مجله اکو هیدرولوژی
سال دهم شماره 2 (تابستان 1402)

The increase in the concentration of greenhouse gases in the atmosphere due to human activities such as changes in usage and use of fossil fuels has led to global warming and global energy imbalance. This increase in greenhouse gases has caused a phenomenon called climate change. In this research, the performance of 4 GCM models named HADCM3, CGCM3T63, 5.CSIROMK3, NCARCCSM3 (from the set of AR4 models) under scenario A2 in simulating the climate parameters of average temperature and precipitation in the Qara-Su basin using artificial neural network. ANN) were evaluated. The forward perceptron model was used to train the artificial neural network. According to the evaluation of the performance of the models by using the coefficients of the maximum absolute error, the average absolute value of the error, the root mean square and the coefficient of explanation, among the set of AR4 models, on average, the NCARCCSM3 model has the best performance in simulating the climatic parameters of the temperature of the Qara-Su area. This model together with CGCM3T63 has the least difference with the observed temperature climate parameter, while the CGCM3T63 model has the least difference with the observed precipitation climate parameter. Also, the results showed that the CSIROMK3.5 and NCARCCSM3 models have the biggest differences with the climatic parameters of temperature and observations, respectively. According to the results of the neural network, the coefficient of explanation for the two climatic parameters of temperature and precipitation are on average 0.97 and 73. 0 was obtained for the entire domain, which indicates the accuracy of the neural network in simulating this parameter.

Soil saturated hydraulic conductivity (Ks) is one of the important factors involved in water, soil, and agricultural sciences. Ks measurement is important for solute and water movement modeling and, in turn, is costly and time consuming. It is also impractical to spatially and temporarily measure the Ks in large scale studies. This parameter can be estimated using early soil parameters. The present research was conducted in order to predict the hydraulic conductivity of soil saturation using random forest, chaid and geostatistical methods in Hirmand city. For this purpose, 130 soil samples were collected from the surface (0-30 cm) and transferred to the laboratory for testing and analysis. In the laboratory, the parameters of hydraulic conductivity of soil saturation, soil texture, organic carbon, acidity, electrical conductivity and Percentage of lime were measured. It was then estimated using measurement parameters and using CHAID, Random Forest and geostatistics models. 20 different patterns of the combination of soil moisture parameters were considered as input to the Chaid model and random forest. Among the different combinations, the best combination was selected based on lower MAE and higher R. The results showed that the random forest model with the highest R2 (0.98) and the lowest MAE (0.0019) is the best model for predicting the saturated hydraulic conductivity of soil in Hirmand region. The results of zoning showed that the amount of saturated hydraulic conductivity of the soil was higher in the west, center and northeast than in other places.

The approach of water, energy and food correlation can be defined as an approach to evaluate the development and implementation of policies that emphasize the security of these things at the same time. The purpose of this research is to provide a method to analyze the relationship between water, food and energy in the crop production chain. Based on the proposed method and according to the amount of water and energy consumption, four indicators of water and energy consumption and water and energy productivity, and also based on these indicators, a combined index of water, food and energy nexus is proposed. This research has conducted on the Borkhor plain of Isfahan province and the MODFLOW model has used to simulate the watershed quantitatively and since the objective functions in this study are linear, multi-objective linear programming was chosen to solve the optimization problem. The goal of solving the optimization problem is 4 scenarios of water consumption minimization, energy consumption minimization, profit maximization, as well as water, food and energy maximization scenario. The results show that although each of the scenarios alone reflect the positive effects of reducing water and electricity consumption, but by using the scenario of combining water, food and energy, in addition to reducing water and electricity consumption, farmers' profits have also increased significantly, so that the amount of water consumption before optimization was 50 million cubic meters per year, but after optimization and applying the scenario of maximizing the correlation of water, food and energy, it decreased by 8% and reached 46 million cubic meters per year, and the amount of consumption Energy decreased by 9.7% from 13150330 kilowatt hours per year to 11867563 kilowatt hours per year and in addition, the profitability of the products before optimization was 6301966 million Rials, which after applying the scenario of correlation of water, food and energy with 21 The percentage of increase reached 8015264 million rials and on the other hand, with the continuation of the optimal scenario, the level of underground water in the state of maximizing the correlation of water, food and energy will decrease by 0.478 meters less than the existing conditions and and on the other hand, by continuing this trend in the long term, we will see a significant impact on the level of underground water.

