majid khazayi; Iman Saleh; reza bayat; Shokr allah Absallan
Abstract
Introduction
The role of water in agricultural development and economic growth is undeniable. The imbalance between water supply and demand in Iran has created a challenge for the management of water resources, especially in agriculture. Paying serious attention to water productivity and improving it ...
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Introduction
The role of water in agricultural development and economic growth is undeniable. The imbalance between water supply and demand in Iran has created a challenge for the management of water resources, especially in agriculture. Paying serious attention to water productivity and improving it through appropriate methods and policies is one of the most effective solutions to address the water crisis and enhance the quantity and quality of agricultural production. The concept of water productivity is to produce the best and most products with the least amount of water. Agricultural water productivity has received serious attention in recent years from scientific societies related to irrigation and agriculture. The variation in water productivity for different crops at the local level and in comparison with other countries with similar climatic conditions indicates the potential for increasing agricultural water productivity. In the present research, the productivity of agricultural and horticultural products was investigated through field surveys, field measurements, and remote sensing analyses.
Materials and methods
First, the status of water resources in the aquifer, including changes in groundwater levels and programmable water, was investigated. Then, the water consumption of agricultural plants was calculated using the difference between effective rainfall and plant water requirement (evaporation-transpiration). In the next step, the cultivated area of Basht Aquifer was examined using Sentinel-2 satellite images in Google Earth Engine software. Yield, dates of planting and harvesting, and irrigation times for agricultural products were verified through questionnaires completed by farmers and experts. After that, the water requirement of the current cultivation pattern was calculated using the FAO Penman-Monteith method. Finally, the productivity of different products was determined by evaluating the products in terms of productivity.
Results and discussion
The area of the alluvial aquifer was 45.5 km², with an average length of about 25 km and a width of 5 km. The total volume of discharge and extraction from groundwater resources was 39.723 MCM. The infiltration amount of the Basht alluvial aquifer was calculated to be 7.905 MCM. By joining the outflow streams, including transfer streams through different elevations, the aquifer was recharged with a total of 20.377 MCM. Calculations using the FAO Penman-Monteith method showed that the water requirements of the dominant crops in the aquifer, including citrus fruits, wheat, barley, corn, canola, watermelon, rice, legumes, and alfalfa, were 9170, 5630, 4821, 7863, 5411, 9291, 20234, 5225, and 14083 m³, respectively. In total, the amount of water consumed by the agricultural products of Basht Aquifer was nearly 45 MCM, which was approximately equivalent to 1 m³m⁻² of the cultivated area. This is 2.64 times higher than the amount of water that can be programmed for agriculture (17 MCM).
Conclusion
The cultivation pattern will be influenced by parameters such as the climatic compatibility of products, the potentials of water and soil resources, regional needs, customs and interests of local people, and economic evaluation and income from production. Any change in the cultivation pattern should consider all social, economic, and environmental factors. However, given the existing conditions of the water sources, any cultivation pattern (even those considering high income) that increases discharge compared to the aquifer's recharge sources will be dangerous for future sustainability and will cause groundwater salinization and aquifer subsidence. Cultivation of high water-consumption plants such as seed corn should be stopped due to the severe water conditions of the region, and more investment should be made in developing crops such as canola, which are better adapted to the region's climate.
Mojtaba Soleimani-sardo; Esmaeil Silakhori
Abstract
Today, land use change is considered as a challenge of environmental issues and known as an ecological problem. Land use changing is one of the most important parameters in planning over time. The purpose of this study is to detect land use changes in the Jiroft Basin in the years 1997, 2008, and 2018 ...
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Today, land use change is considered as a challenge of environmental issues and known as an ecological problem. Land use changing is one of the most important parameters in planning over time. The purpose of this study is to detect land use changes in the Jiroft Basin in the years 1997, 2008, and 2018 and it’s predicting in 2040. For this, Landsat images were collected and the preprocessing steps, including atmospheric and radiometric corrections, were done by ENVI software. A false-color combination, as well as an NDVI vegetation index map, were prepared for these years. Land use maps were prepared by supervised classification using maximum likelihood algorithm. The land use changes evaluated by Land Change Modeler (LCM) in these periods. Finally, land use map for 2040 was predicted by the Markov chain and IDRISI software. According to the Kappa index, the exported maps showed an acceptable accuracy (>0.76). Land use changes between 2008 and 2018 showed that the urban areas, agricultural lands, gardens, salty lands, and barren area were increased, but rangelands and forests were decreased. In the coming years, it is expected that with the current management method, the urban areas, agriculture and barren area will increase, while forest, gardens, and rangeland areas will decrease. To reduce the land use change effects, it is recommended to act according to sustainable development by notice to the ecological potential of the land.
vahid yeganegi dastgerdi; Mohammad Hossein Sharifzadegan; Naghmeh Mobarghei Dinan
Abstract
Adaptation to drought is considered as one of the most important approaches in agricultural and watershed management. The purpose of this study is to assess the social acceptance of drought adaptation policies at a regional scale using the reasoned action theory. Information was collected through a questionnaire ...
