Journal of Water Harvesting Research
Volume:6 Issue: 1, Winter and Spring 2023

The need for potable water is becoming growing drastically and different methods of freshwater production are explored theoretically and experimentally. Meanwhile, water harvesting from soil is a method through which soil water is attempted to be extracted as much as possible in form of vapor and condensed on the inner surface of a plastic cover and collected in a container. In the present study, the maximum amount of harvested water from soil is theoretically calculated and a parametric study is conducted to find the effects of contributing parameters on the highest level of harvested water from soil. Soil of interest is located under a plastic cover which absorbs solar rays and get heated. Therefore, its water turns into vapor and the condensate is collected afterwards. In fact, such a small harvesting water structure resembles a solar greenhouse. So, the governing equations seem roughly the same. Based on the results of the theoretical and parametric study, increases in difference between temperatures of trapped air under the plastic cover and soil surface brought about lower levels of harvested water as a  increase led to a 13% decrease in harvested water. In contrast, solar radiation intensity, area of soil under the plastic cover and soil absorptivity were all directly proportional to the quantity of harvested water. Moreover, it was concluded that solar radiation intensity acts as a marginally (around 5%) more significant parameter in comparison to area of soil in the amount of harvested water.

The most important natural hazard affecting agriculture in Lorestan province is the occurrence of drought and its consequences. Therefore, the main goal of this research is to investigate and determine the effects of drought on agriculture (irrigated and rainfed) in Lorestan province. To achieve this goal, a combination of field and statistical methods was used. The studied data include characteristics of rainfed and irrigated agriculture, characteristics of water resources, land use map, and drought indicators (meteorological and satellite) of Lorestan province. In order to investigate the relationship between the SPI index and each of the VCI, TCI, and VHI vegetation indices, the correlation coefficient between the indices was calculated and investigated, and a relationship was established between them through single and multiple linear regression. The correlation coefficient between the SPI drought index and TCI and VCI vegetation indices was estimated to be 0.77 and 0.70, respectively. Also, the correspondence between meteorological drought classes and vegetation cover was investigated using a mixed matrix. About the evaluation of the impact of agricultural drought on rainfed and irrigated agriculture, the results indicate that there is a positive and direct relationship between the values of the correlation index between the yield of rainfed and irrigated plants (especially wheat and barley) and the values of various drought indicators during the period of 1991-2017. In terms of time, the highest value of the correlation index between yield and drought index values is observed in the time scale of one to six months, and the correlation value decreases in longer time scales. One of the main reasons for these conditions is the physiological characteristics of different products. Based on the obtained results, in general, it can be said that the increase in drought and heat stress in Lorestan province has caused a decrease in yield and an increase in the water requirement of various aquatic crops.

An accurate estimation of the water requirement of saffron, as the most strategic product in the eastern regions of Iran, is inevitable. Considering the field limitations in measuring the water requirement, applying empirical models has always been of interest. However, since each estimation model has unique strengths and weaknesses, relying only on an experimental model cannot obtain a reliable estimate for water requirements. This study intends to evaluate different combined methods' ability to merge the saffron water requirements simulations and obtain an improved output. Six empirical models and four other combination techniques were applied to get some skilful simulations about saffron water requirements in arid regions. Results indicate that the evapotranspiration prediction under the Abtew method (ABM) has more proficiency, such that its RMSE was 0.13 mm. Also, the different comparative tests show that the outputs of combined techniques such as Multi Model Super Ensemble ‘MMSE’ and Modified MMSE ‘M3SE’ outperform others.

Drought is one of the most important problems that humanity is facing today with effects intensifying and causing many problems in different regions due to climate change and the gradual increase in global warming in recent years. Knowing this phenomenon and managing it correctly can reduce the damage caused by it to some extent. In this study, in order to quantify the rainfall changes in the region from the rainfall data of Bukan, Saqez and Takab stations and based on the Standardized Precipitation Meteorological Drought Index (SPI) in the basic statistical period (1959-2020) and the future period (2020-2100). The CanESM2 model was used under RCP2.6, RCP4.5 and RCP8.5 scenarios. The results of the survey in the basic statistical period showed that the change trend of SPI values is decreasing. Also, the average decrease of monthly rainfall in the future statistical period under the RCP8.5 scenario in Takab, Bukan and Saqez stations is about 18, 18 and 23%, respectively, and the change trend of the SPI index under the RCP4.5 and RCP8.5 scenarios is a significant decrease. And in the RCP2.6 scenario, it has an insignificant decrease. Obviously, with the current results and the lack of greenhouse gas management, more severe droughts will occur in the study area.

