Evaluating Potential Crop Water Requirement (Case Study: Islamic Azad University, Science and Research Branch of Tehran)

Urban green space has always faced challenges to estimate the actual water requirement of plants due to the diversity of different plant species, their dispersal, and the different densities. In this research, we have tried to estimate the need for the University of Science and Research Branch with an area of 10.59 hectares. First, it has been necessary to identify and categorize existing species and finally 77 plant species were identified on the site of Science and Research Branch. In addition, due to the diversity in trees and green spaces, the California Journal’s method was used to calculate crop coefficient. The meteorological data required from the meteorological stations in Tehran was then obtained by the Iran Meteorological Organization and processed by the CROPWAT program. In the next step, the potential evapotranspiration was calculated using Penman Monteith method. Finally, the water requirement for green space was determined by the California University method. The results of this study indicate that the maximum water requirement is 246033.7 cubic meters in July. Also, in January, February, November, and December, due to the long-term average rainfall, this amount provides the water requirement of the site and there is no need for irrigation during this period

Hydraulic Evaluation of Center Pivot Irrigation Systems Performance in Different Climate Conditions

One of the most important issues in increasing the efficiency of modern irrigation systems is their field evaluation after exploiting. Irrigation efficiency is the main indicator in measuring and managing agricultural water consumption. This study was carried out in order to evaluate the hydraulic performance of center pivot irrigation system at Shahriar and Eshtehard cities in Tehran and Alborz Provinces respectively. In order to measure water consumption, the systems were evaluated using application efficiency (Ea) and potential application efficiency of low quarter (PELQ) indicators.  Moreover, the irrigation distribution uniformity was evaluation through using coefficient of uniformity (CU) and distribution uniformity (DU). For calculating these indicators, the field measurement was used to collect water under each system. It was found that the Herman and Hein CU for the Shahriar and Eshtehard center pivot systems were 70.2 and 88% respectively and the DU for these systems were, 47.87 and 81.3 % respectively. The adequacy rates and Ea were 36 and 12% and 85, 81% respectively. In terms of efficiency, these systems are in good condition. The calculated PELQ is calculated 85.3 and 66.5% respectively, which are acceptable

Efficiency Comparison of Bayesian and MLP Neural Networks in Predicting Runoff to the Taleghan Dam

The importance of regulating the supply and demand regime shows the need for planning in the exploitation of surface water resources. The aim of this study was to compare the performance of two models of Bayesian network (BN) with a probabilistic approach and MLP neural network for flow prediction and selection of the best structural model. Monthly meteorological data including rainfall, monthly average temperature, evaporation, and the volume of water transferred from five hydrometric stations were introduced as input data to the models, and runoff to the dam was considered as predictable. Input data with different layouts were introduced to BN and MLP models. The results were obtained by comparing 17 selected models according to the index criteria: Nash-Sutcliffe coefficient (NS), mean square error (MSE), mean square error root (RMSE), and MEAN absolute prediction error (MAPE). The best model in BN model with 43.3% similarity and index criteria was estimated to be -3.98, 300, 17.3, and 0.06, respectively. The MLP model with 80% similarity and index criteria were introduced as -10.3, -8266, 23.9, and 122.3 in the best model, respectively. As a result, both models performed well in runoff estimation, but the BN model had much better accuracy in forecasting. Finally, a structural pattern with acceptable results in both MLP and BN models was identified

Studying the Quality of Pollution of the Karst Spring based on Exploitation and Natural Features in Ajabshir Study Area

Springs as one of the groundwater sources and suppliers of high volume of river basin discharge have been less analyzed and studied.  The origin of these resources, due to the passage of natural heights and filtration, has a good quality and only some formations or human activities cause a change in the quality of these resources. This study evaluated the quality of springs in Ajabshir study area in the east of Urmia Lake in 2018. According to the type of geological formations, discharge and location of springs in the region, 13 springs were analyzed for qualitative analysis and evaluation of qualitative changes. Studies have shown that 100% these springs are very good quality in terms of drinking, and the GQI quality index is 33.23-95.32, indicating good to excellent condition for these resources. In terms of exploitation in the agricultural sector, the only issue was the high level of electrical conductivity (157-6490 µs/Cm) in some springs, and the alkalinity of all springs was in class S1 in Wilcox diagram. The quality situation from the industry point of view also indicated a low range of changes, and 77% of the springs in the region were corrosive. Evaluation of water source in this area showed a high ratio of sodium to chlorine and differences in calcium and sodium origin, so that the initial sections of the study area and the east of the area had magnesium source and the rest had calcium source. Finally, the study of geological formations showed their low impact on quality and the high concentration of nitrate in the part leading to the plain and aquifer due to human activities and sewage leakage was evident and reached 27 mg/l

