Somayeh Shirzadi; Mostafa Mardani; Ali Shahnazari
Abstract
Water supply and demand Management plays an important role in the agricultural sector. In recent years, due to inadequate management of agricultural water distribution, agricultural lands in Tajan Irrigation and Drainage Networks are suffering from excessive use of groundwater and salinity. Therefore, ...
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Water supply and demand Management plays an important role in the agricultural sector. In recent years, due to inadequate management of agricultural water distribution, agricultural lands in Tajan Irrigation and Drainage Networks are suffering from excessive use of groundwater and salinity. Therefore, the purpose of this study was to investigate the sustainability of groundwater, water consumption, and distribution management in Tajan Irrigation and Drainage Network after implementing water-pricing policies and reducing available water of upstream lands. For this purpose, Positive Mathematical Programming model and the Asano sustainability index were used. The required data were collected from Agricultural Jihad Statistics, direct referral to Jihad-e-Agriculture Organization and Mazandaran Regional Water Company in years 2016 and 2017. The results showed that the situation of water resources in the region is not stable, while changing the cropping pattern and adopting different irrigation policies in the region will increase the sustainability of water resources from 0.45 to 0.27, which corresponds to changing from critical to good situation. The higher price policy for water up to 30% compared to the current conditions has little effect on irrigation water use. However, reducing available water of the upstream lands, in addition to reducing the amount of consumed water and managing its consumption, would improve the economic benefits of the network, with a minimum reduction in the upstream economic benefits. Therefore, in order to contribute to the sustainability of groundwater in the region, it is suggested that managers of the Tajan Network should adopt the policy of reducing available water to the upstream lands.
Hossin Badibarzin; Mhamood Hashemi tabar; S.Mehdi Hossini
Abstract
Since agricultural sector is the largest consumer of water, it is crucial to introduce effective policies to manage water resources in this sector. In the present study, the economic analysis of allocation and pricing of irrigation water on cropping pattern and water demand management in Sistan plain ...
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Since agricultural sector is the largest consumer of water, it is crucial to introduce effective policies to manage water resources in this sector. In the present study, the economic analysis of allocation and pricing of irrigation water on cropping pattern and water demand management in Sistan plain was investigated by use of a positive mathematical programming model (PMP). In this regard, an economic modeling system including a state wide agricultural production model (SWAP) was used. The GAMS software version 24.1 was used to solve the proposed modeling system. The results showed that the use of pricing and allocation policies for irrigation water led to a decrease in the total area of designated cropping products and a reduction in the farm gross margins in Sistan plain. However, the aforementioned policies resulted in savings of 4.594 to 46.256 and 7.123 to 29.484 million cubic meters of water consumed in the region as a result of applying allocation and pricing, respectively. Decrease in total area of cultivation of selected crops under different scenarios of irrigation water quotas policy, especially higher economical crops such as watermelon, melon, and onion. Total gross yield of Sistani farmers would be reduced from 1425694 to 1292677 million Rials, reducing the gross profit by 2.17% to 9.33% in the region's agricultural pattern. Thus, applying the policy of water allocation could save about 30 million cubic meters of water available to farmers. Compared to pricing policy, the use of water allocation policy is recommended due to its superior effect on preserving water resources in the Sistan plain.
mohammad ali asaadi; Sadegh Khalilian; seyed habibollah moosavi
Abstract
The aim of this study was to determine the optimal cropping pattern in irrigation network of Qazvin plain with emphasis on deficit irrigation policy and reduction of fertilizers and chemical pesticides. For this purpose, the Positive Mathematical Programming approach (PMP) and Maximum Entropy Technique ...
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The aim of this study was to determine the optimal cropping pattern in irrigation network of Qazvin plain with emphasis on deficit irrigation policy and reduction of fertilizers and chemical pesticides. For this purpose, the Positive Mathematical Programming approach (PMP) and Maximum Entropy Technique (ME) were used. The results of the first option (5% deficit irrigation in wheat, barley, grain corn, fodder maize and Sugar beet at the ripening stage, and 5% deficit irrigation in the vegetative growth stage for alfalfa simultaneously with5% reduction in fertilizers and chemical pesticides) showed that sugar beet, alfalfa, grain corn and fodder maize were be desirable for cropping pattern due to their high economical profit in compared to wheat and barley. Also, applying this policy leads to an increase in gross margin (4.5%) and a reduction in water consumption (5.1%) in the agricultural lands of the region.As a result of the implementation of the second scenario, the cropping pattern goes towards products that have a higher economic margin due to their lower irrigation water consumption. This scenario leads to 3.6% increase in gross margin and 17.2% reduction in water consumption. Other results of the research showed that due to the application of these policies in PMP, the sustainability indicators of water resources, fertilizers and chemical pesticides are less than the current values for the region's present cropping pattern. The calculated environmental index revealed that high consumption of water, fertilizer, and other chemical inputs are a barrier to achieve sustainable agriculture.
mehdi elahi; mohammad hasan vakilpoor; Hamed Najafi Alamdarlo
Abstract
Excessive withdrawal of groundwater resources in the agricultural sector has led to an increase in cultivated land area and agricultural production, however, it has led to dropping of groundwater levels and drainage of aquifers. Consequently, most of Iran's plains are now considered as forbidden plains ...
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Excessive withdrawal of groundwater resources in the agricultural sector has led to an increase in cultivated land area and agricultural production, however, it has led to dropping of groundwater levels and drainage of aquifers. Consequently, most of Iran's plains are now considered as forbidden plains for underground water extraction. Therefore, proper policies for management of groundwater resources are essential. For this purpose, the present study aimed to evaluate the effects of economic policies of the agricultural sector on management of ground water resources in Kabodarahang Plain, by using a Positive Mathematical Programming (PMP) and Maximum Entropy (ME). The data and information was collected by referring to the relevant organizations and completing 141 questionnaires with multi-stage cluster sampling by farmers in 2016. The results showed that application of various senarios such as price increases, groundwater allocation , and combination of quotation scenarios simultaneously with increasing prices (combined) at levels of 10%, 20%, and 30% cause reduction in cropped area, decreased net profit of farmers, and reduced water consumption. Also, the results showed that the groundwater price increases scenario was not much effective and only increased the farmers' expenses, but the allocation/quotation polices and the combined policy are recommended as effective policies. Another result revealed that the quotation scenario, compared to the other scenarios, has higher economic returns per cubic meter of water consumption, thus it has been introduced as the best scenario in this research. Finally, it is suggested that the cropping pattern be directed towards products such as wheat and potato that have more gross profit for the water consumed and thus have more economic returns.