Taher farhadinejad; iraj vayskarami; Mehran Zand
Abstract
Introduction
Drought can have serious negative effects on the quality of water needed for irrigated agriculture. The geological formations of the region increase the concentration of minor and rare toxic elements in the waters, and on the other hand, human activities lead to water pollution in the ...
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Introduction
Drought can have serious negative effects on the quality of water needed for irrigated agriculture. The geological formations of the region increase the concentration of minor and rare toxic elements in the waters, and on the other hand, human activities lead to water pollution in the nearby areas. In this research, the effect of drought on the quality of surface water, the effect of various factors such as geological formations and the decrease or increase of rainfall and air temperature on the quality of water resources, how the quality of water changes, determining the limits of water consumption in the drinking sector and agriculture should be paid.
Materials and methods
The Tirah River Basin with an area of 3243.6 square kilometers is considered as one of the sub-basins of the Dez River and a subset of the Karun Basin. The Standardized Precipitation Index (SPI), Standard StreamFlow Index (SSI) and Decimal Index (DI) were used to calculate standard drought indices. Elements and compounds of electrical conductivity (Ec), Total dissolved solids (TDS), pH and Anions of chlorine (Cl-), Sulfate (SO42-), Bicarbonate (HCO3-), Sodium (Na), Calcium (Ca) and Magnesium cations (Mg) were investigated. To draw the pattern of droughts, 3 hydrometric stations of Teng Mohammad Haji (upstream), Rahimabad Silakhor (middle) and Tir-Droud (outlet) stations were tested.
Results and discussion
The most severe hydrological droughts with a duration of 2 years and a minimum SSI value of -1.23 in the Teng Mohammad Haji Station in the water years of 2009 and 2010 and the Tir-Droud Station with a duration of 4 years (-1.19) and the Rahimabad Silakhor Station with a duration of 3 years (-1.16) occurred for the water years 2012, 2013, 2014 and 2015. The analysis of discharge and precipitation data of Teir sub-basins showed that between the discharge and precipitation (SPI and SSI) of Tang Mohammadhaji and Rahimabad Stations, there was an average positive correlation at a significant level of 0.05 (R2=0.526). Examining the relationship between annual discharge and water quality parameters showed that there was a negative correlation for most parameters such as TDS, EC, chlorine, the total of anions and cations, so that the maximum concentration of quality parameters occurred in droughts. In Tang Mohammadhaji Station, the highest percentage of changes was related to sodium and chlorine, respectively, with 62.55 and 39.70% in dry years compared to the long-term average. The results of this research showed that the percentage of changes in calcium, magnesium, sodium, carbonate and chloride
increased in dry years compared to the long-term average in the studied stations in the Tirah River Basin. All the stations in the Tirah Basin have passed the period of relatively dry hydrological drought (-0.84 to -1.28) and none of them have suffered severe hydrological drought.
Conclusion
The analysis of discharge and precipitation data of dark sub-basins shows that between discharge and precipitation (SPI and SSI) of Tang Mohammad Haji Station, which is an upstream sub-basin of dark, there is an average positive correlation at a significant level of 0.05 and in Rahim Abad Station, which is in the middle of the basin It is located in Tire, and according to Pearson, it has a correlation at a significant level of 0.05 at the exit station of Tire basin, no significant correlation is observed between discharge and precipitation variables, which can be caused by snowfall and the persistence of snow in the heights from the previous water year, the construction of Meruk Dam. In the upper part of the basin, as well as the water intake of Bishehdalan Silakhor Wetland in droughts and abundant water harvesting from the Tirah River for agriculture. The upstream basin of Tang Mohammadhaji Station is completely calcareous, which has caused changes in parameters of calcium, TDS, EC, etc. In Rahimabad Silakhor Station and Tire outlet, half of the area of the basin is dedicated to intrusive rocks such as granite and granodiorite, which increases potassium and calcium. In the studied stations in Tirah River Basin, the percentage of changes related to calcium, magnesium and sodium, and carbonate and chlorine anions have increased in dry years compared to the long-term average. In general, it can be concluded that drought can have negative effects on water quality parameters in Tirah River Basin.
