Search

With the aim of investigating the efficiency of biochar for desalination, experiments with adsorbent treatment at four levels including sesame flour, biochar at temperatures of 400, 500 and 600 ℃ and salt water treatment at four levels including 5, 10, 20 and 35 dS/m were conducted in three replications as a factorial experiment in the form of a completely randomized design in a discontinuous environment. The adsorption of the salinity factor ions was studied in the presence and absence of copper ions. The results showed that the desalination capacity without the presence of copper ions in the best adsorbent (Biochar 600) was obtained at the studied salinities of 411.6 mg/g. While the desalination capacity in the presence of copper ions using the same adsorbent at the studied salinities was 382.2 mg/g, indicating competition between ions and 8.0% decrease in adsorption capacity for salinity 35 dS/m. In both the presence and absence of copper, the highest adsorption was assigned to chlorine and sodium ions and the lowest to potassium ion. In summary, sesame flour biochar, owing to its high active surface area, porous structure, and suitable functional groups on the surface, effectively adsorbs salt ions in the presence of copper ions during the adsorption process.

Abstract Drought is one of the abiotic stresses that can reduce crop yields. It has a major impact on crop yield reduction. For crops under stress, organic modifiers such as biochar can be useful. Guar (Cyamopsis tetragonoloba L.), an annual legume from the Fabaceae Family, is highly adaptable to arid and semi-arid regions, with many applications in various industries. Field experiments were carried out in a randomized complete block design with three replications using a split-split plots arrangement. The aim was to evaluate the influence of irrigation levels (Ir1 = 10, Ir2 = 14, and Ir3 = 17 days irrigation cycle) and biochar (B1 = 0, B2 = 5, and B3 = 10 tons ha−1) application on physiological traits [(chlorophyll a and b, chlorophyll index (SPAD), relative leaf water content (RWC), electrolyte leakage (EL), canopy temperature, leaf area, water use efficiency (WUE)], morphological parameters (length and diameter of the stem, pod length, fresh weight of root and plant, root length), yield components (seed yield, number of branch plant−1, number of clusters plant−1, pod plant−1, seed pod−1, seed plant−1, 1000-seed weight, and gum contents), and leaf nutrient uptake (Ca, Mg, P, Na, and K) of two commercial and local cultivars (cv1 = RGC-936 and cv2 = Saravan) of the guar plant. It was observed that the Ir3 irrigation treatment produced the highest seed yield (1921.8 kg ha−1) in terms of water stress. However, the maximum pod plant−1 (75.5), seed plant−1 (454.2), seed yield (1871.1 kg ha−1), leaf area (861.8 mm2), SPAD (92.2), Mg (49.8 mg g−1), Na (43.3 mg g−1) and P (0.49 mg g−1) were observed in RGC-936. The results also revealed that biochar was more effective than cultivars in terms of morphological traits. While yield and yield components were affected by cultivar, irrigation at different levels also had a significant effect on functional traits, physiology, and morphology. The addition of biochar appeared to have a positive effect on water stress alleviation and guar growth and leaf nutrient uptake. According to Pearson’s correlation analysis, plant weight and length, root weight and length, stem diameter, seed pod−1, branches plant−1, and 1000-seed weight are moderately correlated with seed yield, while pod plant−1 and seed plant−1 are strongly associated with seed yield. On the other hand, the pod length, branches plant−1, and gum content showed a positive but not significant relationship.

Several methods have been introduced to control soil erosion. One of the newest methods used to control soil erosion and reduce runoff is the use of polymers.This study was conducted to determine the effects of different rate of Polyacrylamide, PAM, (0, 0.2, 0.4, and 0.6 gm2) on marl soils in rainfall different durations (10, 20 and 30 minute) using FEL3 rainfall simulator with rain high intensity 120 mm/hr at Laboratory. The results showed that all of the PAM levels (0, 0.2, 0.4 and 0.6 gm2) in the three rainfall durations (10, 20 and 30 minute) had significant differences in decreasing splash erosion in comparison with control treatment. However, the interaction effect of rain duration and PAM levels, were not statistically significant. Low rate of PAM (0.2 gm2) cannot control splash erosion as well as, however decreased it less. The statistical analyzes showed there was no statistical significance noted at a rain duration of 10 min, however at rain duration 20 and 30 min, with different amounts of PAM, there was a significant difference in splash erosion control. When rain duration increased from 10 to 30 minute, the splash erosion enlarged. So, the splash erosion decreased due enhancement of PAM level, as the most effect was observed in rain duration 30 min and 0.6 gm2 PAM rate respect to control treatment which is 21.2% effective in decreasing erosion. This reduction was statistically significant at 95% level with Duncan test.

