Showing 40 results for Safa
N. Parsafar , S. Marofi,
Volume 16, Issue 62 (Winte - 2013 2013)
Abstract
In this research, we estimated soil shallow depths temperatures using regression methods (Linear and Polynomial). The soil temperatures at soil depths (5, 10, 20, 30, 50 and 100 cm) were correlated with meteorological parameters. For this purpose, temperature data of Hamedan station (in the period 1992-2005) were employed. Soil temperature data were measured on a daily basis at 3 PM, 9 PM and 3 AM. MS Excel was used for deriving the regressions between soil temperature and meteorological parameters (air temperature, relative humidity and sunshine hours). The results showed that the highest coefficient of determination (R2) of the linear regression was between soil temperature in 20 cm soil depth and air temperature at 3 AM (R2= 98.15%) and the lowest value in 100 cm soil depth at 3PM (R2= 83.96%). Also, the highest R2 of non-linear regression was observed between soil temperature in 10 cm soil depth and air temperature at 3 AM (R2= 98.45%) and lowest value in 100 cm soil depth at 3PM (R2= 84.11%). The results showed that the highest and lowest values of R2 of linear relations between meteorological parameters (relative humidity and sunshine hours) and soil temperature were observed in 10 cm soil depth (at 3 AM) and in 100 cm soil depth, respectively. Correlations of soil temperature with air temperature were greater than those with the other two parameters. Moreover, R2 values of non- linear relation were higher than linear relation.
G. Yousefi, A. Safadoust, M. Mosaddeghi, A. Mahboubi,
Volume 17, Issue 65 (fall 2013)
Abstract
This study was conducted to assess the long-term effects of soil texture and crop management on transport of lithium (Li+) and bromide (Br-) under unsaturated flow conditions. Treatments were two different soil textures of clay loam and sandy loam to be cropped with either wheat or alfalfa for 4 years. Undisturbed soil columns were taken for the steady-state flow condition using tap water prior to applying a pulse of 0.005 M (C0) LiBr solution as the influent. Four pore volumes (4PV) leaching for each column was obtained. Bromide and lithium concentrations of the effluent (C) were measured in 0.2PV intervals using bromide selective electrode and flame photometer, respectively. Relative concentrations (C/C0) of Br- and Li+ in the effluent were drawn vs. pore volumes. The results showed that the effluent concentrations were significantly affected by crop type and soil texture (in combination by soil structure). The breakthrough curves illustrated the early appearance of Br- in the effluent due to anion repulsion and retarded movement of Li+ because of surface adsorption through the soil columns. Both Br- and Li+ concentrations decreased with time and converged at low levels justifying the minor effect of macropores on continuation of leaching and final transport via soil matrix. The Br- and Li+ concentrations were higher in the effluent of clay loam soil under alfalfa due to higher structural stability compared with sandy loam soil under the same crop. It was also shown that in both soil textures the concentrations of Br- and Li+ appeared to be higher under alfalfa than under wheat, indicating the importance of crop management in contaminant transport compared with soil texture. The trends of breakthrough curves of Li+ were similar to Br- with lower concentration in effluent as a result of its adsorbtion on active surfaces.
Y. Safari, I. Esfandiarpour Boroujeni,
Volume 17, Issue 65 (fall 2013)
Abstract
In order to study the precision of qualitative land suitability classification method for main irrigated crops (i.e. potato, sugar beet, wheat and alfalfa) in the Shahrekord plain, qualitative land suitability maps were obtained for all the studied crops according to representative pedon analysis using simple limitation method. In the next step, a regular grid sampling consisting of 100 sample points with a distance of 375 m was designed. Then all required analyses were done to recognize the suitability class of these sites for each land use. Finally, land suitability results for all the observation points in each map unit were compared with the results of its representative pedon. The results showed the average of measured compatibility between representative pedon and other observation points in each map unit in class and subclass levels was about 60 % and 38 %, respectively. Due to the generalization of representative pedon analyses to all unit area, the use of soil map units as land suitability units may lead to unsatisfactory results. Therefore, the use of representative pedon is not recommended in sustainable land management and precision agriculture. However, new techniques like geostatistics can be used to improve the conventional soil mapping methods.
