mohammad taghi heydari; Hosseinali Bahrami; , alireza aliyari
Abstract
Soil moisture is one of the fundamental parameters of the environment that is directly influenced by plant life, animal and activity of micro-organisms and plays a major role in energy exchanges between air and soil. Determination of the exact amount of soil moisture content in agricultural, hydrology ...
Read More
Soil moisture is one of the fundamental parameters of the environment that is directly influenced by plant life, animal and activity of micro-organisms and plays a major role in energy exchanges between air and soil. Determination of the exact amount of soil moisture content in agricultural, hydrology and geological sciences is very important. Therefore, the use of a method that can achieve soil moisture in normal and non-corrosion conditions with high speed and accuracy is very important and fundamental. The Ground Penetrating Radar (GPR) is a non-destructive method for the subsurface investigation that is evolving and seems to be able to greatly help agriculture to identify soil and protect culture systems. Different studies have been done in the field of soil moisture determination using GPR, but in Iran, there are limited studies on the ability of this method to estimate spatial changes of soil moisture content, therefore, this research has been done with these goals. The results indicate that in the study area, the distribution of humidity at each stage of harvest shows limited changes if the time changes of humidity in the time interval between winter and spring are about 10-15% of the difference. Also, the mean square of GPR method error compared with TDR 13.2 method is also compared to the GPR and weighted 81.3 method and the correlation coefficient in these two comparisons is equal to 0.87 and 0.95, which indicates the high accuracy of the GPR method for estimating soil moisture.
Milad Hatefi; Seyed Hamidreza Sadeghi
Abstract
The present study was conducted to make a brief prioritization based on a combined index for flood potential, water stress, rainfall erosivity index and drought severity at province scale in Iran. To accomplish this, the initial country-wide available data were initially collected. The raw data were ...
Read More
The present study was conducted to make a brief prioritization based on a combined index for flood potential, water stress, rainfall erosivity index and drought severity at province scale in Iran. To accomplish this, the initial country-wide available data were initially collected. The raw data were mined and then standardized to neglect differences in units and magnitudes. The standardized data were ultimately analyzed using geometric mean. According to the results, Khozestan, Alborz and Kermanshah Provinces with respective combined indices of 0.61, 0.59 and 0.58 stood at the first priority in viewpoint of water and erosion indicators. Furthermore, the results of the study showed that southwestern provinces of the country were the most sensitive areas owing to high probability of extreme events and as a result, high amount of water resources loss and erosion potential. So that, implementation of soil and water resources management strategies in aforesaid provinces seems to be vital.
Banafshe Yasrebi; Majid Soufi; Mir Khalagh Mirnia; Jahangard Mohammadi
Abstract
This research focused on studying the morphometric characteristics, topographic threshold of gullies and their relationships, dominant process of gully initiation and development stages as well, in agricultural and rangeland land uses. Also, morphometric characteristics of 120 gullies including top width, ...
Read More
This research focused on studying the morphometric characteristics, topographic threshold of gullies and their relationships, dominant process of gully initiation and development stages as well, in agricultural and rangeland land uses. Also, morphometric characteristics of 120 gullies including top width, bottom width and headcut height and surface characteristics of gullies contributing area including vegetation, rock fragment and bare soil by 1 m2 plot and soil samples from top soil and gullies wall were collected in semi-arid part of Ilam Province. Results showed that top width–depth ratio of gullies in cropland and rangeland is 2.1 and 1.5, respectively that widening and deepening has more important role in gully growth. Top width-length ratios are 0.41 and 0.57 in croplands and rangelands, respectively that shows rangeland gullies are more elongated. Negative exponential relationship between those ratios and slope shows the effect of topographic factors especially slope on final shape of gullies. Bottom width-top width ratio in croplands and rangelands is about 0.33 and 0.3, respectively and cross section shapes are trapezoidal and V shape. Results showed that slope describes 16 percent of cross sections area variation and lateral growth of gullies in croplands and rangelands and describes 84 and 73 percent of gully volume variation. Effective factors on gully volume are sand content in top soil, land use and slope. Studied gullies in both land uses have mean fractal dimension of 1.08 and has linear growth with length and power growth with volume of gully. Power of Hack law in studied gullies in croplands and rangelands gullies are 0.5 and 0.54, respectively.
arezoo kheyrkhah
Abstract
Correct and consistent uses of natural resources preserve this valuable wealth. Using optimization knowledge can assist us to achieve this object. Thus, this study aims to compare linear programming as a classical method of optimization with genetic evolutionary algorithm for land use optimization of ...
