مجله محیط زیست و مهندسی آب
سال نهم شماره 4 (زمستان 1402)

The use of antibiotics as major drugs in infectious diseases has always been associated with two problems of side effects and drug resistance. The compounds found in various plants have been used as a treatment method since the past until today because medicinal plants possess side effects compared to other drugs. Given that different species of Echinops dichorus L. plant have indicated good antimicrobial effects, in this study antimicrobial effects of ethanol and aqueous extracts of Echinops dichorus L. plant have been investigated by disk diffusion method and determining the minimum inhibitory concentration (MIC) on the 24-hr culture of Escherichia coli (E. coli) standard strain. Echinops dichorus L. plant was dried after collection and its ethanol and aqueous extracts of were prepared by maceration method. Afterward, the concentrated and dried samples were stored in clean containers under standard conditions for further tests. The antibacterial effect of different concentrations of the extracts was determined by agar diffusion and compared with penicillin, gentamicin, and tetracycline antibiotics. Ethanol and aqueous extracts possessed a MIC of 31.25 µg/ml (diameter of the bacterial growth inhibition (halo): 12 mm) and 125 µg/ml (diameter of the bacterial growth inhibition (halo): 10 mm), respectively, as anti-microbial effect against E. coli.

Identifying the different habitats in wetlands is essential for their protection. This research was carried out with the aim of classifying habitat areas of Maharlu wetland in Fars province using MedWet, Mediterranean Wetland Habitat Classification System. Information on dominant vegetation cover, soil, and hydrology of the wetland was prepared using field surveys. The data on the water regime were obtained with quarterly satellite images from 2016-2019 in remote sensing media using ArcGIS. Sampling was performed for wetland plants and lake bed outcrops from 39 stations in May 2020. Plants were identified and classified on the basis of being an annual or perennial presence and submerged or floating. By stacking this information in ILWIS, different habitat zones were separated. Each was then specified using habitat international standard codes, and habitat maps were prepared. In total, 42 habitats were identified in the Maharlu wetland. The most prevalent habitats were palustrine–emergent–persistent–seasonally flooded–Mixosaline– (P-EPSX-) (14,797,300 m2), palustrine–emergent–persistent–temporarily flooded– Mixosaline (P-EPSX-) (296,600 m2), lacustrine–littoral–emergent–persistent–seasonally flooded–mixosaline– (LLEPSX) (2,079,900 m2), and lacustrine–littoral–emergent–persistent–Semipermanently flooded–mixosaline– (LLEPLX-) (493,000 m2). The results of this research in recognizing habitats are useful for the protection of ecosystem sections, especially plant communities.

This study aimed to present a dynamic simulation of hydrological drought using Vensim and the constant threshold level method in the Dorud-Borujerd basin in the 1991-2019 period. First, the threshold levels were estimated, and then the drought duration and volume were quantified. Next, the frequency of the highest duration and volume values was analyzed to determine the return periods. While confirming the superiority of the systems thinking approach, the results showed that the highest drought duration figures were 229 and 123 days, respectively, at the 70 and 90% threshold levels of the flow duration curve in the Bitun station. Tire station recorded 21.320 and 38.47 MCM for 70% and 90% threshold levels, respectively, which were the largest figures for drought volume. The frequency analysis of these figures obtained from dynamic simulation showed that the drought duration and volume will have a return period of 25 and 8 years and 4 and 14 years, respectively, at 70% and 90% threshold levels. Moreover, 2012 and 2015 were very dry years in terms of both duration and volume. Therefore, drought episodes have been occurring in the Dorud-Borujerd basin for many years and will continue with more intensity in the future.

The aim of this study was to simulate the runoff in the upstream of Chehlgezi hydrometery station in the Gheshlagh Dam watershed, Kurdistan province using SWAT hydrological model. In addition, the results have been evaluated using selected efficiency criteria in the calibration and validation stages, then the performance of the SWAT model is evaluated in simulating the monthly runoff in upland of Gheshlagh Dam. The input model parameters were optimized using the SWAT-CUP optimizer. The calibration and validation of the model was done using SUFI-2 algorithm during 1989-2016 and 2016-2018 periods, respectively. The sensitivity analysis shows that the SCS runoff curve number, Manning’s "n" value for overland flow, minimum and maximum yearly rate of snowmelt, minimum water depth in the shallow aquifer for "revap" were sensitive parameters in flow simulation. The Nash-Sutcliffe and R2 values were 0.62 and 0.65 in the calibration stage, and 0.61 and 0.68 in validation stage, respectively. The results proved the efficiency of the SWAT in monthly flow simulating. According to the results, 55% of the total rainfall entering the watershed has been converted to evapotranspiration, 30% infiltrated into soil and stored as soil moisture, and 15% converted into surface flow component. The results provide useful information on watershed water balance. Flow simulation in different climatic conditions and land-use scenarios in the future can help to sound water resources management.

The maximum scour of the flip-bucket occurs at the jet landing site, so it is important to know the exact path of the jet. In this research, by building two laboratory models of different sizes, the ability to exist relationships in predicting the jet path, length, and coordinates of the jet peak was evaluated. According to the results, Kawakami's relation had better accuracy in predicting the jet path. The average error percentage of the jet trajectory length prediction in USBR and Attari relationships was less than 10% and other relationships were more than 20%. USBR, Attari, and Kawakami relationships had a good estimate of the jet trajectory length along the edge. The error of other relationships in estimating this characteristic was more than 30%. In predicting the horizontal distance of the high point of the jet trajectory, the theoretical relationship and the profile of Kawakami and USBR had an average error of less than 10%. Theoretical relationships, Kawakami and USBR in estimating the maximum height of the jet, have an estimate with an error of 23.7, 33.9, and 21.4% and according to the Nash-Sutcliffe criterion, none of these relationships have been able to get a very good category.