Greenhouse production in areas with suitable potential has developed significantly due to the economic and technical advantages of this method. Khabr region in the south of Kerman province has very good potential for agriculture and renewable solar energy production. In this research, using the design of the greenhouse structure with roofs of solar panels and a rainwater harvest system, the amount of energy produced and collected water has been simulated and estimated. After examining the 20-year rainfall data of the Khabr region, monitoring the amount of radiation in the region, and also determining the suitable location for installing the greenhouse and solar panels, the digital height of the region were obtained and its topology and slope were estimated using ArcGIS software. After determining the appropriate location and designing the greenhouse structure, using PVSol software version 2021, in three different scenarios of solar panel installation, simulation has been done and energy-related parameters have been estimated. The simulation results showed that with this method and placing the flat panel roof with an angle of 28 degrees, on the land of about 2 hectares, more than 60,000 cubic meters of rainwater was collected annually, and the electric energy amounted to 17227057 kilowatts per year and the electric power produced from these installed solar panels is estimated at around 9 MW. In addition to helping the environment and increasing the productivity of the production process, this project also leads to the optimal use of rainwater.

People's Participation (PP) in watershed management and development projects in the Iran, in addition to reducing implementation costs, can lead to the success and more effective implementation of projects. Several factors can cause People's Non-Participation (PNP) in Watershed Management Projects (WMPs), and the purpose of this research is to identify, classify and prioritize these factors in the Siyahposh basin in Ardabil province from the point of view of watershed residents and experts. After determining the sample size and completing the questionnaires, by applying the Fuzzy Analytic Hierarchy Process (FAHP) model and the Friedman test, the main component and sub-component affecting the non-sustainable participation of the people in the WMPs of the Siyahposh basin were prioritized. The results showed that from the point of view of experts, economic, legal and educational and extension components have a greater role in PNP than social and planning and implementation components. From the people's point of view, economic and educational-promotional components are the first and second priorities in the Siyahposh basin. From the point of view of experts, the sub-component of "ignoring people's income as a direct economic incentive (X1)" and "non-continuity of WMPs in the basin (X13)" have the maximum and minimum importance, respectively. From the point of view of local communities, the sub-component of "ignoring people's income as a direct economic incentive (X1)" and "low level of literacy and awareness (X4)" have the highest and lowest levels of importance in PNP, respectively. Two sub-components "ignoring people's income as a direct economic incentive (X1)" and "defects in the laws of natural resources exploitation by people (X16)" are placed in the first six priorities from the point of view of both groups. Considering the interests of the watershed residents, decentralizing the decision-making power, increasing the Non-Governmental Organizations and training the users, and changing the rules for the exploitation of natural resources and the rules for the allocation of water rights can create the basis for trust and attracting the active participation of people in projects.

Drought is an abiotic stress that limits global rice production. Plastic mulch is one of the ways to reduce water consumption. To evaluate the closed water system in the pot, a study was conducted to determine the level of reduction of evapotranspiration that did not have an adverse effect on the vegetative growth of rice. Experimental treatments included: Treatment 1: 100 % control of evapotranspiration (The lid of the pot was always closed), Treatment 2: The pot lid was closed and the lid was left open for one hour every day. Treatment 3: The pot lid was closed and the lid was left open for one hour every two days, Treatment 4: The pot lid was closed and the lid was left open for one hour every three days, Treatment 5 (control): No control of evapotranspiration (pot lid was always open). Results showed that the control treatment (no control of evapotranspiration) had the lowest plant height, stem diameter, number of leaves per plant, leaf area, leaf relative water content, root volume, root weight, leaf fresh weight, leaf dry weight, and water use efficiency compared to the evapotranspiration control treatments. 100 % control of evapotranspiration had the lowest water consumption. In closed pots, due to the high relative humidity of the air inside the pot, the tendency of water molecules to convert from liquid to vapor decreases. Overall, the results of this study showed that it is possible to plant crops such as rice in a closed environment in terms of humidity.

Accurate modeling of the drainage basin, including its spatial and temporal distribution of hydrological parameters and rainfall-runoff process, is very important in many applications. As an example, design flood estimation in hydraulic structures, which has the main role in the construction cost, is a result of rainfall-runoff simulation. The Rudbar Lorestan dam project is a part of the hydroelectric development projects complex in the Dez River basin. This project is located in a mountainous zone 200 Km away from Isfahan on the Rudbar River and 100 Km away from the south of Aligudarz. The aim of the Rudbar Dam and power plant project was to use the hydroelectric potential that is caused by the different elevations between the dam position and the power plant location. Due to the About 300 Meters difference in elevation from the dam axis to the power plant location set as one of Iran's prominent hydroelectricity projects. There are many consulting engineers in these projects, previous studies, and their main study result (flood design) shows a 17% difference from each other. due to the significant mentioned difference caused by using experimental methods and personal judgment, an effort was made in this research to simulate a large part of the Rainfall-Runoff process and model the water movement current on the basin surface with WMS software, and by taking the results of previous studies, the results of executing point of view and theory point of view had been compared. For this purpose, two internal and external representative basins were simulated, and the results were compared to evaluate the ability of the model. Simulating the main basin refuses the older studies by the difference near 20%, and confirms the newer studies by a difference of about 10%.

