Tahereh Nasr; hadi Abdolazimi
Abstract
Understanding the levels of urban resilience and planning to reduce the effects of various risks has a key role in managing urban crises. The purpose of this research is to identify areas with different resilience in the eleven districts of the Shiraz metropolis in order to deal with the flood crisis. ...
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Understanding the levels of urban resilience and planning to reduce the effects of various risks has a key role in managing urban crises. The purpose of this research is to identify areas with different resilience in the eleven districts of the Shiraz metropolis in order to deal with the flood crisis. The current research is based on the Fuzzy-AHP method and uses the criteria of the level of relief (sub-criteria of the density of firefighting centers, emergency, medical centers, hospitals, law enforcement, and Red Crescent), the state of residence (sub-criteria of the density of temporary accommodation places, population density and spaces Occupied), access status (sub-criteria of the density of arterial type and width of passages), worn texture and equipment placement status, identifies areas with different levels of resilience (weak, medium, good and very good). Examination of the level of relief showed that there is a weakness of relief in areas far from the city center. Therefore, it is suggested to increase the emergency services in the neighborhoods and areas far from the center of Shiraz in these places. In terms of criteria and sub-criteria examined in this research, weaker resilience was generally seen in the east and northwest of the city. The results of this research can be considered by executive managers in the phase of crisis management prevention and preparation.
Hydrogeomorphology
Jafar Jafarzadeh; Meysam Argany
Abstract
Groundwater is one of the most important natural resources in arid and semi-arid regions. The purpose of this study is to identify areas that have groundwater capacity and to prioritize the factors affecting it. In this study, 11 indicators affecting groundwater capacity including Slope, Elevation, Aspect, ...
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Groundwater is one of the most important natural resources in arid and semi-arid regions. The purpose of this study is to identify areas that have groundwater capacity and to prioritize the factors affecting it. In this study, 11 indicators affecting groundwater capacity including Slope, Elevation, Aspect, Distance from River, Drainage Density, Distance from Fault, Topographic Wetness Index, and Topographic Position Index, lithology, Land use and Relative Slope Position were used. 30% of the totals of 230 wells were randomly placed in the validation data group and 70% in the training data. To prioritize the effective factors and zoning of groundwater potential in Ghorichay watershed, the random forest method was used using ArcGIS and to evaluate the model of relative performance curve (ROC) and Area Under the curve surface (AUC). The results showed that the groundwater capacity of about 8% of the watershed is higher at the outlet of the watershed. According to the VIP diagram, the TWI layer with a value of 0.329 and the distance from the river layer with a value of 0.175 was the most and the least influential factors on groundwater capacity, respectively. The area below the AUC curve showed an accuracy of 87% in the training phase to identify areas with groundwater potential. The result of this study can be used in groundwater management in the Ghorichay watershed.
Fariba Darabi; Alireza Ildoromi
Abstract
Rainwater harvesting is a way to develop the utilization of water resources in arid and semi arid regions with the aim of increasing the quantity and quality of water resources. The purpose of this study was to determine the factors influencing the location of areas susceptible to the construction of ...
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Rainwater harvesting is a way to develop the utilization of water resources in arid and semi arid regions with the aim of increasing the quantity and quality of water resources. The purpose of this study was to determine the factors influencing the location of areas susceptible to the construction of a rainwater harvesting network (RWH) in the Siahkhore Watershed of Kermanshah using multi-criteria decision making (MCDA) and ANP network analysis. The results of the rainwater harvesting potential map show that poor classes with 2.96, relatively poor 35.49, average 26.06, relatively good 29.2 and good with 6.29 of the catchment area are included. and it indicates that the middle and relatively good and good middle classes with the highest percentage of area level with 61.55%.Field observations and results from the ROC curve show that most of the 115 rainwater harvesting plots are located in areas that are topographically and hydrologically appropriate, all of which are in relatively good, good, and moderate areas. And it represents a very good evaluation of the ANP model. Over 89% of rainwater harvesting sites are in the middle and relatively good and good classes It was found that the combination of Analytical Hierarchy Process (ANP) technique and GIS are useful tools for planning rainwater collection at basin and sub-basin scale.
Davoud Mokhtari; Mohammad Hossein Rezaei Moghaddam; Somayyeh Moazzez
Abstract
1-IntroductionDebris flows are mass movements that always threaten human activities and cause a lot of damage. The aim of this study was to zoning the risk of debris flow in the Leilan Chai catchment located in East Azerbaijan province and the impact of this hazard on the Leylan alluvial fan. For this ...
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1-IntroductionDebris flows are mass movements that always threaten human activities and cause a lot of damage. The aim of this study was to zoning the risk of debris flow in the Leilan Chai catchment located in East Azerbaijan province and the impact of this hazard on the Leylan alluvial fan. For this purpose, 10 effective criteria in the occurrence of this hazard, including slope, aspect, elevation classes, land use, lithology, precipitation, distance to fault, river density, distance to river and distance to road were used to prepare a zoning map for debris flow hazard. Identifying areas with high risk sensitivity helps regional managers and planners to manage and control this risk in the basin.2-MethodologyLeilan Chai catchment as one of the tributaries of Zarrineh Rood River is one of the important rivers in the eastern part of Lake Urmia (Movahed danesh, 1999:45). This basin is located in East Azerbaijan province in terms of political divisions. The area of this basin is 723 Km2 and is located in the geographical coordinates of 37° 00′ 31″ to 37° 38′ 20″ north latitude and 46° 14′ 26″ to 46° 38′ 37″ east longitude. The minimum elevation of the basin is 1356 meters and the maximum elevation in the heights of Sahand Mountain is 3554 meters. This basin forms an alluvial fan at the exit of the mountain that called Leilan. In the present study, the SAW decision-making method has been used to weight the criteria. Layer fuzzy was also performed due to their importance in the occurrence of debris flow in ArcGIS and Idrisi software.3-Results and DiscussionMass movements such as debris flows have always been a threat to the development of human activities. The results of weighting the criteria using SAW method showed that lithology, slope and precipitation criteria with a weight of 0.260, 0.211 and 0.190, respectively, are of more importance in the occurrence of this hazard in the study area. After determining the weight of the criteria and sub-criteria, the layers were overlapped in the GIS environment and a potential map of the risk of debris flow in 5 classes was prepared. The results of the final map show that upstream of the basin area due to having high altitude and receiving more rainfall during the year and also having a high slope are highly sensitive to the occurrence of debris flow. The downstream areas of the basin, despite the high density of river and the presence of numerous faults, but due to the very low slope, show low sensitivity to the occurrence of debris flow.4-ConclusionIn this study, an attempt was made to prepare a map of the risk of debris flow occurrence in the Leilan Chai basin using effective criteria in the occurrence of this risk. The final debris flow hazard map was prepared by overlaying and multiplying the final weight of the criteria in fuzzy layers in GIS environment. The results showed that about 117 Km2 (16% of the area) of the study area is in the high and very high risk classes in terms of sensitivity to debris flow. In contrast, 49% of the total area is low and very low sensitivity to this risk. Areas located in high and very high classes mainly include the upper parts of the basin, which have the potential for this risk in terms of slope, precipitation (more than 400 mm) and lithology (presence of volcanic ash). Also, according to the research results, it can be said that this hazard cannot have much effect on the Leilan alluvial fan. Due to the occurrence of this hazard in the upper parts of the basin, the possibility of transferring these materials to the downstream areas and even the surface of the alluvial fan is very low due to the very long distance.