In the conservation programs of aquatic ecosystems and fish stocks, understanding of the habitat preferences of aquatic species play an important role. In this regard, the study was aimed to investigate the habitat preference and habitat suitability index (HSI) of Chondrostoma regium in its distribution range in Zab River. A number of environmental variables, including pH, temperature, EC, TDS, elevation, water depth, river width, river slope, flow velocity, and substrate type, along with the abundance of C. regium at 6 stations (each with three replication) from the downstream to upstream were recorded seasonally from the fall of 2021 to the summer of 2022. The results showed that habitat suitability of C. regium is different in four seasons and this species prefers habitats with pH in a range 9-10, high temperature, low altitude, low bed slope, moderate velocity, and gravel and slate beds without vegetation, and these environmental factors were almost similar during the four seasons of the year. But EC, TDS, river width and water depth preferences were different in different seasons. In spring, it prefers with greater width and depth, and in summer and autumn, habitats with lower width and depth. EC and TDS were lower in spring and summer and relatively higher in autumn and winter due to seasonal changes. In general conclusion, the little Zab River is moderately suitable for C. regium.

Wetland technology, utilizing natural plants and microorganisms, is an effective approach for removing contaminants from wastewater. In recent years, there has been increased attention towards biological treatment processes for wastewater treatment in rural and agricultural sectors, particularly in developing countries. Rural wastewater facilities play a crucial role in promoting public health and environmental protection within rural areas. Wetland technology has emerged as a viable method for biological wastewater treatment in these regions. This study focuses on assessing the feasibility of implementing wetlands in villages of Tehran Province. Models and methodologies for wetland utilization worldwide and in Iran were collected, and conceptual models were designed according to Iranian standards. Data layers based on three key criteria, namely technical, socio-economic, and environmental factors, were classified. Relevant maps were developed and overlaid using a Geographic Information System (GIS). The findings indicate that approximately 49 villages, primarily located in the western half of Tehran Province, demonstrated the highest suitability for constructing wetlands. Among these villages, 12 are prioritized by the Department of Rural Water and Wastewater in Tehran Province for the development of wastewater treatment systems, with wetland technology being recommended as the preferred option.

In order to carry out the appropriate program for agricultural operations and to know the appropriate planting time of dry wheat crops, the length of the growth period and its beginning and end are special. The studies carried out during the growing period of dry wheat in the country are based on the growth degree day method, which does not exist for dry or semi-arid regions. In this study, the length of the dry season wheat growth period for a statistical length of 30 years (1371 to 1400) for 38 sinopic stations of the country by taking meteorological temperatures and precipitation, with the help of the proposed method of the ecological zoning guidelines of the Food and Agriculture Organization of the United Nations (FAO) and By finding the intersection points of the graphs of precipitation and 50% potential evaporation and transpiration, the beginning and the end, the length of the growth period has been estimated, which corresponds to the results presented for the length of the growth period in the ecological classification publication of the FAO organization. Results of the obtained results, Astara station with 301 days of growth period and Isfahan, Saravan, Tabas, Semnan, Zahedan and Kerman stations with 0 days of growth period are respectively the most and the least. to give have given. Also, the results showed that the use of the FAO method to estimate the length of the growth period in arid regions obtains more realistic estimates than the growth degree day method.

