Mohsen Armin; Sayed Alisaleh Velayatinejad; Vajihe Ghorbannia Kheybari; Fateme Taatpour; Morteza Behzadfar
Abstract
This research was conducted in two watersheds Dasht-e-Room in Boyerahmad county and Kareh in Dena county using IntErO model. After collecting basic information; the 26 input variables were extracted and calculated using topographic, pedologic, and geologic and land use maps and climatic data i. The results ...
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This research was conducted in two watersheds Dasht-e-Room in Boyerahmad county and Kareh in Dena county using IntErO model. After collecting basic information; the 26 input variables were extracted and calculated using topographic, pedologic, and geologic and land use maps and climatic data i. The results showed that the maximum outflow from the watersheds of Kareh and Dashtrom in 100 year return period are 235 and 179 cubic meters per second, respectively, In other words, the amount of runoff produced in the Kareh watershed is approximately 1.3 times the oufflow from the Dasht-e- room basin and the amount of soil erosion in Dasht-e-Room and Kare watersheds, 105162.22 and 71402.58 cubic meters per year, respectively. Considering sediment delivery ratio of 0.195 in Dasht-e-Room watershed and 0.487 in the Kareh watershed, the amount of soil eroded transferred to the outlet of the watersheds (sediment yield) is 20521.32 and 34800.46 cubic meters per year respectively. The erosion intensity coefficient in Dasht-e-Room watershed is 0.338 and as a result, based on the degree of erosion intensity of IntErO model, the erosion process intensity in this watershed is low and the dominant erosion of the region is deep. The erosion intensity coefficient in Kareh watershed is 0.403 and as a result, the erosion process intensity in this watershed is moderate and the dominant erosion of the region is superficial. The amount of sediment yield per unit area in Dasht-e-Room watershed is 133.53 and in the Kareh watershed it is 347 cubic meters per year.
Mohsen Armin; mohammadrasul Rajabi; Fatemeh Barzegari Banadkooki
Abstract
we study the loss of fertility by analyzing the sediments retained behind check dams which was designed to control erosion and fixation of longitudinal profiles in the Safarood watershed of Ramsar during the years 1373 to 1388. For this purpose, soil losses were determined by determining the physicochemical ...
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we study the loss of fertility by analyzing the sediments retained behind check dams which was designed to control erosion and fixation of longitudinal profiles in the Safarood watershed of Ramsar during the years 1373 to 1388. For this purpose, soil losses were determined by determining the physicochemical properties of sediments deposited behind the selected check dams and comparing them with the same soil characteristics. In the analysis of physicochemical properties of soil, the results showed that most of the studied soils are of sandy, non-saline, neutral, calcareous and non-sodium. Based on the classification of organic matter, approximately 60% of the studied soils have poor structure and little structural stability and are often in the moderate class of erodibility. In the soil fertility loss section, the results showed that erosion leads not only to the loss of solid mineral components from the soil but also to the loss of organic matter and chemical nutrients. Changes in the properties of a soil due to erosion affect the level of fertility, basically as a result of a reduction of the effective depth. There is a significant reduction in the carbon and nitrogen contents and all macro and micronutrients. The losses of carbon, nitrogen, phosphorus, potassium, sodium, and total calcium and magnesium content in the study area were 6588.26, 1921.78, 19.71, 53.6, 19.89 and 503.13 g/ha/year respectively, which this level of loss is a serious threat to processes and activities related to soil fertility, including vegetation development in the region.
Mohsen Armin; hasan rouhipour; Hassan Ahmadi; Ali Salajegheh; mohammad Hossein Mahdian; vajihe ghorban nia kheybari
Abstract
Knowledge of soil components controlling aggregate stability is very important to soil structure conservation. Also, identification of the critical soil properties affecting aggregate stability is central to understanding where erosion might be located within a catchment as a result of natural patterns ...
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Knowledge of soil components controlling aggregate stability is very important to soil structure conservation. Also, identification of the critical soil properties affecting aggregate stability is central to understanding where erosion might be located within a catchment as a result of natural patterns in aggregate stability. The objective of this study, which was carried out in surface soils from Taleghan, was to relate aggregate stability to selected soil properties. In this study, based on homogeneity in slope, aspect and lithology work units were prepared, and then by relying on results of geostatistical studies in homogeneous work units in soils of Taleghan watershed, with 3260 hectares in area, 84 points as the soil sampling points were selected. The indices of stability used are the mean weight diameter (MWD) and wet aggregate stability (WAS). Correlation between mean weight diameter and measured properties were extracted using Pearson correlation coefficient and evaluated in terms of their statistical significance. Then based on the results of correlation and using stepwise regression, models of aggregate stability prediction were developed. The unexpected results have been obtained from correlation between soil properties and aggregate stability so that the correlation between aggregate stability and the percentage of Caco3, clay and saturation are negative while that with fine sand and very fine sand are positive. Thus the improvement of aggregate stability and soil erosion control in Taleghan watershed depends on management of these soil properties and soil conservation projects in order to adjust and optimize them
Mohsen Armin; Hassan Ahmadi; hasan Rouhipour; Ali Salajegheh; mohammad Hossein Mahdian; Vajihe Ghorban nia kheybari
Abstract
Due to the constraints in determining of soil susceptibility to water erosion or soil erodibility through field tests, use of laboratory methods on small soil samples, are easy to implement and far less expensive and time-consuming. among different laboratory methods based on the soil properties, those ...
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Due to the constraints in determining of soil susceptibility to water erosion or soil erodibility through field tests, use of laboratory methods on small soil samples, are easy to implement and far less expensive and time-consuming. among different laboratory methods based on the soil properties, those relating to aggregate stability have received much attention. In this study, by relying on observations and changes in the macroscopic scale of homogeneous work units in marly soils of taleghan watershed, with 3260 hectares in area, 84 points as the soil sampling points were selected.In order to distinction between aggregate breakdown mechanisms and assessing of soil structural behavior in different environmental conditions, aggregate stability is measured with respect to three treatments fast wetting, slow wetting and stirring after pre-wetting using Le Bissonnais method. Results showed that aggregate breakdown mechanisms have a significant influence on aggregate stability. The instability main mechanism of marly soils in Taleghan watershed is slaking that caused by the compression of entrapped air during fast wetting and this situation can occur during rain storms on dry soils and irrigation flooding. So it seems that the method of agricultural land irrigation can be one of the most important soil erosion factors in the study area.