Kianfar payamani; Eisa Solgi; Kazem Rangzan; Taher Farhadinejad
Abstract
Sediments can be sensitive indicators for monitoring contaminants in aquatic environments. Therefore, understanding the mechanisms of accumulation and geochemical distribution of heavy metals in aquatic systems and providing basic information for judging environmental health risks, spatial study of metal ...
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Sediments can be sensitive indicators for monitoring contaminants in aquatic environments. Therefore, understanding the mechanisms of accumulation and geochemical distribution of heavy metals in aquatic systems and providing basic information for judging environmental health risks, spatial study of metal concentrations in sediments and their comparison with non-contaminated bases is of great importance. One of the common methods of soil pollution assessment is the use of pollution factor index (CF). The calculation of this index requires determining the background of the elements under study. For this purpose, statistical methods based on mean and standard deviation of data are commonly used. Due to the skuwness of the distribution of geochemical data, the use of this parametric method is limited, so the use of methods resistant to outlier data can be proposed as an alternative approach. In the last two decades, the fractal method has been used to separate communities in data related to many disciplines of earth sciences. In order to evaluate the two mentioned methods, 770 samples of waterway sediments containing six metal elements of As, Cr, Cu, Ni, Pb and Zn were collected in an area that is located in the north of Khorramabad. The background of the elements was determined by both methods (statistical method resistant to outlier data and fractal method) and finally the CF index was calculated. This index based on statistical methods assessed at the intermediate level for arsenic, chromium, copper, nickel, lead and zinc 7.5, 0.8, 5.5, 0.5, 4.7 and 9.2 percent, respectively. For the mentioned elements based on fractal method, the medium level of contamination were 39%, 28.9%, 88.6%, 39.4%, 45.7%, 73.4% of the total sample, respectively. In addition, with the second method, 3% (copper), 0.1% (lead) and 4.3% (zinc) of the number of samples have been evaluated at a considerable level. The results showed that the use of statistical methods in determining the background of the elements, despite the selection of a statistical method appropriate to the distribution of data, has reduced the sensitivity of the pollution index and reduced the efficiency of the index in the separation of pollution classes. While the use of fractal method due to considering the spatial dimension (area) in separating different background communities from anomalies leads to better efficiency of CF index and thus improves regional pollution estimates.
Ghasem Mortezaii; Mahmoudreza Tabatabaei; Mohammad Jafar Soltani; Taher Farhadinezhad
Abstract
Like most of the wetlands in the country, Bisheh Delan Wetland is in poor condition and its ecological balance is fragile and unstable. The purpose of this study was to develop and implement a training program on the importance of Bisheh Delan Wetland and how to use it responsibly by governmental and ...
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Like most of the wetlands in the country, Bisheh Delan Wetland is in poor condition and its ecological balance is fragile and unstable. The purpose of this study was to develop and implement a training program on the importance of Bisheh Delan Wetland and how to use it responsibly by governmental and non-governmental stakeholders with the aim of repairing and supporting its restoration. In this regard, 10 workshops were conducted in a non-randomized purposeful manner in order to gain insight into the economic, social, technological, political, and cultural issues of the study area. Then, using elite ideas, strengths, weaknesses, opportunities and threats of the wetland were identified. After, in accordance with the CEPA Action Plan, four strategies, including: A) public participation-information and socio-economic issues, B) promotion of national conservation and cooperation wetland management, C) achieving optimal environmental status and D) achieving optimum soil and water status were determined and then ranked. Based on the results of the strategy rankings as well as the results from the QSPM matrix, the conservative WO strategy was identified as the main strategy for the study area. In this strategy, handicrafts and indirect sales of its products to tourists are opportunities in the region that can, while directly and indirectly employing local communities, reduce the region's weaknesses (such as lower household income levels, poor infrastructure facilities and etc). Based on the results of this study, empowering local communities in achieving participatory wetland management is one of the best strategies for sustainable utilization of Bisheh Delan Wetland.