N. Parsafar, S. Marofi ,
Volume 17, Issue 66 (winter 2014)
Abstract
In this study, a completely randomized experiment was designed with five irrigation treatments and three replicates. The irrigation programs were raw wastewater (T1), treated wastewater (T2), a combination of 50% raw wastewater and 50% fresh water (T3), a combination of 50% treated wastewater and 50% fresh water (T4), and fresh water (T5). The experiments were run within a greenhouse. The lysimeters were built up in September 2009 and they were filled with a two layer soil. The upper (30 cm) and lower (40 cm) layers were sandy loam and sandy clay loam, respectively. The results showed that the effects of watering treatments on transfer coefficients of heavy metals from soil to shoots (except Cd) and tubers of potato (except Zn and Cu) were significant (p <0.01). Maximum and minimum transfer coefficients of heavy metals were observed in the (T1) and (T5) treatments, respectively. Also, the transfer coefficients of Cd from soil to shoots were lower than tubers. In the case of Zn, Cu and Pb, transfer coefficients from soil to tubers were lower than shoots. In this study, the maximum transfer coefficients to shoots were Cd (0.331-0.463), Zn (0.383-0.230), Cu (0.173-0.386) and Pb (0.003-0.057), respectively. Maximum transfer coefficients toward tubers (except T5) were Cd (0.439-0.572), Cu (0.081-0.138), Zn (0.170-0.217) and Pb (0-0.017), respectively. The combination of wastewater and fresh water use in short-term irrigation might be feasible, but a heavy metal monitoring program is necessary.
I. Esfandiarpour Boroujeni, Y. Safari,
Volume 18, Issue 67 (Spring 2014)
Abstract
Comparison of the land suitability variations among the soil map units in viewpoint of pedodiversity indices may provide a good assessment of the soil mapping precision. The main objective of this study was to assess the significance of functional pedodiversity thorough two detailed map units for irrigated wheat and potato for class and subclass levels of suitability in the Faradonbeh plain, using Shannon and Simpson indices. First, soil samples at 35 and 47 sampling sites in the D and E map units, respectively, were collected from the depths of 0-25, 25-50, 50-75 and 75-100 cm. Then, the qualitative land suitability class and subclass of all sampling points for each studied land use, was evaluated based on simple limitation method. Although both indices showed higher values in the subclass level of suitability, but the average functional pedodiversity of the studied map units, indicate a significant difference (95% confidence level), just in this suitability level. It was observed that the significance of the pedodiversity indices is not influenced by the land use type or the analyzed diversity index. Hence, as a supplementary procedure to study the intra-unit variation of the soil maps, use of diversity indices may provide some worthwhile information
Gh. Vahabzadeh, A. Safari, M.h. Farhoudi, H.r. Abdollahi, H. Fathizad, Gh.r. Khosravi,
Volume 18, Issue 70 (winter 2015)
Abstract
In this research, sediment production and delivery amount by Darabkola forest roads was estimated using the SEDMODL model. To evaluate the model results, the sedimentation rate in the above roads was directly measured using rainfall simulator. Also, the paired t-test, BIAS, RE and RMSE were used to assess the results. The analysis showed that the rate of sediment production from study roads' surface using the SEDMODL model and direct measurement under the rainfall simulation were 420.97 and 341.19 tons per year, respectively, and rate of sediment delivered to the stream with sediment delivery ratios of 42% and 51%, respectively, was about 177.58 and 174.02 tons per year. Also, results of the statistical methods of BIAS, RE and RMSE for the aforesaid model were 0.04, 17.59 and 0.71, respectively, and at 95% confidence level, no significant difference was obtained between the observed and estimated data. Therefore, the aforesaid model has the appropriate accuracy and efficiency to estimate the sedimentation rate of the Darabkola forest roads. It was also found that from among the input parameters of model, longitudinal slope of road, precipitation and sediment delivery factors were the most influential factors in the sediment production and transport, respectively.