yaser hoseini
Abstract
1-Introduction Flood is a natural phenomenon, which threatens the life and properties of a large number of people all over the world, yearly. Flood discharge, regarding water resource exploitation, flood control, construction of dams, basin management, and hydrologic studies, is of high importance in ...
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1-Introduction Flood is a natural phenomenon, which threatens the life and properties of a large number of people all over the world, yearly. Flood discharge, regarding water resource exploitation, flood control, construction of dams, basin management, and hydrologic studies, is of high importance in studies. Therefore, the accuracy of these studies and the safety of waterworks and water structures depend on the methods of studies to a large extent. It is impossible to manage water resources in basins without the accurate determination of the peak flood discharge. The advances in flood estimation techniques have made it possible to use rainfall-runoff models to assess the hydrographic properties of the flood in watersheds and decrease the risks of the flood. In studies on water resources, it is of high importance to determine the flood discharge of different basins. Studies of Dile and Srinivasan (2014) and Hoseini et al. (2017) showed that basin level and rainfall can be the most important factor in runoff flow. Consequently, proper simulation and modeling of flood runoff are the important parameters in flood management in the region. However, it is necessary to use new models to determine flood hydrograph parameters. So, this study aimed to determine the peak flood discharge of the Darrehrood basin using regression mode for return periods of 10, 25, 50, and 100 years. 2-Methodology Darrehrood basin is located in Northwest Iran. The basin is surrounded by mountains and is considered the main basin of Ardabil Province. It lies within 47°30' to 48°55' longitude and 37°45' to 39°42' latitude. Its area is approximately 12900 km2. Discharge data were collected from 16 hydrometric stations with a statistical period of 15 years during 2001-2015. Incomplete data related to stations were completed using statistical methods and considering the best statistical distribution of floods in the studied sub-basins, floods with different return periods were calculated then the physiographic characteristics of sub-basins that affect flood rate include: area, slope, shape factor, height average, concentration-time, and curve number achieved using ArcGIS and WMS (watershed modeling system). To evaluate the model, maximum error (ME), root mean square error (RMSE), relative percentage error (ε), mean absolute error (MAE), coefficient of determination (R2), Coefficient of residual mass (CRM), and model efficiency (EF) were used. 3-Results and Discussion The model calibration results showed that the simulated peak discharge and flow volume are in good correspondence with the observed values, so that, the lowest goodness of fit (R2) value in the return periods of 10, 25, 50, and 100 years were estimated to be 97, 96.6, 95.8 and 94.7 %, respectively. The results showed that the linear regression model with very good accuracy can predict the peak discharge in the sub-basins in Darrehrood using the physiographic parameters of the basin and with increasing the return period, the accuracy of the model is slightly reduced. Model evaluation indicators for the return period of 100 years include root mean square error (RMSE), relative percentage error (ε), mean absolute error (MAE), Coefficient of residual mass (CRM), and model efficiency (EF) were calculated 40.75, 52.12, 0.52, 0.92 and 0.62 respectively. Cross-validation diagrams showed that all models were partially underestimated and the scatter of points around the one by one axis was very suitable for the whole return periods. According to the paired t-test of the difference between predicted and actual values in different return periods in the level confidence of 1% are not significant. 4-Conclusions The results of this study show that the model has good accuracy for estimating floods in sub-basins of Ardabil province.
Zohreh Maryanaji; Abozar Ramezani
Abstract
1- Introduction Natural hazards cause enormous damages every year. Among the natural hazards, floods, earthquakes, and droughts have special importance in financial and human losses. Meanwhile, according to the available statistics and information, floods in some parts of the world, especially in Asia ...
