Showing 7 results for Water Resources Management
N Rouhani, H Yang, S Amin Sichani, M Afyuni, S.f Mousavi, A.a Kamgar Haghighi,
Volume 12, Issue 46 (1-2009)
Abstract
Iran, with an average annual precipitation of about 252 mm (413 BCM) and renewable freshwater resources of 130 BCM, has irregular distribution of water resources. With a high population growth rate, agriculture remains the greatest water user in Iran but its production still does not meet the total food demand of the country. Due to unreliable water availability, the competition for water from other sectors and the increasing demand for food and better diets, Iran will experience water stress. In this study, virtual water trade in relation to water resources availability has been assessed as a way of relaxing water stress in Iran. The results showed that from the 21 food products, cereals, pulses, nuts and oilseeds are water-intensive crops according to their estimated virtual water content, while fruits, vegetables and industrial crops are not water-intensive. Considering the volume of virtual water entering the country through food imports, more water will be available for other essential uses. However, the virtual water trade has been developed rather unconsciously regarding water use and crop water productivity during the past two decades. For instance, wheat with a share of 58.5% in the virtual water import to Iran, was the dominant imported crop during 1983-2003. By importing 10.4 Mt of wheat, 11.6 BCM of water has been saved within the country during 1999-2003. However, Iran became self-sufficient in wheat production in early 2005. Consequently, this latest drive for self-sufficiency in the production of wheat, as a water-intensive crop, put tremendous pressure on domestic water resources. The trend in crop trade in terms of quantity and virtual water for other groups of crops has also been shown in the study. Seemingly, crop production and import have been greatly influenced by the weather conditions. With the increasing water scarcity, the role of virtual water in food security is expected to rise continuously in Iran. Thus, conscious virtual water trade as a policy measure in water management and judicious adjustment in agricultural structure will ensure sustainable food security and water availability in Iran.
S. Dodangeh, J. Abedi Koupai, S. A. Gohari,
Volume 16, Issue 59 (4-2012)
Abstract
Due to the important role of climatic parameters such as radiation, temperature, precipitation and evaporation rate in water resources management, this study employed time series modeling to forecast climatic parameters. After normality test of the parameters, nonparametric Mann-Kendall test was used in order to do trend analysis of data at P-value<0.05. Relative humidity and evaporation (with significant trend, -0.348 and -0.42 cm, respectively), as well as air temperature, wind speed, and sunshine were selected for time series modeling. Considering the Autocorrelation function (ACF) and Partial Autocorrelation function (PACF) and trend of data, appropriate models were fitted. The significance of the parameters of the selected models was examined by SE and t statistics, and both stationarity and invertibility conditions of Autoregressive (AR) and Moving average (MA) were also tested. Then, model calibration was carried out using Kolmogorov-Smirnov, Anderson- Darling and Rayan-Joiner. The selected ARIMA models are ARIMA(0,0,11)*(0,0,1), ARIMA(2,0,4)*(1,1,0), ARIMA(4,0,0)*(0,1,1), ARIMA (1,0,1)*(0,1,1), ARIMA (1,0,0)*(0,1,1) for relative humidity, evaporation, air temperature, wind speed and sunshine, respectively. The fitted models were then used to forecast the parameters. Finally, trend analysis of forecasted data was done in order to investigate the climate change. This study emphasizes efficiency of time series modeling in water resources studies in order to forecast climatic parameters.
S. F. Mousavi, H. R. Vaziri, H. Karami, O. Hadiani,
Volume 22, Issue 1 (6-2018)
Abstract
Exploitation of dam reservoirs is one of the major problems in the management of water resources. In this research, Crow Search Algorithm (CSA) was used for the first time to manage the operation of reservoirs. Also, the results related to the exploitation of the single-reservoir system of Shahid-Rajaei dam, located in Mazandaran province, northern Iran, which meets the downstream water demands, were compared to those obtained by applying the Particle Swarm and Genetic algorithms. Time reliability, volume reliability, vulnerability and reversibility indices, and a multi-criteria decision-making model were used to select the best algorithm. The results showed that the CSA obtained results close to the problem’s absolute optimal response, such that the average responses in the Crow, Particle Swarm and Genetic Algorithms were 99, 75 and 61 percent of the absolute optimal response, respectively. Besides, except for the time reliability index, the CSA had a better performance in the rest of the indices, as compared to Particle Swarm and Genetic Algorithms. The coefficient of variation of the obtained responses by CSA was 14 and 16 times smaller than the Genetic and Particle Swarm Algorithms, respectively. The multi-criteria decision-making model revealed that the CSA was ranked first, as compared to the other two algorithms, in the Shahid-Rajaei Reservoir's operation problem.
