Considering ability of Cs-137 method application to calculate soil sediment and deposition in Taseran watershed (Kabodar Ahang)
2006
Asadi, Turaj | Shahoei, Saber | Asadi, Mohammad | Shahsavar, Amir Mansur
Due to importance of water erosion in reducing the soil fertility, many studies have been done on the quantity and of this destructive phenomenon. Due to difficulties in estimating the erosion with previous methods, other easier but more precise methods which require less enviromental data have also been experienced, first . Tamura & Rogowosky (1970)found a meaningful relation between water erosion and cs-137 loss in soil . This report was the beginning of cs-137 method to estimate soil erosion since 1974. From 1974 , the method has changed gradually and now in used is many studies . In this study air photographs scale 1:20000 and topographic maps scale 1:50000 were used. 12 transects on the hilly lands (compound and uniform slopes) and 3 transects on the piedmont plain were studied. Surface samples were collected from different slop situations. The situations were collected from different slop situations. The situations were summits, shoulders, back slopes, foot slopes and toeslopes, gama spectrometer was used to determin the cs-137 of samples . Soil erosion and sediment were calculeted by cochanouski (1993) Equation. Results show that in summit , shoulder and back slope of the compound slopes , erosion is respectively 68.42 ,45.46And 51.16 Ton/ha/yr . On the same situations of uniform slopes 79.6 , 65.3 and 84.23 Ton /ha/yr of soil losses have been expected . In nonerosional situations (toe slopes), soil losses has been deposited. In foot slopes,i.e. dynamic site, sedimentation process is more dominant than destructive ones. The correlation between USLE and SC-137 models were statistically signification (% 95 probablity).
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