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1- Introduction Natural hazards cause enormous damages every year. Among the natural hazards, floods, earthquakes, and droughts have special importance in financial and human losses. Meanwhile, according to the available statistics and information, floods in some parts of the world, especially in Asia and Oceania, have the highest damage. Iran is one of the arid and semi-arid regions of the world with particular climatic conditions. Inappropriate spatiotemporal distribution of rainfall in such regions has caused devastating floods. In this study, flood vulnerable areas are identified by determining the effective parameters of flood using Shannon entropy model. The results of this study can be used in flood zoning and forecasting and planning and management of water resources in the region. 2- Materials & Methods In multi-criteria decision-making problems having and knowing the relative weights of the existing indicators is a significant step in the problem-solving process. (Relations 1 to 6). (1) Aij= (2) (3) (4) Ej= i=1,2…,m (5) wj=dj/∑dj (6) wj= Entropy method is one of the multi-criteria decision-making methods for calculating the weight of criteria. This method requires a criterion-option matrix. The steps of Shannon entropy method consist of five steps of the decision matrix, normalization of the decision matrix, calculation of the entropy of each index, the calculation of deviation, and calculation of weight value Wj. In the Shannon method using the experience and knowledge of experts appropriate factors are determined and weighed. After collecting the questionnaire data and considering the geography of the study area, the scores of each factor are adjusted. 3- Results & Discussion Natural parameters of flood occurrence in Hamadan province include: climate, snowmelt, slope, soil type, Gravilius coefficient, and vegetation. Due to the climatic characteristics of the province, most of the province's rainfall is due to the Mediterranean systems. In winter, the rains are in the form of snow, and in the early spring the melting of snows is accompanied by spring rains which most of the time causes the rivers to overflow. Due to the severe destruction of vegetation in the province, the potential of the region in flooding has been increased. In general, it can be said that the occurrence of floods in any region is due to the confrontation and alignment of human and natural factors. This study only examines the natural causes of flood. The study of the effect of each parameter in the occurrence of floods based on the data-expert method showed that the six factors studied in these studies do not have the same effect on reducing or increasing floods in the basins. 4- Conclusion Based on scoring the natural factors that cause floods, according to the intensity of their impact, the flood-prone areas of the province have been identified. Based on the combined data model and Shannon entropy, the highest weighting was given to the maximum 24-hour precipitation. Vegetation factors, snow melting time, basin slope, soil type and Gravilius coefficient were identified as the most effective natural factors in causing floods in Hamadan province, respectively. Based on the final weights, a hazard map was drawn using the GIS. According to the hazard map, the very high risk regions are located in the central and southern parts of the province. Also, the northern areas including the cities of Razan, Kaboudar Ahang and Dargazin are located in high risk area. Using the results of this study, it is possible to identify the approximate time of flood occurrence and flood-prone areas in Hamedan province.
Ali Shahidi; Fahime Khadempour
Abstract
1-Introduction Increasing water consumption due to population growth has led to a reduction in the quality and quantity of extracted water. Given this situation, quantitative and qualitative knowledge of suitable sources for drinking and farming is necessary and inevitable. Meanwhile, ground water ...
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1-Introduction Increasing water consumption due to population growth has led to a reduction in the quality and quantity of extracted water. Given this situation, quantitative and qualitative knowledge of suitable sources for drinking and farming is necessary and inevitable. Meanwhile, ground water is considered a safe source for water supply. Today, due to the excessive use of groundwater resources in many plains, water levels have fluctuated and groundwater levels have fallen, and these plains have been hit by decreasing water quality. Therefore, water resources control and optimal use of them are of high priority. Since, groundwater resources are considered as important sources of water supply for various uses. In order to better understand the qualitative status of water resources, water quality indicators are used. To do this, by conducting experiments on water samples and using mathematical relationships defined for each index, a value is obtained that can be used to describe the qualitative state of water based on it and refer to the relevant tables. 2-Methodology Based on international standards for drinking and agriculture uses, some of the parameters examined are lower and others are more than global standards. Basically, these differences indicate the presence of pollution in various water sources. The water quality index is, in fact, simply a numerical value that reduces the large amounts of data, including physical, chemical, and biological parameters, and generally indicates the overall quality of water for various uses, especially for drinking. Typically, heavy metals are included in the water quality index to assess overall water contamination. In this study, the quality of groundwater in the Jangal plain in Khorasan Razavi province has been investigated. 10 wells in this plain were analyzed for concentrations of Ca2+, Mg2+, Na2+, HCO3-, SO42-, Cl-, pH and TDS with GWQI and AWQI indices in the period 2007-2016. Also, plain zoning was performed using the GWQI index and Arc GIS 10.2 software. In cases where the AWQI value is zero, it means that there is no pollutant in water, and if this value reaches 100, that is, all pollutants have reached their maximum permissible limit. The high level indicates the high level of contamination and the passage of this value from 100 indicates serious contamination. 3-Results The results showed that most of the Jangal plain wells pollution are less than the contamination level during the statistical period. Fayez Abad, Kheirabad Ali Akbar Rahmani and Bandazik Salehi Wells have passed through the limit of contamination over the years and have serious pollution and are not suitable for drinking and farming. Based on the zoning, the indicator status in all wells (except wells of Fayez Abad (well No. 2), Kheirabad Ali Akbar Rahmani (well No. 9), and Badazaki Salehi Forest (well No. 10) have inappropriate water (red)) and in the whole area of the Jangal zone is poor (orange color), so the pollution of these wells is not serious and is suitable for drinking and farming. The total amount of all parameters except total dissolved solids (TDS) in all wells is standard. The reason for this is the lack of industrial activities and human communities near these wells. The highest mean total dissolved solids is 5378.49 mg/l. In this study, the least amount of GWQI and AWQI indices for Janet Abad Khordemalkin well were 69.66 and 56.49 (highest quality in 2008) and the highest of these two indicators were 239.12 and 189.48, respectively. 4- Conclusion According to the results of this study, the GWQI index in the region ranges from 69.66 to 239.12 and the AWQI index is between 56.49 and 189.48, that is, the quality of groundwater in the Jangal area is weak and inappropriate. The cause it is also the high solids content of the total solution of water. In fact, in this region, all of the measured quality parameters, except the total dissolved solid, are at the standard level. According to the results of this study, although the amount of calcium and magnesium is in the standard range but at lower levels, and given the body's need for these micronutrients, it is necessary to plan the provision of these elements through other sources or add them to the water in the refinery.
leila Biabani; Arash Malekian; Behrooz Akbarpoor
Abstract
The management of groundwater resources is a major for identifying areas with high potentials for groundwater. In this study, we tried to identify areas with the potentials for groundwater in Sufi chay Watershed by using frequency ratio model. Conditioning Factors used in this study include: elevation, ...
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The management of groundwater resources is a major for identifying areas with high potentials for groundwater. In this study, we tried to identify areas with the potentials for groundwater in Sufi chay Watershed by using frequency ratio model. Conditioning Factors used in this study include: elevation, slope, drainage density, landuse, Lithology, Soil, Faults and Topography. In the frequency ratio, at first wells with a discharge rate of above 11 liter per second were extracted in the region; then, 70 percent Training wells (6981 pcs) and 30% of the wells for validation (2992 pcs) were randomly selected. Based on the frequency ratio, necessary analyses were conducted in classes and maps and maps were overlapped. Finally, the groundwater resources map for model were produced. ROC curve method was used to evaluate the performance of model. Based on this, the percentage of the area achieved in the Frequency model ratio are as follows 63% of the areas were low; 18% Average; 12% high, and 7% Very high.
