مجله اکو هیدرولوژی
سال یازدهم شماره 1 (بهار 1403)

Estimating the amount of evaporation from water resources is one of the important and key factors in calculating the water balance and managing water resources in each region. In order to calculate the average evaporation from water resources in Kashan plain and to check the amount of enrichment, the information of stable isotopes of water molecules was used. In this study, 42 water samples were collected from groundwater, Playa Lake and Serajeh salt pan in order to analyze the hydrogeochemical and isotopic characteristics. The amount of 18O isotopic enrichment factor was determined based on and the amount of deuterium based on . According to the results, the overall enrichment value due to evaporation, under the specified conditions and an average annual temperature of 30°C, was determined to be -16.4‰ and -82.25‰ for oxygen-18 and deuterium, respectively. Additionally, based on the Rayleigh distillation, the amount of water losses due to evaporation was calculated based on the differences between the initial sample and the 18O value of the Playa using the simplified Rayleigh equation. Since the remaining water fraction was found to be 0.40, hence the water loss rate in the northeastern part of the aquifer was estimated to be 60 percent.

One of the effects of droughts on the catchment area is the impact on sediment production. The purpose of this study was to investigate the effect of drought on the amount of sediment production estimated by the sediment gauge curve located at the Chamriz hydrometric station. In this study, using the long-term data of the Chamriz hydrometric station located upstream of the Darudzen dam, the rate of changes in the produced sediment discharge in each year was calculated using different methods of the sediment curve. Then, by evaluating the applied methods, the best method for performing the subsequent analyses was selected (the non-parametric method (CF2)). Then, using the station's meteorological data, two SPI and RDI drought indicators were calculated, and finally, they were compared with the average annual sediment discharge rate. The results showed that by increasing the amount of drought index (SPI) and RDI (toward tiredness), the amount of sediment discharge increased, indicating the positive effect of climate conditions on the sediment yield of a basin. Finally, by examining the state of sediment production in many years of drought, it can be concluded that during the year of the drought, due to the effect of drought on vegetation status, soil moisture, and other factors, in the years after the occurrence Drought has caused a significant increase in sediment deposition compared to years when the drought was normal on the floor, and since then it has been terrible.

Dez dam has an essential role in controlling the floods and water supply in Khouzestan. Accurate and reliable prediction of the flow input to the reservoir is crucial to make decisions about the exploitation and management of this reservoir. In this research, a novel WAVELET-ARIMA-NARX model was developed to predict the monthly inflow to Dez dam reservoir. The WAVELET method was used to break down the time series into sub-series and better analyzing, the ARIMA model was used to model the linear component of the analyzed series, and the NARX model used to model the error resulting from WAVELET-ARIMA model. The NDVI index was also used to measure the accuracy change of the WAVELET-ARIMA-NARX hybrid model. The results showed that the prediction performance of the WAVELET-ARIMA-NARX hybrid model has improved significantly compared to the ARIMA model. In such a way according to the RMSE criterion, the prediction accuracy in the verification and training stages has decreased by 74% and 82%, compared to the ARIMA and WAVELET-ARIMA model, respectively. The NDVI parameter with average temperature and rainfall of the basin as an input of the NARX model has increased the accuracy of the model. In the model with 10 neurons in the hidden layer, compared to the two-parameter model of rainfall and NDVI with 15 neurons, in evaluation section, the MAE values have decreased from 27.2 to 18.5 and the RMSE from 0.45 to 0.26. These values indicate the importance and impact of simultaneous consideration of three parameters on forecasting accuracy.

This research assesses and investigates the impact of automating the Abshar irrigation network's main canal using a decentralized control system on the adequacy and stability of surface water distribution. To achieve this, the study analyzes 30 years of historical discharge data at the Abshar diversion dam and selects seven representative operational scenarios. It then employs the Integral-Delay (ID) hydraulic simulation model to simulate surface water distribution in the main canal under each scenario (a total of 540 simulations). These simulations are compared with results obtained using a simplified Integral-Delay (ID) mathematical model. Additionally, the research develops a decentralized PI automatic control system model for the network. This control system model is then integrated with the Integral-Delay (ID) hydraulic simulation model within the MATLAB environment. By utilizing system identification techniques, the study determines the proportional and integral gains for each controller in the control system. Finally, the performance of the automated control system is evaluated by analyzing the simulated surface water distribution results for the chosen scenarios using performance indices related to water distribution adequacy and stability. This allows for a comparison of the automated control system's effectiveness with the pre-automation scenario.

Changes in land use and climatic variables cause changes in sediment yield, filling of reservoirs in dams, and challenges in the demand of residents of the region for access to fresh water. Therefore, understanding the trend of hydroclimatic indicators to evaluate the impact of climatic and hydrological changes on sediment yield seems very necessary. The purpose of this study is to investigate the effect of land use changes and hydroclimatic indicators on sediment production in the Minab Basin using Mann-Kendall and Pettit trend analysis. The results showed that there is no significant trend in rainfall, but the maximum flood discharge, volume and concentration of sediment have a significant increasing trend that occurred in the 1980s. On the other hand, the investigation of land use changes in the Minab basin during the last three decades, 1990, 2005 and 2021, showed that 11% of the area of pasture lands decreased and agricultural and residential lands increased by 220 and 280%, respectively. Therefore, despite the non-significance of the precipitation trend, due to obvious land use changes that have a controlling role on the flood peak flow and sediment production, an increase in the peak flow and sediment production is evident in the basin.

