Showing 46 results for Soltani
A. Talebi, F. Souzandehpour, M. T. Dastorani, A. A. Karimian, M. Soltani,
Volume 19, Issue 72 (summer 2015)
Abstract
Land use is one of the basic factors for controlling the hydrologic behavior of watersheds. Therefore, it is generally assumed that land use change is the cause of variation in hydrological dynamic of watersheds. In this paper, the land use effect in present and optimum conditions on sedimentation of watershed was studied using GIS and applying the HEC-HM model in Shoor-Shirin watershed in Fars province. Land use map was provided based on curve number map, and this map was considered as the important factor for HEC-HM model. The results showed that the estimated sediments in two different conditions were completely different. In fact, the estimated sediment in the optimum condition was 12% less than the current land use. This means that land use change and land use type play important roles in decreasing or increasing the peak flow and erosion.
S. Azadi, S. Soltani Kopaei, M. Faramarzi, A. Soltani Tudeshki, S. Pourmanafi,
Volume 19, Issue 72 (summer 2015)
Abstract
The Palmer Drought Severity Index (PDSI), which uses hydrometeorological variables to solve a simple water balance equation in the soil and considers the drought or wet conditions as dynamic phenomena, is used for the assessment of drought conditions in many parts of the world. The main goal of this study was to assess the PDSI based on its original assumptions, its regionalized status, using the outputs of already calibrated and validated SWAT model in central regions of Iran. The PDSI was assessed through five methods: 1) original Palmer Index without calibration in which the climate coefficients and the severity equation were derived for Kansas and central Iowa 2) original Palmer Index in which the coefficients of severity equations were adjusted 3) the Palmer Index with the calibration of equations in central areas of Iran 4) the Palmer Index using the soil moisture and potential evapotranspiration from SWAT model and 5) the Palmer Index using the soil moisture, potential evapotranspiration and runoff from SWAT model. The evaluation was conducted for 17 major basins covering the entire country with a monthly time step for the period 1990-2002. Then, using all five methods, the severity of the drought for 160 sub basins located in central Iran was calculated and evaluated. The results of this study indicated that method 4 provides more acceptable results. Also, the results of this research showed these methods clearly demonstrated (1992) as the wettest year and (2001) as the driest year. The approach used in this study is applicable to regional calibration of Palmer Index and the outputs of other hydrological models.
J. Abedi Koupai, S. Soltanian, M. Gheysari,
Volume 19, Issue 72 (summer 2015)
Abstract
Lack of knowledge on soil geotechnical properties can cause many problems in the construction and maintenance of irrigation and drainage networks. In general, all of unconventional soils such as gypsiferous soils can cause some problems to irrigation canals. Some studies have been conducted on a variety of problematic soils, but still there is a need for more research activities and field studies. This research was conducted to study the impact of adding perlite and pumice (5%, 10% and 15%) and micro silica (1%, 5% and 10%) on some mechanical properties of soil including shear stress, bearing capacity and Atterberg limits. Statistical analysis was done to compare their averages (P<0.01). Results showed that micro silica had the most effect on shear, bearing and condensation parameters and Atterberg limits of gypsiferous soil, and it improved these parameters of soil. Pumice improved shear, bearing and condensation properties of gypsiferous soil. Perlite reduced the shear, bearing and condensation properties of gypsiferous soil.
N. Moshtagh, R. Jafari, S. Soltani , N. Ramezani,
Volume 19, Issue 73 (fall 2015)
Abstract
Spatial estimation of evapotranspiration (ET) rates is essential for agriculture and water resources management. This study aimed to estimate ET v an ET estimation algorithm called Surface Energy Balance Algorithms for Land (SEBAL) and also by using TM June 2009 satellite data in Damaneh region of Isfahan province. To calculate the ET, all the energy balance components and related parameters including net radiation, surface albedo, incoming and emitting shortwave and longwave radiation, surface emissivity, soil heat flux, sensible heat flux, NDVI vegetation index, Leaf Area Index(LAI), and surface temperature were extracted from the geometrically and radiometrically corrected TM images. Results showed that ET rate was about 7.2 mm day-1 in agricultural areas, which was almost equal to 6.99 mm day-1 extracted from the FAO Penman-Monteith method in the synoptic weather station of Daran. Results here indicate that the extraction of ET rate which is almost equal to plant water requirements from remote sensing data can be used in selecting appropriate plants for agriculture and rehabilitation purposes in extensive arid and semi-arid regions of Isfahan province where severe droughts and water shortage are major problems.