Mehdi Teimouri; Omid Asadi Nalivan
Volume 6, Issue 21 , March 2020, , Pages 155-179
Abstract
1-IntroductionThe main objective of this research is to prioritize the factors affecting the occurrence of landslide and its susceptibility zoning in Lorestan province using the maximum entropy and MaxEnt models. To do this research, 11 factors affecting the occurrence of landslide including height, ...
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1-IntroductionThe main objective of this research is to prioritize the factors affecting the occurrence of landslide and its susceptibility zoning in Lorestan province using the maximum entropy and MaxEnt models. To do this research, 11 factors affecting the occurrence of landslide including height, slope, aspect, surface curvature, distance from the stream, fault and road, lithology, land use, rainfall, and topographic humidity index have been used. In this research, 30, 40, 50, 60 and 70 percent of landslides were evaluated for validation to determine the sensitivity and accuracy of the model. For evaluation of the model, the relative recognition function curve (ROC) was used. From the total of 176 landslides, 70% of the data was used as the test data and 30% as the validation data using Mahalanobis distance method and the accuracy of the model in the testing and validation stages based on the curve level was reduced. The results showed that 35.5% of the province of Lorestan has a landslide sensitivity. Based on jackknife diagram, rainfall, distance from road, lithology and land use layers were the most important factors influencing the sensitivity of landslide. The AUC level based on the relative function recognition curve indicated a 90% accuracy (excellent) of the maximum entropy method at the training stage and 83% (very good) at the validation stage to determine the landslide susceptibility. The results of this study will be suitable for provincial administrators and managers in order to land planning and reduce the damage caused by landslide occurrence.Mass movements, including landslide, is one of the most important issues in natural hazards, because its occurrence can cause many human and economic losses, especially in mountainous areas (Symeonakis et al., 2016). Regarding the destructive effects of landslides on natural resources, as well as human habitats and erosion of significant volumes of valuable soils, the identification of susceptible areas and zoning of potential occurrence or landslide susceptibility is vital and very important (Zhang et al., 2019). In recent years, the use of GIS and remote sensing along with machine learning methods has created a new step in the zoning of landslide occurrences. Lorestan province is a vulnerable area to landslide hazard due to the mountainous and wetness conditions. Therefore, the main objective of this research was to prioritize the factors affecting the occurrence of landslide and its susceptibility zoning in Lorestan province using the maximum entropy and MaxEnt model.2-MethodologyLorestan province with an area of 2829612 hectares is one of the major provinces in the west of the country. To do this research, 11 factors affecting the occurrence of landslide including altitude, slope, aspect, surface curvature, distance from the stream, fault, and road, lithology, land use, rainfall, and topographic humidity index have been used. The required maps were prepared using GIS and RS techniques. In this research, 30, 40, 50, 60 and 70 percent of landslides` division were evaluated for validation to determine the sensitivity and accuracy of the model. For evaluation of the model, the relative recognition function curve (ROC) was used. Using Mahalanobis distance method, from the total of 176 landslides, 70% of the data was used as the test data and 30% were utilized as the validation data for having the best classification. The difference of the current research with other similar studies was that in this study, use was made of Mahalanobis distance method for classification of validation data and training instead of random classification. The Mahalanobis distance helps to classify data richness and prevents random selection of points for validation. Maximum entropy method (MaxEnt model) is one of the methods of machine learning and one of the main advantages of MaxEnt model is the ability of this model to identify the most important variables and sensitivity analysis of variables using Jackknife method, which has been investigated in the current study.3-ResultsThe results showed that 35.5% of the province of Lorestan had landslide susceptibility. Based on Jackknife diagram, rainfall, distance from road, lithology and land use were, respectively, the most important factors influencing the susceptibility of landslide. The AUC level, based on the relative function recognition curve, indicated 90% accuracy (excellent) of the maximum entropy method at the training stage and 83% (very good) at the validation stage to determine the susceptibility of landslide occurrence.4-Discussion and conclusionLandslide is considered as one of the most dangerous natural disasters in the world. In this study, taking into account the affective environmental and human factors, and using the maximum entropy method, the map of landslide susceptibility of Lorestan province was prepared. The results showed that factors such as rainfall, distance from the road, lithology, land use, distance from the fault and slope were the most important factors influencing landslide susceptibility with the participation of over 60%, regarding which, land use management and road construction principles need human activity interventions. The drawn ROC curve showed that the accuracy of the model in the estimation of landslide susceptibility regions both in the stage of the test and in the validation stage was excellent and very good, which meant the excellent performance of the model. According to the obtained results, it can be said that MaxEnt model had a high ability to determine areas with landslide susceptibility and due to the speed and accuracy of the model,it is suggested that in similar researches, especially in developing countries, due to the lack of facilities and financial resources, as well as the time consuming of identifying areas with landslide susceptibility, it can be used. In addition to natural factors, some human factors such as road construction, play an important role in the occurrence of landslide, which requires avoiding ecosystem change as a disaster risk factor to reduce relative risks. The results of this research can be applicable to the decision making and management of provincial lands as well as urban planning, and they can have a significant role in preventing and reducing the damage caused by landslide.
Aghil Madadi; Elnaz Piroozi; Leila Aghayary
Volume 5, Issue 17 , March 2019, , Pages 85-102
Abstract
Introduction
One of the most striking natural hazards in the world is flood which generates a lot of financial and human losses every year. It can be said that in comparison with other natural hazards, it occurs with high abundance and in vast expanses. Some of its causes can be severe or prolonged ...
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Introduction
One of the most striking natural hazards in the world is flood which generates a lot of financial and human losses every year. It can be said that in comparison with other natural hazards, it occurs with high abundance and in vast expanses. Some of its causes can be severe or prolonged rainfalls, melting, breaking the dam and landslide, high waves, channel closure, rainfall intensity, type of rainfall, time and volume of rainfall, previous river conditions, drainage basin, inappropriate use, and falling of forest trees in the sources of the rivers. Knowing susceptible areas to floods is one of the basic measures in natural resource management and development planning. One of the most important flood management methods is flood zoning. The zoning of potential flooding is to identify and describe areas with potential for surface runoff. The Khiyav Chay Watershed Basin, with an area of 318 km2, is located in Meshgin shahr. Due to the specific circumstances of the region, such as topography, slope, and climatic conditions (sudden precipitation and spring precipitation, melting, flooding of rivers in the spring), there is a high potential for flood occurrence. Therefore, the purpose of this research was to study the area's potential for flood occurrence.
