نشریه پژوهش های کاربردی مهندسی آب
سال یکم شماره 1 (پاییز و زمستان 1402)

The river flow-suspended sediment load relationship in basins due to the rivers flow and natural and unnatural changes does not lead to providing an accurate relationship, so it is necessary to use new methods for the development of this sector. Multivariate methods and simulation and modeling based on copula functions can be considered in this regard due to the consideration of data distribution. In this study, two-dimensional copula functions were used in the period of 2010-2019 in order to simulate and joint frequency analysis of river flow-suspended sediment load and estimate the conditional probabilities in the sub-basin of Qale-Shahrokh, Zayanderood Dam basin. While examining the dependence of the studied pair-variable and choosing appropriate marginal distributions, Frank's copula was selected as the best copula in joint frequency analysis of the pair-variable of discharge-suspended sediment load according to the RMSE and NSE values. By using the selected parameters, the simulation of the studied pair-variable of river flow-suspended sediment load with the probability of more than 80% was carried out in the selected station. So that with a probability of more than 80%, it is possible to estimate the amount of suspended sediment load given by the river flow in studied station. Finally, with the probabilities of 90-95% and 95-99%, it was suggested that the equation of forecasting suspended sediment load given by the corresponding river flow in the study area, which presented the efficiency of 84% and 82%, respectively, according to the Nash-Sutcliffe statistic.

In this research, the physical and economic productivity of water was investigated in cultivation of bread wheat cultivars (in Qazvin, Iran in 2020). The main treatments were included rainfed and irrigated cultivation, and the sub-treatments were included cultivars of Sorkh-tokhm (E1), Backcross Roshan (E2), Bam (E3), Azar2 (E4) and Kavir (E5). The experiment was performed in a randomized complete block design and with three replications. The amount of dry biomass, grain and straw was measured between 3495-4377 and 3501-4363 kg.ha-1 (in rainfed cultivation) and between 5022-9027 and 4525-8440 kg.ha-1 (in full irrigation), respectively. As a result, the Backcross Roshan cultivar (in full irrigation) was introduced as a suitable bread wheat cultivar. The amounts of physical water productivity in production of seeds, straw and biomass of Backcross Roshan cultivar were 1.67, 1.57 and 3.24 kg.m-3, respectively. Also, the economic water productivity for above parameters was estimated as 68,791, 39,896 and 124,842 Iranian rials.m-3, respectively. By changing the seed cultivar, the economic water productivity amount in full irrigation cultivation was increased to 20% (in compared to rainfed cultivation). By using the empirical models, economic water productivity amount was simulated based on the physical water productivity. The polynomial model with the R2 coefficient = 0.996, was recognized as the optimal model. The results showed that the seed cultivars with high water consumption and low economic productivity, should be removed from the region crop cultivation pattern. By the optimal use of fresh water resources in the agricultural sector, are provided the more economic benefits for farmers.

To study the effect of green harvesting and preservation of plant residues on the soil surface, simultaneously with subsurface drip irrigation management, germination and tillering was tested in the first ratoon Sugarcane. This experiment was conducted at the number one research station of sugarcane cultivation and industry in Khuzestan. The experiment was carried out in the form of a statistical design of split plots. The treatments included the harvesting method and the depth of the driper installation. Harvesting methods in this experiment was green harvesting and burning harvesting. The treatment was to install drippers at three depths of 15, 25 and 35 cm. The results showed that the harvesting method and plant residues caused a significant decrease in sugarcane germination and tillering. So that plant residues caused a decrease of 48% in germination and 33.3% in tillering of sugarcane. No significant difference was observed in the depth of installation of dripers on sugarcane germination and tillering. interaction effect of the installation depth of the drippers and the harvesting method did not make a significant difference on sugarcane germination and tillering.

Todays, the conditions of the earth and it's changing due to the development of modern life have caused quantitative and qualitative changes in water resources in different regions. For this reason, it is necessary to investigate water resources, especially rivers, as the most important parts of available fresh water. Absardeh River located in the west of Iran in a period of 45 years (1974-2017) were investigated using the Mann-Kendall test. The results showed that the river has suffered a quantitative decline, which was not statistically significant at the 95% level (Z=-1.33). Qualitative changes also indicate the intensification of pollutants, especially the values of EC with Z=3.9 and TDS with Z=3.85, which were statistically significant at the 99% level. On the other hand, the quality of this river has not limited irrigation and agricultural uses.

