sajad neisi; bizhan khalili moghadam; amin zorati pour
Abstract
Gully erosion is one of the aprogressive forms of soil degradation in ranges and agricultural lands which is a warning sign of land degradation and progressive erosion. Monitoring effective factors of gully length development over time is a necessity for sustainable development in watersheds. In this ...
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Gully erosion is one of the aprogressive forms of soil degradation in ranges and agricultural lands which is a warning sign of land degradation and progressive erosion. Monitoring effective factors of gully length development over time is a necessity for sustainable development in watersheds. In this research, the advancement of 30 headcuts were assessed through digital interpretation of multi-temporal aerial photos, photometric methods, field observations and GIS data analysis over two periods of 1964-1993 and 1993-2013, and its contribution to sediment suspended and bed load, using sediment balance model which was carried out on DarbKhazine basin. Moreover, the stepwise regression analysis procedure was applied to extract the effective factors on gully head advancement (such as topography, physio-chemical soil attributes and morphology of gully). The results indicated that the mean of gully head advancement over the periods of 1964-1993, 1993-2013 were measured 0.37, 0.65, respectively which implies on average, 77percent have increased. Further, regression analysis revealed by 9 main factors and R 95%, as themodel indicated among main factors, the Na, EC and organic matter factors with R2 , 0.83 and R , 0.91 leave the most effect on gully head advancement. The gully sediment balance showed that two-thirds and one-third of sediment discharge are formally suspended load and bed load, respectively. This topic is useful as a suitable criterion to distinguish active gullies in order to prioritize conservation activities.
