فهرست مطالب

Water Harvesting Research - Volume:5 Issue: 1, Winter and Spring 2022

Journal of Water Harvesting Research
Volume:5 Issue: 1, Winter and Spring 2022

  • تاریخ انتشار: 1401/04/22
  • تعداد عناوین: 12
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  • Rahim Kazemi *, Bagher Ghermezcheshmeh Pages 1-8
    Low flows are one of the most important hydrological parameters required for quantitative and qualitative analysis of watersheds and play an important role in water resources engineering and management. In this study, 9 low flow indices including mean annual 3,7,15,30, days average minimum flow, flow duration curve indices (FDC) and exceeded 95, 90, 75 and 25% of the time respectively, and base flow index (BFI) were used. Daily stream flow of 20 hydrometric stations with a period of 30 years were used. BFI was extracted using One-parameter recursive digital filter algorithm and FDC indices were determined by plotting FDC. Then, the relationships between selected indices were analyzed. The results showed that there was a good correlation between base flow and FDC indices with a coefficient of determination above 68%. MAM3, MAM7 and MAM30 indices had a good correlation with a coefficient of determination higher than 0.90 and a suitable standard error for FDC indices that can be used for regional analysis of low flow. The MAM30 low flow showed the minimum standard error and the maximum coefficient of determination with FDC indices. The MAM15 low flow index had no correlation with FDC indices and not recommended for regional analysis of low flow in the research area.
    Keywords: Base flow index, FDC, Hydrograph analysis, Iran
  • Hadi Memarian *, Firozeh Amirafzali, Seyed Mohammad Tajbakhsh, Abolfazl Akbarpour Pages 9-20

    Due to the fact that ecosystems are more fragile and sensitive in arid and semi-arid regions of the world, the phenomenon of floods and the resulting damage and loss will be more severe in these areas. The subject of river canals and their morphology is one of the key topics in engineering and river management, which can be used to obtain a useful set of information about the geometric shape, bed shape, longitudinal profile, cross sections, over time. Default geometric relationships in hydrological models such as Kineros2 are based on field measurements in US watersheds and cause uncertainty in model results. Therefore, the purpose of this study is to determine the regional statistical relationships between the width and depth of the canal with the area of the upstream watersheds for employing in hydrological models such as Kineros2, and the width and depth of the canal with other basin characteristics. The data in this research are mainly topographic maps of Neishabour Bar watershed. Thus, according to topographic maps, preliminary studies were carried out to identify sub-basins. In this study, the basin is divided into 34 sub-basins that involve Lar Formation (in 16 sub-basins), and marl (in 18 sub-basins), where, 27 sub-basins in upstream are non-orchard lands. The linear and nonlinear regressions and equations were studied and evaluated using the software such as Excel, SPSS, Curve Expert, and XLSTAT. The results of correlation of physical parameters with canal width and depth, nonlinear regression analysis and analysis of variance in the relationships between canal depth/width with upstream area in the whole basin (R2=0.58 for canal depth and R2=0.14 for canal width), in upstream Lar formation, in downstream and non-orchard lands, showed a greater impact of the upstream acreage on the canal depth relative to the width (due to the higher coefficient of determination and less error). Furthermore, the separation of sub-basins in terms of geological formation and the presence of orchards had a significant effect on improving equations and reducing errors. The greater impact of the canal depth than the width from the upstream area is mostly related to successive droughts and the absence of flash floods in the area to change the canal depth, while the width of the canals has been mainly a function of human manipulations on the river bed. Stepwise linear regression analysis also showed a higher correlation between canal depth than the canal width with the physical parameters of the basin (R2=0.85 and R2=0.77, respectively).

    Keywords: Canal width, depth, Regression analysis, River morphology, Semi-arid region, Statistical equations, Regional equations, watershed
  • Zakeyeh Aftabi, Morad Kaviani Rad, Hamid Kardan Moghaddam * Pages 21-30
    Climate change, disturbed various dimensions of national security within numerous countries. In the interim, declining the rainfall pattern in those countries which are positioned on the world desert strip, has had the greatest consequence and incidence on their food security sectors. This study objective is to investigate the impact of global climate change on nourishment security. The field study zone of this research is based upon analysis and data which had gathered from Iran. Due to the immensity of the study area, 6 provinces were selected by random sampling technique. To obtain the affiliation between climate change and the current food security complications, the rainfall data and the area under crop cultivation with rain fed planting method, the area under irrigated crops and the number of goats which have raised between 2004-2018 were applied within this research study. The Data which had accumulated was analyzed for variance in the R script environment. The conclusion of analyses of the researched variance showed that the amount of rainfall ratio had a positive and significant result; simultaneously, on the area under cultivation of rain- fed crops as well as the area under cultivation of irrigated crops system. The ratio of rainfall to the number of goats raised, except for the Chaharmahal and Bakhtiari Province, in the remaining states the outcomes were momentous.  Henceforth, by generalizing the sample to the statistical population, it can be expressed that the climate change has had a positive and substantial consequence on food security in Iran.Henceforth, by generalizing the sample to the statistical population, it can be expressed that climate change has had a positive and substantial consequence on food security in Iran.