There are many slopping lands in Chaharmahl-Bakhtiari Province of Iran, located in the central Zagros, which have suitable conditions for production of rain-fed horticultural products. This study was an attempt to determine the appropriate regions for almond and vine rain-fed cultivation in this province. Water requirement (ET) of the trees was calculated by local information of weather and plants. Annual precipitation (P) and ET were probabilistically analyzed. Required area for micro-catchment (Ac) and suitable regions for rain-fed gardening were then determined at different probability levels (p ) or return periods (T). Finally, average expected yields of almond and grape was estimated. Mapping the gardening-suitable area showed that inappropriate regions for rain-fed almond and vine culture are concentrated in the eastern part of the province due to less P and higher ET. Moreover, almond generally needed larger Ac than vine (about 43%) due to higher ET. Results also showed that increasing runoff coefficient (C) was more effective than enhancing water storage efficiency (E) in reducing required Ac, therefore, increasing 10% and 20% of C and E lead to 48% and 28% smaller Ac, respectively. Average required Ac for almond was calculated as 17.4 m2 which resulted in production of 549.0 kg/ha with p =50% (T=2). The corresponding values for the grape were 9.5 m2 and 2,128.8 kg/ha. Overall, the western areas in the province were more appropriate for rain-fed almond culture, whereas rain-fed vineyard gardens are preferred to be constructed in the eastern parts of the province.

Soil pollution is a highlighted concern of modern society, particularly in developing countries. The Drosh-Shishi valley, which is a hilly region near Afghanistan with a land area of around 15,000 km2, is situated in the south of Chitral District (Pakistan) and has a population of approximately 450,000. Nowadays, this region is being explored for soil pollution, specifically heavy metals which pose a potential risk to human health. Therefore, our main goal was to investigate possible sources of heavy metals’ spread and to assess the content levels in soil and the associated risks for human. We collected 34 representative samples from transported sediments and 31 from agricultural crops. We analyzed the soil samples for the contents of Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn using ICP-OES analyzers. These values were used to obtain the contamination factor (CF) and to estimate the potential health risk caused by heavy metals according to the USEPA dose–response model. Our results suggest that the heavy metal pollution has a geogenic source, but it is also aggregated by chemical fertilizers used in farming. Regarding levels, most of the metals except Pb showed contents above the permissible level, with CF values from moderate to high. Overall, Cu and Ni showed a significant total cancer risk (TCR > 1 × 10−4) in children. Therefore, we conclude that heavy metal pollution is causing a serious threat to humans in this area, and we recommend that authorities should make more efforts in monitoring the heavy metals content in soils to reduce potential health risks.

Urban soil pollution with heavy metals is one of the environmental problems in recent years, especially in industrial cities. The aim of this study is to evaluate the role of geogenic and anthropogenic sources in the urban soil pollution in Yazd, Iran. For this purpose, 30 top-soil (0-10 cm) samples from Yazd within an area of 136.37 Km2 and population of nearly 656 thousand are collected, and the concentration of heavy elements is measured. To evaluate factors affecting the concentration of heavy elements in urban soils and determine their possible sources, Multivariate statistical analysis, including correlation coefficient, principal components analysis (PCA) and cluster analysis (CA) are performed. Enrichment Factor (EF), Geo-accumulation index (Igeo), and Modified potential ecological Risk Index (MRI) are used to assess the level and extension of contamination. Results of this study suggest that As, Cd, Pb and Zn are affected by anthropogenic source, while the concentrations of Fe, Mn, Ni, Cr, Co, Cu and Cs have come from mostly natural geologic sources. As, Cd and Pb are considerably enriched in the area, provided moderately enriched for the elements Mn, Zn and Cu. However, the other heavy elements show minimal enrichment. Igeo reveal that Co, Cr, Cs, Cu, Fe, Mn, Zn and Ni with negative values are unpolluted, Pb posed unpolluted to moderately polluted, and As and Cd represent high polluted. Based on the results of the ecological risk factor, the heavy metals of Mn, Ni, Cr, Zn and Cu have a low ecological risk level. More specifically, we find that Pb shows a moderated ecological risk in 39% of the urban soil in the studied area. As and Cd with respectively 100 and 72% contribution have considerable and very high ecological risk. According to the results of MRI, the area is in a very high ecological risk level, and appropriate management practice is essential to reduce the pollution of heavy elements in this area.

