فصلنامه مهندسی منابع آب
پیاپی 58 (پاییز 1402)

Flooding in urban areas is increasing due to population growth with improper land use planning and climate change-induced increase in extreme rainfall events. Flood risks have affected the largest proportion of the world's population (45%) compared to other natural disasters and caused 5424 recorded deaths between 2000 and 2017, and if our cities are to be resilient and better able to deal with the consequences of floods. city to cope, it is expected that they will adopt sustainable strategies to adapt to the new climatic and socio-economic conditions. Accordingly, the purpose of this research is to evaluate the resilience of Shiraz city against floods in order to identify areas of low resilience and take the necessary measures to increase it. Their resilience should be done.

The research method of this research is descriptive-analytical and practical in terms of purpose. Based on the background of the research and refinement of the variables based on the conditions of the research area, four dimensions and 24 criteria were determined, including demographic (8 variables), economic (3 variables), environmental (4 variables) and infrastructure (9 variables).

AHP method was used for weighting and access to critical infrastructure for action and recovery has the highest weight with a weight of 0.115, and infrastructure with a weight of 0.395 has the highest weight. The estimated CR of the model is equal to 0.07, which it shows the acceptable accuracy of the model. For zoning, the Vikor model has been used, and based on the output of the model, 9.92% of the area is in the zone with low resilience, where about 16.63% of the population of Shiraz lives in this zone, and about 75.43% of the area is in the zone with medium resilience. 74.56% of the population lives in it, and the area with high resilience is 14.65%, where 8.81% of the population of Shiraz lives.

Sustainable land management is of great importance as one of the components of global sustainable development. In order to achieve sustainable management, planning is necessary, because accurate assessment of the land and reducing the destructive effects of the soil provide a safe environment for production. Knowing the changes and evolutions of land use over a period of time is very important to show the change process over time. . Considering the trend of droughts and destructions in Darab city, the aim of this research is land use based on knowing the capacity and allocating it to the best and most profitable type of use.

In this research, changes in solutes, well ring data and irrigation methods were investigated. Sampling was done from 36 points. In this research, the type of irrigation including four types of drip, strip, rain and strip irrigation was identified and based on that seven factors pH, EC, OC, TNV, N, P2O5, K2O were measured. In the next step, the depth of the well and the volume of the annual water harvest were determined, and based on that, the changes in soil solutes were investigated. Pearson correlation tests were used to check the relationship between variables.

In rain irrigation, pH and EC were standard, TNV was higher than standard, OC, P2O5 , K2O and N were lower than standard. In drip irrigation, the pH in one sample was higher than 8 and one sample was lower than 7, the EC value was higher than the standard in two cases and the TNV value was lower than the standard in 5 samples. OC, N and K2O were below standard in all cases, P2O5 was standard in 5 cases. In strip irrigation, soil pH was between 7 and 8 in all cases, EC was standard in 7 cases, T.N.V was lower than standard in 7 cases. The amount of soil O.C, N, K2O and P2O5 was lower than the standard value in all cases. In strip drip irrigation, the pH of the soil was lower than the standard in one case. The value of EC was lower than the standard value in one case, the value of TNV, OC, N and K2O was lower than the standard in all samples, and the value of P2O5 was standard in one case. The correlation coefficient between the annual water harvesting volume and soil changes showed that, in the tested lands, the relationship between the water harvesting volume with O.C, pH, EC, S.P, T.N.V was negative and the correlation with P2O5, K2O, N was positive. The correlation coefficient between the depth of the well and the fluctuation of soil changes showed that the relationship between the volume of water withdrawal with O.C, pH, EC, SP, TNV was negative and the correlation with N, P2O5, K2O was positive.