H. Daliran Firouz, F. Mokhtari, S. Soltani , S. A. Mousavi,
Volume 19, Issue 74 (Winter 2016)
Abstract
Floods are considered as most destructive among all natural hazards which impose lots of damages on human societies. Hence, it is important to estimate such damages and losses and to determine flood impact areas for management plans. HEC-FIA software as a new model (Sep. 2012) was used in Ghohrood and Ghamsar watershed basins to estimate flood-driven losses and impacts. In this model, HEC-RAS and HEC-Geo RAS are used to produce inundation map in different return periods of flood as HEC-DSS file and by using the data collected in relation to regional agricultural land, building and human, human and financial losses are directly estimated. According to the results of this model, agriculture, building and human losses respectively in Ghohrood watershed are about 354 million rials with 24 buildings affected, and in Ghamsar watershed this is about 12879 million rials with 36 buildings damaged. The advantages of this model over the previous models are estimating the direct economic and human losses for what has occurred and for possible floods in the future. The results can help with watershed management, flood insurance and risk management.
P. Almasi, S. Soltani, M. Goodarzi, R. Modarres,
Volume 20, Issue 78 (Winter 2017)
Abstract
With regard to the confirmation of climate change in most regions of the world and its effects on different parts of the water cycle, knowledge of the status of water resources is necessary for proper management of resources and planning for the future. Hence many studies have been done in different areas with the aim of analyzing the impact of climate change on hydrological processes in the upcoming periods. In present research, the effect of climate change on surface runoff in Bazoft watershed has been studied. Bazoft watershed, located in North-West of Chahar Mahal & Bakhtiari province, has significant contribution in the production of water resources of the region due to its special topographical and geographical status. In this study, climatic model – HadCM3- and A2 and B2 emission scenarios have been used to assess uncertainty in forecasting climate change. For this purpose, a statistical model –SDSM- has been applied to downscale large- scale precipitation and temperature data and hydrological model –WetSpa- has been used to simulate runoff. After calibration of the hydrological model, downscaled precipitation and temperature data in near future (2020-2050) and far future (2070-2100) periods were introduced to WetSpa model and runoff was simulated for mentioned periods. Results of this study represent suitable performance of SDSM model in downscaling climatic data, especially minimum and maximum temperature. Also, performance evaluation of Wetspa model shows proper performance of this model for runoff simulation in Bazoft watershed, so that Nash- Sutcliffe efficiency during calibration and validation was 0.63 and 0.65, respectively. Moreover, assessing the amount of predicted runoff for future periods indicates an increase in annual runoff in the Bazoft watershed under both A2 and B2 scenarios.
S. Pourhossein, S. Soltani,
Volume 22, Issue 2 (Summer 2018)
Abstract
Bhalme & Mooley Drought index is one of common indices used in drought studies. Due to the fact that drought indices can have different sensitivities to different region conditions and the length of data recorded, 62 synoptic and climatological stations were selected within a homogonous region to study this index advantages and to assess the effect of climate, precipitation regime, and data record on the index. The best results were found for the humid climate. Also, this index had acceptable results for semi- mediterranean regimes regarding all different time scales,; however the situation was different for Mediterranean regimes, showing the best results for the time scales simultaneous with the precipitation period. From the data record point of view, the best results were estimated during the first 31- years of the common period which has correspondence with the results of the 36-year period.
