陆表切割密度(Land Dissection Density,LDD)的空间格局与陆地表面土壤侵蚀息息相关,国内相关研究主要基于流域或局地尺度分析黄土高原和东北地区的陆表切割情况,全国尺度上陆表切割情况仍未知。该文基于ALOS World 3D-30 m DEM数据和...陆表切割密度(Land Dissection Density,LDD)的空间格局与陆地表面土壤侵蚀息息相关,国内相关研究主要基于流域或局地尺度分析黄土高原和东北地区的陆表切割情况,全国尺度上陆表切割情况仍未知。该文基于ALOS World 3D-30 m DEM数据和全国二级流域数据,利用Geomorphons地形元素分类方法制成全国陆表切割密度分布图,并结合地貌区划分析各地貌区内不同等级切割密度的分布情况。结果显示:全国二级流域的陆表切割密度介于0~7 km/km^(2)之间,强烈切割(3~<5 km/km^(2))流域面积约占国土面积的0.54%;切割密度与流域地形因素密切相关,缓斜坡(2°<~5°)、高丘陵和小起伏山地(100~400 m)以及低海拔(<1000 m)地区是切割易发区;一级地貌大区间的切割密度空间格局差异显著,中度及以上切割(LDD≥2 km/km^(2))流域空间分布呈现出不同模式,体现了地貌区内外营力的共同作用;陆表切割易发生在受剥蚀外营力作用影响的二级地貌区,且不同等级切割密度在不同地貌类型上具有一定聚集性。研究结果可拓展现有陆表切割研究的空间尺度,为宏观层面的陆表切割现状和全国各地土壤侵蚀评估提供科学依据。展开更多
Land dissection density(LDD)provides morphological evidence regarding prior intense soil erosion and quantifies the distribution of land dissections.A comprehensive understanding of the potential factors influencing t...Land dissection density(LDD)provides morphological evidence regarding prior intense soil erosion and quantifies the distribution of land dissections.A comprehensive understanding of the potential factors influencing the spatial pattern and value of the LDD is vital in geological disasters,soil erosion,and other related domains.Land dissection phenomena in China affects large areas with different morphological,pedological,and climatic characteristics.Prior studies have focused on the potential factors influencing the LDD at a watershed scale.However,these results are insufficient to reflect the status quo of dissection development and its primary influencing factors on a national scale.LDD’s spatial patterns and the dominant factors at a regional scale in millions of square kilometers remain to be ascertained.This study used the geomorphon-based method and the geographical detector model to quantify the spatial pattern of LDD over China and identify the dominant factors affecting this pattern in China’s six first-order geomorphological regions(GR1~GR6).The results yield the following findings:(1)LDD in China ranges from 0~4.55 km/km^(2),which is larger in central and eastern regions than in other regions of China;(2)dominant factors and their dominant risk subcategories vary with each geomorphological region’s primary internal and external forces;(3)the influence of natural factors is more significant on the large regional scale in millions of square kilometers compared to anthropogenic factors;relief degree of land surface(RDLS)is dominant in GR1,GR2,and GR5;the slope is dominant in GR6,soil type is dominant in GR3 and GR4,and lithology plays a critical role in the dominant interactions of GR3,GR4,and GR6;(4)the interactions between factors on LDD’s spatial pattern have a more significant effect than individual factors.展开更多
基金supported by the Natural Science Foundation of China(Grants No.42167038,42161005)the Guangxi Scientific Project(Grants No.AD19110140)the Guangxi Scholarship Fund of the Guangxi Education Department and Guangxi Education Department project(Grants No.2022KY1168).
文摘Land dissection density(LDD)provides morphological evidence regarding prior intense soil erosion and quantifies the distribution of land dissections.A comprehensive understanding of the potential factors influencing the spatial pattern and value of the LDD is vital in geological disasters,soil erosion,and other related domains.Land dissection phenomena in China affects large areas with different morphological,pedological,and climatic characteristics.Prior studies have focused on the potential factors influencing the LDD at a watershed scale.However,these results are insufficient to reflect the status quo of dissection development and its primary influencing factors on a national scale.LDD’s spatial patterns and the dominant factors at a regional scale in millions of square kilometers remain to be ascertained.This study used the geomorphon-based method and the geographical detector model to quantify the spatial pattern of LDD over China and identify the dominant factors affecting this pattern in China’s six first-order geomorphological regions(GR1~GR6).The results yield the following findings:(1)LDD in China ranges from 0~4.55 km/km^(2),which is larger in central and eastern regions than in other regions of China;(2)dominant factors and their dominant risk subcategories vary with each geomorphological region’s primary internal and external forces;(3)the influence of natural factors is more significant on the large regional scale in millions of square kilometers compared to anthropogenic factors;relief degree of land surface(RDLS)is dominant in GR1,GR2,and GR5;the slope is dominant in GR6,soil type is dominant in GR3 and GR4,and lithology plays a critical role in the dominant interactions of GR3,GR4,and GR6;(4)the interactions between factors on LDD’s spatial pattern have a more significant effect than individual factors.