Water is life and, law is the order of life. The water crisis is not a new issue, although it has taken new forms in recent years. On the other hand, unwritten laws, custom and religion also have an ancient history in the culture of this country. But the official laws, especially the laws related to water, are not very old in the country and go back to the first decades of the current century. The law of water and its nationalization, the law of fair distribution of water and the law of inspection of water wells without exploitation license are some of the most influential laws in the field of water. Unfortunately, despite the passage of several decades since the approval of public water rights laws in Iran, targeted regulations have not been formulated as it should be. For this reason, many ecosystems have been damaged and their sustainability has been threatened. As a result, they cannot remain stable and have high biodiversity. With the passage of time, they have been replaced by simple systems with low biodiversity, which are often influenced by alien species that will not be useful for humans in the future. A step to problem solving, it is necessary to consider a certain amount of water that is continuously released into the ecosystem and its exploitation be prevented by legal approaches. In fact, management solutions based on law should be such that there is a balance between water consumption using humans and the environment. The result of this balance is environmental sustainability and coordination with other sectors in order to achieve sustainable development in all fields.

Modeling the uncertainty of the parameters of a mathematical model during the calibration process is very important in making decisions about its performance. The texture of the soil is one of the main factors of the uncertainty of soil infiltration. In this research, the Kostiakov model was fitted to the data of cumulative soil infiltration considering eight different soil textures from sandy to clay. In the following, using the Monte Carlo method and performing 1000 simulations for each of the soils texture, the range of coefficients of the Kostiakov model was calculated within the 95% confidence level. The obtained results showed that there is a very good agreement between the results of Kostiakov's model and the observational data. In general, it was found that the uncertainty of Kostyakov model coefficients in silty loam and clay loam soils is more than other soil textures. The lowest uncertainty of the coefficients of this model is in soils with silty-clay-loamy, sandy-clay-loamy, loamy and clayey textures.

Due to the lack of sufficient precipitation in Iran, proper management of water resources is necessary, especially in the agricultural sector. For this purpose, in 2022, a research was conducted with the aim of investigating the effect of vermicompost and absorbent as soil conditioners in Khorram Abad region, in the research farm of Lorestan University, in a factorial manner with a randomized complete block design in three replications, the first factor being irrigation water treatment at 4 levels including 100, 80, 60 and 40 percent of the  water requirement and the second factor also includes different soil moisture modifiers, vermicompost (C) 6 tons per hectare, superabsorbent (S) 63 kg per hectare and the control treatment (I). The results of the research showed that the highest productivity, dry yield and plant height were related to the I1-C treatment, which were 126.71 tons per hectare, 46.27 tons per hectare and 2.35 meters, respectively, and the maximum amount of productivity (16.79 kg of fresh fodder per cubic meter of irrigation water) and biological productivity (5.9 kg of dry fodder per cubic meter of irrigation water) at the probability level of 5% was I2-C. In general, vermicompost increased the wet and dry yield, height and water productivity of corn. Superabsorbent also showed lower performance in full or less stress irrigation treatments, but with increasing stress, it had better results. Therefore, in Khorramabad region, the amount of 6 tons per hectare of vermicompost and 80% of the water requirement in the form of tip irrigation for fodder corn is recommended.

The phenomenon of global warming has always affected different parts of the world. Therefore, it is necessary to investigate and predict the factors affecting it in different regions. In this study, the ARIMA time series method was used in order to investigate the future temperature changes in Aligudarz, Lorestan, Iran. For this purpose, the temperature data in the period of 1990-2021 was used from Aligudarz station. The results of the time series investigation showed that the model with the value of autocorrelation component=1, moving average=1 and differentiation=1 had the best result, so the forecasting was done with ARIMA (1,1,1) model. The forecast results showed that in the next five years (2022-2026) the temperature will decrease. In general, the results of this study showed the acceptable effectiveness of the time series model in temperature forecasting.

