Journal of Water Harvesting Research
Volume:5 Issue: 2, Summer and Autumn 2022

Water harvesting has been widely applied in different climate zones, proving to be a valuable approach to sustainable water resource management. Regional estimates of the potential of water harvesting are generally based on purely hydrological assessments and mostly neglect the flow duration dimension of river. The purpose of this study was to analyze the indices to be extracted from flow duration curve (FDC) in the different climate areas. In this research, the basins in each climatic region were first separated by intersecting of climatic map and the border map of the basins. Then, 30 hydrometric stations with the common period (1976-2017) in two climate areas were selected. FDC using daily stream flow data were extracted by Hydro Office - software (2015) and then indices of Q2, Q5, Q10, Q15, Q20, Q50, Q75, and Q90 were computed. The slope of FDC were computed and finally the results were analyzed and interpreted. The results showed that variation of FDC slope in the basins of humid area was in the interval of (0 to 39%) and in the semi-humid climate in the interval (0 to 48%). In humid basins, the minimum difference between the indices were related to the beginning and end of FDC (Q2 and Q90) and the maximum changes were in the middle part of FDC (Q15 and Q20).

Water is an important element of the economic and social development of any region, and the availability of safe and clean water is one of the most important issues facing for human. As water consumption increases, the need to extract water sources and use new sources increases. Many problems related to the quantity and quality of water originates from the cities development and the increase in the urban population. On the one hand, successive droughts and the declines of groundwater tables and on the other hand, the increase in water demand have caused other approaches to be used to supply water from other basins. In this research, the opportunities and challenges of transferring water from the Oman Sea and the Persian Gulf to provide drinking water and industrial use in the three eastern provinces of Iran (South Khorasan, Razavi Khorasan, Sistan and Baluchestan) have been investigated. The spatial and temporal non-uniform rainfall in the eastern regions of the country and the increase in population growth has caused hydrological and qualitative problems in the region. There is no permanent river in the study area, and these regions need transboundary water from Afghanistan. Rainfall amount in these provinces is between 75 and 200 mm. Therefore, the majority of water supply in these areas is from groundwater resources. Also, in addition to climate change effects, high evaporation in these provinces (more than 3000 mm) is one of the most challenging issues in these three provinces, which has caused a negative water balance and water deficit and a decrease in the quality of groundwater. In current situation, the amount of extra groundwater pumping of these regions is equal to 856 million cubic meters (MCM) per year. Toward overcoming this problem, and assessing all approaches carefully, it can be said that the justification of water need for industry sectors from an economic point of view can only be achieved in the cities near the origin of the transfer (southern border areas close to the Oman Sea) and therefore, a mega project of water transfer can be redefined in such a way that it only needs to supply industrial uses for the cities close to the source.

Providing clean and suitable water for drinking, farming and living organisms in the ecosystem is essential. Therefore, qualitative assessment of water resources using qualitative indicators as one of the most suitable methods for managing water areas and having a regular program for water quality protection is essential. In this research, the quality of water from Shahid Bavi and Samen Al-Aeme Stations on the Behmanshir River and Dreifam Station on the Arvand River have been used by the National Institutes of Health (NSFWQI) index and using nine qualitative parameters such as turbidity, temperature, fecal coliform, phosphate, nitrate, PH, DO, TS and BOD. In the present study, due to the ease of calculation, the Water Quality Calculator software was used to calculate the NSFWQI index. After collecting data and performing the NSFWQI index analysis, the results of this study showed that during the summer and winter seasons in Shahid Bavi and Samen Al-Aeme stations on the Behmanshir River and Dreifam Station on Arvand River, the NSFWQI index for all months and mentioned stations were in the range of 25-50, which according to the standard classification table, this range of the NSFWQI index, indicates the weak quality of water in these rivers. Also, the EC index for all months and above stations was above the 2250, which indicates the bad status of the EC in these rivers.

