Ali Mohammad Ghaeminia
Abstract
One of the natural landscapes observed in arid and desert areas is the accumulation of loose sand in and around plants, which over time causes the formation of sand masses. In Arabic, this type of land is called “نَبکَة: /næbkæ/”, which means small hill and ridge. The word ...
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One of the natural landscapes observed in arid and desert areas is the accumulation of loose sand in and around plants, which over time causes the formation of sand masses. In Arabic, this type of land is called “نَبکَة: /næbkæ/”, which means small hill and ridge. The word has been translated from Arabic into English as well as Persian, and in most scientific texts in these two languages, the word “nebkha” and “نبکا /nebkɑ/” are used to express this form of land, respectively. Studying the scientific texts, it was found that there are other writing methods such as nabkha, nebka, nabka and nabkhah for this word, which with the images used to show this phenomenon, indicates that all the authors meant nebkha. These differences in spelling prevent researchers from accessing most of the research done on this phenomenon. In addition, terms such as coppice dune and phytogenic hillock are found in the equivalent of nebkha in the literature. In this short article, the use of the word nebkha in the texts as one of the landform of deserts has been studied. The results showed that in order to obtain more comprehensive information when studying this phenomenon from different aspects such as geomorphology and ecology, it is necessary to search for different writing methods and equivalent words.
Yaser Mehri; Jaber Soltani; Mojtaba Saneie; Mohammad Rostami
Abstract
A side weir is a structure which is set in a side of main channel and used for discharge of additional flow, diverting excess water and water level control of channels and in irrigation and drainage systems. Due to difficulties presented in mountainous regions, lateral ‘piano key weirs’ could ...
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A side weir is a structure which is set in a side of main channel and used for discharge of additional flow, diverting excess water and water level control of channels and in irrigation and drainage systems. Due to difficulties presented in mountainous regions, lateral ‘piano key weirs’ could be used in arc-shaped channels. In addition, curved channels, which are commonly used in mountainous areas, are places that can be used to locate the side piano key weirs. In this research, experimental investigation was performed on side piano key weirs type B, type c and sharp crest side weir on flow in the 30 degree curved channel. Among the findings of the above survey, one could point out to the equality of the specific energy on the two edges of piano key lateral weirs, the changes of which equal 0.277% for type C piano key lateral weir and 1.98% for type B weir. Also, focusing on the empirical analyses, it becomes evident that the coefficient of discharge for piano key weir bears a higher quantity considering the more effective length corresponding to rectangular weir. Comparing the coefficient of discharge of the two weir types C and B, it becomes evident that type B weir has a better functioning in relation to type C.
Hamidreza Masoumi; Alireza Habibi; Mohamadreza Gharibreza
Abstract
In recent years, flooding of rivers has resulted in destructive implications, especially in the coastal areas. Dashtyari coastal plain is located in the southeastern of Iran. The occurrence of destructive floods has led to extensive damage to agricultural facilities, buildings, and residents of the region ...
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In recent years, flooding of rivers has resulted in destructive implications, especially in the coastal areas. Dashtyari coastal plain is located in the southeastern of Iran. The occurrence of destructive floods has led to extensive damage to agricultural facilities, buildings, and residents of the region in recent years. Morphometric factors of the river and its surroundings land-uses and their changes in the future are effective and necessary factors in the planning of coastal plains. Remote sensing is an applicable tool to investigate the past, present, and postcondition of rivers. The GIS-Ready layers included satellite images (Landsat 5, 1987; 7, 2001; 8, 2019; Sentinel-2, 2020), and specific software (Envi 5.3, ArcGIS 10.4.1, and Idrisi TerrSet), as well as the existence and fieldwork documents, have been used to achieve the research aims. Probability values of land-use changes in 2019 were obtained based on Markov chains. Accordingly, the highest probability of changes 24.87% and 23.5% were obtained between the river and plain units, and between farms and river, respectively. Then, an automatic cell prediction map of 2019 is accomplished with the overall kappa coefficient of 95%. According to the accuracy of the output of the cellular Automata Markov model, forecasted Land use and river morphology maps for 2030 were developed. Further, possible changes in the river environment were obtained by fitting the two maps of 2019 and forecasting 2030. Moreover, bank erosion was identified in the 6 critical points along the Kajo, Dashtyari, and Bahu rivers. Finally, the destructive flood event in January 2020 in the Dashtyari region was investigated to match the results with natural events.
Mahsa Tashakori; Mehdi Hayatzadeh; Ali Fathzadeh; Javad Chezgi; Akram Bemani Kharanagh
Abstract
Introduction The most important problem in the development and construction of underground dams is the complexity of determining suitable areas for dam construction. This problem arises from the fact that many criteria and factors including social, economic, geological and hydrological criteria are involved ...