Water is the infrastructure for the development of various sectors, and it is one of the important components of maintaining, the balance and stability of the ecosystem and the environment. In Iran, limited available water, non-uniform distribution, and inappropriate patterns of water consumption, It has caused problems in the supply of water in many parts of the country. Because the purpose of this research is to prioritize the use of water supply sources, This ranking was determined based on the type of climate and building type and with the approach of reducing costs and reducing water consumption, Therefore, the identification of different sources of water supply was done based on Köppen-Geiger climate classification and 4 building types. The economic analysis of water supply resources per unit volume of water was evaluated in a thirty-year period. In this research, the profitability and investment return period in case of implementation and exploitation of each of the water supply sources Based on three different water prices, i.e. mineral water price, export water price, and government water price, was examined. The results show that the highest cost of implementation and operation belongs to the humidity methods and the lowest cost is related to the methods of purifying sea and ocean salt water with modern methods. It has been the most economic profit based on the price of mineral water and export water in modern saltwater purification methods, And it is based on the price of government water in the method of water supply through the surface and subsurface water, the lowest economic profitability is in water supply methods through humidity methods.

It is necessary to evaluate the effects of the construction of man-made structures, including dams, on river regimes to optimally exploit water resources. Therefore, in the current study, the effects of the construction of the Shamil and Nyan dams in Hormozgan province on the hydrological indicators and environmental flow components of the Shamil River were evaluated and analyzed using IHA hydrological indicators. The results of the evaluations showed that the construction of the Shamil and Nyan dams has changed the flow regime. After the construction of Shamil and Nyan dams, the flow of the river has decreased only from the middle of November to the end of February at the same time as the harvesting of off-season crops in Hormozgan province, and the flow of the Shamil river has increased in the rest of the months. Also, floods with a return period of more than 10 years after the construction of the dam did not occur and the trend of small floods after the construction of the dam became regular so that the peak discharge of small floods in the period before the construction of the dam was 80.23 and in the period after the construction of the dam was 75.50 m3.s-1 and has decreased by about 6%. Day numbers of minimum flow have increased from 294 days before the construction of the dam to 301 days after the construction of the dam. On the other hand, the low limit flow timing index showed that the lowest flow limit changed from 46 days after the construction of the dam to 275 days in the period after the construction of the dam. The results of the present study can be used as a basis for the sustainable management of water resources of the Shamil River.

The quantity and quality of river flow is one of the factors that are related to the health of humans and living organisms, and it is strongly affected by watershed activities, which are naturally or artificially caused by human activities. In this regard, it is necessary to evaluate the effects of human activities on river flow regime to optimally use of water resources. Therefore, in the present study, the temporal changes in the flow health of water outflow from Neor Wetland has been assessed in pre and post construction of Neor Dam in (1978-1987) and (1987-2019) periods. Therefore, temporal changes in the flow health of Neor river flow were evaluated using Flow Health software. The results indicated that the value of the Flow Health index was equal to 0.77 in the period before the construction of the Neor Dam. While in the period after the construction of the dam, the value of the Flow Health index has been decreased (0.74). Among the nine investigated indicators, the indicators of persistently very low and lowest monthly flow had not changed in the study period. In addition, the index of flood flow interval has the most deviation from the natural condition. On the other hand, the results showed that the precipitation in the study area had a non-significant increasing trend, while the flow discharge had no-significant decreasing trend. The results of the present research can be used in interpretating the effects of storage dam on the flow variability and hydrological river flow health.

Land subsidence is a natural hazard that occurs gradually in many regions of Iran. Investigating the causes of subsidence is important in order to prevent its progression, and decisions should be based on the characteristics of each region. While the drop in groundwater level is an important factor affecting subsidence, there is no direct linear relationship between changes in groundwater level and subsidence due to the complexity of other influencing factors. Therefore, this research aims to investigate the relationship between subsidence and changes in groundwater levels in the Esfarayen region of plain during the period of 2015 to 2021. The study analyzed the time series of radar interferometry and the water level of piezometric wells in the area of Esfarayen. The results show that there is a correlation between the decrease in groundwater level and the increase in subsidence in the studied area. However, due to the complexity of the relationship between subsidence and its contributing factors, further investigation and more comprehensive models are necessary.