The purpose of this research is to joint frequency analyze of precipitation anomaly percentage as a meteorological drought index and flow rate at Chalekhmaz station located in the Zarinerood basin at south of Lake Urmia in the period of 1995-2016, which is based on the duration of the mentioned indicators. The results of the analysis of investigated copula functions in Zarinerood basin showed that, based on evaluation criteria, Frank's copula function describes well the dependence between two variables of the duration of anomaly percentage and the duration of hydrological drought. In Chalekhmaz station, the expectation of drought duration of 4 to 7 months for the hydrological variable and 9 to 12 months for the meteorological variable in the coming years is not far from reality. The results of the study of the return period of drought characteristics showed that in the case of the frequency of the stream flow drought index, the return period also increases with the increase in the severity of the drought. The joint frequency analysis of drought characteristics shows how meteorological and hydrological drought characteristics can be determined simultaneously in one station by using joint probabilities. This can provide users and researchers with very useful information related to the probable behavior of drought characteristics in order to optimally use of surface water. For the duration of a certain meteorological drought in a station, the duration of the hydrological drought in the hydrometric station can be determined based on the conditional probability of occurrence and also certain return periods.

Aquifer regeneration is one of the essential primary solutions to better the crisis of these resources. Optimum locating of injection and considering the influencing factors of the aquifer's features are the most critical issues that have always been challenging for researchers. Hence, this study addressed the efficiency of two developed numerical methods in simulating artificial recharge. For this purpose, three scenarios were defined to evaluate the performance of numerical methods (comparison of analytical and numerical solutions), simulating the rise of the groundwater level, and analyzing the sensitivity of the hydrodynamic features of the aquifer. The concept of two numerical methods (i.e., Finite Difference 'FD' and Finite Element' FE') was performed as open-source coded in MATrix LABoratory (MATLAB), and their efficiency was examined. Results indicated that the simulated groundwater drawdown due to extraction wells is compatible with the analytical solutions regarding RMSE and NSE. Also, the performance evaluation results showed that the accuracy of the FE method is better than the FD. The experiment's results of artificial recharge into the aquifer through the injection well also showed that the groundwater level rise in the FE method is faster than in the finite difference method. Also, after 1500 days of recharge, the height of the groundwater level is up to about 90 cm.

Currently, South Khorasan province is facing a crisis of water resources and consumption. So that many of the plains of the province have been banned after continuous decline, and as a result, consequences such as the subsidence of the plains and the reduction of the useful volume of aquifers have occurred. To implement the process of artificial recharge, estimating the benefit-cost of the plans are very important and must be done with sufficient accuracy. In this research, the measurement of benefit-cost, and the discount rate were compiled in a systematic way, and the value of each artificial recharge option was determined using the basis of measurement, and after comparing with other options, the option with the lowest price has been selected. Among the three scenarios: 1) artificial recharge with the aim of increasing the groundwater level; 2) Harvesting water from recharge and using it in the agricultural sector and 3) Using a part of recharged water in different consumption sectors and increasing the level of groundwater. The results of the investigations showed that according to the Shapley value, the third scenario (with a value of 567.92) has a higher priority than the other scenarios, therefore, the implementation of artificial recharge plans with the sole aim of increasing the groundwater level will not be suitable. It should be noted that not paying attention to the economic aspect of such plans will cause them to be ineffective in the long run due to the lack of compensation for implementation and operation costs.

In this study, modified Mann-Kendall test by removing the effects of internal autocorrelation, slope of trend line test and Pettitt test were used to investigate the time and spatio-temporal changes of the quality parameters of the groundwater of Dezful aquifer in the period of 1999-2017. In this regard, the parameters of potassium, sodium, magnesium, calcium, sulfate, chlorine, bicarbonates, acidity, total dissolved solids and electrical conductivity were used in 30 wells in Dezful aquifer. The results of examining the trend of changes in the investigated values based on the modified Mann-Kendall statistic showed that on average, 74% of the investigated wells experienced an increasing trend in the mentioned qualitative values. While the trend of changes in pH values in the entire studied range was decreasing, the trend of increasing changes in potassium, sodium, magnesium, calcium, sulfate, chlorine, bicarbonates, total dissolved solids and electrical conductivity was in 4, 10, 10, 0, 14, 37, 37, 27 and 27% of the wells are significant at the 5% level, respectively. According to the investigation of the time of changing point of trend in the studied qualitative values, the results showed that the time of changing of the trend in qualitative variables started from 2000 in potassium, sulfate and chlorine variables and included other variables until 2001. The decreasing changes of pH values at the level of the studied area also started in 2005. The increase in the changes of the investigated qualitative values, especially in the central and southeastern regions, has caused a decrease in the usefulness of groundwater in the studied region, and this issue affects its use in different sectors. Investigating the changes in the qualitative values of groundwater is one of the important methods in monitoring the quality of groundwater, and using the obtained results, restrictions can be applied regarding its use in different sectors.