Read More
Correct and consistent uses of natural resources preserve this valuable wealth. Using optimization knowledge can assist us to achieve this object. Thus, this study aims to compare linear programming as a classical method of optimization with genetic evolutionary algorithm for land use optimization of the Bayg watershed. Results showed that linear programming reduced dry farming acreage and increased the acreage of irrigated agriculture. After minimization, surface runoff and sediment yield declined by 1.16, 12.91 percent, respectively. Genetic algorithm led to an increase in rangeland, irrigated agriculture and horticulture acreages, while almond orchard and dry farming acreages were reduced. Furthermore, surface runoff and sediment yield declined by 13.95 and 31.99 percent, respectively. Linear programming acted stronger in satisfying the constraints, as compared with genetic algorithm. The constraint “total acreage” was satisfied by linear programming, while genetic algorithm could not meet this constraint. Sensitivity analysis of linear programming showed that the most critical factor in minimizing runoff and sediment yield function was the coefficient of dry farming with a reduced cost of 67.52. Results also established that the constraints “total acreage and minimum acreage of rangeland” with the shadow prices of 397.40 and 233.28, respectively had the highest negative impact on the optimal solution. Meanwhile, the constraints “maximum acreages of irrigated horticulture and almonds garden” with the shadow prices of -134.97 and -118.44, respectively had the highest positive impact on the optimal solution. As a general conclusion it can be stated that in land use optimization problems with a large number of constraints, genetic algorithm show poorer performance in satisfying constraints, as compared with linear programming.
Mehdi Sepehri; Seyyed Abbas Atapourfard; Alireza Ildoromi; Hamid Nori; Saba Goodarz; Mohammadmehdi Artimani; Morteza Solgi
Abstract
Peak flow estimation is one of the major issues in water resources and flood management that have basic role in the design of hydraulic structures and biomechanics activities in basins. So that a proper assessment has a basic role in the success of administrative works. In this paper, using artificial ...
Read More
Peak flow estimation is one of the major issues in water resources and flood management that have basic role in the design of hydraulic structures and biomechanics activities in basins. So that a proper assessment has a basic role in the success of administrative works. In this paper, using artificial intelligence methods (MLP Neural Network, the mixture of SOFM with MLP, the mixture of FCM with ANFIS) to estimate Yalfan River’s peak discharge in hydrometer local station. For these models, eight variables have been considered as the inputs that includes rainfall amount in the occurrence time of flood, rainfall of five days ago from occurrence of flood, curve number of the basin (CN), basic discharge and finally peak discharge are considered as the output. In the artificial intelligences after preprocessing of the data, the optimal structure of the models are determined with input and output data, evaluation criteria and trial and error. At the end, the MLP model had better performance compared to ANFIS+FCM, MLP+SOFM, GRNN models.
Davood Nikkami; Samad Shadfar
Abstract
Soil, as one of the components of any ecosystem and an important source of food production, has a very serious role in the continuation of human life. Therefore, the need to support and protect the soil and prevent its erosion is essential. Regarding the amount of soil erosion and sediment yield in the ...
Read More
Soil, as one of the components of any ecosystem and an important source of food production, has a very serious role in the continuation of human life. Therefore, the need to support and protect the soil and prevent its erosion is essential. Regarding the amount of soil erosion and sediment yield in the country, different figures have been mentioned and in some studies, the difference is with several times. These figures vary from less than one to more than five billion tons per year. Therefore, calculating and plotting erosion and sedimet yield maps provides important information that is used in the design of dams, reservoirs, canals, soil protection operations, onsite and offsite erosion damage assessment, and land use planning and land capability assessment projects. Soil erosion map is one of the basic, scientific and applied maps in various executive, research and educational sectors. Due to the need of determining the amount of soil erosion and sediment yield for the entire country and determining the executive priorities in areas with high soil erosion potential, this project was defined and carried out by the Soil Conservation and Watershed Management Research Institute. Accordingly, the watersheds of the seventh category were divided into seven regions or districts, including 1) Eastern Alborz 2) Middle Alborz 3) Western Alborz 4) Central Iran 5) North Zagros 6) Middle Zagros and 7) South Zagros. Long-term sedimen data of 118 hydrometric stations in these areas were analyzed and the amount of sediment in each station was determined by the logged mean load within discharge classes method. According to the amount of river bedload rates and using EPM model, the amount of sediment yield and cosidering sediment delivery ratio of watersheds, the amount of soil erosion were etermined and the soil erosion map of watersheds overlooking hydrometric stations was prepared. Results showed that the average sediment yield and soil erosion in the watersheds overlooking hydrometric stations are 3.3 and 16 tons per hectare per year, respectively. The lowest and highest soil erosion rates of 9 and 32.4 tons per hectare, belong to the Middle Zagros and South Zagros regions, respectively.
