Heshmatolah Agharazi; Aliakbar Davudirad; Mahdi Mardian; Majid Soufi
Abstract
Recognition of effective processes of erosion, especially, threshold is one of the most important strategies in water and soil resources management. Gully erosion is one of the most important sources of sediment yield in watersheds that is defined as different thresholds like area-slope or topography. ...
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Recognition of effective processes of erosion, especially, threshold is one of the most important strategies in water and soil resources management. Gully erosion is one of the most important sources of sediment yield in watersheds that is defined as different thresholds like area-slope or topography. In this paper, the area- slope threshold was investigated in Zahirabad Watershed in Markazi province, Iran. First, based on field surveys and digital elevation model, morphometric characteristics of 14 gullies were measured, accompanied by soil sampling and vegetation cover measurements. Second, homogeneous groups of gullies were defined by factor and cluster analysis and power relations of area-slope was prepared. Results demonstrated that there was no considerable correlation between area and slope of gully watersheds. So, coefficient of determination of creation point and head-cut of gullies were 0.111 and 0.181, respectively. According to the results, the dominant process in creation and head cut development of gullies in Zahirabad was related to flow concentration and rill erosion of high slopes. Considering the prevail of loamy texture of soils land use changes and deterioration of vegetation cover, it is suggested to investigate the optimization of land use schemas, and land cover improvement on sloppy lands with the objective of gully control.
Ali Akbar Davoodirad; Davood Nikkami; Mehdi Mardian
Abstract
Increasing in production and welfare of rural household along with soil erosion mitigation are the most important objects of a watershed management program. Land use optimization is an efficient approach that leads to a sustainable development plan. In this research, the land use optimization was applied ...
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Increasing in production and welfare of rural household along with soil erosion mitigation are the most important objects of a watershed management program. Land use optimization is an efficient approach that leads to a sustainable development plan. In this research, the land use optimization was applied using a two-objective linear programing model and geographic information systems by Lingo 11.0 software in Adineh-Masjed Shahzand watershed of Markazi province, Iran. The model was defined with three scenarios of current conditions, applying management conditions, and standard conditions for two objectives of maximizing net benefits and minimizing soil erosion. Results showed that the annual soil erosion decreased by 1.27, 18.69 and 26.93% in current land use, land use management, and standard land use conditions, respectively. Also annual net income decreased by 18.56% in current land use; but increased by 48.01 and 220.07% in land use management and standard land use conditions, respectively. Considering weighting value of decreased soil erosion of 1.27% that is less than weighting value of decreased net income in current conditions, land use optimization with no management practices or land standardization is not justifiable.
