不同地貌类型水土流失区的地面坡谱分析

Cartorgraphic Analysis on Slope-spectrum for Regional Soil and Water Loss

坡度是影响水土流失的重要因素之一,然而坡度作为一种微观定量因子,并不能有效表达区域地形的总体特征。本研究采用地面坡谱统计分析方法,研究地形对水土流失的影响,并以福建省宁化县为例,选取5个不同地貌类型的典型水土流失区,通过均值、中位数等7个统计值对坡谱特征进行刻画,并与研究区的水土流失程度进行拟合分析。研究结果表明:1)丘陵和山地地貌类型分别具有特定形态的坡谱,反映了不同地貌类型的地形起伏差异,以及地表的破碎程度;2)从坡谱统计值与其水土流失程度商值的拟合曲线上,可以看出宁化县水土流失程度除与坡谱锋态不相关外,与其他统计值均相关,并且在水土流失越轻区域,水土流失程度对坡谱统计值的微小变化越敏感;3)坡谱蕴含丰富的地貌信息,有望较准确地量化地形对水土流失影响的程度。

Slope is one of the important factor for soil and water loss. Slope is always regarded as a kind of micro quantitative criteria,but it is unable to describe the general characteristics of regional topography. Using the statistical analysis method of slope-spectrum to study the influence of topography on soil and water loss in Ninghua County,choosing five samples on different physiognomy with different levels of soil and water loss,using Mean,Median,etc to describe the slope-spectrum,fitting analysis with soil and water loss. It is implied from the analysis result that： 1） Hills and mountain landform types have different specific morphological slope-spectrum and show differences in terrain and fractured surface; 2） Soil and water loss correlation with statistic unless kurtosis from curve of statistical value and the level of soil and water loss. The less soil and water loss the less sensitive on slope-spectrum statistic value; 3） The slope-spectrum contains plenty of geographic information,it hopes to quantify the terrain on the impact of soil and water loss accurately.