我国北方山区坡地分布规律研究

坡度和海拔是制约山区土地利用至关重要的影响因子。基于SRTM-DEM数据对北方山区的坡度和海拔信息进行提取和分级,通过叠加分析,研究了山区各级坡地在不同海拔带下的面积分布变化规律。结果表明:北方山区坡度25°的土地面积为3 061 639.8 km2,占北方山区总面积的89.47%;坡度2°—6°的缓坡地和6°—15°的坡地分别占山区总面积的38.23%和28.69%,其中分布在海拔1 500 m以下的土地分别占各自面积的79.80%和73.41%;同坡度级不同海拔带下坡地分布面积的变化表现出分阶梯起伏的规律,其中6°—15°和15°—25°的坡地表现尤为明显。

Distribution Laws of Slope Lands in Northern Mountainous Area in China

Slope and elevation are the most important affecting factors that restrict the land use of mountainous area.The paper extracts and classifies the information of slope and elevation of the northern mountainous area based on SRTM-DEM data and studies the distribution and variation of slope lands at different elevation through overlay analysis.The outcomes show that a) the land area with slope less than 25° is 3 061 639.8 km2,making up 89.47% of the total area of the northern mountainous area;b) the slope land with 2°～6°and the slope land with 6°～15° account for 38.23% and 28.69% respectively of the total area of the northern mountainous area,of which,the land below the elevation of 1 500 m makes up 79.80% and 73.41% respectively of each number;c) the variation of slope land under the conditions of same slope grade and different elevation shows undulating pattern in topographic steps,of which,the slope lands with 6°～15°and 15°～25°are particularly obvious.