Drought begins with a lack of rainfall and depending on its duration and severity, Drought can affect parameters such as soil moisture, volume of surface and subsurface water, and human and ecosystem activities. For this purpose, in this research, by using the estimated soil moisture data by the SWAP model and the data of the fifth climate change report, agricultural drought was determined by using of the soil moisture deficit index for the future period (2020-2039) and then they compared with the base period (1992-2011). The results showed that the climatic parameters such as minimum temperature, maximum temperature and precipitation have increased in the future period compared to the base period. The RCP8.5 scenario has estimated the temperature is higher and the precipitation is lower compared to the RCP4.5 scenario. Moisture changes at a soil depth (30 cm) showed that the percentage of soil moisture increases slightly for each scenario in the future period (2020-2039) compared to the base period (1992-2011). The presence of error values of R2=0.81, NS=0.79 and RMSE=0.02 showed that there is a high correlation between the measured and observed results of soil moisture obtained from calibration and validation of the SWAP model. The results show that calculated SMDI drought index values in the future period (2020-2039) for RCP4.5 scenario has higher than the RCP8.5 scenario, and the predicted SMDI value for the future period is higher than the base period. The results of SMDI drought index uncertainty under RCP4.5 and RCP8.5 scenarios showed that CanEsm2 model has the most certainty and IPSL models have the least certainty compared to other models. The results of this research determined that drought can be estimated in the future by using the vegetation model.

Bandsar is a traditional large plot, which is built by creating an embankment on the level lines in the plains around ephemeral rivers, or is built across the waterways like small dams in the hill region, and directing and maintaining the flood or runoff of the hillslopes and uplands. So, it is a solution for harvesting rainwater in arid and semi-arid areas. Therefore, the purpose of this research is to locate and prioritize the suitable areas of the Bandsar in the watersheds of the Qaenat region to control floods, recharge the Qanats, wells, and springs in arid areas with the Best-Worst Method (BWM) and Geography Information System (GIS). In order to determine and locate suitable sites for the construction of Bandsar from 12 different criteria, including slope, distance from rivers, distance from villages, distance from Qanats, distance from roads, distance from faults, distance from wells, geomorphology, geology, permeability, available source, and land use has been used. Criteria were weighted using the BWM method, and the priority of each criterion was determined. Results showed that among the considered criteria, distance of river with a weight of 0.214 has the first rank, permeability with a weight of 0.151 has the second rank, and slope with a weight of 0.1123 has the third rank. The study area divided into 12 zones based on natural resource priority, that named the English alphabet (A-J). Finally, region B with a score of 0.63 is the best region and region J is the worst region with a score of 0.15.

This research investigates the utilization of copula functions in the water resources field, encompassing meteorological and hydrological aspects. A review of the Web of Sciences archive revealed 15143 studies featuring copula keywords. Notably, 40% of these studies pertain to copula-based simulation within this field. Groundwater studies were the least conducted, accounting for only 3% of all studies in the field. Regarding copula functions, studies were generally divided into two parts: frequency analysis and simulation, encompassing all dimensions of copula functions. Researchers confirmed the performance of copula functions in both parts. Studies in copula functions have revealed a new approach in joint frequency analysis and conditional probability estimation, based on the marginal distribution of data and their conditional density. The results indicate that in more than 2 dimensions, the tree sequence of vine copula has reduced computational complications and allows for the determination of different structures based on independent and dependent variables. Various studies have shown that the use of copula functions has been successful due to its lack of assumptions and restrictions and has good performance. For this reason, this approach is considered. The approach has been increasingly utilized in 2-dimensions and multi-variables, and continues to progress and develop.

Considering the climatic changes and the increase of extreme values in recent years, in this study, the effect of time series decomposition based on wavelet transform in improving the performance of the optimized support vector regression model in the simulation of annual precipitation in Dashband and Tapik stations has been discussed and investigated in the Lake Urmia Basin in the period of 1971-2020. In this study, the Ant colony algorithm was used to optimize the parameters of the support vector regression model. Daubechies 4 wavelet with three decomposition levels 1, 2 and 3 was used to decomposition the time series of precipitation in the studied stations. The SVR model takes in annual precipitation data as input, while the decomposition-based models take in decomposed precipitation values. The results of investigation the error rate and efficiency of the 4 investigated models include optimized SVR, W1-SVR (optimized SVR based on level 1 decomposition), W2-SVR (optimized SVR based on level 2 decomposition) and W3-SVR (optimized SVR based on level 3 analysis) showed that the error rate of all 4 mentioned models is acceptable and the observed values are in the 95% confidence interval. The error rate of 5.20 and 6.68 mm in the simulation of precipitation in Dashband and Tapik stations using the optimized SVR model by time series decomposition based on wavelet theory in level 1 decomposition in the mentioned stations, 31 and 35 percent improvement has been found. The level 2 decomposition of the time series of precipitation obtained the lowest error among the different levels of decomposition, which was 3.42 and 3.26 mm in Dashband and Tapik stations, respectively. Considering the increase in simulation complexity with the involvement of wavelet theory, the error rate improvement and model performance are acceptable. The hybrid W-SVR model in this study provides reliable results for precipitation simulation. Analyzing the annual precipitation series makes it possible to develop the dimensions of the optimized SVR model.