M. Goodarzi, J. Abedi Koupai, M. Heidarpour, H. R. Safavi,
Volume 19, Issue 73 (fall 2015)
Abstract
Due to the time and space changes of hydrological events in the arid and semi-arid regions, recharge measurement in these areas is very difficult. Hence, groundwater recharge is a complicated phenomenon for which there is not a fixed method to determine. The aim of this research was to develop a method for estimation of groundwater recharge based on a hybrid method. In this study, a hybrid method for calculating recharge was presented by combining empirical methods with a mathematical model, MODFLOW, and AHP analysis. The results showed that the most important parameters affecting groundwater recharge are soil properties, unsaturated thickness, land cover, land slope, irrigation and precipitation, from which the soil properties and precipitation are most important. The results showed that the overall impact of small changes in precipitation and temperature significantly affect the groundwater recharge, and heavy soils are much more sensitive to these changes than light soils. By changing 10% precipitation, the recharge rate is changed between 16% and 77% and by changing 1ºC temperature, the recharge rate is changed between 6% and 42%. Also, results showed that precipitation and evapotranspiration changes in four months including December, January, February and March had significant effects on annual recharge rate. Using the results of this research, the vulnerable areas of the plain, appropriate places and time for artificial recharge could be identified. Overall, the results of this study can be useful in various aspects of groundwater management.
M. Khoshoei Esfahani, H.r. Safavi, A. R. Zamani,
Volume 20, Issue 75 (Spring 2016)
Abstract
Drought is an extended period of low precipitation which resulted in injuries to consumers of water and reducing their performance, especially in agriculture. Different indices have already been proposed for evaluating drought, based on one of the varieties of meteorological, hydrological and agricultural droughts, but no indices has been identified yet, encompassing all factors. This study has been carried out to assess existing indices for drought monitoring and proposing an integrated index including main factors of drought and is applied to the Zayandehrood river basin as study area, because of its sensitive situation in the central Iran plateau. An integrated index includes various drought factors such as meteorological, hydrological, agricultural, socio - economical and environmental factors. In designing of this integrated index, a combination of static and dynamic layers has been used. Static layers include land use, slope and soil type. Dynamic layers include precipitation, evaporation, temperature, surface water storage, groundwater levels position, and environmental needs. All these layers are analyzed in GIS software and drought zoning maps is prepared. Results showed that based on values of integrated index, water year 1371-72 was a wet year and water year 1378-79 was the most critical, in terms of drought.
M. J. Zareian, S. S. Eslamian, H. R. Safavi,
Volume 20, Issue 75 (Spring 2016)
Abstract
This study investigated the effects of climate change on the evapotranspiration amount and water balance in the Zayandeh-Rud river basin. Two important weather stations; Isfahan and Chelgerd stations, located in the East and West of the basin respectively, were selected for investigation in this study. The combination of 15 GCM models were created based on the weighting method and three patterns of climate change including the ideal, medium and critical were defined. Using the proposed patterns, the effects of climate change on temperature and evapotranspiration in Isfahan station and precipitation in Chelgerd station were estimated under the A2 and B1 emissions scenarios. Two indices were considered to determine the sustainability of agricultural water consumption in the study area. Ratio of evapotranspiration in the East part of the basin to precipitation in the West part was defined as EPR index (Evapotranspiration-Precipitation Ratio), and the ratio of maximum agricultural water deficit to the amount of agriculture water need, was considered as maximum deficit index (MD). Results showed that the annual temperature would increase between 0.63-1.13°C in the eastern part of the basin. The west precipitation in the basin would reduce between 6.5-30% in the ideal to critical patterns. Summer season, showed the most amount of increase in the temperature, and winter season, showed the most amount of decrease in precipitation. The A2 emission scenario showed more temperature increase and more precipitation decrease in comparison with the B1 emission scenario and also indicated that the potential evapotranspiration would increase by 3.1 to 4.8% in the basin. The EPR index will increase between 13-52% and MD index will increase between 9-35% in Zayandeh-Rud river basin under different climate change patterns. The results revealed the imbalance between agricultural water use in eastern part and the precipitation in the western part of the basin. In other words, in these conditions, appropriate management strategies and planning should be implemented to ensure the sustainability of water resources in Zayandeh-Rud River Basin.