Milad Baghalani; Noredin Rostami; Mohsen Tavakoli
Abstract
Urban flood is the volume of water that is out of the capacity of the drainage network of the city and results in many problems and damages. Most researches around the world shows an increase in urban floods, especially metropolitan areas. The concentration of human population in urban areas with urbanization ...
Read More
Urban flood is the volume of water that is out of the capacity of the drainage network of the city and results in many problems and damages. Most researches around the world shows an increase in urban floods, especially metropolitan areas. The concentration of human population in urban areas with urbanization and changing the face of the earth's nature has caused an increase in impervious surfaces and change in hydrological cycle. This study was done to simulate runoff of Ilam City Catchment using of the SWMM hydrologic-hydraulic model. The model validation results showed that the simulated peak discharge and flow volume are in good correspondence with the observed value (BIAS= 3.25, RE= 0.065). According to the results obtained from the analysis of the sensitivity of the important parameters of the model, the factors affecting the flood occurrence in the study area include the inadequate size of urban channels, increase of impervious areas, coefficient of roughness of permeable areas, slope, area, equivalent width and roughness coefficient of impermeable areas. The results of the study show that sub-area 2 has the highest risk of flood due to land use changes, non-standard construction and inappropriate drainage network, which results in an increase in impervious surfaces, and in the absence of attention, the city of Ilam face severe flood risks due to the drainage network infrastructure and the lack of observance of the urbanization developments criteria. Also, the SWMM model has the accuracy required for urban flood simulation and it can be used for urban runoff management plans and designing superficial water collection and disposal networks.
Nadegholi Ebrahimi; Aliakbar Davudirad
Abstract
In order to investigate of geological formation effects on sediment yield in Gharah Kahriz watershed at first by overlaying the base maps such as land type, geology, slope and vegetation, the unit land map were obtained. The amount of sediment yield calculated using MUSLE model in each homogen unit. ...
Read More
In order to investigate of geological formation effects on sediment yield in Gharah Kahriz watershed at first by overlaying the base maps such as land type, geology, slope and vegetation, the unit land map were obtained. The amount of sediment yield calculated using MUSLE model in each homogen unit. In order to achieve the objectives of the study, units that was widespread in the region and were almost homogenous in land use, slope and vegetation and the only difference was the type of geological formation, were selected. The results show that the maximum amount of sediment yield during flood events were observed in Kmml unit that contains layers of limestone and marl with average of 13.34 t.ha-1, and the minimum amount of sediment yield belongs to the Js unit that compound of Jurassic sandstone with average of 0.20 t.ha-1.
Reza Talaei; Arash Mohammadalizadeh
Abstract
The southern areas of Ardebil Province have clay sedimentary rocks and many damages have been made because of new landslide occurrence or reactivation of old landslides every year. The clay sedimentary layers are related to the Upper Red Formations to the Neogene period in the study region. The clay ...
Read More
The southern areas of Ardebil Province have clay sedimentary rocks and many damages have been made because of new landslide occurrence or reactivation of old landslides every year. The clay sedimentary layers are related to the Upper Red Formations to the Neogene period in the study region. The clay minerals could be the main reason of the landslide occurrence because of swelling and shrinkage characteristics of soils. This research was carried out to test the hypothesis of the effect of clay expansive soils in slope instability. This area extends to 164500 ha, and 11.91% of it found to be affected by landslides. 32.8% of the whole area of the clay sedimentary rocks had experienced landslides. Minimum percentages of sand, silt and clay particles in the soil samples are 0.0, 23.4 and 8, and the maximum values are 39.9, 72 and 54.5, respectively. Minimum liquid limit of samples is 36.7% and its maximum is 67.66. The plastic limit of the samples also varies between 19 and 33.13%. Soils have a pH above 8. The cation exchange capacity above 30.41 milligrams per 100 grams of soil, which reaches up to 76.52, is one of the main characteristics of the soils in the region. The swelling potential rates of the soils of landslide area have been classified to four respective zones indicating the low, medium, high and very high swelling potential using physical and chemical properties of soils and based on different methods. At least 80% of the soil samples in the area have a swelling potential with medium to high intensity and 87.2% of them are located in zones of high and very high landslide hazard. The expansive clay soils are one of the main causes of landslide occurrence in the region.
Ramyar Aliramayee; Abdulvahed Khaledi Darvishan; Mahmood Arabkhedri
Abstract
Various factors such as rainfall intensity and slope affect hydrological processes such as infiltration and runoff. Study on rainfed soils is very important because of intense degradation and sensitive ecosystem. The present research was conducted to investigate the effect of rainfall intensity and slope ...