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Introduction The most important problem in the development and construction of underground dams is the complexity of determining suitable areas for dam construction. This problem arises from the fact that many criteria and factors including social, economic, geological and hydrological criteria are involved in its proper location. Therefore, it is important to use methods that can determine suitable places for the construction of underground dams with high accuracy and with the least amount of time and cost. The construction of an underground dam is recommended as one of the solutions for water supply in arid areas where there is no access to usual sources, such as wells and permanent rivers, or they have few water resources. For this purpose, in the present study, the location of the prone areas for the construction of such dams has been investigated. The studied area is the Rodan Watershed in Hormozgan Province, which has a good potential for the construction of an underground dam due to its dry climate and special geological conditions.Materials and methodsIn this study, the number of eight initial locations were identified as potential points for construction underground dam by combining digital elevation model, topographic features, geological and hydrological features in GIS. In the following, after forming the decision matrix using Vicor model, ranking, determining the index and selecting the smallest index as the best option were done. Finally, the options were sorted based on the values of desirability index, dissatisfaction index and Vicor index. Then, the best option that has the smallest Vicor index was selected.Results and discussionAccording to the obtained results, the value of Vikor index (Q) was 0.0158 and 0.097 for sites 5 and 2, respectively, and that way, based on Vikor index, the first rank belonged to the site 5 and the second rank belonged to the site 2. Therefore, out of the initial eight locations, only two places were suitable spots and other suitable sites were rejected due to the distance from the centers of population concentration and agriculture. Rank one, located in the east of Ziarat Ali, is one of the best places to build an underground dam due to the hydrological and topographical conditions, including the fact that the slope in this site is less than five percent. The second priority, located in the north of Brentin district, was considered as a suitable option for the construction of an underground dam due to its location in the vicinity of a sparsely populated village where drinking water is supplied through a well. Among the criteria used in the present research, the criteria of water need, distance from the village, pH and EC parameters, and water quantity were the most important in the sites that have been assigned the first and second priority.Conclusion Examining the results of the reservoir surface factor in this research showed that the larger the reservoir surface, the higher the priority in locating this structure. In underground dams, unlike surface dams where the large reservoir surface is considered a disadvantage due to losses by evaporation, regardless of other factors, the best place to build an underground dam in a river is the canyons that have the maximum area of the reservoir in upstream. Looking at the axes selected in the current research, it can be seen that the highest priorities and the most valuable axes are selected in the quaternary formations, which can indicate the accuracy of the structure's positioning. Since the peak of water consumption in the region is in the spring and summer seasons, therefore, by constructing an underground dam in the proposed sites, part of the water shortage and crisis in the hot seasons can be compensated.
Saeed Sarkamaryan; Mehdi ghomeshi
Abstract
As a method for dimension reduction and elimination of energy damper structures that are located downstream of rapids, obstacles that are put on rapids are sometimes employed. In this research, damping capabilities of floating cubic obstacles were investigated using an experimental model. To do this, ...
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As a method for dimension reduction and elimination of energy damper structures that are located downstream of rapids, obstacles that are put on rapids are sometimes employed. In this research, damping capabilities of floating cubic obstacles were investigated using an experimental model. To do this, various experiments were performed on four different slopes of rapids with and without obstacles in a laboratory open channel in the hydraulic laboratory of Shahid Chamran University of Ahvaz. Results of the experiments without obstacles on discharges contained in this research’s scope showed that the amount of damped energy relative to the upstream energy ranges from 10 percent for a slope of 1:4 to 63 percent for a slope of 1:5. According to comparison of energy loss in different slopes, we can conclude that the reduction of chute bed slope increases the relative damped energy. We can also argue that the reduced chute bed slope leads to a slower energy loss procedure. Energy dissipation had an increase of 17 to 44 percent according to the studied results of models with and without obstacles. According to comparison of energy loss in different slopes of models with obstacles, we can conclude that the amount of relative damped energy increases and the damped energy reduction occurs on lower slope by reducing the chute bed slope. Using multi-variable regression, some equations were extracted in the final section in order to predict energy damping in such rapids with or without obstacles.
Barat Mojaradi; javad mirmiri; Alizadeh Hosein
Abstract
Drought management is an essential task to exploit water resources. In this study, the monthly rainfall of 35 synoptic stations in Qazvin province during 30-year were considered for drought monitoring. In this study two drought monitoring indices including modified standard Precipitation index (MSPI) ...