E. Esfandiary Ekhlas, M. Nael, J. Hamzei, A. A. Safari Sinegani, M. Sheklabadi,
Volume 22, Issue 2 (Summer 2018)
Abstract
Evaluation of the ecological sustainability of different cropping systems is crucial to achieve sustainable agriculture. This evaluation is accessible via soil quality assessment. Therefore, to study the mid-term effects of different conservation tillage systems (no tillage and minimum tillage) and cover cropping on the biological indicators of soil quality, a factorial experiment in a completely randomized block design was conducted in Dastjerd region (Hamedan). Three levels of tillage (NT: no tillage, MT: minimum tillage and CT: conventional tillage) and two levels of cover cropping (C1: Lathyrus sativus and C2: no cover crop) were applied for four consecutive years. Soil sampling was performed in the fourth year of experiment in two steps (1- before cover crop plantation, and 2- after harvesting main crop) with three replications. Most indices (total organic carbon, active carbon, basal respiration, phosphatase activity) were significantly affected by cover crop, tillage systems and sampling time, as the highest values were obtained in NT-C1 in time 2 and the lowest ones in CT-C2 in time 1. For instance, after four years application of treatments, the mean active carbon content was increased from 927 mg/kg in the conventional tillage + no cover crop to 1350 mg/kg in the conservation tillage systems + cover crop. Therefore, conservation tillage practices combined with Lathyrus sativus cover crop were shown to be the most appropriate management for soil quality maintenance and improvement.
S. M. Sajjadi, H. R. Safavi, O. B. Haddad,
Volume 22, Issue 3 (Fall 2018)
Abstract
In this study, the WEAP model was used for the simulation and the Gravitational Search Algorithm (GSA) was applied as the optimization model. Due to the necessity of multiple simulations in the optimization process to achieve the optimal solution, the linkage of simulation and optimization models was done in the MATLAB software environment. To evaluate the performance, hedging policies achieved in the base period were investigated for the near future period under climate change. The results showed the poor state of aquifers under the baseline scenario; also, the continuation of the current management caused the Zayandehrood river basin to experience significant problems. So management of water resources using conjunctive hedging policies could improve the situation. The use of conjunctive hedging rules showed 11 percent increase in the group sustainability index for demands, in comparison with the baseline scenario. Also, according to the group sustainability index for the resources, applying the conjunctive hedging policies could increase the sustainability of surface water and groundwater resources as much as 5.2 and 6 percent, respectively, relative to the baseline scenario. The results also indicated the better performance of conjunctive hedging policies in comparison to the baseline scenario policies.
Gh. Safarinejadi, M. Heidarnejad, A. Bordbar, M. H. Pourmohammadi, A. Kamanbedast,
Volume 23, Issue 4 (Special Issue of Flood and Soil Erosion, Winter 2019)
Abstract
The use of free launch jets in flip bucket structures with associated submerged ponds, in the appropriate geological, and topographic and hydraulic conditions, could have significant economic and safety benefits. In this research, the downstream scour phenomenon of a flip bucket jet was investigated in free conditions, as well as in the presence of a trapezoidal and triangular slot in the coastal manner with different layout intervals at flow rate of 9, with a total of 45 experiments. The results of this study showed that the presence of the slot had significant effects on the depth and range of scour, so that the fit bucket jet with alternate triangular slots reduced the scour by about 12.7%, as compared to the no slot mode. Moreover, the maximum scour depth occurred in the bucket mode with the alternate trapezoidal slots in the more favorable interval than the rest of the models. Then, the results were compared with several empirical formulas and Veronese A relation showed closer results to the actual values.
