The Ephemeral Gully Geomorphic Features In Loess Plateau Of Northern Shaanxi Province And The Study Of Its Affection To Vegetation

Based on high resolution Quickbird remote sensing image, DEM and supported by GIS, this paper extracted characteristic information of ephemeral gully.and established the critical relational expression of ephemeral gully occurrence, analyzed the influence of site type to the distribution density of ephemeral gully and spaces between ephemeral gully heads, and compared the distribution features of vegetations in and out of the ephemeral gully under different site tyes. Then, analyze the vegetation differences between ephemeral gully plots and usual plots under different slope position, slope direction and slope gradient. The results can be the basis of the further research of ephemeral gully soil erosion in China, and provide a reasonable scientific basis for restoration of vegetation on soil erosion of the ephemeral gully area. The main conclusions of this study are as follows:(1) The distribution rules of ephemeral gully geomorphic features.The average length of ephemeral gullys in Hejiagou basin between 10-90m; the average spacing of ephemeral gullys center between 6-15m and the average gradient of ephemeral gullys between 26～38°. The S-A critical relation of the area is: S=0.74A-0.16, the index of catchment area a=0.61, Critical Value of ephemeral gully occurrence t=0.74. Under the conditions of the same slope gradient, the variation of the average ephemeral density is:sunlit slope