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Drought management is an essential task to exploit water resources. In this study, the monthly rainfall of 35 synoptic stations in Qazvin province during 30-year were considered for drought monitoring. In this study two drought monitoring indices including modified standard Precipitation index (MSPI) and Standardized Precipitation Index (SPI) are accomplished and compared to the reports of four indices in the study area. The obtained results showed that the MSPI is more accurate than the SPI and other indices. Having the drought conditions in the stations, zoning of drought were calculated by Interpolation methods such as IDW, Kriging, GPI, and RBF.The obtained results demonstrated that IDW method with first power is the best method in terms of average error. Moreover, zoning of the precipitation is conducted using Kriging interpolation then the MSPI value for each cell is computed for monthly precipitation. The results show that if the precipitation interpolation is conducted firstly, the drought index is calculated more accurately than the method that drought index calculated in the stations. In order to assess the drought condition more accurately, the vegetation condition index (VCI) is computed using monthly NDVI product of MODIS. The correlation between VCI and MSPI was calculated that the results illustrated that MSPI confirms the results obtained by VCI. As a result, VCI can be used to monitor drought in the watersheds which suffer from sufficient ground stations.
Afshin Partovi; Hamidreza Peyrowan; Samad Shadfar; Fazel Iranmanesh
Abstract
Land cover change is one of the most effective factors of environmental change. So, understanding and predicting the causes, processes and consequences of land cover has become a major challenge. The remote sensing and satellite data technologies can be used effectively to detect and quantify land cover ...
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Land cover change is one of the most effective factors of environmental change. So, understanding and predicting the causes, processes and consequences of land cover has become a major challenge. The remote sensing and satellite data technologies can be used effectively to detect and quantify land cover changes and its effects on the environment. This research used the MODIS MCD12Q1 yearly data at 500 m resolution to evaluate the spatio-temporal changes in the national land cover of Iran from 2001 to 2015 in five years periods. Land cover maps of Iran were generated based on 12 classes for years of 2001, 2005, 2010 and 2015 and then evaluated using “Landcover Change Matrix”. Areal distribution analysis showed that the most parts of Iran covered by barren areas (more than 60%). The area of forests, croplands and grasslands were reduced from 0.8, 4.8 and 21.4 percent respectively in the year of 2001 to 0.6, 4.5 and 20.9 percent of Iran’s area in 2015. Furthermore, to evaluate land cover changes in five years’ period, the land cover map of the first and last years of each period were compared using “Landcover Change Matrix”. Results showed that in the five years periods of 2001-2005, 2005-2010 and 2010-2015 land cover of Iran changed increasingly as 2.13, 3.25 and 3.30 percent respectively of Iran’s area. And the overall changes of land cover in Iran from 2001 to 2015 is 6.08 percent of Iran’s area.
Alireza Entezari; Rahman Zandi; Maryam Khosravian
Abstract
It is very important to be aware of the quantitative and qualitative characteristics of land changes in environmental planning, land management and sustainable development. At present, the use of vegetation map is one of the important pillars in generating information for macro and micro planning. In ...
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It is very important to be aware of the quantitative and qualitative characteristics of land changes in environmental planning, land management and sustainable development. At present, the use of vegetation map is one of the important pillars in generating information for macro and micro planning. In this study, temporal and spatial variations of vegetation were used in Fars Province. The data from Landsat satellite were calculated from OLI and ETM sensors during a thirty years period (1986-2016) and the NDVI index was measured. Quantitative changes of vegetation were also classified. The index is classified into three classes, including rich, poor and vegetation-free. The temperature changes of the ground level in the study period were also calculated using MODIS images. Results showed quantitative and qualitative changes of vegetation over 30 years for the studied area, so that the vegetation-free areas increased by 107. 49 ha and the areas with poor vegetation decreased by 366.56 ha and the rich vegetation cover has dropped by 455.55 ha. The largest reduction in the area was made on lands with rich vegetation. The MODIS images revealed that surface temperature has increased in the province. The temperature variation is more than 3 degrees (from -2.8 to 0.96° C) and it was observed that the highest temperature reduction was in the eastern and heading to the province. Finally, in order to investigate the relationship between vegetation and LST, the annual isobars were plotted along with the difference in NDVI in the studied period. The results showed that in most areas the vegetation cover was denser with lower temperatures.
Mansour Jahantigh
Abstract
Soil erosion is an important chalenge in arid and semi-arid regions which has a negative impact on soil productivity and lose soil. Improper management of natural resources causes soil erosion. This reaearch was implemented in the north of Sistan and its aim was to idintyfy the effect of sand on increased ...