    Keywords: Climate change, Food Management, Global Warning, R Software
  • Rahim Kazemi * Pages 31-39
    Understanding the flood phenomenon and its effective factors is, the prerequisite of its control and management. This phenomenon is influenced by hydrological, climatic and physiographic factors and it has always been one of the most important issues in hydrology. In this research 94 watersheds with corresponding hydrometric stations with the common period (1976-2011) were selected. Instantaneous peak discharge was calculated with a 50-year return period. 15 hydrological, climatic and physiographic parameters, affecting the flood intensity, including: average altitude, catchment area, Gravelius coefficient, slope, main river length, annual average precipitation, average number of rainy days, base flow index, hydrograph recession coefficient, curve number, permeability and percentage exceedances of, Q2, Q5, Q20 Q50 were calculated for each catchment. Factor analysis was performed after data standardization and the most important independent factors affecting flood intensity were chosen and multivariate regression equations were extracted by stepwise method. Results showed that R2 value of all models were between 82% and 93% and indicates that the models were in good agreement with the data. The first model yields an adjusted R2 of more than 88%. The second, 80% and the third model, more than 91%. The value of predicted R2 of models ranges between 74% and 80%. The Durbin Watson statistic were between 1.81 and 2. The first model yields a standard deviation of 2.1 and the second 1.4 and the third model, less than 2.7.
    Keywords: effective factors, Factor analysis, Flood intensity, Infiltration, Ungauged catchment
  • Hamzeh Noor *, Ali Bagherian Kalat, Ali Dastranj Pages 40-52
    Identification and prioritization of critical sub-watershed is essential to sediment control at watershed scale. Many studies have been carried out on the topic of identifying and prioritizing the critical source areas (CSAs); however, only few researches have been conducted to prioritize sub-watersheds in terms of their contributions to the sediment yield of the main watershed outlet. In fact, observations alone are not enough for CSAs prioritization; hence, hydrological models may be applied for prioritization of sub-watershed. Therefore, in the present study, prioritization of sub-watershed was considered based on (1) on-site effects of soil erosion: specific sediment yield at sub-watershed scale (sediment yield/area), (2) offsite effect of soil erosion: sub-watershed contribution to the sediment yield of the main watershed outlet. In this study, Soil and Water Assessment Tool (SWAT) was applied for prediction of runoff and sediment load at sub-watershed scale and the main watershed outlet. The Unit Response Approach (URA) has also been applied to prioritize sub-watersheds in terms of their contributions to the sediment yield at the watershed outlet. The proposed model was applied in Mehran watershed, in West of Tehran (capital of Iran). The study watershed was divided into 37 sub-watersheds. The results showed that the contribution of sub-watershed No.14 and No. 17 had the largest sediment contribution into the main outlet of watershed. The results of this ranking can differ entirely from those based on single sub-watershed sediment production at the sub-watershed outlet. Targeting the placement of Best Management Practices, based on the CSAs concept, will assist sediment control in watersheds.