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Adaptation to drought is considered as one of the most important approaches in agricultural and watershed management. The purpose of this study is to assess the social acceptance of drought adaptation policies at a regional scale using the reasoned action theory. Information was collected through a questionnaire in Chaharmahal and Bakhtiari Province. The population size was 66019 and the sample size was 382. Samples were distributed according to the proportion to size of regions’ population. In each region, four settlements were selected randomly and the questionnaires were distributed randomly to the farmers. The response rate was 96%. Content validity has been approved by nine experts. Reliability of the questionnaire was confirmed by test retest method. The correlation coefficients of the study constructs were confirmed; knowledge (r=0.84), attitude (r=0.91), subjective norm (r=0.87), and behavioral intention (r=0.86). The findings showed that knowledge, attitude, subjective norm and behavioral intention of farmers were at a moderate level, although the level of subjective norm was higher than other components. There were significant correlations between the knowledge and attitude (r=0.72), knowledge and subjective norms (r=-0.62), behavioral intention and subjective norms (r=0.67), income and knowledge (r=0.59), income and subjective norms (r=-0.63), literacy level and behavioral intentions (r=0.74). There were a significant difference between the attitude and subjective norms of farmers who engaged in dry farming and other farmers. Analysis of the findings showed that despite the increasing droughts, adaptation policies have not been seriously accepted by farmers. The level of knowledge and attitude of farmers about drought adaptation were not high and farmers' behavior was influenced by the behavior of other farmers rather than influenced by the policies of the institutions.
Ata Amini; Jahangir Porhemmat; Hossein Sedri
Abstract
Virtual water concepts and water productivity are considered as powerful tools for analyzing issues related to water resource management. This research was conducted to use the indicators of physical and economic productivity of water, in water resources management in Talvar Watershed, Kurdistan, Iran. ...
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Virtual water concepts and water productivity are considered as powerful tools for analyzing issues related to water resource management. This research was conducted to use the indicators of physical and economic productivity of water, in water resources management in Talvar Watershed, Kurdistan, Iran. The data from field observation, meteorological and climatic, water resources, agriculture, irrigation and watershed management were collected. The crop area of the irrigated products in the watershed was identified and their cultivation percentage was determined. Data on the growth of these products and their water consumption were calculated using CROPWAT software and field data. Using the results of data analyzing, management indicators such as physical productivity and economic productivity of products were calculated. Results showed that five crops of wheat, potato, barley, alfalfa and clover make up more than 93% of the irrigated products area of the watershed. It was found that the potato and wheat were with highest and lowest physical efficiency, respectively. The potato is with highes productivity as 3.46 and wheat was with lowest one as 0.43 kg m-3. Despite of low physical efficiency for wheat, the major part of water consumption in this crop was from green water, while the potato is using the lowest rate of green water. In terms of economic productivity, barley and potato products were with most net economic benefits. The results of this research can lead to proper management and appropriate water resources in the basin.
Kianush Behrahi; Gholamabbas Sayyad; Ahmad Landi; Hamidreza Peyrowan
Abstract
Study of effective factors on runoff quantity to achieve optimum measures for runoff controlling is an essential subject in watershed management. This study aimed to investigate the effects of land use type and land slope degree on runoff quantity using an artificial rainfall simulator in Kakasharaf ...
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Study of effective factors on runoff quantity to achieve optimum measures for runoff controlling is an essential subject in watershed management. This study aimed to investigate the effects of land use type and land slope degree on runoff quantity using an artificial rainfall simulator in Kakasharaf watershed from branches karkhe watershed (Lorestan Province). Based on the land use map, at 6 work units (sub basins), three land use types of pasture, forest and agriculture; and three land slope degrees of 10, 20 and 30 percent was chosen. In total 93 tests were run using an artificial rainfall simulator and the runoff quantities were collected and measured. Artificial rainfall simulator was a plexiglass non-pressure rainfall simulator with a plot size of 83.5 × 119 cm2 and height 160 cm. Statistical analysis was done using SAS software. Results showed that the average, minimum and maximum runoff quantity were 1499, 0, and 9100 cm3, respectively. Analysis of variance showed a significant difference (p<0.01) between sub basins and runoff quantity. Also, the interaction of sub-basins and land use showed a significant difference (p<0.01) on runoff quantity. There was a significant difference (at 1% level) between runoff quantity and the land slope so that by increasing the slope from 10 to 30 percent, the produced runoff volume increased. Besides, there was a significant difference (1% level) among runoff quantity of pasture, forest and agriculture. The volume of runoff in the forest regions was more than pasture and agriculture land use types.
