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; Ebrahim Karimi Sangchini; iraj vayskarami; Mehran Zand
Abstract
IntroductionManaging a pervasive and effective phenomenon such as drought in different sectors of the economy requires close cooperation and careful planning. Lack of strategic drought planning and delays in decision-making have increased costs to reduce drought damage. The aim of this study was to develop ...
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IntroductionManaging a pervasive and effective phenomenon such as drought in different sectors of the economy requires close cooperation and careful planning. Lack of strategic drought planning and delays in decision-making have increased costs to reduce drought damage. The aim of this study was to develop strategic for drought adaptation using the SWOT model in Lorestan Province. Materials and methodsIn this research, the methods of reviewing sources and interviewing with a questionnaire were used in order to provide macro strategies to adapt to drought. For this purpose, the current status of ecological resources, environmental changes, economic sectors and their dependence on water resources, population and employment, management of ecological resources, organizations and institutions were analyzed, then by reviewing the upstream laws and documents, interview with resource managers, local and national decision makers, experts, published background and other available information identified the causes of problems and obstacles to drought management in the province. The statistical sample consisted of 27 experts and scientific and executive experts were selected. Scoring was done on two occasions by experts, and finally, by averaging the opinions of experts and scientific and executive experts, the weight of internal and external factors was determined. In the final stage, in addition to identifying important factors in each of the criteria of strength, weakness, opportunity and threat, necessary management strategies were determined based on the conditions of Lorestan Province through SWOT analysis. These issues were categorized in the form of environmental opportunities and threats and internal strengths and weaknesses, then analyzed by SOWT analysis approach and Delphi method. Results and discussionThe study of strength factors shows that the existence of companies and organizations with resource monitoring units in the province with a weight of 0.25 has a higher effectiveness and degree of importance among other factors. Lack of proper planning and organization for monitoring and evaluation of drought weighing 0.33 has a very high effectiveness among the factors of poor adaptation to drought in the province. Among the opportunities, the factor of technological advances in the field of precision agriculture with a weight of 0.1 have a very high effectiveness. The factor of endangering the livelihood of farmers in case of drought is the most effective among the studied factors of threats with a weight of 0.22. Factors of irrigation of lands in some areas with polluted water and gradual destruction of agricultural soil and population increase and as a result increase in demand for water with a weight of 0.02 were recognized as having the least effectiveness among the threats of drought adaptation in Lorestan Province. ConclusionAfter scoring using the Delphi method, it was found that the presence of faculties and centers of agricultural education and natural resources in Lorestan Province was recognized as the most important strength. But despite this strong point in the province, unfortunately, the lack or inappropriateness of available data and information for the purpose of monitoring and evaluating the effects of drought is known as the main weakness. According to these results, in the direction of the conservative strategy, the strategy of balancing aquifers with the priority of aquifers with a negative water balance was suggested. The government's support for water harvesting projects at the level of cities and villages and the monitoring of better water management in cities provide suitable opportunities to improve the ability of farmers to deal with the negative effects of drought. The final result has been the presentation of drought coping strategies for different regions of the province in the areas of surface and groundwater supply, irrigated and rainfed agriculture, urban and rural drinking water and river water environment.
Mehran Zand; Morteza Miri; Mohammadreza Kousari
Abstract
Climate change can lead to changes in the frequency, intensity, and duration of extreme climate events in different parts of the world. The purpose of this research is to investigate temperature and precipitation extremes in Lorestan Province. The data used in this study included precipitation and the ...