Research on the status of the irrigation and drainage network in Iran based on the viewpoint of water users and experts using SWOT analysis

In many arid and semi-arid regions, such as Iran, traditional irrigation systems consume a large proportion of surface water and groundwater resources. In the last few decades, due to the undesirable effects of climate change and continuous drought, many studies have been conducted on reducing threatening factors using the capacity of irrigation and drainage networks and participating water users in irrigation management. This study aimed to evaluate the performance of the irrigation and drainage network of the Varamin Plain using the SWOT model that is an analytical model used based on the results of the strengths, weaknesses, opportunities and threats of the subject, considering the cooperative management of water users. In addition to conducting interviews, a questionnaire was used to collect data from two groups of network water users and experts. According to the results, the farmers and water users of the network are in a relatively good situation in terms of access to water, possibly due to the available three annual planting seasons (due to the existence of irrigation and the drainage network and the use of grey water, conditions for irrigation and crop cultivation are available in four seasons of the year). The most critical concerns of the water users were the lack of knowledge about the organization of water collectors, the inconsistency among governmental organizations and the insignificant action of the Agricultural Jihad Organization (a government ministry in Iran to advance agricultural goals and all related matters) in solving issues related to water rights. Failure to inform the users about the costs of creating network infrastructure, maintaining facilities and canals, not accepting water shortage conditions and the state of groundwater resources, consecutive cropping seasons throughout the year, cultivation of crops with high water demand, people with political and social influence obtaining excess water rights, and the lack of coordination among related governmental policies were the most critical concerns of the expert

The effect of climate change on surface and groundwater resources using WEAP-MODFLOW models

Abstract In addressing management scenarios and climate changes, it is necessary to consider surface water and groundwater resources as an integrated system. In this context, the present research first simulates and evaluates surface water and groundwater simultaneously; then, it examines the possible effects of climate change on these water resources in the study area (Mahabad, Northwest of Iran). In the first stage, the WEAP-MODFLOW model was applied to a 10-year period (2006–2015) in order to take into account the interactions between surface water and groundwater and calibrate the amount of recharge and drainage from the aquifer. In the second stage, in order to study the effect of climate change on surface water and groundwater resources, we compared the micro-scale model outputs under the RCP4.5 scenario for different climate change models in the period 2021–2045. The results show that root-mean-square error (RMSE) and mean absolute error (MAE) scores are equal to 0.89 and 0.79 in unsteady conditions, respectively, which confirm the efficient performance of groundwater simulation. In addition, the results of the WEAP model based on MARE assessment criteria for calibration and validation modes are equal to 0.54 and 54.0, respectively. This finding provides evidence for the efficient performance of the simulation model. Once the interactions between groundwater and surface water were specified, the results R 2 and NS suggested that indices were equal to 0.62 and 0.59, respectively, for Mahabad hydrometric station. The efficient performance of the proposed model for runoff simulation was therefore confirmed. Owing to climate change in the study period, groundwater decreased by about 1.6–1.9 m. Moreover, the amount of runoff declined from 0.1 to 0.001 MCM/month in all months except December. Unless appropriate decisions are taken to improve groundwater and strategies are applied to reduce the effect of climate change, under the present conditions this region will suffer irreparable damages in the future

Non-conventional sources of agricultural water management : Insights from young professionals in the irrigation and drainage sector

Distribution and availability of global resources is highly variable over time and heterogeneous in space. With the natural or conventional supply of these resources no longer meeting a growing demand, the need to promote resource efficiency is now being paralleled with innovative approaches to conserve resources within their use cycle. These ‘innovative approaches’ herewith referred to as non-conventional was the subject of a 10-weeks extensive discussion among Young Professionals (YPs) in the field of irrigation and drainage. The discussion aligns to a higher objective of breeding a generation of YPs with an open mindset and multi-disciplinary approach to the challenges in irrigation and drainage. Cutting across development corridors in the water sector, this review paper presents insights on non-conventional sources of agricultural water management (AWM) as viewed from the lenses of YPs. The discussions underscore the need for broad-based approaches to resource management, building on the premise that all forms of resources are linked to form a system that provides the most effective service when managed in an integrated fashion. Non-conventional requires divergent approaches and flexibility; underlining the invaluable capabilities YPs present in AWM. Besides highlighting these roles, insights provided by YPs suggests that feeding a growing population necessitates looking beyond system efficiency to multivariate approaches of resource optimisation and utilisation in the field of irrigation and drainage