Methodology
In this study, ten factors of slope, height, rainfall, CN, runoff height, distance from the river, soil, lithology, vegetation, and user-use were identified as effective factors for flood formation in the region. Using Landsat 8 images including OLI and TIRS sensors and the Maximum Likelihood supervised classification method, in the ENVI 5.3 environment, the land use map was obtained. Then the user map was compared with the index table and integrated with the hydrologic group data, and the CN curve number was prepared. In the next stage, with mean precipitation and CN, and by using SCS method, ARC GIS software and Arc-Hydro and Arc CN-Runoff subtraction, the runoff height of the range was calculated. Also, the NDVI index, one of the most widely used indices for vegetation monitoring, was undertaken to prepare a vegetation map of the basin. Then, the other layers of information were provided in the GIS environment. The weights of the layers using the Critical method based on the correlation, interference, and standard deviation of the factors were determined. The final analysis and modeling was done using the WLC model as one of the methods of multi-criteria analysis techniques.
Discussion
By studying the zoning of the potential flood area of the study area and comparing it with each of the standard maps, it was concluded that the high risk areas were mainly in the hilly and mountainous areas of the area (slope over60%). Due to the slope and elevation of the area, the main role was with runoff, flood discharge, penetration, precipitation losses, and flow and water velocity. In these high risk areas, due to the fact that most of the formations belong to the formation of volcanic activity in the late third and early fourth centuries, the degree of permeability was very low but the runoff and CN amount were high. Secondly, areas with potential hazard were located within the urban boundaries of Meshkinshahr. In the city of Meshgin Shahr, on the east side, is the deep valley of khiyave chay, where the khiyave chay River flows. Two other radial valleys in the natural pathway formed the surface water stream, along which residential neighborhoods were developed that were subject to flood and extreme flow of surface water. Due to the fact that most of the city is made up of asphalt and residential surfaces, the permeability was very low, in contrast to the amount of runoff (99%) and CN (curve above 8).
Conclusion
According to the results of weighing, height factors with weight coefficients (0.173), lithology with weight coefficients (0.163), slope with weight coefficient (0.139) and rainfall with weight (133/0) were the most important factors on flood formation in the region. The results of the study showed that 13.33% and 22.88% of the study area were in high risk and high class. According to the final map, high-risk areas, in the first priority, were mainly in the hilly and mountainous regions of the region, but in the second priority they were within the urban boundaries (especially in the central regions of the city due to lower construction and permeability). The results of the study also indicated that due to the high potential of the study area in terms of the risk of flood, water protection and protection measures at the basin level should be considered. In addition, the simultaneous use of remote-sensing and GIS and using the SCS-CN model could be useful in preparing a flood zoning map.
Vahid Nourani; Saleh Mohsenzadeh
Volume 4, Issue 11 , September 2017, , Pages 83-103
Abstract
Introduction
In this study, the MPSIAC model was used to consider the effects of the dominant factors in sediment production in order to estimate the rate of the erosion and sediment load in sub-basins of the Aji Chay River. Since the sediment rate of this model is the annual average, the variations ...
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Introduction
In this study, the MPSIAC model was used to consider the effects of the dominant factors in sediment production in order to estimate the rate of the erosion and sediment load in sub-basins of the Aji Chay River. Since the sediment rate of this model is the annual average, the variations of the nine fold factors of this model was examined in order to calculate the sediment for each year. Then, the annual and monthly sediment rates were quantified using a cascading method.
Methodology
In order to estimate the sediment production and the relationship between the degree of the sediment yield and the amount of production, equation (1) which was based on determining the scores of the factors considered in the PSIAC model and obtaining their total scores in each hydrological unit was used
38.77e0.0353R = Equation(1): QS
Qs=sediment yield (m3/km2/year) R= sedimentation rate
The PSIAC model specifies some variations for each factor, which is somewhat selective and requires an expert judgment. Johnson and Gombard (1982) have made the nine-fold factors for this method as numerical equations.
The estimated sediment rate using MPSIAC method is based on the annual average. Therefore, the variations of the factors of MPSIAC model were examined and compared to estimate the sediment for each year. Due to the fact that sediment is not the same throughout the year, it was not possible to equally consider annual sediment for all months of the year. Thus, for the purpose of the quantification of the monthly sediment, the cascading micro-scale was used through verifying the existing data and filling the deficiencies of the data. In the process of disintegration, the sediment, which was the annual sediment in the initial intervals, was sequentially broken into smaller surfaces with specific coefficients and calibrated.
Equation(2): SNij = Sij
Equation(3): SijNky = Sk
Results and discussion
In this paper, the annual sediment rate was estimated using remote sensing, GIS techniques, and the application of the experimental model of MPSIAC in hydrological units and its zoning in the area. Then, by inserting the DEM into the GIS environment and by modifying the ups and downs, the flow direction, the network of waterways, and the primary and secondary sub-basins were produced. As a result, the production rate of the sediment and the scores of the each of the factors in the sub-basins were calculated using the equations presented in the MPSIAC model. The results showed that there was a high correlation between the estimated sediment load with the MPSIAC model and the observed and recorded results.
The results of the MPSIAC model for the estimated sediment rate were based on the annual average, so the existing data and nine-fold factors of MPSIAC model, which were time-consuming, were used for the monthly sedimentation. To measure the amount of the precipitation and runoff for different months of each statistical year and to study the amount and manner of changes in vegetation and land use in the studied area, the annual precipitation and annual erosion were calculated for each statistical year. Then, sub-scaling was done through the calculation of the sub-scale coefficients of annual to monthly sediment.
Conclusion
The estimated sediment rate using MPSIAC model and observational and measured data of the sediment in the hydrometric stations of the Aji Chay basin has high accuracy and acceptable correlation. In addition, by comparing and verifying the available and measured data in the hydrometric stations of the AjiChay basin at low scales with extractive data of this method, it turns out that the sediment values can be estimated at low scales by specifying the sub-scale coefficients and calculating the sediment for each year.