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Soil erosion is an important chalenge in arid and semi-arid regions which has a negative impact on soil productivity and lose soil. Improper management of natural resources causes soil erosion. This reaearch was implemented in the north of Sistan and its aim was to idintyfy the effect of sand on increased moisture in the plant root zone. For this pupose, three soil samples were collected from 0-50 cm depth and their pH, EC, C, Ca, Mg, K, Na, ESP, available phosphor, cations and texture were tested. This research had eight treatments including plant, soil and irrigation which have been done in split split-plot in four replication durig tow years. After plating a 20 cm layer of sand was applied on the soil surface in each pit. In this experiment, soil moisture was measured monthly and plant growth was measured in growing season. Statistical analysis of the data was performed using MSTAT software. Result showed that the amount of moisture was 28% higher in sand compared to other treatments at the level of 99%. According to the findings of statistical analysis on the impotance of methods used for soil moisture, the sand along with subsurface irrigation of toot had better groth at the level of 99% and were in class A and the other treatments were in class B. The conclusion was that sand causes decreasing in capillary, reducing soil evaporation, increasing moisture around root zone of the plants and water and soil conservation.
seyed jafar seyed akhlaghi; mostafa taleshi
Abstract
Resilience is one of the strategies to reduce the vulnerability of communities in dealing with natural hazards. Among environmental hazards, drought is the most costly natural hazard due to the decrease in production and severity of suffering for villagers and farmers. Assessment of the effects of recent ...
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Resilience is one of the strategies to reduce the vulnerability of communities in dealing with natural hazards. Among environmental hazards, drought is the most costly natural hazard due to the decrease in production and severity of suffering for villagers and farmers. Assessment of the effects of recent drought in the country, Indicators of low resilience of societies against this natural hazard are therefore indispensable for resilience of societies against drought. This is an applied research and has been done by descriptive-analytical method with the aim of measuring and evaluating the level of rural resilience in facing drought risk. To conduct research, using library resources, indicators and factors affecting rural resilience were identified and defined operationally. Then, using the field method and the questionnaire, the required information was gathered and the information collected using SPSS software Processed. The statistical population of the rural farmers is Hablehrood. For this purpose, 9 villages from different areas of the province with different levels of drought and development were selected and based on the Cochran formula, 271 farmers were selected as sample size. The tests used in this research are single sample T, Friedman test and Pearson correlation coefficient. The results showed that the level of field fluctuation was at an undesirable level and lower than the average level, and the rural areas of Hablehrood watershed were at risk of drought occurrence in the vulnerability to resilience.
Elham Rezaei; Babak Shahinejad; Hojatola Yonesi
Abstract
One of the important issues in rivers qualitative discussion is the prediction of amount of Total Dissolved Solids (TDS) in water. In this study, the performance of the intelligent models Support Vector Machines (SVM) with different kernel functions, Gene Expression Programming (GEP) and Bayesian Network ...
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One of the important issues in rivers qualitative discussion is the prediction of amount of Total Dissolved Solids (TDS) in water. In this study, the performance of the intelligent models Support Vector Machines (SVM) with different kernel functions, Gene Expression Programming (GEP) and Bayesian Network (BN) was investigated in the prediction of amount of total dissolved solids (TDS) in Kashkan River. For this purpose, quality parameters obtained monthly from Poldokhtar station in Lorestan Province from year 1991 to 2016, including hydrogen carbonate, chloride, sulfate, magnesium, calcium, sodium, electric conductivity, flow rate and PH these parameters were applied to predict the amount of total dissolved sediments of water in this reach. Correlation Coefficient (CC), Nash-Sutcliff coefficient (NS), Root Mean Square Error (RMSE), and bias were used to evaluate the performance of the models. The results showed that in all three models, the combined structures have acceptable accuracy. Also, based on the evaluation criteria, Support Vector Machines with kernel of the radial base functions (RBF) had the highest accuracy 0.982 and the lowest root mean square error (mg / lit) 0.232, and the lowest bias 0.001 and the Nissan Sutcliff coefficient 0.963 compared to other models.
Seyed Sajad Mehdizadeh; Milad Ghoroqi; Amin Shadi Miandoab
Abstract
In sedimentary rivers, mining of materials regardless of their location, can lead to rapid river displacement, destruction of river banks, arable lands, water structures and consequently makes social and economic problems. The main aim of this study is to recognize and evaluate all the effective parameters ...