S. M. Sajjadi, H. R. Safavi, O. B. Haddad,
Volume 22, Issue 3 (11-2018)
Abstract
In this study, the WEAP model was used for the simulation and the Gravitational Search Algorithm (GSA) was applied as the optimization model. Due to the necessity of multiple simulations in the optimization process to achieve the optimal solution, the linkage of simulation and optimization models was done in the MATLAB software environment. To evaluate the performance, hedging policies achieved in the base period were investigated for the near future period under climate change. The results showed the poor state of aquifers under the baseline scenario; also, the continuation of the current management caused the Zayandehrood river basin to experience significant problems. So management of water resources using conjunctive hedging policies could improve the situation. The use of conjunctive hedging rules showed 11 percent increase in the group sustainability index for demands, in comparison with the baseline scenario. Also, according to the group sustainability index for the resources, applying the conjunctive hedging policies could increase the sustainability of surface water and groundwater resources as much as 5.2 and 6 percent, respectively, relative to the baseline scenario. The results also indicated the better performance of conjunctive hedging policies in comparison to the baseline scenario policies.
E. Mokallaf Sarband, S. Alimohammadi, Sh. Araghinejad, K. Ebrahimi,
Volume 24, Issue 4 (2-2021)
Abstract
In determining the allocation of water resources, the probable conditions of water resources and water demands are considered as the water allocation scenarios in the basin scale. Then, these scenarios are evaluated in the context of integrated water resources management and from the perspective of sustainable development indicators. The best scenario is selected in order to determine the water allocations. In these evaluations, there are spatial distributions and their interactions are simultaneously the key charaterictics in the decision matrix. These features are not often considered in the evaluation process. In the present study, distributed indicators and simple and integrated multi-criteria evaluation models, including ANP and CP methods, were used to evaluate the water allocation scenarios in the Aras Basin. The results showed that modeling of the spatial distribution and interactions of water allocation impacts was not possible through any of the simple multi-criteria evaluation methods. Simplifying and discarding one or two key features in the evaluation process can lead to significant uncertainties on rankings with a Spearman coefficient of -0.1. By implementing the integrated spatial decision-making approach and applying two features simultaneously, the fourth scenario was ranked first. The proposed approach was compared with the individual models, showing more accurate, with the correlation coefficients of 0.5, 0.6 and 0.7.
S. Moghim, J. Rahmani,
Volume 25, Issue 1 (5-2021)
Abstract
Improper water managements and overuse of surface water and groundwater mainly for agricultural purposes in Iran have led to the drying of many rivers and groundwater. Climate change adds an extra pressure on the water resources. These changes indicate the necessity of adjustment in water management plans. This study used hydroclimatic variables including precipitation and temperature in Urmia Plain to find appropriate crops that needed the minimum irrigation water. In addition, the best time for planting each crop is determined. To find the proper crops for the region, the daily water, as required for each crop, was calculated based on climate condition, crop type, and crop growth stage. The results indicates that grape could be the best crop for the region. In addition, early planting (e.g. in spring) reduced the irrigation water needed due to more rain and soil moisture in spring than summer, which could provide crop water requirement. On the other hand, the increased temperature in spring could satisfy heat units required for the fully grown plants like barley.
A. Rezapour, M. Hosseini, A. Izady,
Volume 25, Issue 4 (3-2022)
Abstract
Integrated assessment of the watershed is critical in arid and semi-arid areas due to the severe water stress in these regions. Data and information are an essential part of decision making and water governance to obtain integrated water resources management at the watershed scale. Water accounting is a helpful tool to organize information and present them as the standard indicators to achieve this goal. Therefore, the objective of this study is to implement the Water Accounting Plus framework (WA+) in the Ferizi watershed located in the Khorasan-e Razavi Province. In this study, water accounting indicators of the Ferizi watershed for a period of 28 years (1990-2017) and wet (1990-1997) and dry (1998-2009) periods were calculated using the SWAT model. The calculated indicators showed that the amount of manageable water and usefulness of consumption (transpiration) is low in the watershed and a large part of the share of irrigation in the watershed is provided by groundwater resources. Generally, the results of this study showed that the use of the SWAT model, WA+ framework, and analysis of water accounting indicators play a significant role in assessing the agricultural and hydrological conditions of the watershed. The proposed approach in this study can help managers make enlightened decisions to keep the sustainability of the watershed.