Due to the lack of rainfall and the negative balance of groundwater aquifers in recent years, the use of unconventional water sources such as effluents and sewage for artificial feeding is one of the important methods to deal with decline in groundwater aquifers. In the Borujen-Faradonbeh plain, in order to reduce the effects of drought on groundwater resources, the aquifer of this plain has been artificially fed using the effluent of the Borujen treatment plant. The aim of this study was to investigate the effects of the effluent of Borujen water treatment plant on the quality of groundwater resources in this plain.

To investigate the quality of effluent and its effect on the downstream water of the treatment plant, water wells downstream and upstream were sampled. The samples were immediately transferred to the laboratory and analyzes including the concentrations of Mg, Ca, K Li, Na, S, St, Si, Sc, V, Ba, Cr and V were performed on the samples.

The results showed that except for calcium, potassium and chromium elements which were not statistically significant differences between the water samples taken from the upstream and downstream of the treatment plant (sig> 0.05) but the number of other elements differed between the upstream and downstream wells of the treatment plant. Were significant (sig <0.05). But the same amount is within the set standards. Also, IDW maps related to these elements showed that the northern and northwestern parts of the plain (downstream of the Borujen city treatment plant) have areas with high concentrations of these elements.

Accurate forecasting of runoff and flooding to avoid human and financial losses is one of the most challenging tasks in hydrological studies of a given locale. Therefore, researchers have paid more attention to the development of accurate flood forecasting models, including the use of artificial intelligence methods.

In this investigation, the efficiency of 3 models, ANN, GMDH and ARIMA, has been investigated in order to simulate the flood of a part of Halil river basin in Kerman province. ANN model is a non-linear modeling method that improves its performance over time. The GMDH composed code is an artificial intelligence model with exploratory self-organizing features, at the conclusion of which a complex system with optimal performance is formed. Composed ARIMA code builds a model to describe the structure of the data and then predict the time series. The input data to the above models included discharge, precipitation, temperature, wind and monthly humidity, and the simulated runoff values ​​were compared with the observed values.

In order to evaluate the accuracy of the models in this research, statistical indices were used and the results showed that the ANN model (RMSE=0.042, MSD=0.001, MAE=0.027) had the possibility to estimate the runoff with higher accuracy compared to the GMDH model (RMSE=0.068, MSD=0.005, MAE=0.056) and the ARIMA time series (RMSE=0.096, MSD=0.009, MAE=0.063) in the studied basin. The mean error in runoff estimation with ANN model has been reduced by 38.23% and 56.25%, respectively, compared to the values estimated with GMDH and ARIMA models. According to the results obtained in this study, the artificial neural network model has been able to show a better performance than the other two models in predicting the outputs due to its suitable structural ability to find the nonlinear relationship between the input and output data.

The phenomenon of subsidence is one of the geological hazards, which is mostly created and aggravated by human and natural activities such as long-term extraction of underground sources of water, oil and gas or the extraction of minerals from mines and the dissolution of subsurface formations and the collapse of karst. turns Shahryar plain is one of the forbidden and critical plains of the country, which is also active in terms of industry and agriculture, this plain has been affected by land subsidence for the past several years. In this research, in order to analyze, investigate and predict the subsidence rate, the poroelasticity flow module was used in COMSOL software, which can determine the changes in the thickness of the soil sedimentary layer due to groundwater loss and also in the coming years. He nosed.

In this research, by coupling Darcy's law and changing the soil skeleton by COMSOL software, it was tried to calculate the subsidence in 22 selected points of the study area during the years 2003-2019 and after verifying and obtaining a high agreement with real data and images. Radar interferometry estimated the amount of subsidence until 2031.

The general result of finite element numerical modeling showed that the subsidence rate of the area during the year 2031 was estimated at 12.8 cm and at critical points 20.98 cm. Therefore, the maximum settlement caused by the drop in the underground water level in the early years appeared at a higher rate in the upper layer of the aquifer, which over time after filling the voids between the soil particles and due to the hydraulic connection between the layers It is observed at a slower rate than in the past in the upper layers of the aquifer surface and the ground surface. Therefore, changes in the groundwater level, soil type and distance from the fault have also been among the factors affecting the subsidence pattern and rate.