Z. Noori, M. A. Delavar, Y. Safari,
Volume 24, Issue 4 (Winter 2021)
Abstract
The present study was intended to improve the chemical properties of a saline-sodic soil using the individual application of alfalfa residue and two biochars produced from sugarcane bagasse and walnut shell, at the weighting ratio of 5%; their concomitant application with gypsum, aluminum sulfate and the mixture of these two chemical amendments was considered. The experiment was conducted in three replications using the factorial experiment in a completely randomized design. After four months of incubation, the soil samples were measured for their main chemical properties. The results showed that alfalfa residues were the most effective treatment to reduce the soil pH; so the concomitant application of this organic amendment with gypsum lowered the soil pH from 9.13 in the control (untreated soil) to 7.24. It was also observed that the addition of gypsum and/or aluminum sulfate to the soil led to the increase of the soil electrolyte concentration and consequently, the increase of soil electrical conductivity to three times greater than control, through an increase of ions, like calcium and sulfate in the soil solution. Increasing the soluble sodium concentration by replacing exchangeable sodium by other similar ions showed that the studied treatments enhanced the sodium adsorption ratio (SAR), which could be regulated by washing. Concomitant application of the walnut-shell biochar with gypsum had the most increasing effect on the soil SAR, enhancing it from 22.6 in the control to 54.3. Potassium was released from organic amendments, improving the soil general conditions; addition of chemical amendments elevated soil exchangeable potassium contents; however, the elevated soil available phosphorus contents were less influenced by chemical amendments application. As the conclusion, it seems that the positive impacts of the applied chemical and organic amendments would supplement each other; as a result, the concurrent use of both treatments not only improves the bad soil chemical properties, but also enhances the soil fertility.
M. Motamedi, H. R. Eshghizadeh, A. Nematpour, A. Gohari, B. Safa,
Volume 25, Issue 2 (Summer 2021)
Abstract
World climate change is an accepted important subject but its negative effects are severe in arid and semi-arid areas of Iran. So, in the present study, two climate scenarios including RCP 8.5 (critical scenario) and RCP 4.5 (moderate scenario) during 2020, 2030, and 2040 decades and their effects on temperature changes in the wheat growth period in five cities of Isfahan province including Isfahan, Najaf Abad, Chadegan, Burkhar, and Meimeh have been investigated. The survey of temperature changes during wheat growth in the next decades showed that Burkhar, Isfahan, Najaf Abad, Chadegan, and Meimeh, respectively will experience more days with a temperature higher than 30°C in 2020, 2030, and 2040 decades than the mean of two recent years (2017-2018). Furthermore, in comparison with present conditions, the most changes in the number of days with a temperature higher than 30°C in next decades climates (2020, 2030, and 2040 decades) will be in Burkhar, Meimeh, Chadegan, Najaf Abad, and Isfahan, respectively. The range of changes percent in the number of days higher than 30°C in next climate conditions rather than present condition will be varied between 5 percent (Isfahan) till 97 percent (Burkhar). The changes percent in all studied cities were more in RCP 8.5 than RCP 4.5. During wheat growth, the number of days less than zero°C will be less in Isfahan, Burkhar, and Meimeh while will be more in Najaf Abad and Chadegan. The evaporation- transpiration will be increased in the next decades during wheat growth. As a result, planning and using compatibility strategies for each city is important to guarantee wheat production.
A. Mehrabi, M. Heidar Pour, H. R. Safavi,
Volume 25, Issue 4 (Winiter 2022)
Abstract
Designing an optimal crop pattern and on-time water allocation of water resources along with deficit irrigation are among the optimal solutions to maximize the water economic efficiency index. In this paper, the simultaneous optimization of crop pattern and water allocation are discussed using the deficit irrigation method. The study area is located west of the Qazvin plain irrigation network. The six different levels of percentage reduction of irrigation rate (0, 0 to 10, 0 to 20, 0 to 30, 0 to 40, and 0 to 50%) in three climatic conditions consist of dry, normal, and wet years were compared. The best irrigation scenario was selected for each year, and the results were compared with the existing crop pattern of the same year. The new crop pattern included the main crops of the region and the addition of rapeseed. The objective was to reach the maximum net benefit per unit volume of water by considering the maximum extraction of monthly and annual surface and groundwater. The results showed that the best scenario in the dry year was maximum deficit irrigation up to 20%, in a normal year full irrigation, and a wet year maximum deficit irrigation up to 10%. The improvement of economic water productivity in a dry year was 52.2%, in a normal year 41.5%, and in a wet year is 19.6% compared to the existing crop pattern. The average percentage of annual irrigation supply increases from 64.3 to 91.7% in a dry year, from 70 to 100% in a normal year, and from 77.5 to 97.1% in a wet year. Also, the relative yield of all crops, especially wheat, alfalfa, and sugar beet significantly increases. Therefore, the gravitational search algorithm as an optimization model can be considered in selecting the suitable crop pattern and allocation of surface and groundwater resources concerning economic benefits in irrigation networks management.