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Climate change can lead to changes in the frequency, intensity, and duration of extreme climate events in different parts of the world. The purpose of this research is to investigate temperature and precipitation extremes in Lorestan Province. The data used in this study included precipitation and the maximum and minimum daily temperature of nine synoptic stations in Lorestan Province during a 28-year (1990-2017) common period. The matrices of minimum and maximum temperatures and precipitation daily data for each station were prepared and used to compute the extreme climate indices (26 precipitation and temperature extreme indices based on the recommendation of CLIVAR \ CLL expert group) using the R programming software. The results of studying the trend of cold and hot extreme weather indicators during the period 1990-2017 in the province using the Mann-Kendall trend test showed that for all stations, the hot indices have increased and more cold indices have decreased. In different regions of the province, positive and negative trends of hot and cold indices with different intensities have occurred. The highest upward trend of the warm extreme indices has occurred for the hot night’s index. Among the cold indicators, the greatest decrease occurred for several frost days and cold days indices. The decreasing trend of ice days is significant for 45% of stations at 99% level and the decreasing trend of cold days for 77% of stations at different levels of 90, 95, and 99%. The results of the study of the frequency of occurrence and trend of precipitation extreme indicators in Lorestan province showed that the total rainfall of this province, like many regions of the country, has decreased. In contrast, the occurrence of maximum rainfall in addition to being significant in the province has an increasing trend during the period 2017-1990. These conditions can indicate an increase in the number of occurrences of heavy and short-term rainfall events and, shorten the period of the rainfall season in the region.
Morteza Miri; Mohammadreza Kousari; Mehran Zand
Abstract
One of the most common and effective problems in long-term climate studies is the presence of gaps in the time series of various climatic and hydrological data. Therefore, the present study evaluates the accuracy of methods for infilling missing data of daily, monthly and annual temperature time series ...
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One of the most common and effective problems in long-term climate studies is the presence of gaps in the time series of various climatic and hydrological data. Therefore, the present study evaluates the accuracy of methods for infilling missing data of daily, monthly and annual temperature time series in the arid regions of Iran. For this purpose, the observed daily minimum, average and maximum temperature data for the period 1987-2014 measured at 73 synoptic stations distributed all over arid regions of Iran were used. Methods of readjustment used include: Normal ratio method, linear regression, multivariate regression and Inverse Distance Weighting (IDW). In this study, the capability of each mentioned methods for infilling missing data of daily, monthly and annual precipitation time series in the arid regions of the Iran was investigated, while the proportion of missing data varies from 5 to 50% of total data. In order to compare and evaluate the accuracy of the four mentioned methods three statistical indicators, namely the correlation coefficient (R), the Root Mean Square Error (RMSE) and Nash coefficient were used. The results showed that in general, each of the methods mentioned had different functionalities at a special level of readjustment and time scale. On annual and monthly scales, linear regression and normal ratio methods are the most accurate method in readjustment temperature data in the arid region of Iran. The correlation value between the readjustment and observational data at different levels reaches more than 0.95 using these methods. On the daily scale, there is no significant difference between the accuracy of the methods used in the readjustment of temperature data, and almost all four of these methods have appropriate accuracy because in all methods the correlation between readjustment and observed data is more than 90%. However, multivariate regression methods with an average correlation of 0.99 showed the most accurate performance in readjustment daily data at different levels of readjustment. Generally, each method should be used in accordance with the conditions, and therefore it is recommended to develop a software package for infilling missing data.
Arash Derik; Ghavamoddin Zahedi Amiri; Mohammad Jafari; Mehran Zand
Abstract
Increased concentration of atmospheric carbon dioxide due to human activities has resulted in accelerated global warming process. Forestation is the most effective way to absorb atmospheric carbon dioxide and store it in terrestrial ecosystems in order to reduce and mitigate global warming. This study ...
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Increased concentration of atmospheric carbon dioxide due to human activities has resulted in accelerated global warming process. Forestation is the most effective way to absorb atmospheric carbon dioxide and store it in terrestrial ecosystems in order to reduce and mitigate global warming. This study aimed to investigate the comparison of soil carbon sequestration in various stands in Kuhdasht Aquifer and to present the best regression model for carbon sequestration based on all soil characteristics. In each stand (20-year old) of Ficus carica, Punica granatum, Pistacia vera, Amygdalus lycioides and Cupressus arizonica species as well as control rangeland, a number of 10 sample plots (5×5 m) were randomly selected and soil samples were taken in each plot at 0-10, 10-30 and 30-50 cm depths. All soil samples were transferred to the laboratory in order to measure soil characteristics including soil texture, organic carbon, bulk density, electrical conductivity, lime percentage and soil acidity. The results showed that the highest value of carbon sequestration in soil of Pistacia vera stand (54.94 tha-1) significantly (P <%1) higher compared to other stands, followed by Ficus carica (50.23 tha-1), Amygdalus lycioides (31.53 tha-1), Punica granatum (27.09 tha-1), Cupressus arizonica (24.17 tha-1) and control rangeland (9.01 tha-1) stands. Results also showed significant differences (P <%1) between the studied stands in terms of soil texture, acidity, organic carbon, electrical conductivity and soil bulk density. Also, the result of stepwise regression indicated that soil texture and acidity were the most important components affecting soil carbon sequestration, respectively.