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In sedimentary rivers, mining of materials regardless of their location, can lead to rapid river displacement, destruction of river banks, arable lands, water structures and consequently makes social and economic problems. The main aim of this study is to recognize and evaluate all the effective parameters in material mining and determination of optimal site selection. In this study, the effective parameters that influence the extraction of river materials in Talvar River of Kurdistan Province have been evaluated using indexes as environmental, geological, geotechnical, hydrologic characteristics, social and economic conditions. For this purpose, Analytical Hierarchy Process (AHP) and Geographic Information System (GIS) are used. The priority of input indexes into the model is obtained using questionnaires from experts related to water and river engineering. The weighting of the parameters is performed afterward using AHP method binary comparison. The GIS technique is then applied to integrate the information layers by overlaying them. Eventually, the maps of optimum and suitable points were extracted for river mining. The morphological results of this study showed that the straight lengths of the river are more sensitive to the variations of bed level compared to meander sections and it is necessary to extract the material in these lengths with same depth and width. According to the results, sediment hydraulic index has the maximum weight due to determination of sediment deposit sites. The results also demonstrated that the first priority of river materials mining came to places that have low longitudinal slopes, placed in bends and are close to access roads.
Somayeh Shariati; Abolfazl Azizian; Najmeh Yarami; Abbas Paydar Ardakani
Abstract
Rainwater harvesting using micro-catchment is one of the water resources development options in arid regions that can partly supply water requirement of rain-fed agriculture. Some operations can be performed for increasing the harvesting rainwater in micro-catchment. In this study, the effect of simple ...
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Rainwater harvesting using micro-catchment is one of the water resources development options in arid regions that can partly supply water requirement of rain-fed agriculture. Some operations can be performed for increasing the harvesting rainwater in micro-catchment. In this study, the effect of simple treatments including furrowing, clay cover, furrowing and clay cover and control treatments on runoff production were investigated in the form of a complete randomize design with three replications during 2014 and 2015 in Zarrin-Dasht region of Fars Province. Results confirmed the potential of rainwater harvesting in the region. The highest runoff coefficient was observed in control treatment as 6.5 and 9.3% in 2014 and 2015, respectively. Disturbing of surface soil (in various treatments except control) led to average reduction of 11 and 14% runoff amount and coefficient, respectively compared to the control treatment. Threshold Precipitation for Runoff Production (TPRP) was 1 mm in control treatment during two years of the experiment. In other treatments TPRP values reduced in the second year. In view point of the runoff amount and coefficient and also TPRP, control treatment is recommendable in the region. The catchment area varied almost between 15 and 150 m2, respectively, for supply water requirement of 300 and 600 mm with rainfall occurrence probability of 0.50 and 0.67 and runoff storage efficiency of 25 and 50%. In fact, micro-catchment area can be economically determined with crop type.
Seysd Mostafa Tabatabaei; Hossein Khozeymehnezhad; Abolfazl Akbarpour; Peyman Varjavand
Abstract
Deposition of density current the main threats reservoir and its watershed numerous areas of application.In this study Six types of vegetation arrangement similar impact convergent, divergent similar, parallel, z(ed) shape, zigzag and checkered studied the density current control is completed. The experiments ...
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Deposition of density current the main threats reservoir and its watershed numerous areas of application.In this study Six types of vegetation arrangement similar impact convergent, divergent similar, parallel, z(ed) shape, zigzag and checkered studied the density current control is completed. The experiments were performed in a channel length of 10 meters. Made of plastic and the covering vegetation was three meters. Then density current speed in 6 sections 0.5 and 4 meters between the Vegetation was measured after coating. Experiments with 3 Slope bed 0, 1 and 2%, with a salt concentration of 40 and 80 g/l was repeated. The results show if there are vegetation in front of density currents, the speed of the front reduces consequently. Also results showed that vegetation leading to an average of 21-59 per cent density current. After passing density current vegetation Density current rate rises at one point that this speed is not impressive and always density current Substrate without vegetationis also affected.
Parviz Abdinejad; Mohammad Roghani
Abstract
The present research was carried out at a research station in Qarehchryan, located in north-west of Zanjan City, Iran. Rainwater catchment systems had dimensions of 5×8 m, with five treatments of control (withness)(A), without vegetation and gravel with gravelly filter (B),without gravelly filter ...
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The present research was carried out at a research station in Qarehchryan, located in north-west of Zanjan City, Iran. Rainwater catchment systems had dimensions of 5×8 m, with five treatments of control (withness)(A), without vegetation and gravel with gravelly filter (B),without gravelly filter (C), impervious a part of the system with gravelly filter (D) and without gravelly filter (E) in a randomized complete block design with three replications. There were nine daily rainfall events from April until late August 2013, with two times irrigation with an interval of 60 days, 45 liter for every seedling and 33 times of measurement of moisture at depths of 20 and 50 cm. Results showed that spring rainfall had not been able to produce runoff in the control treatments and had no effect on soil moisture. Soil moisture influence has been increased by daily rainfall in both B and C treatments compared to control treatments.. Soil moisture influence from daily precipitation has been increased up to 30 percent in D and E treatments due to insulating surface of existing systems and impervious surface of rainwater catchments. Timeline of the average moisture at the depths of 20 and 50 cm is almost similar in all treatments. This situation indicates that the distribution of moisture in depth of 20 to 50 cm is similar with no significant difference, but, the moisture at the depth of 20 cm is more than 50 cm.