    Keywords: CSAs, Spatial Prioritization, Hydrologic model, Watershed management
  • Kourosh Kamali *, Davood Nikkami, Abdonnabi Abdoh Kolahchi, Asghar Pourghasem, Hojjatollah Kazemi Dogholsar, Davood Javadi Mojadad, Hamid Davoodi Pages 53-66
    Air humidity is one of the sources of water and one of the components of the hydrological cycle. All the water vapor caused by the radiation of the sun's energy does not turn into precipitation, but a part of it does not turn into precipitation due to its kamali low density and is scattered in the space in a visible or invisible form. The important issue is how to actualize this environmental potential. In order to collect water from the fog, small droplets that cannot rain must fall into the trap. This can be done in different ways, including the use of mesh nets and when the fog passes through them. The materials of these nets, along with environmental factors such as the frequency of fog and wind speed, have a significant effect on the volume of water collected. In this research, two types of fog water collection systems made of metal mesh curtain and polypropylene mesh with dimensions of 1*1 meter and each with three repetitions were designed and installed in the Vishki mountain village of Eshkevarat, Roudsar city, which had many foggy days. A one-year data review recorded 76 fogging incidents. In these events, the average performance of metal mesh and polypropylene mesh collectors was 6.14 and 6.48 (L m-2 day-1), respectively, which did not show a significant difference in the type of water absorbing nets. The average water collected for each square meter of metal net collectors was 466 (L year-1) and polypropylene net 492 (L year-1), which doubles the hope of developing this method in susceptible areas. The highest amount of water collected was in the months of May and August and the lowest was in the months of February and January. The benefit-cost ratio in this project for metal and polypropylene collectors was calculated as 1.77 and 1.96, respectively. Undoubtedly, fog harvesting is useful when access to other sources of water supply, including underground water sources and base water flow, is low and the people of the region feel the need for it.
    Keywords: Compatibility with water scarcity, Eshkevarat, Fog Collectors, water supply
  • Massoud Goodarzi *, Saeed Elmi, Ali Khalkhali Pages 67-79
    The Tropical Rainfall Measurement Mission (TRMM) provides an important rainfall database for hydrological applications in aquatic basins. However, its accuracy and usage have not been sufficiently studied due to the occurrence of network-scale rainfall and water basins. In this study, the accuracy of the prediction of TRMM 3B42 V7 rainfall values ​​in Iran is investigated. For conducting this study, the daily net precipitation values ​​of TRMM 3B42 V7 from an Iranian basin were extracted with a 0.25-degree spatial resolution over the period 01.01.1998 to 31.12.2015. Precipitation data recorded at synoptic stations were also provided during this period. The accuracy of TRMM precipitation is evaluated using the nearest neighbor spatial resolution function. The findings show that not only in terms of temporal coherence but also in magnitude, there was a significant difference between the predicted TRMM rainfall values ​​and the rainfall recorded by the stations. The bias value (BIAS), mean absolute error of magnitude (MAE) and root mean the square of error (RMSE) of the Caspian, Urmia, and Persian Gulf basins were reported much higher than in other regions. The Precipitation indicators of the probability of detection (POD), Fault Alert Ratio (FAR), Mean Critical Success Index (CSI) indicates lower accuracy for TRMM 3B42 V7 in the prediction of rainfall at the grid-scale and catchments of Iran.
    Keywords: accuracy evaluation, Fault Alert Ratio, precipitation, TRMM
  • Yahya Parvizi *, Mahmood Arabkhedri Pages 80-92
    In the analysis of the relationships between precipitation, flow and erosion events, large and important events that occur with a relatively long return period have a very high contribution to the sedimentation of the entire watershed. Today, the analysis of these events and their mutual behavior has been the focus of researchers. Dehgin representative and paired watershed is one of twelve representative and paired watersheds of the country, which are designed and equipped with the aim of obtaining basic hydrological data and other data needed for watershed management and also evaluating watershed management operations. However, comprehensive study has not been done to analyze and evaluate the quantity and quality of monitored data and data mining of climatic data, flow and soil erosion. In this research, while introducing precipitation extreme events, their impact on flow and soil erosion values in sample and control sub-watersheds of Dehgin watershed were compared. The results showed that data sufficiency in climate and flow monitoring units made it possible to provide a suitable and competent analysis of simultaneous rainfall and flow data as well as the comparison of control and sample sub-watersheds. Also, in the relevant rainfall and erosion events, clear and valuable analyzes of the difference in the behavior of the sample and control sub-watersheds can be observed against rainfall events. But the investigation of erosion and flow in the mentioned sub-watersheds was faced with few comparable scenarios. This shows that with the continuation of data collection in the long term, generalizable data can be obtained from this representative watershed for hydrological modeling in the watershed. In this watershed, extreme flow events have more consistency with higher intensity rainfall events with about 70% overlap in terms of time and quantitative ranking, but most of the extreme erosion events follow the maximum values of rainfall quantity.