Water is a vital substance that cannot be replaced. Excessive exploitation of water resources and drought have caused a severe decrease in the country's water reserves. In this research, the SWOT strategic management model was used in order to provide management strategies for the sustainable development of Songhor plain, Kermanshah, Iran. The obtained results indicate that the weaknesses and threats of the region prevail over the strengths and opportunities. So, a defensive strategy was proposed to get out of this situation. Considering that the SWOT model was not able to prioritize strategies, hierarchical analytical model was used for prioritizing strategies. The criteria of economic, feasibility, protection of natural resources and environment, social acceptability, adaptability, flexibility and durability were considered as the most important criteria for evaluating strategies. Finally, the strategy of promoting the correct culture of water consumption and mechanization of agriculture were placed in the highest priority from the expert's point of view with a relative weight of 0.139 and 0.134 respectively.

Groundwater is one of the most important sources of fresh water. With the increase in world population and water demand for agriculture and urban use, the need for water resources has risen, with groundwater playing a crucial role. In this study, Dasht aleShtar, a typical region of Iran with a temperate climate, was selected as a case study to evaluate the quality of groundwater in the region using data from 17 observation wells between 1366 and 1397. For this purpose, information from deep wells in the plain, including pH, K, Cl, EC, TDS, Mg, HCO3, Na, SAR, SO4, TH, and Ca, was utilized. The Mann-Kendall test was used to check the trend of changes. The results showed that the patterns of changes in pH, K, Cl, EC, TDS, and Mg parameters had an increasing trend, and this increase was significant at the 95% confidence level. On the other hand, because the Z-statistics of HCO3, Na, SAR, SO4, TH, and Ca parameters were negative, their changes are decreasing. However, the decreasing trend of Ca is significant at the 99% confidence level. To measure the relationship between groundwater quality variables, Pearson's correlation coefficient was calculated for the Al-Shatar area. The highest positive correlations were between TDS and EC (R=0.98), Na and SAR (R=0.93), and HCO3 and TH (R=0.93). The correlation between Ca and TH (R=0.80) is also noteworthy. Using ArcGIS software, a map of groundwater quality parameters was prepared in the study area for quality assessment. According to the water is suitable for agricultural use in the region. Schuler's diagram shows that all examined samples are in the good drinking class.

Iran is located in the dry part of the earth and the average rainfall is much lower than the global amount, so the proper management of water resources is so importance, especially in the agricultural part.  For this purpose, this research aimed at investigating the effect of different levels of irrigation on the yield and morphological traits of green basil in greenhouse conditions was conducted in the research greenhouses of Lorestan University in a completely randomized design with three replications. ​Irrigation treatments were considered at 4 levels, including 100, 80, 60 and 40% of the water requirement of the plant. Weighing micro lysimeters (pots) were used for irrigation. The results of the research showed that the effect of deficit irrigation on the yield and morphological traits was significant. The highest amount of yield, biological yield, plant height, stem diameter, number of side branches, number of leaves and root length was observed in the treatment of 100% readily available water, which is equal to 7 t/ha, 1.8 t/ha, 0.84 m, 4.67 mm, 35 numbers, 344 and 52.33 cm were obtained. Also, in most of the measured traits, no difference was observed between the 80% and 60% readily available water. Therefore, in case of emphasis on the application of deficit irrigation, it is recommended to treat 60% humidity of the surface.

First step in reducing the destructive effects of flood is identifying flood prone areas and flood management. Flood management is one of the basic measures in water resources planning, which is used to minimize potential damages and achieve sustainable development of communities. In this study susceptible areas to flood for a 10 km reach of Silakhor River (73 km2) was mapped using Evidential Belief Function (EBF) model. For this purpose, flood points of the study area (training and testing sets), were overlaid with the maps of flood influential factors including: elevation, slope, aspect, distance from river, river density and topographic wetness index and the map of susceptible areas to flood was prepared. According to validation result (using flood points that were not used for training phase) the EBF model with AUC value of 76% is suitable for identifying prone areas to flood. Also, the results of the research showed that the elevation, the distance from the river and the drainage density are very influential factors in the region's flood proneness.