In this study, the quality of the treated wastewater of Kish Island, which is the main source of irrigation for the urban area of Kish, was evaluated. First, samples were taken from 12 water storage points and transferred to the water and wastewater laboratory of Tehran University. The samples were transferred to the Laboratory of Tehran University and the physicochemical parameters include pH, EC, BOD5, COD, TSS, TDS, SAR, phosphate and nitrate, Mg, Ca and Na were measured. The results showed that in green space irrigation tanks, the water is pH and EC are between 0.2 and 1.9, which is lower than the standard; 7 reservoirs including Marjan Park, Hangman, Cactus Pool, Convention Center Pool, Iran Pool, Bagh Rah and Golestan Park Pool have BOD higher than the standard, which is considered a biological hazard for the environment. TSS is higher than the standard in 7 reservoirs, which include Marjan Park, Hangman Park, Cactus Pool, Iran Pool, Bagh Rah and Golestan. According to international standards, the amount of phosphate in water reservoirs is high and requires its management, especially in sewage treatment plants. The highest SAR was in the convention center, North Water Treatment Plant and Golestan Park, but its level in Pavion, Marjan Park, Simorgh and Cactus was less than 4, indicating its desirability for irrigation. But the reservoirs of the convention center and the northern treatment plant require more management, because the long-term use of this wastewater can lead to salting of the soil of Kish Island.

Drought is one of the natural disasters that can occur in any climate. In recent decades, Iran has been continuously affected by severe and widespread droughts and has imposed harmful effects on various economic sectors, including the country's water resources. One of the needs for the growth and development of every country is water. On the other hand, due to the lack of permanent or even seasonal surface water flows in many plains of the country, one of the most important sources of water harvesting is the use of underground water reserves. Therefore, it is very important to investigate the status of these resources and determine the influencing factors on them. In this research, it has been tried to identify the areas that are exposed to severe groundwater drought and the impact of the factors affecting groundwater drought using the maximum entropy model and using MaxEnt software in the basin. The Jiroft plain watershed should be identified. To implement the maximum entropy model, 70% of the data were used for model training and 30% for model testing. The results of this study, based on the jackknife test, showed that the most important factors affecting groundwater drought are altitude, distance from the river, and soil moisture, and the model shows the most sensitivity to these parameters. gave Also, the results showed that the model has an acceptable accuracy in identifying groundwater drought, so that the accuracy of the model was estimated at 0.76.

The use of underground dams has been human interest since ancient times and was built at any time according to the common scientific techniques of different eras. In this study, AHP decision making system method was used to establish the relationship between effective criteria and make a more accurate decision and save time and money. In this method, four watersheds were selected according to the location of Shahdad catchment area, and the statistics and available information were used from four main criteria and 3 sub-criteria and 17 indices in the process of analytic hierarchy process. Then, according to the relative importance of the mentioned criteria and their analysis in Expert Choice software, the final result was obtained. Generally, in Shahdad catchment, the water criterion has the highest weight and importance in the construction of underground dams in Shahdad catchment area and the axis criterion has the least weight and importance. In general, the results showed that Keshit watershed with a weight of 0.573 had the highest priority among the studied watersheds for underground dam construction. Then, the Pashueeyeh watershed with the weight of 0.202 was the second priority for underground dam construction, then Samoon Jahar watershed with a weight of 0.183 had the third priority and finally the Kahnooj Shah watershed with 0.042 had the lowest priority for underground dam construction.

Limited groundwater resources and their overuse have become fundamental challenges for sustainable development worldwide. In this study, a combination of step-by-step weighted evaluation ratio analysis (SWARA), deep learning method of convolutional neural network (CNN), whale optimization (WOA) and bee colony algorithms (ABC) be applied, which approach provides an innovative method to produce the groundwater spring potential in Kermanshah province. In the first stage, a map containing 301 spring locations with a flow rate of more than 30 cubic meters per second and 304 points without springs was prepared. Thirteen parameters were created as independent variables. The SWARA method was used to determine the weight of the criteria, decision-making indicators and determine the relationship between the spring creation potential and the selected factors. Then, CNN-WOA hybrid model be applied to prepare the groundwater spring potential, and then it will be evaluated from the performance characteristic curve (ROC) and some other statistical evaluations. The validation of the training dataset illustrated that the success rate for SWARA-CNN-WOA, SWARA-CNN-ABC models is 86%, 91%, respectively. The results showed that the SWARA-CNN-ABC model performed better than other models with a small difference. In addition, the prediction rate evaluation revealed that the values under the ROC curve for SWARA-CNN-ABC, SWARA-CNN-WOA models are 87%, 88%, respectively. Based on the results, despite the excellent performance of all models, the SWARA-CNN-ABC model has made more accurate predictions. The hybrid models presented in this study can be used as an efficient and effective methodology to improve groundwater potential.

Water saving in the soil during planting is one of the main challenges of biological stabilization, especially in dry and desert areas. The effect of hydrophilic materials in maintaining soil moisture caused that in this study, completely biological hydrophilic panels with the brand name Plantback were used for three years (1397-1399) on Tag Haloxylon persicum in the research station of dry and desert areas of Kashan and compare it with the witness to be tested. For this purpose, seedlings were planted on plantback plates that were placed inside holes 30-40 cm deep. Seedlings were irrigated once every four weeks and once every two weeks for six months in two years (spring and summer) in amounts of 10 and 20 litres for each base. The data were statistically analysed based on the design of two split plots in the form of randomized complete block design using SAS software program and the comparison of means was done by Duncan's method. The results showed that the effect of water consumption treatment on crown diameter, crown volume and biomass amount is significant. From the interaction of the average biomass production in the treatments that were significant, it was concluded that Plantback is more than 20% superior to the average of the control treatments. Therefore, it can be said that the use of Plantback hydrophilic plates in the soil were more effective in reducing water consumption by at least the same amount compared to the control.