The significant reduction of surface water resources and recent recurrent droughts have increased the reliance on groundwater sources, leading to a decline in their quality. In this study, 28 samples of well water from different locations in Khanmirza, Lordegan, Borujen, Ardal and Kiar were collected in 2020-2021 and underwent chemical analysis in the laboratory. To evaluate the quality of the samples for use in agricultural, drinking and industrial sectors, the Wilcox diagram, Schuler diagram and Langlier index were used. Using interpolation methods, the chemical properties of the samples taken within the study area were examined and qualitative zoning maps were prepared using Kriging and inverse distance weighting methods. The results showed that according to the Wilcox diagram, most of the samples are within the range of C2S1 and are suitable for agricultural purposes. According to the Schuler diagram, these samples are within the range of good quality for drinking and based on the Langlier index, they are within the range of precipitating and consumable. This study helps decision-makers to have a clear view and plan comprehensively and effectively for the exploitation and preservation of groundwater resources, taking into account the qualitative maps of groundwater.

This research focused on the application of Support Vector Machine (SVM) and Boosted Trees (BT) algorithms for simulating precipitation and runoff in two stations, Akhula and Pole Senikh, in the Tabriz Plain, Iran. Meteorological and hydrometric data were collected from 24 stations in the Tabriz watershed, obtained from the Regional Water Company and East Azerbaijan Meteorological Organization. Precipitation and runoff values were used as input to the model with a one-day time lag, and monthly runoff values were estimated and compared with monthly observations using evaluation criteria. The results showed that for both study periods, SVM model performed better than BT model for Akhula station, while BT model performed better than SVM model for Pole Senikh station. Additionally, the cross-correlation coefficient for the two study periods was found to be 0.83 and 0.82 for Akhula station, and 0.83 and 0.77 for Pole Senikh station, respectively. In the time series results, there was no clear trend in precipitation over the observation period. However, river flows at the Ahvaz and Pole Senikh stations, particularly after 1995, showed a significant decline, mainly due to factors such as runoff, agricultural expansion, and industrial development

The aim of this study was to evaluate the effectiveness of estimated soil moisture data obtained from the GLDAS, ESA and SMAP sensor databases with the observed data of the Silakhor Agricultural Meteorological Station to investigate the spatial and temporal variation of soil moisture in Lorestan province. The data used in this research include the soil moisture data of the Silakhor station, GLDAS database, ESA center and SMAP sensor products during a six-year period (2016-2021). Estimated soil moisture data were evaluated against observed data using R2, RMSE and MAD statistics. The results showed that the SMAP satellite is associated with underestimation and the GLDAS model and the ESA satellite are associated with overestimation of soil moisture. However, in general, the estimated soil moisture values of the three mentioned sources have good accuracy. The value of the correlation coefficient between observed soil moisture data with soil moisture data obtained from SMAP and ESA satellites and GLDAS model was obtained as 0.62, 0.59 and 0.72 respectively, and in the combined case (SMAP, ESA and GLDAS) the value of correlation coefficient was increased to 0.77, therefore, it is suggested to use combine data to use soil moisture estimation.

Evapotranspiration is one of the most important elements of the hydrological cycle. Estimation of evapotranspiration is imperative for effective forest, irrigation, rangeland and water resources management as well as to increase yields and for better crop management. The aim of this study is to calibrate the SEBAL algorithm in estimating evapotranspiration in the Sohrin-Qaracheryan plain, which is affected by flood spreading. In this study, Landsat 8 satellite images were used in 2020-2021 to obtain the coefficients of the relevant bands. Then, the net radiation flux on the earth’s surface and the earth’s heat flux is obtained using incoming-outgoing radiation fluxes from albedo, surface emissivity, land surface temperature, and plant indicators. Next, the sensible heat flux is calculated by determining the hot and cold pixels. Finally, evapotranspiration maps are plotted. Based on the results of this research evapotranspiration obtained from soil water balance model and SEBAL algorithm were estimated as 24115 and 19642 m3, respectively. Also, the calibration of the results obtained from the SEBAL algorithm with reference evapotranspiration was done using R2 and RMSE statistical indices, and were calculated the values of these two indices as 0.64 and 2.15, respectively.

Dams leave various environmental effects on local communities and watersheds, during the stages of construction, operation and end of useful life. The current research was carried out to evaluate the environmental effects of the Farrokhi Dam in the operation phase on the physical, cultural, economic and social environments. In this research, the modified Leopold matrix and the modified rapid impact assessment matrix were used. Positive and negative effects were studied and valued. The stability of the Phillips method was evaluated and its results were compared with the modified Leopold matrix and the modified rapid impact assessment matrix. The results of the rapid impsct assesment  method showed that evaporation with a coefficient of -14.25 has the most negative effect. Besides, regardless of secondary consequences, agricultural development is the most positive effect of dam construction with a factor of 105. Based on the results, the Phillips stability factor for Farrokhi Dam was equal to 2.87. Therefore, despite the presence of some positive effects, it was found that the cultural effects of Farrokhi dam construction were completely negative and the most negative effect of Farrokhi dam is in the field of evaporation.