Assessment of gully erosion in a semi-arid catchment of the Loess Plateau, China using photogrammetric techniques

摘要: The semi-arid catchment of the Loess Plateau China is severely affected by soil erosion as it revealed commonly occurring deep and wide gullies. Recent studies in loess hill-gully terrain area show Gully have a very significant contribution to total loss. Traditionally, gully had been measured using combination field survey techniques analogue, advances computing powering digital photogrammatric solution are now offering an affordable cost effective way estimating erosion. This paper uses elevation models (DEMs), which constructed from multi-date (1959,1981 1999) aerial photographs (1:55000, 1:20000 1:35000) tool sediment yield small 9.06 km 2 located China. High-resolution DEMs (2 m grid) were derived stereo image pairs separately analyzed means geographical information system techniques. breaklines borderlines positioned measure dynamics loss was estimated computed volumes bulk density, DEM-measured degradation rate discussed well. DEM-measurement integrates due overland flow mass movements deepening, put forward improvement locate areas within gullies with higher possibility.