Landform morphologic relations between inter-gullied and gullied land areas: a case study of the Wangjiagou watershed in the west of Shanxi Province

Abstract

Previous studies on erosion relations between inter-gullied and gullied lands have mainly concentrated on exploration of water and sediment relations, with few quantitative studies of evolution relations between inter-gullied land and gullied land form erosion in small catchments. This paper, using information from a 1:5000 digital orthophoto map (DOM), digital elevation model (DEM), and topographic map of the same period and of the same scale, quantitatively analyzes the impact and interactions of inter-gullied and gullied land geomorphologic characteristics on the dissected extent of a catchment using orthogonal polynomial regression analysis. Results indicate that gullies play a leading role in the catchment morphologic evolution and extent of cracked ground surface. When inter-gullied land areas are the same, a 0.1 km2 gullied land area has the maximum effect on the erosive evolution intensity of the catchment cracked degree. The smaller the catchment area is, the greater the extent of cracked ground surface and gully intensity would be. The geomorphologic evolution mechanism of gullied catchments can be explained as a function of geomorphologic indicators of inter-gullied and gullied land characteristics.