Jamshid Yarahmadi; Ghobad Rostamizad; Malek Rafieai; Karim Mehrvarz
Abstract
Since the most consumed water is in the agricultural sector, available water resources, especially in arid and semi-arid regions, are the main limiting factor for agricultural production. Therefore, by rain water harvesting systems and its proper management, it is possible to compensate part of water ...
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Since the most consumed water is in the agricultural sector, available water resources, especially in arid and semi-arid regions, are the main limiting factor for agricultural production. Therefore, by rain water harvesting systems and its proper management, it is possible to compensate part of water shortage in the mentioned region. The purpose of this study was to select the most suitable rain water harvesting techniques based on multi-criteria decision-making system using Analytic Hierarchy Process (AHP) and investigation of its effectiveness in supplying the water demand of pistachio gardens. The results of the AHP analysis indicated that the environmental impact criterion with a weight of 0.342 and permanency criterion with a weight of 0.284 were the most effective criteria for selecting of the best rain water harvesting system. Finally, the rain water harvesting system with geomembrane insulator with a weight of 0.371 was selected as the most suitable insulator cover, and two other rain water harvesting systems with plastic and isogam insulator were weighted with the weight of 0.350 and 0.279, respectively in the following priorities. Also, the results showed that from the insulated surface with an area of 800 m2 and an average annual rainfall of 300 mm, it is possible to harvest at least 200 m3 rainwater per year. With this volume of harvested water and the choice of drip irrigation with gravel filter, the annual irrigation water demand of 200 fruitful pistachio trees will be supplied during a crop season. Therefore, due to rainwater harvesting techniques, some parts of irrigation water demands of gardens will be provided in arid and semi-arid regions, as well as maintaining sustainability of production and increasing gardeners' revenues, the double pressure on surface water and underground water will also be reduced.
Jamshid Yarahmadi; Davood Nikkami; Ali Shahnavazi; Mohammad Ebrahim Sadeghzadeh
Abstract
Watershed residents' benefit increasing and soil erosion controlling are the main goals of agricultural sustainable development. Landuse optimization operation is an effective solution in order to maximizing the benefits, as well as minimizing soil erosion damages. Current research was executed in southern ...
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Watershed residents' benefit increasing and soil erosion controlling are the main goals of agricultural sustainable development. Landuse optimization operation is an effective solution in order to maximizing the benefits, as well as minimizing soil erosion damages. Current research was executed in southern parts of Ahar Chaey Watershed in East Azerbijan Province. In this research, Multi-Objective linear programing based on Simplex method applied for optimizing landuse in form of three different scenarios: current landuses, implementation of management into current landuses and performance of the standard landuses by WinQSB software. Results showed that due to landuse optimization, irrigated orchards could be increased from 1.736 to 6.629 km2. In addition, based on suitable soils and adequate rainfalls, it is expected to expand the rainfed orchards up to 9.72 km2. Also, the weighted average of soil erosion reduces from 16.3 to 14.8 and from 10.11 to 9.5 tha-1year-1 within the first and second scenarios, respectively. This rate will reduce up to 6.8 tha-1year-1 in the standard landuse situation. On the other hand, maximizing results showed that the annual net benefits increases from 6.6 to 12.9 and 8.46 to 14 million Rails per unit area in the first and second scenarios, respectively. This rate increases up to 15.67 million Rails per unit area for standard landuse situation. Sensitivity analysis results showed that irrigated and rainfed orchards are of high sensitivity in maximizing profit functions due to high profitability of these landuse in unit area. In contrast, the rangelands, forests and drylands are of high sensitivity in soil erosion minimization, so that with increasing their area, soil erosion will increase significantly in the region.