Read More
Various factors such as rainfall intensity and slope affect hydrological processes such as infiltration and runoff. Study on rainfed soils is very important because of intense degradation and sensitive ecosystem. The present research was conducted to investigate the effect of rainfall intensity and slope gradient on infiltration and surface runoff using rainfall simulator in rainfed lands of Kalaleh region, Golestan Province. To achieve the study purposes, four rainfall events with the intensities of 33, 64, 80 and 110 mm hr-1 and duration of 15 min were simulated. Three slope gradients of 6, 12 and 25% were selected and infiltration and surface runoff were measured in four 25×25 cm2 plots. The results showed that the infiltration average rate and runoff average coefficient were increased with increasing rainfall intensity and slope gradient. The main and interaction effects of rainfall intensity and slope gradient on infiltration and surface runoff were significant (p≤0.01). The results of subgroups of rainfall intensity and slope gradient using Duncan test showed that two turning points in hydrological response of plot are distinguishable, one between rainfall intensities of 64 and 80 mm hr-1 and another between slope gradients of 12 and 25%. In other words, at the rainfall intensity more than about 70 mm hr-1 and the slope gradient more than about 15%, average infiltration rate and average runoff coefficient were significantly decreased and increased, respectively. These results emphasized on land use management via avoiding change from rangeland to rainfed land especially when the slope is more than 15%. Agricultural and land cover management was also emphasized especially in high rainfall intensities (more than 70 mm h-1).
samere rajabnejad sheikhani; Mohammadali Ahmadian; Hamid Jafari; Mehdi Jahani
Abstract
The purpose of this study was to survey of tourism in sustainable economic development in sustainable rural development, focusing on economic dimensions of Fouman County. Rural tourism creates a chain of economic and service activities, increasing the demand for handicrafts, traditional arts and activities ...
Read More
The purpose of this study was to survey of tourism in sustainable economic development in sustainable rural development, focusing on economic dimensions of Fouman County. Rural tourism creates a chain of economic and service activities, increasing the demand for handicrafts, traditional arts and activities that require more labor, and extrinsic flows, inject costs into the region and affect on traditional multiplier and encourages. The present research is a descriptive and analytical method in term of its purpose. The information was collected through questionnaires and fieldwork. The statistical population of the research is all household caregivers of 12 villages in Fouman City, which are tourism destinations. The total number of households was 2019 families and the population of 12 target villages was 7,256. According to research population, a proportional volume sampling method was chosen. Using the Cochran sample size formula, the sample size of 324 households was determined. To measure the variables, a researcher-made questionnaire consisting of 35 questions and four components was used. The reliability of the questionnaire was 0.73 using Cronbach's alpha coefficient. Data were collected using questionnaires using Sign and Friedman tests. Based on the results of the sign test in sub hypothesis 1, it was found that there is a significant relationship between tourism and employment growth in the studied villages. The sign test in sub hypothesis 2, it was found that there is a significant relationship between tourism and increase in income level of villagers. According to the test results of hypothesis 3, it was found that there is a significant relationship between tourism and increasing the wealth of villagers. There was a priority between the impacts of tourism on sustainable development of rural economy. These priorities were important in order of importance: 1. Income generation; 2. Employment creation; 3. Rural economy sustainability.
sakineh Lotfinasabasl; fatemeh Dargahian; Mohammad Khosroshahi
Abstract
Water quality, as its quantity, is one of the most important determinant factors for its application in various uses. Physical and chemical properties of water play an important role in categorizing and evaluating water quality. With the aim of detecting the water chemical quality of Gupal river in the ...
Read More
Water quality, as its quantity, is one of the most important determinant factors for its application in various uses. Physical and chemical properties of water play an important role in categorizing and evaluating water quality. With the aim of detecting the water chemical quality of Gupal river in the south of the country and studying its annual changes during the years 1982 to 2011, its physical and chemical parameters were studied. Since the presentation of the results of water quality analysis in the graphical form simplifies and makes faster understanding of complexity of surface water systems, graphical methods such as Wilcox, Schuler, Piper and Collins diagrams were also used. The results of variation and trends analysis of water quality parameters showed that in spite of the decreasing in the trend of acidity and flow rates, other chemical parameters of water had an increase in their trend and their terms was in order of 5, 10, 20 and 30, respectively. Increasing in the trend of variation in the water quality parameters and dissolved salts indicates a decrease in water quality and an increase in dissolved salts. The Wilcox diagram showed that the water lied in the class of C4S3and was inappropriate for irrigation and agricultural uses, and Schuler’s diagram showed the water quality is not acceptable and in terms of industrial water consumption the river was precipitate and the Piper diagram showed that the dominant ions in this river are sodium and sulfate, and water has type and facies of sulfate sodic.
Meisam Samadi; Abdolreza Bahremand; Abolhasan Fathabadi
Abstract
In any water resource management plan, there is a pivotal need to undertake the future conditions to allocate the water resources to different sectors (e.g. drinking-water supply, agriculture sector, etc.) more efficiently. Meanwhile, it is important to forecast water resources inflow for future months. ...