M. H. Tarazkar, M. Zibaei, G.r. Soltani, M. Nooshadi,
Volume 22, Issue 2 (Summer 2018)
Abstract
Nowadays, water resource management has been shifted from the construction of new water supply systems to the management and the optimal utilization of the existing ones. In this study, the reservoir operating rules of Doroodzan dam reservoir, located in Fars province, were determined using different methods and the most efficient model was selected. For this purpose, a monthly nonlinear multi-objective optimization model was designed using the monthly data of a fifteen-year period (2002-2017). Objective functions were considered as minimizing water scarcity index in municipal, industrial, environmental and agricultural sectors. In order to determine the operating rule curves of reservoir, in addition to the nonlinear multi-objective optimization model, the methods of ordinary least-squares regression (OLS), fuzzy inference system and adaptive network fuzzy inference system (ANFIS) were used. Also, the reliability, resiliency, vulnerability and sustainability criteria were used to compare the different methods of reservoir performance rules. The results showed that ANFIS model had the higher sustainability criterion (0.26) due to its greater reliability (0.7) and resilience (0.42), as well as its lower vulnerability (0.13), thereby showing the best performance. Therefore, ANFIS model could be effectively used for the creation of Doroodzan reservoir operation rules.
R. Soltani, M. R. Mosaddeghi, M. Ayuni, Sh. Ayoubi, M. Shirvani,
Volume 23, Issue 1 (Spring 2019)
Abstract
Long-term use of treated wastewaters for irrigation adds compounds and/or ions to soils which might alter the soil physical, hydraulic and mechanical properties. Soil mechanical properties are closely linked with the plant growth. This study was conducted to investigate the effect of short-, mid- and long-term applications of the treated wastewater of Mobarake Steel Company in Isfahan on the soil penetration resistance and shear strength in the company green space. Soil penetration resistance and shear strength were measured using a pocket penetrometer and in situ shear box, respectively. The results showed that soil penetration resistance (i.e. soil hardness) at both dry and wet conditions significantly was increased upon short-, mid- and long-term applications of wastewater; 19 years of the application of wastewater resulted in the highest soil penetration resistance at wet condition, but the well water did not significantly affect it. Surface crust in the non-irrigated locations increased the soil penetration resistance, but the irrigated sealed soils were not significantly different from the virgin soil in terms of dry and wet penetration resistances. For the soil shear strength parameters, wastewater, well water and surface crust did not significantly affect soil cohesion (c), they but significantly affected the angle of internal friction (φ). Overall, soil shear strength parameters were not greatly affected by the irrigation water treatments because of the dominant effect of the soil fractions (texture and gravel content) and the microstructure.
S. V. Razavi Termeh, K. Shirani, M. Soltani Rabii,
Volume 23, Issue 2 (Summer 2019)
Abstract
Today, supplying water to meet the sustainable development goals is one of the most important concerns and challenges in most countries. Therefore, identification of the areas with groundwater potential is an important tool for conservation, management and exploitation of water resources. The purpose of this research was to prepare the potential groundwater map in Nahavand, Hamedan Province, using the weight of evidence model and combining it with logistic regression. For this purpose, the information layers of slope angle, slope aspect, slope length, altitude, plan curvature, profile curvature, TWI, SPI, distance from fault, fault density, distance from river, drainage density, lithology and land use were identified as the factors affecting groundwater potential and digitized in the ArcGIS software. After designing the groundwater potential map with these three methods, ROCs were used to evaluate the results. Of 273 springs identified in this study, 191 (70%) were used to prepare the groundwater potential map and 82 springs (30%) were used to evaluate the model. The area under curve (AUC) obtained from the ROC curve showed an accuracy of 80.4% for the weight of evidence model and 82.5% for the weight of the evidence- regression combined model
S. Jafari, M. Golsoltani, M. Lajmir-Orak Nejati,
Volume 23, Issue 3 (Fall 2019)
Abstract
The aim of this study was the effect of raw water quality on the efficiency of domestic reverse osmosis apparatus in Khuzestan province. The results showed that the purified water quality was related to the quality of entrance raw water. With increasing in salt concentrations (EC) or TDS, purification efficiency was decreased. The cation and anions content of refinery water was related to TDS and EC. The Ca/Na and Mg/Na were decreased due to refinery. The ability of these apparatus to reduction of two valence cations were more than mono valence. As same as this trend was observed for anions. Also, the comparison of the EC of raw water and refinery from these apparatuses had different EC from different raw water entrance. This means of these apparatuses had different efficiency with changes of raw water quality. Generally, domestic water purification systems have better performance in Karun river water treatment than in Kheiryrabad and Karkheh rivers.