Abolghasem Amir Ahmadi; Mahnaz Naemi Tabar; Bahar Gholkar ostadi
Volume 4, Issue 11 , September 2017, , Pages 105-125
Abstract
Absract:
Introduction
Landslide is one of the natural phenomena causing many financial losses and casualties in Iran every year (Kamranzadeh, 2014: 101). This phenomenon occurs when the force of materials’ weight is higher than the shear strength of the soil shear force (Memarian et al. 2006: ...
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Absract:
Introduction
Landslide is one of the natural phenomena causing many financial losses and casualties in Iran every year (Kamranzadeh, 2014: 101). This phenomenon occurs when the force of materials’ weight is higher than the shear strength of the soil shear force (Memarian et al. 2006: 105). The Shannon entropy is a function of probability distribution and standard for measuring uncertainty in the information content of a parameter, and by considering occurrence frequency of subgroups of that parameter, it shows heterogeneity level. As a result, it calculates the effect of each parameter on the results of the system (Hosseinpour Mil Arghadan et al. 2014). Objectives of the present study are the selection of criteria and standards, preparation of digital factors layers, preparation of the landslide hazard zonation map, diagnosis of high risk points via the Shannon entropy, presentation of strategies appropriate for preventing possible risks and solutions to reduce damages in the study area. Bajgiran is the central district of Bajgiran County and a part Doulatkhaneh Rural District of Ghouchan Township. According to climate divisions, Bajgiran has a moderate mountainous climate. Geologically and structurally, it is a part of Kopeh Dagh Sedimentary Basin. In terms of stratigraphy, outcrops from the Jurassic rock units to the present era can be observed in the study area.
Materials and methods
In the present study, first of all factors affecting the occurrence of landslide including height, precipitation, slope, slope direction, slope shape, distance from the waterway, distance from the road, distance from the fault, land cover and lithology were identified as factors affecting the occurrence of landslides, and the mentioned maps were digitized in GIS. to this end, using the topographic map on a scale of 1:50000, the Digital Elevation Model Map (DEM), factors of slope degree, slope direction, slope shape, height level, distance from the waterway, and distance from the road were prepared. Using the land-use map on a scale of 1:25000, information layers of land use were extracted. To draw the lithological map, the distance from the fault of the geological map on a scale of 1:50000 was used. To draw the precipitation map, statistics of the rain gauge stations of five Daroungar, Mohammad Taghi Beig, Aman Gholi, Kikan, Hey Hey Ghouchan, and Bahman Jan Stations were used. The information content available in the decision matrix in entropy process is calculated via equation 1:
Equation 1: Ej = -K
Where Ej is the entropy value and Pi,j is the decision matrix.
Equation 2: Pij =
Where rij is the value or the special score assigned to each layer.
Equation 3: K= (lnm)-1
Where k is the fixed coefficient and m is the number of landslides.
After the formation of the decision matrix and extraction of the value of Ej, the value of Vj can be calculated via equation 4:
Equation 4: Vj = 1- Ej
Where Vj is the deviation degree of uncertainty.
And finally, to calculate the final weight of all factors (Wj), equation 5 is employed.
Equation 5: Wj =
To prepare the final map, equation 6 is used:
Equation 6:
Where Hi is the landslide hazard occurrence coefficient, Wj is the final weight of all factors, rij is the weight of each factors (Moghimi et al. 2012: 82).
Results and discussion
After converting criteria into integers and the formation of the initial matrix, the value of Pij was calculated via equation 1 and the value of K was calculated via equation 2. To calculate Ej for each criterion, equation 2 was used. The results are indicated table 2. In this equation, the value of E which is a function of n, for each n where Pi is equal, the value of E becomes maximum which is statistically calculated via probability distribution of Pi. Then, uncertainty or degree of deviation of each criterion (dj) obtained from the fraction of the value of Ej from 1 were calculated per each indices effective on landslides of the study area (table 2). After that, using equation 5, the weight of each parameters used in the entropy matrix of landslides (Wj) including height (0.02113), precipitation (0.031142), shape of slope (0.0116110), slope (0.011342), distance from the waterway (0.045161), distance from the road (0.113401), distance from the fault (0.099871), land use (0.997110), and lithology (0.095148) were obtained. Therefore, the regional model of the landslide hazard degree in the area was obtained via equation 6. Hi is the landslide hazard degree in the area (equation 7).
Conclusion
The aim of the present study was to prioritize factors affecting the occurrence landslides and zone their sensitivity in Bajgiran Region via the Shannon entropy. The results of the study shows that the most important factors affecting landslides in the study area are slope layers, slope direction, lithology, distance from the fault, and height. After weighting parameters and formatting the entropy matrix, the zonation mapping were conducted. To this end, information layers were prepared in Arc GIS and converted into Raster formats. With regard to zoning maps obtained from the entropy model, 15 landslides have occurred in the area among which 9 landslides have occurred in a high risk zone (42%), 4 landslides in a moderate risk zone (31%), and 2 landslides in a low risk zone (27%). Regarding the factor of slope, it can be said that the most landslides have occurred in slopes with 60%. It may because the lack of the soil-formation process prone to slippery movements. In case of the factor of slope direction, the most landslides have occurred in northern domains and in heights with 1600 m high. This results is compatible with the faults and calcareous, marl, and Pyura Chilensis organizations of the area. The results of the present study also show that the entropy model has appropriate performance in identifying risk areas and their zonation. In addition, the results can be used in decision making and management of land use and urban planning.
Majid Ramezani Sarbandi; Reza Ghazavi; Siamak Dokhani; Seyyed Mostafa Mortazavi
Volume 4, Issue 10 , June 2017, , Pages 65-80
Abstract
Groundwater is one of the most important natural resources in the world. Currently, the considerable part of Iran's water consumption, minly its drinking water, is provided from underground water sources. The emission of the surface contaminants to groundwater resources, especially in the arid and semi-arid ...