Read More
In any water resource management plan, there is a pivotal need to undertake the future conditions to allocate the water resources to different sectors (e.g. drinking-water supply, agriculture sector, etc.) more efficiently. Meanwhile, it is important to forecast water resources inflow for future months. To this aim, it is of prime interest to adopt models that are capable of coping with data scarcity problem and able to forecast the stream flow with the least possible error. The current study was aimed at forecasting the monthly inflow of the Boustan Dam by employing three models namely: time series method, Artificial Neural Network (ANN), Support Vector Machine (SVM), and their ensembles. The hydrometric data was obtained from the Tamar Station. Afterward, the models were compared by using several evaluation criteria. According to the Akaike and Schwarz criteria, the ARIMA (2, 0, 0) (1, 0, 1) was found to be the best time series model with a parsimonious behavior. Moreover, the ANN model with two and four input neurons and the SVM model with three input neurons were the best performing models compared to their other counterparts with different input numbers. Considering the evaluation criteria altogether, the time series method was the best performing model with the RMSE, AARE, MBE, and CE values of 0.88, 4.71, -0.024, and 0.36, respectively. Therefore, the time series method was introduced as the premier model for monthly inflow forecasting in the studied stations.
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 ...
Read More
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.
touraj sabzevari; Ali Talebi
Abstract
In many civil engineering projects such as urbanization, road and dam construction, before designing and operating, the subject of landslide of the hillslopes, especially in the conditions of high rainfall, which may have financial and human damages, should be considered. TOPMODEL is a subsurface model ...
Read More
In many civil engineering projects such as urbanization, road and dam construction, before designing and operating, the subject of landslide of the hillslopes, especially in the conditions of high rainfall, which may have financial and human damages, should be considered. TOPMODEL is a subsurface model used to estimate surface and subsurface runoff of watersheds based on the Dunny-Block mechanism. This model is capable of detecting catchment saturation area and estimating the soil moisture deficit (SMD) across catchment. There is a relation between the hillslope saturation index, which is a key parameter in landslide models, and SMD. In this study, the relationship between the two models of SINMAP (landslide model) and TOPMODEL and their parameters have been studied. For this purpose, the data of the ILAM Dam catchment data located in the southeastern province of ILAM in IRAN was used. The ten hillslopes of the area were taken to calculate the sliding. Using GIS, maps of SMD and index of saturation were calculated based on TOPMODEL, and finally, stability maps of SINMAP were calculated for the region. Hillslopes 3, 4, and 5 are quasi-stable according to the model, stability probability is less than 50% and stability probability is more than 50%, and in nature these hillslopes are unstable. The 8, 9, and 10 hillslopes that are used in nature from the vegetation of oak trees are stable, according to the model of these three hillslopes.
Fazel Iranmanesh; Hamid Reza Peyrowan
Abstract
Tectonic activity affects the formation, deployment and evolution of landforms as well as erosion processes. The existence of several faults and anticline in the west of Khuzestan Plain has also led to changes in morphology and the establishment of landforms such as sand dunes. Therefore, the research ...
Read More
Tectonic activity affects the formation, deployment and evolution of landforms as well as erosion processes. The existence of several faults and anticline in the west of Khuzestan Plain has also led to changes in morphology and the establishment of landforms such as sand dunes. Therefore, the research is aimed to determine the effect of tectonic activities on the morphology and behavior of sandy hills in west of Khuzestan Plain. To achieve the above goal, the following information layers were provided. The layers included Ahwaz geological map with a scale of 1: 100,000 and a topography of 1: 25000, field observations, as well as results from the processing of Landsat satellite images and IRS from 1991, 1998, 2002 and 2006. In addition, other GIS layers was used such as faults, anticlines and units, geomorphic units, sedimentary environments and drainage networks. Data analysis was also conducted based on field observations and geomorphic techniques and a comparison method. The results of geomorphologic indices such as coefficient of sinousity and integral hypersometry showed that the study area was strongly influenced by tectonic activity and morphotectonic units such as Hamidyeh-Ahwaz, Zeynol Abbas and Abol Gharib anticlines. However, other secondary factors such as the wind direction and the pattern of the flow of the Karkheh River, change the overall trend of sand dunes. It also causes sediment transfer from sand dunes to flood plains and dust production centers in the west of Khuzestan Plain. Therefore, the findings of this research can lead to the provision of necessary information for soil protection against wind erosion in the province, especially in the center of number one dust (Hooralazim), erosion and sediment sources along the Karkheh River Basin.