M. Madanian, A. R. Soffianian, S. Soltani Koupai, S. Pourmanafi, M. Momeni,
Volume 23, Issue 4 (winter 2020)
Abstract
Land surface temperature (LST) is used as one of the key sources to study land surface processes such as evapotranspiration, development of indexes, air temperature modeling and climate change. Remote sensing data offer the possibility of estimating LST all over the world with high temporal and spatial resolution. Landsat-8, which has two thermal infrared channels, provides an opportunity for the retrieval of LST using the split- window method. The main objective of this research was to analyze the LST of land use/land cover types of the central part of Isfahan Province using the split- window algorithm. The obtained results demonstrated that the "other" class which had been mainly covered with bare lands exhibited the highest LST (50.9°C). Impervious surfaces including residential areas, roads and industries had the LST of 45°C. The lowest temperature was observed in the "water" class, which was followed by vegetation. Vegetation recorded a mean LST of 42.3°C. R2 was 0.63 when regression was carried out on LST and air temperature.
H. Alizadeh, A. Hoseini, M. Soltani,
Volume 24, Issue 3 (Fall 2020)
Abstract
The construction of irrigation network and the water transfer from Karkheh Dam to Dashte-Abbas, due to neglecting the groundwater resources has increased groundwater level and waterlogging of the agricultural land in the recent years. The aim of this study was, therefore, to optimize the conjunctive use of surface and groundwater resources in Dashte-Abbas to minimize waterlogging problems and achieve the maximum net income. For this purpose, the behavior of groundwater was simulated using the system dynamics (SD) approach. The conjunctive use of surface and groundwater resources was then optimized using the Vensim multi-criteria optimization method with the objective function of maximizing the net income of the plain. The SD model calibration was done using climatic, hydrological, agricultural, and environmental data from the 2001-2009 time period; then it was validated based on the information from the 2009-2016 period. Evaluation of the developed SD model showed that the model had high accuracy in simulating key variables such as groundwater levels (ME=60cm, R2=97%, RMSE=47cm) and groundwater salinity (RMSE=100μS/cm, R2=74%, and ME=123μS/cm). Furthermore, the results of the optimization model showed that the optimum use of surface and groundwater resources for the agricultural demand was 65% and 35%, respectively. To sum up, it could be concluded that with the optimization of the conjunctive use of surface and groundwater resource, s about 10 MCM of water consumption could be annually saved to irrigate almost 800 ha of the new lands.
P. Mohit Esfahani, S. Soltani, R. Modarres, S. Pourmanafi,
Volume 24, Issue 3 (Fall 2020)
Abstract
Drought, as one of the most complicated natural events, causes many direct and indirect damages each year. Hence, single variable identification and monitoring of drought may not be appropriate enough for decision-making and management. In this study, in order to monitor the meteorological-agricultural drought in Chaharmahal and Bakhtiari province, Multivariate Standardized Drought Index (MSDI) was calculated using precipitation and soil moisture variables. In addition, to evaluate the performance of MSDI in drought identification and monitoring, Standardized Precipitation Index (SPI) and Standardized Soil Moisture Index (SSI) were used for meteorological and agricultural drought monitoring, respectively. MSDI was calculated based on the soil moisture and precipitation joint probabilities. We used the Gringorten probability as an empirical method and Archimedean copulas as the parametric method to calculate the joint probability between soil moisture and precipitation time series. The results indicated that MSDI was twice more capable of detecting drought as SSI and SPI. Furthermore, the MSDI-based drought monitoring results showed Charmahal and Bakhtiari province had experienced severe meteorological-agricultural drought in 2000, 2008, 2011 and 2014.
F. Saniesales, S. Soltani, R. Modarres,
Volume 25, Issue 2 (Summer 2021)
Abstract
Several indices are used for drought identification and quantification. In this paper, the new Standardized Palmer Drought index (SPDI) was introduced and then the drought condition of Chaharmahal-Va-Bakhtiari Province was studied using this index. For this study, 11 synoptic, climatology, and evaporation meteorology stations were selected. Essential information in this investigation includes monthly temperature, monthly precipitation, and soil moisture measurement. To estimate SPDI, moisture departure, was first calculated on a monthly time scale. Then, converted to cumulative moisture departure values in different time scales including 3, 6, 9, 12, and 24 months. The best statistical distribution (GEV) was then fitted to cumulative departure. These values were then standardized to have the SPDI. The results showed that, as soil moisture affects SPDI estimation, it will be more valid for analyzing and monitoring drought conditions, especially for agricultural drought. Also, the results showed that 2000, 2001, and 2008 years were the driest time in this Province from 1988 to 2012. Moreover, drought frequency was found out in the western half of the Province more than in the other parts.