Ali Seif; Hoda Ghasemieh; Hossein Zeinivand; Mehran Zand
Abstract
Today, with the increase in population, land use has been changed to meet the needs, which has made it more important to know the future status of land use. Investigating land use changes plays a fundamental role in environmental studies, modeling and simulation of land use changes and water resources ...
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Today, with the increase in population, land use has been changed to meet the needs, which has made it more important to know the future status of land use. Investigating land use changes plays a fundamental role in environmental studies, modeling and simulation of land use changes and water resources management and helps managers in better land use planning. So, in this research, first, the land use map of Rahim-Abad Basin was extracted for 1999 and 2016, using ETM+ and Landsat 8 sensors in ENVI5.3 software environment, with a kappa coefficient of 95% and overall accuracy of 97% that indicates the high accuracy of the 2016 map.Then, the maps of affecting factors on land use change including maps of distance from the road, distance from the river, distance from the city, distance from the village, distance from the fault, geology, soil texture, rainfall, evaporation, elevation digital model, gradient, groundwater level and the amount of solar radiation were prepared in Arc-GIS 10.6.After, using logistic regression, the role of effective factors on land use was determined and the Relative Operating Characteristics curve (ROC) was used to evaluate the logistic regression. Finally, the land use map of the study basin was simulated for 2026 using the CLUE-s model.Results showed that the area under the ROC curve was 0.9, 0.88, 0.9, 0.92 and 0.91 for grasslands, rain-fed lands, irrigated lands, water and, residential zones, respectively, which expresses the acceptable accuracy of the regression method in investigation of affecting factors on land use.Also, the most changes of land use in 2026 would be related to conversion of rangelands to rainfed lands, and 6.47% rangelands would decrease and 18% rainfed lands would increase.
Mehran Zand
Abstract
This research was designed and implemented with the aim of determining the Effectiveness of Reclamation Operations of watershed management implemented by the forest, rangeland and watershed management organization in increasing the carbon sequestration potential of the land and selecting the optimally ...
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This research was designed and implemented with the aim of determining the Effectiveness of Reclamation Operations of watershed management implemented by the forest, rangeland and watershed management organization in increasing the carbon sequestration potential of the land and selecting the optimally implemented patterns. In order to estimate the carbon sequestration of three basins were selected as three sites. Then, samples were weighed and their weighs were identified according to plot in each area and hectare. After that, 10 grams of each sample was transferred to the laboratory and the amount of sequestration was determined per unit area.The Research results show that sample basin of Rimeleh with 2025 kg per ha is the maximum carbon sequestration amount while control sample Abkandari Kohdasht with 122 kg has the minimum carbon sequestration among biological projects.From biological operations. point of view, seeding project with wheat in Rimeleh basic with 1064.56 kg per had the best performance in terms of carbon sequestration and was ranked highest. According to the results of experiments and analysis of data from the study sites, was determined In Bio-mechanical project of flood spreading Rumshkan, that they have been cultivated Eucalyptus species ,Conditions of carbon sequestration are better than the other varieties cultivated in Rimele and Koohdasht and the average rate is 37/31 ton/ha. The amount of soil carbon sequestration from mechanical operations was estimated to be 45.7, 45.4, 78.4, 54.8 ton / ha Respectively for the three catchment basins of Rimla, Rumshkan and Kohdasht, and the average of the control samples was 26 tons per hectare. Finally acccordind to results of this research Flood spreading Rumshkan project with carbon sequestration of almost 78 tons in each hectar is a successful project from carbon sequestration with a correct management and for mechanical and biological operations of watershed.