Drought is a natural phenomenon that causes water resources shortage in various sectors such as drinking water, industry and agriculture. Drought is one of the climatic phenomena that can be observed not only in arid and semi-arid regions, but also alternately in wet areas. It should be noted that aridity and drought are different, aridity is a climatic trait specific to arid and semi-arid regions and is a permanent feature of the climate of the dry region (Eslamian et al, 2012). Liu et al (2011) with the study of meteorological and hydrological droughts in Oklahoma State discovered the two-day drought incidence of 2 months and the correlation coefficient between SPI and SDI profiles in an optimal state was 0.63. Eskandari-Damaneh (2015) investigated temporal and spatial relationships between meteorological and hydrological droughts in Tehran province. The results showed a correlation of 99% between meteorological and hydrological droughts and the increasing trend of drought in Tehran province. Mahmoudi et al. (2015) assessed the drought of meteorology in Sistan and Baluchestan Province using a standard score index and its impact on water quality in the province. Delpla et al (2009) examined the impact of climate change on the quality of surface waters in relation to drinking water production and concluded that climate change has reduced the quality of drinking water that has potential health impacts. Also, Mosley (2015) indicated that drought increased salinity, algae and soluble ions, which greatly reduced the quality of freshwater. According to drought studies, the main objective of this study is to study the drought of meteorology and hydrology, as well as to determine the probable delay between the occurrence of these two types of drought and their impact on river water quality, for water resources management in Godarkhosh basin which is one of the most important basins in Ilam province.

Predicting of the river discharge is one of the most important issues in the planning and management of water resources in terms of energy generation, water allocation and use of water resources. In this study, the trend of climate parameters such as temperature and precipitation and so discharge as a hydrologic parameter were investigated based on the Mann-Kendall test and then was modeled and predicted the discharge of monthly streamflow Godarkhosh in the period 1992-2012, using linear time series SARIMA. To investigate the static model, tests autocorrelation (ADF) and partial autocorrelation (PACF) were used. The results of the Mann-Kendall test indicated the temperature parameter has an increasing trend and precipitation and discharge parameters showed reduction trend at all stations of the studied area at 99% confidence level. Also, the result of time series model indicated that the time series data of river flow were non-static data that with the differencing method, the non-static data transformed into static data. Then different models were fitted into static series to estimate the river flow and finally, model ARIMA (1, 0, 0) (0, 1, 1) was selected as an appropriate model to predict discharge and the river flow was predicted for 4 years from 2013 to 2016. The results showed that the discharge has increased at the end of the period, in which the model estimated river flow as well based on rainfall data from Meteorological Organization in the 2015-2016 year. Therefore, application of time-series models in water resources management can be useful.

River morphology is the science of knowing the river system in terms of general shape, dimensions and characteristics of hydraulic geometry, the direction and longitudinal profile of the bed, as well as the mechanism of its changes. Morphological study is needed to understand the current conditions and the potential for future river changes in the future, and perhaps it is only that it is possible to predict the natural behavior of the river in relation to natural changes or actions arising from the implementation of various river engineering projects. Most of the water structures such as dams, bridges and pumping stations are located in the margins of rivers that can be affected by changes in river morphology. Application of remote sensing images and Geographical Information Systems (GIS) can be effective to achieve a more accurate analysis. Today, land use change, vegetation cover and morphological changes of rivers in River Engineering Sciences are of great importance using remote sensing and GIS techniques. Yamani and Sharafi (2012) showed that morphological changes and erosion of the Herrud River from the upstream downstream has decreased. Also, the geological and lithological structures of the bed and river bank are the most important factors in the stability of the bed. Yousefi et al. (2013). In order to investigate the changes of some Meander parameters in the Karun River using Landsat satellite images, morphological parameters of 20 Meanders were determined in an interval of 128 km length of Karun River after the preparation of a land use map for each period. Rashidi et al. (2016) studied geomorphologic changes of the Karoon River bed and its causes from 1334 to 1391. The results indicate significant changes in river morphology including latitudes, meanders, and sedimentary islands due to the decrease in the discharge, the construction of multiple bridges along the path, geological factors and vegetation. The study of past research shows that the study of river morphology in other countries has also been of great importance. Clerici et al. (2015) examined the morphological changes of the Taro River in Italy over the last two centuries and showed that human beings have made the most of the changes for agricultural and industrial purposes, the construction of multiple bridges and casualization. According to the research, the main issue of this research is to investigate the changes in the Gamasiab River, which in recent years has threatened the communication paths, landscapes and, in summary, human structures along the river banks. Therefore, the objective is to study the variation of the morphology of the Gamasiab river from the point of view of the central radius and angle, and the number of archs during the 1990-2013 period, and the extent of the development of the piers.