S. Parvizi, S. Eslamian, M. Gheysari, A.r. Gohari, S. Soltani Kopai, P. Mohit Esfahani,
Volume 26, Issue 3 (Fall 2022)
Abstract
Investigation of homogeneity regions using univariate characteristics is an important step in the regional frequency analysis method. However, some hydrological phenomena have multivariate characteristics that cannot be studied by univariate methods. Droughts are one of these phenomena their definition as univariate will not be effective for risk assessment, decision-making, and management. Therefore, in this study, the regional frequency analysis of drought was studied in multivariate methods using SEI (Standardized Evapotranspiration Index), SSI (Standardized Soil Moisture Index), and SRI (Standardized Runoff Index) indices in the Karkheh River basin from 1996 to 2019. The indices calculated probabilistic distribution between the variables of evapotranspiration, runoff, and soil moisture using multivariate L-moments method and Copula functions and considered meteorological, agricultural, and hydrological droughts simultaneously. The results of multivariate regional frequency analysis considering the Copula Gumbel as the regional Copula showed that the basin is homogeneous in terms of severity of SEI-SSI combined drought indices and is heterogeneous in terms of severity of SEI-SSI combined drought indices. However, after clustering the basin into four homogeneous areas in terms of characteristics of SPI (Standardized Precipitation Index), the basin is homogeneous in all areas in terms of univariate SEI, SSI, and SRI indices and is heterogeneous in the third and fourth clusters of SRI and SSI drought indices. Pearson Type (III), Pareto, normal, and general logistics distribution functions were found suitable to investigate the characteristics of SEI, SSI, and SRI drought indices in this case. Finally, large estimates of the types of combined droughts and their probability of occurrence showed that the northern and southern parts of the Karkheh River basin will experience short and consecutive droughts in the next years. Droughts in areas without meteorological data can be predicted in terms of joint probability using the multivariate regional frequency analysis method proposed in this study.
R. Khalaf, A.m. Akhoond-Ali, Saeid Soltani, K. Rezazadeh,
Volume 27, Issue 1 (Spring 2023)
Abstract
Due to developing abstractions and their impacts on surface runoff, the recorded flow has been changed by human activities in most water gauging stations. Therefore, there is not found natural regime in the catchments. Accordingly, the objective of naturalization is to remove the effect of human activity factors and determine the actual amount of the river flow before the abstraction and the upstream development. Researchers have presented different methods that are mainly based on volume budget. In this way, this research presented the conventional methods as well as investigated their weak points. These new and innovative methods have been applied based on the available data. The methods have been planned based on the net consumption in which, the different types of water demands related to the upstream of each hydrometric station, are estimated for each month of a long-term series. Then, the amount of natural flow is determined by adding them to the observed flow. The accuracy and validation of the results are investigated by comparing the observed and calculated flow. As a case study, this method was utilized and implemented for Tireh and Marbareh sub-basins in Dez as well as Solgan and Beheshtabad sub-basins in the Karun basin. The results showed the role of the human activity factors decreasing the long-term outflow in the Tireh basin a 23.2%, in the Marbareh basin a 28.7%, in the Vanak watershed a 26%, and in the Beheshtabad basin a 9.5%. The results validation indicated the appropriate compatibility of the observational and estimated data for the control points (the stations). In this research, natural flow is obtained by presenting a practical method based on available information in the country. The proposed method has been in the preliminary stages. To verify and comprehend it, it should be used in future research on the interaction of surface and underground water and the use of new technologies such as remote sensing.