During recent decades, global climate change has been one of the most important research topics in the study of the earth, and its consequences have been reported in many types of research. The aim of this research is to investigate the trend of monthly, seasonal and annual temperature changes in Isfahan province, Iran using the non-parametric Mann-Kendall test. In this research, to investigate the trend of temperature changes in Isfahan, the mean monthly, seasonal, and annual temperature data during a 67 years period (1951-2017) has been used. Then, the occurrence time and direction of trend of all studied temperature series were specified using sequential Mann-Kendall test. The statistical analysis of the results showed that all three parameters are distributed symmetrically and follow the normal distribution. The results showed that the mean monthly temperature time series had non-significant trend at level of 5%.  The average seasonal trend of temperature using the sequential Mann -Kendall test indicates non-significant trend in the winter and an increasing trend in other seasons, but this trend is nonsignificant at level of 5%. The results revealed an increasing trend in the annual temperature series, which was significant at level of 5%.

Today, quality monitoring of water resources played an influential role in its exploitation and use. Water sources usually contain heavy metals in minor concentrations. The research showed various methods of removing heavy metals in aqueous solutions, such as chemical reduction, ion exchange, adsorption, etc. Hence, the widespread applications of nanotechnology to remove toxic pollutants from different contaminated water sources are known. In this study, while the existence of other methods for pollutants elimination from water, the use of iron nanoparticles was investigated. Eco-friendly and cost-effective nanomaterials are vital to ultimately removing contaminants from water. Meanwhile, iron nanoparticles are available, cheap, and practical in water and wastewater treatment. Therefore, Nano Zero-Valeant Iron (nZVI) with high surface area, nanoscale particle size, unique catalytic activity, more reactivity than bulk iron, and mobility in the underground has attracted significant consideration due to their performance in removing pollutants from aqueous solutions. Since nZVI could have aggregated, various linkers have been used to stabilize these particles on the substrate, and the use of some linkers to support these nanoparticles was examined. The results showed that hydrophilic and biodegradable linkers such as Starch, Carboxymethyl cellulose (CMC), Polyethylene glycol (PEG), Polyacrylamide (PAM), and Polyvinylpyrrolidone (PVP) could increase the speed of chemical reaction in reducing pollutants from water. Because linkers often had different functional groups that could enhance the stabilizing of these particles on the substrate. Among these linkers, PVP, as a hydrophilic, cheap, and biodegradable polymer, has performed an excellent function in supporting nZVI.

Snow cover holds significant importance in hydrology as it plays a vital role in the water cycle and water resource management. Acting as a natural reservoir, snow stores water during winter and gradually releases it as it melts. This process contributes to streamflow, groundwater recharge, and overall water availability. Main goal of this study is the modeling and prediction of the changes in snow cover extent in Baranduz River basin, in Iran. Accurate modeling of snow cover area is crucial in hydrology as it enables precise predictions and assessments of water resources. These models incorporate snow accumulation, melt rates, and distribution, allowing informed decision-making for water management, agriculture, and ecosystem preservation. Therefore, the snow cover extent of the basin was extracted from MODIS 8-day maximum snow extent production from 2000 to 2019. Forty meteorological parameters, 20 satellite based and 20 surface stationary collected data, were used as the independent variables. The PCA was performed to parameters, and the PCA6 vector was used as input to the machine learning models. ANN, SVM, CART, and RF machine learning approaches were performed in this study. The results showed, all machine learning models had satisfactory performance and efficiency in modeling and predicting the snow cover extent. The PCA-RF model showed the highest accuracy. The RMSE and R2 values for the PCA-RF model were 0.345 and 0.895, respectively, in the testing phase. Despite the fact that models have not been able to predict some of the boundary points accurately, they have still demonstrated acceptable performance.