Ahmad Ahmadi; Farhang Ghasriani; Anvar Sanaei; Mina Bayat
Abstract
The purpose of this study was to determine the Evaluation of different cutting intensity on some attributes of Teucrium polium and Helichrysum globiferum Gharebagh key species. In this first region and two key area of half hectare in area Gharebagh and in the first year and was grazed, and fencing. Selected ...
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The purpose of this study was to determine the Evaluation of different cutting intensity on some attributes of Teucrium polium and Helichrysum globiferum Gharebagh key species. In this first region and two key area of half hectare in area Gharebagh and in the first year and was grazed, and fencing. Selected and removed from any of 0, 25, 50, 75% and control is exercised (a basic 10 treatments). Monthly by the clipper and the area is grazing season. Effective utilization of changes in the phenological characteristics, forage and seed production, vitality, mortality and other characteristics of selected plants species were studied. Finally, the combined analysis of data from yield and vigority with a split plot design in SAS software was analyzed. Results of studies of the effects on forage production and harvest of T. polium and H. globiferum Gharebagh species studied showed that effects of different levels, different years, and their interactions on the production level is a significant percentage (p<0.01). This shows that in different years with different weather conditions of production are different. The research findings can be taken as authorized by the 50% cutting intensity for the T. polium and 25% for H. globiferum are suitable.
Ata Amini; Jahangir Porhemmat; Hossein Sedri
Abstract
Virtual water concepts and water productivity are considered as powerful tools for analyzing issues related to water resource management. This research was conducted to use the indicators of physical and economic productivity of water, in water resources management in Talvar Watershed, Kurdistan, Iran. ...
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Virtual water concepts and water productivity are considered as powerful tools for analyzing issues related to water resource management. This research was conducted to use the indicators of physical and economic productivity of water, in water resources management in Talvar Watershed, Kurdistan, Iran. The data from field observation, meteorological and climatic, water resources, agriculture, irrigation and watershed management were collected. The crop area of the irrigated products in the watershed was identified and their cultivation percentage was determined. Data on the growth of these products and their water consumption were calculated using CROPWAT software and field data. Using the results of data analyzing, management indicators such as physical productivity and economic productivity of products were calculated. Results showed that five crops of wheat, potato, barley, alfalfa and clover make up more than 93% of the irrigated products area of the watershed. It was found that the potato and wheat were with highest and lowest physical efficiency, respectively. The potato is with highes productivity as 3.46 and wheat was with lowest one as 0.43 kg m-3. Despite of low physical efficiency for wheat, the major part of water consumption in this crop was from green water, while the potato is using the lowest rate of green water. In terms of economic productivity, barley and potato products were with most net economic benefits. The results of this research can lead to proper management and appropriate water resources in the basin.
Hoshang Behravan
Abstract
In mountainous watersheds, snow melt can have a significant impact on the water balance and at certain times of the year it could have the most important contribution to runoff. In many parts of the world snow acts as a natural reservoir that can play an important role for water supply. Specifically, ...
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In mountainous watersheds, snow melt can have a significant impact on the water balance and at certain times of the year it could have the most important contribution to runoff. In many parts of the world snow acts as a natural reservoir that can play an important role for water supply. Specifically, high-altitude basins in semi-arid regions with a significant snow component can have a large capability to balance and distribute scarce water resources. In this study the spatially distributed process-oriented hydrological model J2000g was used for the 431 km² large Latyan catchment in Iran. The target was to derive spatially distributed estimates of the quantity and timing of hydrological balance terms and state variables like rainfall, runoff, snow water equivalent (SWE) and snow melt. The model uses the distribution concept of Hydrological Response Units (HRU) to take the spatial variability in the basin into account. The comparison of the separate SWE models resulted in values between 0.28-0.68 for NSE and values between 0.53-0.83 for R². For the catchment models the comparison of the simulated runoff with measured data showed NSE values between 0.78 and 0.82. By these values it can be stated that the hydrological dynamics and the snow processes of the sub-basins within the Latyan catchment could be simulated sufficiently well with J2000g. It can be summarized that the single modules and in particular the snow components of J2000g along with the HRU distribution approach can be considered as suitable for the given project objectives i.e. the assessment of the hydrological dynamics of the Latyan catchment. Hereby, the model can be used to elaborate important hydrological information for a sustainable management of the water resources.