S. Gholizadeh Tehrani, S. Soltani Koupai, R. Modarres, V. Chitsaz,
Volume 27, Issue 3 (Fall 2023)
Abstract
Drought is one of the most destructive and important climate phenomena, whose effect is usually more important on a regional scale. The importance of this phenomenon is more evident in the Karkheh basin due to its size and important role in providing the country's water resources. We aim to monitor hydrologic drought using the accurate calculation of standardizes streamflow index (SSI) in one month time scale based on fitting frequency distribution to monthly data and goodness of fit test for each station in Karkheh basin for 30 years (1986-2016). The findings of this research showed that the generalized Pareto distribution was selected as the most appropriate distribution in most months, unlike the previous research that fitted and used only the Gama distribution on the data. The time series of the standard flow index indicated the occurrence of super-drought in 2008 to 2015 years. Also, the significant impact of the construction of hydraulic structures upstream of the basin on the average flow rate was observed in some stations. The results of direct and annual monitoring of the drought situation showed that the Karkheh basin has experienced hydrological drought in recent years, and the drought trend is increasing.
A. Mahdavi, S. Soltani Koopaei, R. Modares, M. Samiei,
Volume 27, Issue 4 (Winter 2023)
Abstract
Land use changes are one of the main factors in the amount of surface runoff changes in watersheds. Therefore, it is necessary to investigate it to reduce the damages (human and financial) caused by floods and to modify watershed management. The watershed of Nahre Azam is located in the north of Shiraz city and a lot of loss of life and money to the residents of Shiraz due to floods has occurred in previous years. The present research was conducted to investigate the relationship between land use change and runoff in the Nahre Azam watershed in Shiraz using the SWAT model in the period of 2004-2020. The model was calibrated using data from 2004 to 2014 and validated for 2015 to 2020. These images were classified into 6 main land uses using the supervised classification method after performing necessary pre-processing, and a land use map was prepared for 2040 using the Markov chain method. Then, the effect of the land use change in 2003 and 2040 on the amount of simulated runoff was evaluated with the recalibrated model. The calibration results of Nahre Azam watershed for the values of statistical parameters in the calibration step for the coefficient of determination, P-Facor and R-Facor are 0.77, 0.72, and 2.43, respectively, and for the validation step we obtained 0.69, 0.65, and 2.3 respectively. The analysis of the land use map showed that the main land use change in the region related to the conversion of pastures to agricultural land and urban land, which caused a decrease in pastures. Also, the results of the model simulation using the land use maps of 2003 and 2040 indicated that the amount of runoff decreased. The results revealed that if all the uncertainties are minimized, the calibrated SWAT model can produce acceptable hydrological simulation results for the user, which is useful for water resource and environmental managers and politicians as well as city managers of Shiraz.
M.j. Aghasi, S.a.r. Mousavi, M. Tarkesh, S. Soltani,
Volume 28, Issue 3 (Fall 2024)
Abstract
Astragalus is the vegetation of many mountains of Iran's plateau and plays a major role in providing ecosystem services due to its pillow shape and deep rooting system, they facilitate the control and penetration of precipitation into the soil. The correlation of Astragalus ecosystems with arid and semi-arid climates has made them vulnerable to climate change. In this study, a runoff yield map based on the Budyco curve under current and future conditions of climate change (2050) was prepared using climate and temperature data from the Chelsea site (CanESM2 GCM) in TerrSet software and by using maps of sub-watersheds, annual precipitation, annual potential evapotranspiration, soil depth, plant accessible water and the current and future "Land Cover - Land Use" map, with a combination of field methods and species distribution models at the local scale of the Shur River watershed of Dehaghan (Central Zagros). Finally, the excess runoff damage produced due to climate change was estimated using the replacement cost method. The results indicated an increase in the annual runoff volume of the watershed from 70 million cubic meters to 105 million cubic meters under climate change conditions for the RCP26 scenario in 2050. Taking into account the cost of 10 million Rials for controlling 530 cubic meters of runoff through various watershed management projects, preventing the damages of excess runoff produced requires a credit amounting to 660 billion Rials based on the present value. This study proved the ability of TerrSet software to predict and produce an ecosystem service map of runoff yield under climate changes or land use changes and with the purpose of valuation on a local scale. Also, the above valuation can be the basis for planning and providing credit for the study and implementation of watershed management projects to deal with the threats of climate change.