Nowadays, comprehensive and integrated water management, especially in areas facing relative limitations of water resources, is accepted as an unavoidable necessity and the main pioneer of this management is modeling the water resources system.

In this study, using the WEAP model, fluctuations in the flow level of the Zarrineh River aquifers in the Ajabshir catchment area, which is located in the southeast of Lake Urmia for a period of 15 years (1995 to 2009 AD) were calibrated and performed. Also, scenarios were considered according to the plans under study and implementation, which are the artificial feeding plan of Ajabshir plain and the plan of transferring water from Zarrineh river to Ajabshir plain (called Shahid Kazemi plan). Also, in developing some scenarios, consumption management measures (implementation of pressurized irrigation system in all agricultural lands of the plain, although it may not be completely practical) have been considered and in all scenarios, the plain is assumed to remain forbidden. This means that in the scenarios, no overdraft of groundwater has been applied. Also, in all scenarios, drought conditions are considered in the simulation period.

The results indicate that the groundwater balance of Ajabshir plain is very negative and if exploited with the current trend, Ajabshir plain will lose its groundwater storage in a 30-year period. Different scenarios were investigated and the results showed that in order to balance the groundwater resources of Ajabshir plain, reduction of harvest through consumption management programs and reduction of pressure on groundwater resources of the plain through water transfer from Zarrineh river (called Shahid Kazemi dam project) Is required.

One of the effective issues on water resources quality like dam reservoirs and other water bodies is thermal stratification. For studying the stratification in reservoirs, turbulence dynamic and internal flows must be analyzed in reservoir. Because of many phenomena that effect on stratification, studying this phenomenon is possible just with use of dynamic models. In this way using numerical models beside yield measurements are unavoidable.

Due to the water usage of Yamchi dam as a drinking water and irrigation, studying the water quality has more importance, so in this research for studying the status of thermal stratification of Yamchi dam, modeling of temperature with CE-QUAL-W2 software in one year period from (May, 2015) until (April, 2016) was done. The value of observed temperature from various points of the reservoir were compared with modeled data and with the results of modeled data, variation trend of the stratification phenomena in Yamchi dam was studied.

In this research, the value of the observed temperature was in good agreement with modeled data. The results showed that the stratification phenomena happen in reservoir and lasts about 4 months in the year. This phenomenon begins at the late May and improves in July and reaches its peak in August. At last, it would end in early September. From the September due to decrease of the temperature, stratification in the reservoir is declined and Turbulence is also seen in Autumn and Winter. This turbulence continues until late May.

Managing and monitoring the quantity of groundwater resources, along with assessing the intensity and direction of their flow, constitute fundamental principles for sustainable utilization of such resources. This study aims to utilize GMS software to simulate and analyze groundwater resources in Nobandegan plain, Fars, Iran. The objectives include deriving long-term variations in these resources, evaluating the water balance, and ascertaining the direction and intensity of groundwater flow.

Data related to pumping wells, observation wells, topographic features of the plain, and rainfall, among other pertinent information, were gathered using reports from Fars Regional Water Company. Subsequently, a comprehensive hydraulic model was developed to simulate, calibrate, and validate the groundwater flow within the plain. Following this, the overall trajectory and flow intensity within the plain aquifer were simulated.

The hydrograph pertaining to groundwater within the plain reveals a ~50 meter water table drop over the course of the investigation period.  The predominant groundwater flow within this plain is directed from the northern mountainous regions toward the southwestern expanses. The maximum hydraulic head is recorded at approximately 1283 meters, while the minimum stands at 1175 meters above mean sea level, indicating a 108-m drop in the aquifer water table elevation. The simulation results of the groundwater flow within the plain reveal an increased velocity in the northern regions and, to some extent, in the southern reaches of the plain. The findings of this study may be employed for groundwater quality studies on this plain.