摘要
如何在保证基本地貌单元完整性的前提下,实现基于DEM的平原、丘陵、山地、高原等多种地貌类型界线的自动、准确划定,一直是我国数字地貌研究的技术难题。四川省是我国地貌类型相对最全及地势最为复杂的省份之一,具有地形高差巨大、河流侵蚀切割强烈、山原丘陵广布等特点,开展四川地貌分类和分区,对自然资源开发利用和自然灾害防治等具有重要意义。通过构建河流相对侵蚀基准面,计算了四川省地形起伏度,提出了基于DEM的完整地貌实体单元的提取方法,采用起伏度、海拔高度和坡度等指标对四川省地貌形态类型进行自动划分和区划。结果表明:全省地形起伏度地域分布差异巨大,总体由西北向东南递减,纬度向的起伏度变化较经度向更为剧烈;全省平均起伏高度为560 m,最大4615 m,起伏高度200~2500 m的区域面积最大,约占全省面积的65%。地貌形态类型可分为13类,以山地为主,面积达33.02万km^(2),占全省的67.93%;高原次之,占12.21%;丘陵占11.44%;平原占6.09%;台地面积最小,仅占2.33%。本文分类方法和结果更符合传统地貌分类体系和原则,工作效率较人工勾绘有所提升,各级地貌区界线的划定更为精确,结果体现了全省地势和各种地貌类型的空间分布格局。研究成果可为自然资源开发利用和自然灾害防治工作提供基础数据。
Sichuan is one of the provinces with the most comprehensive geomorphological types and complex topography in China.It has the geomorphological characteristics of large topographic relief,strong river erosion,and widespread mountain and hills.The geomorphological classification and regionalization are of significant for natural resources utilization and disaster prevention in Sichuan.Firstly,in this paper it calculated topographic relief amplitude by a reference surface,called regional erosion datum,which interpolated with elevation point of river confluence node.Secondly,the basic landform elements(such as the single mountain and hill)for geomorphological classification were also been extracted by watershed hydrological model in ArcGIS software base on Digital Elevation Model(DEM).Finally,the landform elements were classified into 13 geomorphological types,by the classification indexes of slope,topographic relief and altitude.The results show that the distribution of topographic relief in the province was quite different.The relief generally decreased from northwest to southeast,and the relief amplitude along latitude direction were more severe than those along longitude direction;the average relief altitude of Sichuan province was 560 m,the largest relief altitude was 4615 m,and about 65%of the province’s area relief was 200~2500 m.The geomorphological morphology was divided into 13 types,such as plain,platform,low hill,high hill,low mountain and plateau,etc.The mainly geomorphological type was mountainous area with 330200 km^(2),accounting for 67.93%of the province;The second was plateaus,accounting for 12.21%;Hills and plains accounted for 11.44%and 6.09%,respectively;The terrace area was the smallest,only accounting for 2.33%.A three-order(major-region,sub-region,and small-region)geomorphological regionalization was proposed and divided according to previous research.The classification and regionalization results of this paper are more in line with the traditional geomorphological classification system and principles,and with more accurate boundary,and the geomorphological regionalization also reflect the spatial distribution pattern of different geomorphological types in the province.
作者
曾超
ZENG Chao(Ministry of Natural Resources of the People's Republic of China,Sichuan Geomatics Center,Chengdu 610041,China;Ministry of Natural Resources of the People's Republic of China Emergency Surveying and Mapping Technology Innovation Center,Chengdu 610041,China)
出处
《山地学报》
CSCD
北大核心
2021年第4期587-599,共13页
Mountain Research
基金
国家对地观测科学数据中心开放基金项目(NODAOP2020020)。
关键词
地貌形态分类
地貌区划
地形起伏度
地貌实体单元
四川省
geomorphological types classification
geomorphological regionalization
topographic relief
landform unit
Sichuan province