Ramin Salmasi; Mohsen Farahbakhsh; Hossien Asadi
Abstract
Phosphorus (P) loss in runoff can promotes weed and algae growth in water systems as a result of high concentrations of surface water P. As a result, relationship between available soil P and P concentrations is necessary for management of P concentrations in surface waters and for critical soil P determination. ...
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Phosphorus (P) loss in runoff can promotes weed and algae growth in water systems as a result of high concentrations of surface water P. As a result, relationship between available soil P and P concentrations is necessary for management of P concentrations in surface waters and for critical soil P determination. For this purpose, from 30 points of Talkherood Watershed surface soil samples with widely available P contents were selected. After determining some of general properties, four soil P tests including Olsen, Mehlich-3, Iron oxide and Soltanpour were measured. Then, soil samples were poured with imperative compaction and rainfall was applied onto 30×60 cm soil boxes on a 5% slope for 30 minutes by applying 75 mm h-1 rainfall. Their runoff was sampled in different times and their dissolved P concentration was measured. Significant correlation was obtained between dissolved runoff P and the four methods of available P for the soils. Critical concentrations of phosphorus for Olsen, Mehlich-3, Iron oxide, and Soltanpour methods were 86, 140, 52 and 49 mg l-1, respectively. Also, the four methods showed critical dissolved runoff P concentrations in narrow range of 0.38 to 0.4 mg l-1.
mohammmad javad rezaei; mohammad reza rezaei
Abstract
AbstractIn dry and semi-arid areas, water is the most factor of limiter in agriculture. In these areas, due to the lack of surface flows, major pressures enter on groundwater. Groundwater resources in the studied area (Dashte-Abbas plain) also suffered a severe drop in surface water due to unplanned ...
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AbstractIn dry and semi-arid areas, water is the most factor of limiter in agriculture. In these areas, due to the lack of surface flows, major pressures enter on groundwater. Groundwater resources in the studied area (Dashte-Abbas plain) also suffered a severe drop in surface water due to unplanned use. In this study, we compared four different models of evolutionary neural network, a multi-layered perceptron neural network with Genetic Algorithm (ANN-GA), a multilayered perceptron neural network with particle swarm optimization (ANN-PSO), a multilevel perceptron neural network with Imperialism competitive algorithm (ANN-ICA) and multi-layered perceptron neural network with ant colony optimization (ANN-ACOR) for estimating groundwater level according to groundwater inflow, effective penetration of rainfall, effective penetration of surface flow and flood, effective penetration of return water Agriculture, underground outflow, withdrawal from aquifer for agriculture, evaporation from groundwater level and past groundwater data Were used. groundwater level comparisons are the combination of inputs has been prepared using Auto-correlation analysis, partial Auto-correlation and cross-correlation for each model. Optimal models are obtained by changing the control parameters. The best results are obtained from the input models (GWLt-1, GWLt-2, Qint, Qpt-1, Qrt-1, Qit-1, Qoutt-1, Qwt-1, and Qet-1). The accuracy of the mean squared error in the test phase for ANN-PSO, ANN-ICA, ANN-ACOR models was 1.2208, 0.9456 and 1.7720, respectively, and for the ANN-GA model, it was 0.8739. The mean relative error of ANN-GA model is 3.6% and its determined coefficient is 0.9388. According to the results, the ANN-GA model showed better performance than the other three models for estimating groundwater level.
massoumeh zeinalie; mohammad reza golabi; mohammad reza sharifi; maryam hafezparast
Abstract
Having predicted river flow, we can predict and control natural disasters such as flood and drought in addition to managing utilization of water resources. New models in this domain can help correct management and planning. In this study, three models are evaluated: Gene Expression Planning (GEP), Bayesian ...
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Having predicted river flow, we can predict and control natural disasters such as flood and drought in addition to managing utilization of water resources. New models in this domain can help correct management and planning. In this study, three models are evaluated: Gene Expression Planning (GEP), Bayesian Network (BN), and Support Vector Machine (SVM). The data used for this research is precipitation data and daily flow of Gamasiab River in Nahavand during 10 years period (1381-1391). Results indicated that the relative superiority of the gene expression planning model to other models and better performance of SVM model in comparison with BN in daily river flow modeling. In addition, implementing gene expression planning model was faster than other models and could provide results in a short time. The SVM model is also more fitted to estimate the final minimum values. Finally, GEP model with coefficient of determination of 0.9230 and root mean square of 0.5867 in the training phase and coefficient of determination of 0.9025 and root mean square of 0.4936 in the test phase was selected as the superior model.