M. Safavi, A. Asareh, M. Khorramian, D. Khodadadi Dehkordi, A. Egdernezhad,
Volume 26, Issue 1 (Spring 2022)
Abstract
The present research was conducted to determine water stress tolerance and water productivity (WP) of 5 alfalfa cultivars as a split-plot design in a randomized complete block with 3 replications in the Safiabad Agriculture and Natural Resources Research Center (SARRC) with Silty clay loam soil texture during 2018-2019. The main plot was 4 levels of water irrigation depth (including 25, 50, 75, and 100% water requirement supply) with a constant irrigation cycle and the sub-plot was the five alfalfa cultivars (Baghdadi, Yazdi, Nikshahree, Omid, and Mesasirsa). Two-year data on forage yield and WP for six harvests (from June to November) were analyzed by SAS software. The results showed that the wet and dry forage yield decreased by applying water stress and the percentage of dry forage increased. The highest yield of dry matter (12.4 tons ha-1) and WP of dry forage (0.94 kg m-3) were obtained from 75% water requirement supply treatment. Baghdadi genotype with wet and dry forage yield 39.1 and 10.7 tons ha-1, respectively, and the WP of dry forage 0.9 kg m-3 was higher than other genotypes. However, the Yazdi genotype had the lowest yield of wet and dry forage (30.3 and 8.5 tons ha-1, respectively) and dry forage WP (0.75 kg m-3). Therefore, the Baghdadi genotype with a 75% water requirement supply is recommended for similar conditions to the climate of Northern Khuzestan to increase water productivity.
S. Jamali, H. Banejad, A. Safarizadehsani, B. Hadi,
Volume 26, Issue 1 (Spring 2022)
Abstract
This research was conducted to study the effect of deficit irrigation and saline water on yield and yield components of Peppermint in the experimental research greenhouse of Ferdowsi University of Mashhad from 2018 to 2019. This research was performed as a factorial experiment based on the randomized complete design with three replications. In this research, irrigation levels consist of 4 levels (100 (I1), 80 (I2), 70 (I3), and 55 (I4) percent of FC) and saline water factors consist of 4 levels (0.9 (EC1), 1.9 (EC2), 2.5 (EC3), and 3.4 dSm-1 (EC4)). The result showed that a decrease of the water to 15, 30, and 45 percent have resulted in the reduction of shoot fresh weights (to 15.8, 28.4, and 30.1 percent), shoot dry weights (to 7.1, 11.5, and 11.5 percent), and root dry weights (to 4.6, 9.2, and 9.2 percent), respectively. Also, results showed that irrigation with EC2, EC3, and EC4 has resulted in a decrease in shoot fresh weights (to 12.7, 28.5, and 34.0 percent), shoot dry weights (to 3.6, 11.6, and 11.6 percent), and root dry weights (to 6.7, 12.4, and 14.6 percent), respectively. The result indicated that interaction effects of salinity and water stress decreased peppermint water productivity, as the highest and lowest peppermint water productivity with 3.54 and 2.06 Kgm-3 were in the EC1I4 and EC3I1 treatments, respectively. Results revoluted that maximum dry yield and peppermint water productivity were in the EC1I4, so this treatment was recommended for irrigation of peppermint.
