion. In conclusion, gully density was significantly indicative on understanding the spatial pattern of loess landform.
出处
《地理科学》
CSCD
北大核心
2013年第5期622-628,共7页
Scientia Geographica Sinica
基金
国家自然科学基金项目(40930531
41101365
41001294)
"资源与环境信息系统国家重点实验室"开放基金项目(92010KF0002SA)资助
关键词
黄土高原
DEM
沟谷密度
空间分异
the Loess Plateau
DEM
gully density
spatial variation
