基于流域地貌熵的黄土流域地貌侵蚀时空演化特征  

Spatial-temporal evolution characteristics of geomorphic erosion in loess watershed based on watershed geomorphic entropy

作　　者：赵卫东[1] 刘洋[1] 田剑[1] 季斌[1] 马雷[1] Zhao Weidong;Liu Yang;Tian Jian;Ji Bin;Ma Lei(School of Resources&Environmental Engineering,Hefei University of Technology,Hefei 230009,Anhui,China)

机构地区：[1]合肥工业大学资源与环境工程学院,安徽合肥230009

出　　处：《地理科学》2023年第8期1484-1494,共11页Scientia Geographica Sinica

基　　金：国家自然科学基金项目(42271417,42072276)资助。

摘　　要：基于流域地貌熵和室内人工降雨条件下的9期人工模拟黄土小流域地貌演化DEM数据,从小流域、子流域和坡面与沟谷3个尺度开展流域地貌熵熵变量及其空间分异性研究,在一定程度上阐明室内黄土小流域地貌的时空演化特征。结果表明:①在人工降雨条件下的黄土地貌演化过程中,流域地貌熵的局部熵增过程是该区域黄土堆积或以黄土堆积为主的地貌演化过程;②在时间上,该流域幼年期的熵变量变化速率大于壮年期的熵变速率,反映出其幼年期的黄土侵蚀速率快于壮年期的演化特征;③在空间上,坡面侵蚀具有在幼年期逐渐增强而在壮年期逐渐减弱的特点;沟谷侵蚀在黄土侵蚀过程中占主导地位,具有幼年期以沟谷边缘侵蚀为主,壮年期以沟头侵蚀为主的演化特征;④黄土小流域具有位于下游的子流域侵蚀能力更强,位于主沟谷左右两侧相同位置的子流域侵蚀能力相近的演化特征。Due to the influence of rainfall,vegetation,tectonic movement and many other factors,the evolution characteristics of loess small watershed are very complicated and have not been effectively revealed.Although many previous studies have been carried out on the morphological,erosion and development of loess small watershed geomorphology,there are few studies on the spatial-temporal evolution of loess small watershed geomorphology based on watershed geomorphic entropy.Therefore,based on watershed geomorphic entropy and DEM data of geomorphic evolution in a loess small watershed simulated in 9 periods under the condition of indoor artificial rainfall,the basin geomorphic entropy variables and their spatial differentiation were studied at three scales of small watershed,sub-watershed,slope and gully,and to some extent,the spatio-temporal evolution characteristics of geomorphic evolution in a loess small watershed were illustrated.The results show that:1)In the process of loess geomorphic evolution under artificial rainfall,the local entropy increase of watershed geomorphic entropy in the basin is the process of loess accumulation or loess accumulation.2)In terms of time,the change rate of entropy variable in the juvenile period was higher than that in the adult period,indicating that the loess erosion rate in the juvenile period was faster than that in the adult period.3)In terms of space,slope erosion is gradually enhanced in childhood and gradually weakened in adulthood.Gully erosion plays a dominant role in loess erosion process,which is characterized by gully edge erosion in juvenile stage and gully head erosion in adult stage.4)The loess small watershed has the evolution characteristics of stronger erosion capacity of sub-basins located in the lower reaches and similar erosion capacity of sub-basins located in the same position on the left and right sides of the main gully.

关 键 词：数字地形分析 DEM 流域地貌熵 黄土小流域 流域地貌演化 

分 类 号：P931.6[天文地球—自然地理学]