A. Safadoust, S. Ghanizadeh, M. Nael,
Volume 26, Issue 1 (Spring 2022)
Abstract
This study was conducted to investigate the effects of vegetation type (Alfalfa and Wheat) and slope (5% and 20%) on runoff and drainage pollution in clay loam soil. Sampled soils were repacked in the box with one soil drainage outlet and one surface flow outlet and were cultivated by wheat or alfalfa. A solution containing 0.05 M KCl was poured quickly and uniformly, over the surface of each box, after plant growth. Simulated rainfall was applied to the soil box with the intensity of a constant rate of 64 mm h-1 for 2 hours immediately. Then the concentration of Cl- and K+ were measured in the collected samples of runoff and the drainage outlet. Results showed that the measured concentration of K+ was lower than the Cl- concentration as a result of its absorbable property. The breakthrough curves (BTCs) of Cl- and K+ showed that slope and vegetation type affected the transport of Cl- and K+. The peak of the BTCs for Cl- and K+ in runoff ranked in the order of wheat and 20% slope> alfalfa and 20% slope> wheat and 5% slope> alfalfa and 5% slope, and in the drainage changed to alfalfa and 5% slope> wheat and 5% slope> alfalfa and 20% slope> wheat and 20% slope. For each slope, the intensive vegetation cover of alfalfa than wheat considerably reduces Cl- or K+ pollution in runoff; whereas drainage development of larger and deeper root systems was the cause of higher leached concentrations for both tracers. Based on our research changes in soil surface vegetation cover from wheat to alfalfa are suggested in slope land to prevent surface water pollution; although other factors such as the climate, soil texture, and structure should also be considered.
M. Khoshoei, H.r. Safavi, Abbas Kazemi,
Volume 27, Issue 1 (Spring 2023)
Abstract
Drought is a continuous period of lack of rainfall that leads to damage to a variety of water consumers, especially in the agricultural sector and reduces their yield. Drought is considered one of the unpredictable disasters. Drought is different from other natural disasters such as floods, earthquakes, storms, etc. Based on the type of meteorological, hydrological, or agricultural droughts, various indices are designed to assess droughts such as SPI, PDSI, and SWSI. The objective of this study is to evaluate an integrated index that includes the main causes of drought. The integrated index includes various drought factors such as meteorological, hydrological, agricultural, socio-economic, and environmental. Isfahan province has been selected as a case study due to successive droughts in recent decades. A combination of static and dynamic layers has been used for designing the integrated index. Static layers include land use, slope, and soil type of the basin. Dynamic layers include precipitation, average temperature, available surface water, available groundwater, groundwater quality, and cultivated area. The results showed that the highest water stress occurred in the 1386 and 1391 years in the province and the lowest water stress and wet season in different parts of the province in 1387 and 1390 years.
S. Koohi, B. Bahmanabadi, Z. Partovi, F. Safari, M. Khajevand Sas, H. Ramezani Etedali, B. Ghiasi,
Volume 27, Issue 4 (Winter 2023)
Abstract
Water supply remains a significant challenge in arid and semi-arid regions, and in addressing this concern, unconventional water sources have gained prominence. Notably, the extraction of water from air humidity, classified as an unconventional water source has seen increased adoption. Diverse techniques have been developed to achieve this goal, with the utilization of mesh networks being particularly prevalent. Consequently, this study assesses the evaluation of the performance of the ERA5 dataset in the simulation of atmospheric variables that influence the ability to assess water harvesting from air humidity (including temperature, wind speed, and water vapor pressure). Also, the possibility of water harvesting from air humidity was investigated in Qazvin Province. The outcomes demonstrated the benefit of incorporating adjustment coefficients in estimating temperature and wind speed using the ERA5 dataset. Based on these findings, the northwestern and southern regions of the province (Kuhin and Takestan) exhibit notable potential during spring and summer for water harvesting from the atmosphere. The peak water harvesting for these stations in the summer is estimated at 10.2 and 9.7 l/day.m2, respectively. Using the ERA5 reanalysis dataset, the annual average potential for water harvesting in the stations was evaluated at 7.9 and 4.6 l/day.m2, respectively. Notably, the minimum water harvesting capacity during the summer season recorded in Qazvin is equal to 3.39 l/day.m2, which can be planned for use in irrigation requirements of green spaces, fields, or gardens.