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Groundwater is one of the most important natural resources in the world. Currently, the considerable part of Iran's water consumption, minly its drinking water, is provided from underground water sources. The emission of the surface contaminants to groundwater resources, especially in the arid and semi-arid regions with a limited water resources is a serious problem. In this research, the DRASTIC and GODS methods were used to study Rafsanjan plain's potential vulnerability to pollution. To this end, seven layers including groundwater depth, net recharge, aquifer media, soil, topography, and unsaturated zone hydraulic conductivity were produced for the DRASTIC method. In addition, to create potential vulnerability maps using GIS for the GODS method, four layers including type of groundwater, unsaturated zone, water table depth, and soil environment were combined. The degree of the changes of the electrical conductivity of the plains was used for the validation of the models. According to the results, the DRASTIC index is between 61.33 and 183.75 for the region, categorizing Rafsanjan plain to five classes of vulnerabilities including very low 0/54%, low 32/93%, medium 55/40%, high10/54%, and very high 0/59%. The GODS model, in contrast, classifies the region to three classes of vulnerability including low 32/27%, medium 67/04%, and high 0/69%. In both models, the most part of the study area was classified into medium level of vulnerability which were respectively 55.40 and 67.04 in the DRASTIC and the GODS models.
Davood Mokhtari; Fatemeh Mohammazadeh Golani; Mohammadreza Nikjoo; Shamsollah Asghari
Volume 3, Issue 6 , January 2017, , Pages 1-16
Abstract
Estimates of Erosion Sediment of Gavi River Catchment Using Mpsiac Method in GIS Environment Davood Mokhtari[1] Fatemeh Mohammazadeh Golani[2]* Mohammadreza Nikjoo[3] Shamsollah Asghari[4] Abstract Gavi river catchment is located in the south west of Ilam city covering the area of 460 km² ...
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Estimates of Erosion Sediment of Gavi River Catchment Using Mpsiac Method in GIS Environment Davood Mokhtari[1] Fatemeh Mohammazadeh Golani[2]* Mohammadreza Nikjoo[3] Shamsollah Asghari[4] Abstract Gavi river catchment is located in the south west of Ilam city covering the area of 460 km² where different types of erosion incidences are noticeable therefore, estimating the amount of erosion and deposition is essential for soil and water conservation projects. The method of this study is based on litrature review, field and empirical models of erosion and sedimentation estimation. Empirical model of MPSIAC whit considers the most effective parameters in erosion and sediment is used as a chosen technique and the environmental parameters are analyzed in this format. At the end the results were compared to Bajk strait sediment station. GIS software is used to prepare the information layers. The results show that MPSIAC model is a good model in this area, because as a sample, the estimated amount of sediment in the area using MPSIAC model was 20.453 tons per square kilometer of sediment per year and estimated sediment in hydrometeric station of Bajak strait is 23.460 tons per year. It was also observed that the estimated sediment in this basin is in erosional Class4 and in terms of quality classification, erosion is in high level and according to the definition of this level it can be said that in this basin the relocation of the soil particles (dust) is in a rate that accomplishment of soil and water conservation programs should be in priority and lands usage should be limited. Keywords: Gavi catchment, Erosion and sediment, MPSIAC, GIS. [1]- Professor of Geomorphology, University of Tabriz, Tabriz, Iran. [2]- Master Student of Geography, University of Tabriz, Tabriz, Iran, Email:fa.mohammadzade@yahoo.com. [3]- Associate Professor of Geomorphology, University of Tabriz, Tabriz, Iran. [4]- Lecture of Agricultural Research Center of Ilam Province.
Hashem Rostamzadeh; Mohammad Reza Nikjoo; Ismaeil Asadi; Jafar Jafarzadeh
Volume 2, Issue 3 , January 2017, , Pages 43-60
Abstract
Ardabil Plain is an intermountain area of approximately 820 square kilometers in northwestern Iran, located in the eastern plateau of Azerbaijan within the province of Ardabil. Plain water needed for agriculture, industry and drinking are provided from rivers, deep and semi-deep wells and springs in ...
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Ardabil Plain is an intermountain area of approximately 820 square kilometers in northwestern Iran, located in the eastern plateau of Azerbaijan within the province of Ardabil. Plain water needed for agriculture, industry and drinking are provided from rivers, deep and semi-deep wells and springs in the current area. To check the quality of groundwater in Ardabil, the data on 56 deep wells, 3 semi-deep wells, 3 aqueducts and fountains, and 7 mouthpiece of streams based on 1389 Regional Water Authority records were sampled. The purpose of this study was to provide an overview of the quality of potable groundwater of Ardabil Plain by using electrical conductivity, PH, SO4--, Cl-, Na and total hardness (in CaCo3) and geostatistical techniques in GIS software through ArcGIS10.3 to produce thematic maps of groundwater quality is Ardabil Plain. The ordinary kriging interpolation method to obtain the spatial distribution of parameters and simple additive weight for weighting and ranking layers were also used. Finally, with regard to the quality of the final map, it was detected that approximately 34 percent (about 280 kilometers) of groundwater for drinking at an optimal level in Ardabil Plain is located on the east side and that the lower quality water belonged to the southwest and northwest of the plain. Also, it was found that there is a direct relationship between the density of population and density of existing wells in the Plain.
Sorayya Abbasi; Masoud Heydari
Volume 3, Issue 6 , January 2017, , Pages 75-93
Abstract
Sorayya Abbasi[1] Masoud Heydari[2] Abstract One of the important issues in water resources management is the identification of ground water behavior. The aim of this paper is the estimation and comparison of two methods for potential ground water, sites by the use of Analytical Hierarchy Process (AHP) ...
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Sorayya Abbasi[1] Masoud Heydari[2] Abstract One of the important issues in water resources management is the identification of ground water behavior. The aim of this paper is the estimation and comparison of two methods for potential ground water, sites by the use of Analytical Hierarchy Process (AHP) and fuzzy logic. In order to achieve this objective 8 parameters including lithology, rivers, slpe changes, land use, topography, population, springs, wells, faults and fractures were used as information layer in the northern part of Ilam provicne with an area of 5218 km2. The final map obtained by AHP shows that high groundwater recarge potential exists in the limestone areas with high fractures. The evaluation of different overlap models, according to the level of compliance with the lithology indicates that fuzzy integrated method (algebraic sum) is mor appropriates than other methods in finding groundwater potential sites of reservoirs in the area. The method using 1000 km2 scope proves high potentials in the central parts of the map, which shows an acceptable consistence with the final map obtained by analytic hierarchy process while consistency of the related maps of springs and wells map in the region also confirm accuracy of these methods. [1]- Ph.D. Candidate of Geology, Faculty of Sciences,University of Birjand, Iran, Emil:s.abbasi1363@yahoo.com. [2]- Master Student Candidate of Geology, Faculty of Sciences,University of Birjand, Iran.