    Keywords: erosion plot, extreme precipitation, flood hydrograph, paired watersheds
  • Zahra Baazm, Ehsan Mohtashami, Abolfazl Akbarpour * Pages 93-101
    Due to the difficulty in measurement of transverse velocity in floods, it is necessary to use appropriate models for this aim. Hydrodynamic complexity of the flow in the middle of the flood is another reason for usage of precise models. Accurate prediction of flows is very difficult due to the complexity of its nature and the lack of accurate data. Here, two-dimensional modeling of the flood has been done using the finite element method (FEM). The case study is a real field river. The achieved results from the finite element model are compared with the observational data at three stations. In order to evaluate the model performance, the root mean square error (RMSE) is calculated. The relative error and the RMSE are 0.143 and 0.229 m, respectively. This amount of value indicates the high accuracy of the proposed model. In addition, computational cost including time spending and efficiency of FEM is satisfactory and this model can be used as a good tool for flow simulation.
    Keywords: Finite Elements, Flood, River, Simulation, Shallow Water Equations
  • Parva Mohammadi, Kumars Ebrahimi *, Ali Vanaei, Javad Bazrafshan Pages 102-120
    Surface water, especially rivers, is one of the most important water resources that play an important role in supplying water for various activities. The purpose of this study was to investigate the temporal and spatial variability of water quality parameters in three different basins, in terms of land use, at 50 hydrometric stations in 9 rivers in the period 1992-2015 by using multivariate and GIS statistical methods. In this study, factor analysis based on 10 qualitative parameters was performed to determine the most important parameters affecting the surface water quality of the study area. The results of Principal component analysis showed that the North, Northwest and Southwest basins have two significant main components with 82.38%, 79.86% and 81.60% of the total variance, respectively. Cluster analysis of hydrometric stations located in northwestern and southwestern regions was divided into two clusters and north into three clusters. In the cluster analysis, some stations in Aji Chay, Atrak and Zayanderood rivers had different water quality characteristics than other stations. These stations are located downstream of the rivers. Based on the pattern of mean water quality parameters in GIS and land use map, station 2 had the lowest values for most parameters.
    Keywords: GIS, PCA, surface water quality, WARD
  • Mahtab Helmi, Abbas Khashei-Siuki * Pages 121-130
    Optimal exploitation of dams’ reservoirs and provision of dam downstream water demand is of great importance. The use of water resource planning models has been recently very effective. For this purpose, this paper has analyzed and investigated the optimal utilization of Galmandareh River basin water resources using a combination of MODSIM as a simulation model and election algorithm as an optimization model and the development of the EA-MODSIM model. The objective function of the problem was considered as minimizing the sum of squared deviations between the required amount and the amount released from the reservoir. Efficiency, reliability, and vulnerability in reservoir operation were also used to evaluate the proposed model. Results indicated the acceptable performance of the simulation-optimization approach used in the research to solve the problem of planning the optimal allocation of water resources at the basin. Studies showed that in the simulation-optimization approach, the amount of water demand in the basin increased by about 32% compared to the simulation model. The results of the reliability index for industrial, agricultural, and environmental demands at the dam downstream were 86, 87, and 96%, respectively. These results indicated the importance of adopting policies for the optimal exploitation of system reservoirs to increase the water supply and reduce the water resource loss at the level of the basin.
    Keywords: allocation, EA, modeling, MODSIM
  • Gholamreza Ahangi, Keivan Khalili *, Mohammad Nazeri Tahroudi Pages 131-143
    In this study, in order to analyze the frequency of surface water quality variables (EC-Cl and EC-SO4) and to simulate the dependent variables, the applicability of copula-based functions was addressed. Since meteorological and hydrological variables are dependent on other variables in their surroundings, their analysis using single variable models is not able to estimate the desired results. In this regard, EC, Cl and SO4 data were used in the period of 1971-2017 at Bitas, Gardeyagoub and Kotar stations in the Mahabadchai sub-basin in the south of Lake Urmia. By choosing log logistic, generalized extreme values and also log normal marginal functions, the superior copulas regarding the mentioned pair-variables were investigated. While confirming the accepted correlation between the investigated pair-variables in Bitas stations (EC-Cl=0.39 and EC-SO4=0.38), Gardeyagoub (EC-Cl=0.81 and EC-SO4=0.78) and Kotar (EC-Cl= 0.54 and EC-SO4=0.51) and also based on RMSE, MAE and NSE criteria, Galambos copula was chosen as the best copula in all stations. The joint analysis of the mentioned pair-variables using the Galambos copula led to the presentation of typical curves regarding the estimation of Cl and SO4 values corresponding to the specific EC unit with different probabilities in the studied stations. Given that the presented curves are based on the statistical distribution of data, they are specific to the studied station.
    Keywords: Bivariate Copula, Conditional density, Electrical conductivity, water quality