Hassan Moghim; Masoud Nejabat
Abstract
From the viewpoint of landslide occurrence, Parsian dam Watershed is one of the high risk regions for landslide hazard based on its geological and climatological conditions. Landslide occurrence usually make huge damages and also high amount of sediments. Landslide control and management is planned according ...
Read More
From the viewpoint of landslide occurrence, Parsian dam Watershed is one of the high risk regions for landslide hazard based on its geological and climatological conditions. Landslide occurrence usually make huge damages and also high amount of sediments. Landslide control and management is planned according to Landslide Hazard Zonation (LHZ) that is obtainable through empirical models. The aim of this research was to assess the efficiency of two empirical models, Modified Nilsson and Relative Effect in LZH. First, prepared maps such as landslide distribution, slope, geology, land use, land cover, roads, drainages, faults, isohyet and hypsometric were imported into GIS environment and then the landslide hazard zonation was carried out by applying Modified Nilsson and Relative Effect models. Capability assessment of two models and determination of the more efficient one were evaluated using two statistical analysis methods namely quality summation (Qs) and correlation coefficient (R). Comparison of results from above two models with real map of happened landslides at Parsian dam Watershed showed that the relative effect model with quality summation of 1.00 and correlation coefficient of 0.941, is more efficient for landslide hazard zonation in Parsian dam Watershed.
Touraj Sabzevari; Mehdi Karami Moghadam
Abstract
Time-area hydrograph and Clark’s methods are commonly used for prediction of runoff in catchments. In the both methods, the Time-Area Diagram (TAD) of the catchment is needed. In this study, two methods for estimation of Dimensionless Time-Area Diagram (DTAD) are introduced. In the first method, ...
Read More
Time-area hydrograph and Clark’s methods are commonly used for prediction of runoff in catchments. In the both methods, the Time-Area Diagram (TAD) of the catchment is needed. In this study, two methods for estimation of Dimensionless Time-Area Diagram (DTAD) are introduced. In the first method, called geometric method, a hyperbolic function for the geometry of the catchment is assumed. Furthermore, travel time is assumed to be proportional to an exponent ( ) of flow distance to outlet. It was shown that the resultant DTAD equation is equal to USACE (1990) equation when is one. In another method, called Nash-TA, DTAD equation was derived as a function of Nash model parameters. The two developed methods were applied to Ajay catchment, in India, and Kasilian, Jafarabad, Shourandika catchments, located in Iran, and the results were compared to those obtained from the kinematic wave method. The efficiency coefficients for geometric method with being 0.6 and for the Nash-TA method were 0.971 and 0.955, respectively. The efficiency coefficient for geometric method in cases of =1, 1.5, 1.67 were 0.824, 0.484 and 0.161, respectively. The efficiency of the geometric method ( =0.6) and the Nash-TA method was satisfactory.
Davood Niknezhad
Abstract
Optimal use of rainfall in arid and semi-arid regions can play an important role in meeting the water needs of green space in low water seasons. On the other hand, poor vegetation can cause erosion and destruction in sloping lands that can be partially resolved if water and soil resources are properly ...
Read More
Optimal use of rainfall in arid and semi-arid regions can play an important role in meeting the water needs of green space in low water seasons. On the other hand, poor vegetation can cause erosion and destruction in sloping lands that can be partially resolved if water and soil resources are properly managed. Rainfall is one of the most important sources of water supply for various uses. One of the methods of collecting rainwater is to make the ground impermeable and to maximize rainwater runoff. Impermeable surfaces can exist naturally like rock surfaces, or can be artificially created by covering the ground with materials such as asphalt, concrete, insulation sheets such as plastic, geomembrane and decamond. This study, which was carried out in the northern part of Tabriz, was conducted in four treatments, each with three replications of 4 m2 (2m×2m), including geomembrane cover area, plastic cover with sand protection, natural surface and natural surface with sand mulch. Results of 78 rainfall events over two years showed that in intermediate slopes of 33-38.6%, runoff from rainfall for geomembrane, plastic cover with sand protection, natural surface and natural surface with sand mulch were 84, 67, 3 and 2% of rainfall respectively and rainfall threshold for runoff at mentioned surfaces was 0.28, 2.56, 9.95 and 11.12 mm, respectively. Therefore, with respect to annual normal rainfall (245.7 mm), the volume of runoff accumulated for geomembrane, plastic cover with sand protection, natural surface and natural surface with sand mulch will be 206, 164, seven and five Lm-2 ina year, respectively. Comparing the means, the geomembrane cover treatment was identified as a suitable option for runoff production. Also, sand mulch on the natural surface reduces soil erosion from 97 to 9.5 grm-2 in two years.
