Masoud Eshghizadeh; Mohammad-Taghi Dastorani; Ali Talebi
Abstract
The management of sedimentation problems in rivers and reservoirs depend greatly on the sediment yield from the catchment land surface. In this research the effects of biological measures and ranges enclose on suspended load in two sub-catchments of Kakhk experimentalWatershed in Gonabad has been studied. ...
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The management of sedimentation problems in rivers and reservoirs depend greatly on the sediment yield from the catchment land surface. In this research the effects of biological measures and ranges enclose on suspended load in two sub-catchments of Kakhk experimentalWatershed in Gonabad has been studied. This catchment contains both control and experimental sub-catchments. These sub-catchments are similar in all aspects and differ only based on watershed management operations. Experimental sub-catchment has been under rangeland enclosures and operation of biological, biomechanical and mechanical measurements since 1998 whereas control sub-catchment is under normal operation. To determine the biological impact of management and biological measurements on sediment production, the yield suspended load on hillslopes in 18 experimental erosion plots during 4 rainfall events occurred in 2011-2012 has been analyzed in both control and experimental sub-catchments. Analysis was performed in SPSS software using independent-sample T test and ANOVAwith repeated measure test. Based on these comparisons, difference between the amount of suspended load in two sub-catchments was significant at 1 percent level, while runoff depth was significant at 5 percent level. Also results showed that correlation between the runoff depth and suspended load has been 94 percent in Control sub-catchment and 62 percent in Sample sub-catchment. Slope of the line changes between the runoff depth and suspended load in Control sub-catchment has been 5.3 times of the Sample sub-catchment. The research clearly showed the effect of the biological measures and ranges enclose on reduction of suspended load and runoff depth in experimental sub-catchment.
Ali Golkarian; Davoud Davoudi Moghaddam; Seyed Amir Naghibi; Masoud Eshghizadeh
Abstract
Soil erosion is undoubtedly one of the most important problems in natural areas and has a devastating impact on grassland ecosystems. The present study was conducted to assess the ability of Rangeland Hydrology and Erosion Model for estimating sediment yield on rangeland’s hill slopes in dry regions ...
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Soil erosion is undoubtedly one of the most important problems in natural areas and has a devastating impact on grassland ecosystems. The present study was conducted to assess the ability of Rangeland Hydrology and Erosion Model for estimating sediment yield on rangeland’s hill slopes in dry regions at Shahid Noori paired watershed of Kakhk. RHEM is a mathematical, distribution and physical model that is capable to simulate hydrological and erosional processes with climatic data and hill slope’s characteristics. Measuring of sediment yield performed on 18 erosion plots in both disturbed and undisturbed rangeland conditions. In order to implement the model, the parameters of climate, soil texture, slope length, slope steepness, canopy cover and ground cover were measured and entered into the model to estimate amount of runoff and sediment yield in each year. The analysis showed no significant difference between observed and estimated values at 5% level in both all erosion plots and the average of measured values of all three different aspects. The results indicate that the model is capable to determine the quantity effects of rangeland conservation practices in hydrological and soil erosion processes. Overall, the present study suggested good potential for application of the model in the same rangelands of dry regions.