Alireza Eslami; Rahim Kazemi
Abstract
Regional flood frequency analysis is a powerful tool for estimating and analyzing flood flow in watersheds. In this research, different methods of regional flood analysis and hydrological homogeneity of catchments that has been done in the country has been investigated. Among the many methods for determining ...
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Regional flood frequency analysis is a powerful tool for estimating and analyzing flood flow in watersheds. In this research, different methods of regional flood analysis and hydrological homogeneity of catchments that has been done in the country has been investigated. Among the many methods for determining the homogeneity of sub-catchments, cluster analysis due to the ability of factor analysis to select the most important factors, simplicity of considering various factors, independence of effective factors, accuracy of separation of homogeneous groups, and advantage of using proper diagnostic functions, was the most appropriate method. Multivariate regression method, especially when the homogeneity of catchments have been accurately determined, has shown good performance in regional flood analysis. L-moment method, due to uniqueness and existence has good performance in estimating parameters and selecting appropriate statistical distributions. So that in the regional flood frequency analysis, the L-moment method performs better than other methods, particularly in the case of shortage and skewed data. The analysis of the intelligent models such as artificial neural networks (ANNs) and fuzzy logic, showed the high ability to establish nonlinear relationships between multiple input variables. The results of the Investigation of different factors used in regional analysis methods showed that Physiographic factors were highest (72.11%) followed by climatic factors (17.69%) and land cover parameters (7.48%). Also, the lowest contribution was related to hydrological factor with 2.72%. Among the physiographic parameters, the area factor with 30.19% of the contribution had the most influence on the regional flood analysis. Among the climatic factors, the highest application was related to the average annual rainfall factor with 73.08% contribution.
Parvaneh Mahmudi; Baharak Motamedvaziri; majid hosseini; Hasan Ahmadi; Ata Amini
Abstract
This study focuses on simulation and management the various hydrological responses to climatic changes. The semi-distributed hydrologic model SWAT (soil and water assessment tool) was used to evaluate runoff and water balance due to climate changes in Siminehroud and Zarrinehroud watersheds. The simulation ...
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This study focuses on simulation and management the various hydrological responses to climatic changes. The semi-distributed hydrologic model SWAT (soil and water assessment tool) was used to evaluate runoff and water balance due to climate changes in Siminehroud and Zarrinehroud watersheds. The simulation period was selected between 1990 and 2014. The assessment results in the calibration and validation periods using the NS and R2 obtained 0.75, on average. Using statistical multisite downscaling of LARS-WG climatic models MIROC-ESM-CHEM، GFDL-ESM2M and NorESM1-M the future climatic condition entered to the model using two optimistic RCP2.6 and pessimistic RCP8.5 scenarios. The largest changes in runoff in the upcoming period, May, reduced by 2.4 m3 s-1 and in April, increased by 1.49 m3 s-1 in the optimistic scenario. In RCP8.5 pessimistic scenario in May and June, also the highest runoff was observed. The rate of actual monthly evaporation will increase in the optimistic scenario up to 3 mm and in the pessimistic scenario up to 8 mm increase will have a negative impact on the available water resources in the watershed. With estimation the climate changes and its effect on the stream flow discharge is possible performing a suitable management in Siminehroud and Zarrinehroud watersheds.
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.
Shahbaz Shamsoddini; Sayed Naeim Emami; Solaiman Bahmani
Abstract
Chaharmahal and Bakhtiari Province with one percent of total area in Iran, covers 10 percent of total precipitation. Also, Karoon and Zayandehrood rivers are originated from this province. In recent years, the different watershed operations have been performed to control and maintain surface water in ...
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Chaharmahal and Bakhtiari Province with one percent of total area in Iran, covers 10 percent of total precipitation. Also, Karoon and Zayandehrood rivers are originated from this province. In recent years, the different watershed operations have been performed to control and maintain surface water in the province. This research analyzed effective factors on rural participation in watershed management operations in Monj-Bideleh Basin of Lordegan in Chaharmahal and Bakhtiari Province. Required data were compiled with questionnaire and analyzed with descriptive and inferential statistics in SPSS. The results showed that relationship between age, main gob and experience in agriculture with participation is negative and insignificant. In contrast, the relationship between satisfaction, social versatility, socio-economic situation, membership in public institutes and village, and use of informational resources with participation is positive and significant in one percent. The results of multiple regression estimation in stepwise indicate that knowledge of the objectives and characteristics of the watershed management plan has the highest portion in participation in watershed management activities.