Hamideh Afkhami; Hossein Malekinezhad; Esmat Esmaeilzade
Abstract
In this study, urethalate floating cover is designed using soft drinks bottles and foam polyurethane in order to prevent evaporation losses of water reservoirs of Sarcheshme Copper Complex. Designed urethalate is including four square coatings with two layers of bottles that foam polyurethane is ...
Read More
In this study, urethalate floating cover is designed using soft drinks bottles and foam polyurethane in order to prevent evaporation losses of water reservoirs of Sarcheshme Copper Complex. Designed urethalate is including four square coatings with two layers of bottles that foam polyurethane is injected into these coatings to maintain and shaping and liners of anti-acid concrete has been created on its surface to protect of the upper layer. For evaluating the performance of two layer urethalate cover to reduce evaporation, two ponds with an area of nine m2 in the vicinity of Sarcheshmeh tailing dam were constructed and then the evaporation losses was measured for two month in each pond. The obtained results using designed cover showed performance of two layers urethalate in evaporation reduction. More than 92.5% of the expected evaporation was reduced. Due to the durability and performance of urethalate, this project can be considered as a worthwhile project to be used elsewhere. It would also be a useful application of environmental waste material to save water in the region with water scarcity in Iran.
Mahdi Erfanian; Mansor Bayazi; Hirad Abghari; Abazar Esmali Ouri
Abstract
Soil erosion from socio-economic and environmental aspects of view is important, and decision making for applying proper watershed management practices is essential to control or mitigate it. In recent years, the Soil and Water Assessment Tool (SWAT) model as widely-used tool have been applied to simulate ...
Read More
Soil erosion from socio-economic and environmental aspects of view is important, and decision making for applying proper watershed management practices is essential to control or mitigate it. In recent years, the Soil and Water Assessment Tool (SWAT) model as widely-used tool have been applied to simulate flow discharge, sediment yield, and to evaluate watershed management practices in reducing runoff and sediment yield. This research aims to simulate monthly flow discharge and sediment yield using the SWAT model to identify critical sub-watersheds yielding specific sediment in Nazlochai watershed, located in the West of the Urmia Lake. In this study, a monthly stream flow and sediment discharges data series were used during 1997–2007 for model calibration and 1993–96 for validation. To evaluate model efficiency, some statistical criteria consist of the determination coefficient (R2), the Root Mean Square Error (RMSE), the Nash-Sutcliffe Efficiency (NSE), and the Mean Bias Error (MBE) was used. For the sake of model calibration, validation and uncertainty analysis, the SUFI2 program was utilized, which it is included in the SWAT-CUP software as a public domain program. The NSE values for simulating monthly flow discharge in calibration and validation periods were 0.7 and 0.85, while for monthly sediment discharge simulation were 0.65 and 0.75, respectively. The evaluation criteria showed that the model is satisfactory capable to predict monthly flow and sediment discharges. To identify critical areas, the calibrated model was applied in validation period. Out of 17 sub-watersheds, sub-watersheds 17, 13, and 16 with the highest amounts of Specific Sediment Yield (SPY) in ton/ha/year were identified as critical sub-watersheds and were prioritized respectively for soil conservation and management purposes.
Soghra Malekpurlarki; Zohre Khorsandi kouhanstani; Mohammad Faraji
Abstract
Conservation and utilization of water resources are principles of sustainable development of each country. Surface waters or rivers are one of the most important water resources which have important role in supplying water demands in different sectors such as agriculture, industry, drinking water and ...
Read More
Conservation and utilization of water resources are principles of sustainable development of each country. Surface waters or rivers are one of the most important water resources which have important role in supplying water demands in different sectors such as agriculture, industry, drinking water and energy. Shavoor River which is one of the effective rivers in Shoosh City is important due to its quality in water urban and agricultural usages. Land use and its changes have important effects on river water quality. In this research, the effect of land use change is investigated in water quality of Shavoor River in 1985-2015. For this reason, land use maps of 1985 and 2015 were prepared by satellite imageries and land use changes were investigated. Results showed an increase in residential and agricultural lands and a reduction in rangelands and forests. Also, the changing trend of water quality factors in Shavoor River was studied with Mann-Kendall test and graphs. Results demonstrated that the changes overall trend of Hco3, Cl, TDS, EC, Ca, Mg and So4 were increasing in the period. According to meaningful changes of parameters, it can be concluded that the increase in residential and agricultural lands and reduction in rangelands and forests cause the water quality of Shavoor River in the study period.
Omid Rahmati; Naser Tahmasebipour; Ali Haghizadeh; Hamidreza Pourghasemi; Bakhtiar Feizizadeh
Abstract
Gully erosion is an important challenge in natural resource management and sustainable development that often has severe environmental, economic, and social consequences. Thus, the objective of the present study is to assess the capability of maximum entropy (ME) model for spatial prediction of gully ...
Read More
Gully erosion is an important challenge in natural resource management and sustainable development that often has severe environmental, economic, and social consequences. Thus, the objective of the present study is to assess the capability of maximum entropy (ME) model for spatial prediction of gully erosion susceptibility at Kashkan-Poldokhtar Watershed, between Lorestan and Ilam provinces, Iran. At first, a gully erosion inventory map was produced using GPS in field surveys. The gully conditioning factors including lithology, soil texture, land use, drainage density, distance to streams, topographic wetness index, altitude, slope percent, slope aspect, plan curvature, and distance from road were selected, and their maps were prepared in geographical information system (GIS). A total of 65 gully locations were divided into two groups (1) training of the model (45 gully occurrences), and (2) validation of the model (20 gully occurrences). The prediction of gully susceptibility and variables importance analysis were carried out based on maximum entropy model using MAXENT software. Finally, the validation of the prediction results was conducted based on the receiver operating characteristic (ROC) curve method, and the area under the curve (AUC) was calculated using MedCalc software. Results indicated that highest gully erosion susceptibility is located on the center parts of the study area. According to validation results, the resulting map of areas susceptible to gully erosion obtained by ME model has a prediction accuracy of 90.7%. In addition, the results demonstrated soil texture, drainage density, lithology, and distance to streams are most important factors and their variable importance index (VII) 23, 18, 15.2, and 15.1 were obtained, respectively. However, altitude, distance from road, slope aspect, land use, topographic wetness index, and plan curvature have a less influence on gully erosion occurrence. Therefore, it was established in current study that the ME is promising of make accurate prediction in gully erosion susceptibility.
Mohammad Gholampoor; abdolhalim Ghazali; Ahmad Roodzi; Shahab Araghinezhad
Abstract
In arid regions,like most of the Iran, human is suffering fromwater shortage. Water harvesting can be effective, especially in correct exploitation of existing waters in arid regions. With an average rainfall of less than one-third of the world, there are different climates in Iran, even in southern ...
Read More
In arid regions,like most of the Iran, human is suffering fromwater shortage. Water harvesting can be effective, especially in correct exploitation of existing waters in arid regions. With an average rainfall of less than one-third of the world, there are different climates in Iran, even in southern parts like Minab and the areas around Estaghlal Dam. In current situations, rainfall pattern has been changed and the length of drought periods has been increased in Minab. Last designed standard operating systems for estimating the amount of water entering to reservoirs like Esteghlal Dam are not sufficient. So, it is necessary to use new methods with higher accuracy in estimating and predicting watershed surface runoff. To achieve this objective, the use of numerical models for estimating and predicting is inevitable. In this research, SWAT and artificial intelligence models are used to estimate and forecast surface runoff. Calibration, validation and prediction of surface runoff were computed using soil, land use, topography and hydro-climatic data layers in the yearly and monthly basis. The annual values of evaluation criteria such as Mean Square Error (RMSE) and mean absolute error (MSE) in the calibration of the SWAT model were 6.89, 8.37 and for FTDNN were 5.35, 7.76, respectively, while, the monthly calibration results were 16.29, 32.02 for the SWAT and 9.46, 22.86 for FTDNN models. Linear regression coefficients in monthly calibration of models were 0.96 and 0.60 and in annual calibration of models were 0.94 and 0.98, respectively. Comparing criteria of evaluation of two models concluded that artificial intelligent model (FTDNN) has more accuracy and superior performance compared to SWAT model.
ehsan bazrafshan; Elhame Naghipour; Mina Dehghani; Omid Nazri Zade Sisakht; mehdi sepehri; ali reza ildoromi
Abstract
Flooding is one of the most important environmental hazards that can cause severe damage to life and financial damage. In many cases land use changes cause flooding. In this study in Gonbad Chi warershed to assess the impact of proposed and the built watershed mechanical operations (check dams) on flood ...
Read More
Flooding is one of the most important environmental hazards that can cause severe damage to life and financial damage. In many cases land use changes cause flooding. In this study in Gonbad Chi warershed to assess the impact of proposed and the built watershed mechanical operations (check dams) on flood mapping, firstly the fuzzy logic and AHP were used to prepare base map based on combination of layers i.e. slope, land use, Permeability and flow accumulation. In next step by determining the location of check dams and separation of the operation according to dam height and determine the extent of the effect of the check dams using elevation contour lines, the mapping of impact of watershed management operations was prepared. In the end with composition of base mapping with impact of check dams, a new map that called flood mapping is created. Although the results have a positive impact 9% and less than it on reducing the risks of flood but these results in built check dams is very low than proposed check dams but in total the impact of built and proposed dams is low that it’s result is from low number and distribution of check dams.