Hasan Fathizan; Hamid Alipoor; Seideh Negar Hasheminasab; Haji Karimi
Volume 3, Issue 8 , December 2016, , Pages 1-20
Abstract
Hasan Fathizad[1]* Hamid Alipoor[2] Seideh Negar Hasheminasab[3] Haji Karimi[4] Abstract Groundwater is considered as an important part of renewable waters of the world. With the increasing population, urbanization trend, etc., the demand for these resources, day by day is increasing. Nowadays, ...
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Hasan Fathizad[1]* Hamid Alipoor[2] Seideh Negar Hasheminasab[3] Haji Karimi[4] Abstract Groundwater is considered as an important part of renewable waters of the world. With the increasing population, urbanization trend, etc., the demand for these resources, day by day is increasing. Nowadays, remote sensing and geographic information system (GIS) has become one of the most powerful and affordable tools for assessing and exploration of accessible groundwater resources. The purpose of this study is to identify potential areas of groundwater in the Mahdishahr area located in Semnan using Analytical Hierarchy Process (AHP), remote sensing, and GIS. The parameters which are considered to identify the areas of potential groundwater are: lithological units, lineaments, slope, topography, drainage density, vegetation, and isoheytal maps which prepared by using the 1:50000 scale topographic maps, digital elevation model, ETM+ satellite images, 1:250000 scale geological map, and precipitation data of meteorology stations by remote sensing and GIS techniques. To determine potential areas of groundwater, all layers in different classes were weighted through hierarchical analysis and after modeling in the GIS medium, Mahdishahr basin was subdivided in the groundwater potential point of view. The results showed that among the 7 examined criteria determined by the expertise and analytic hierarchy process method, the geology and lineaments have relative importance of 0.33 and 0.22 respectively as the highest priority in groundwater potential determination in this area. Quaternary alluviums including old and new terraces and alluvial deposits have the highest relative importance and desirability in the study area. Terrace storages and old elevated and recent low elevation alluvial fans are as fair potential groundwater area. [1]- Ph.D. Student in Department of management the arid and desert regions, College of Natural Resources and Desert, Yazd University, Iran; hasan.fathizad@gmail.com. [2]- Ph.D. Student in Department of management the arid and desert regions, College of Natural Resources and Desert, Yazd University, Iran. [3]- M.A.of Management the arid and desert regions. [4]- Associate professor of Pasture and Watershed, Ilam University, Iran.
Davood Mokhtari; Arash Zandkarimi; Sheida Zandkarimi
Volume 3, Issue 8 , December 2016, , Pages 53-72
Abstract
Received: 2015.07.09 Accepted: 2016.10.19 Davood Mokhtari[1]* Arash Zandkarimi[2] Sheida Zandkarimi[3] Abstract Rainfall is counted as the main entrance in hydrologic modeling. Efficient network of the rain gauge stations are the ones having an appropriate density and favorable estimations of rainfall ...
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Received: 2015.07.09 Accepted: 2016.10.19 Davood Mokhtari[1]* Arash Zandkarimi[2] Sheida Zandkarimi[3] Abstract Rainfall is counted as the main entrance in hydrologic modeling. Efficient network of the rain gauge stations are the ones having an appropriate density and favorable estimations of rainfall in locations without any station. In order to optimize the position of the rain gauge stations, different methods have been proposed, among which the geo-statistical methods are widely used. The present study aimed to assess the status of the rain gauge stations of Kordestan Province, and to optimize their position based on geo statistical methods. In this study, in order to evaluate the accuracy of various interpolation methods, the Ordinary Kriging method with circular function was detected to be more credible compared to other models and that it was the most suitable interpolation method in the distribution of rainfall in the province. Furthermore, in order to optimize and estimate the errors of the current stations, the precipitation data from 145 meteorological stations were used, and given the sheer size of the study area and great changes to rainfall data, area segmentation or clustering of the stations was done, and the whole area was divided into 8 clusters. The results of the optimization based on the Kriging coefficient of variation indicated that, by the addition of new 17 proposed stations to the rain gauge network in the province, the values of spatial coefficient of variation of annual rainfall has decreased between 0.21 to 6.67 percent, and close to 12% from the central to the south, and in western areas, respectively. The results of this study have a great importance on the use of geo-statistical methods in optimization, and the generated maps are of high practical value for the executive agencies (Ministry of Energy, the National Weather Service, etc.). [1]- Associate Professor Professor Department of Geomorphology, University of Tabriz (Corresponding Autor), Email:d_mokhtari@tabrizu.ac.ir. [2]- Master Student Remote Sensing, University of Tabriz . [3]- M.A. Land Use-Environmenta, University of Payam Noor Tehran East.
Volume 2, Issue 2 , January 2015, , Pages 99-115
Abstract
In order to use the best of any land patch, planners are often required to make decisions in short periods of time to create environmental and economic competitions which will lead to sustainable development. In this regard, a series of land use suitability maps would be very efficient. In the ideal ...
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In order to use the best of any land patch, planners are often required to make decisions in short periods of time to create environmental and economic competitions which will lead to sustainable development. In this regard, a series of land use suitability maps would be very efficient. In the ideal case, these maps should be compiled and finally integrated through a complex process. Using instructions by FAO land evaluation and tables of soil and climate requirements for wheat production in the geographic information system (GIS), this study aims to evaluate the appropriateness of qualitative land suitability for the current and future production of dry land wheat in Shir Dar Kola watershed. The results indicated that the watershed’s climate, soil moisture regime, and soil hydrology, as the most important criteria for land suitability, and limiting features like rocky outcrops, steeps and slopes, and water erosion are high. The information obtained in the assessment of the current land suitability show that 12% of the land area is suitable for dry land cultivation (S1), 15% is moderately suitable (S2) and 73% is unsuitable (N2). For any future planning 19% of the land area were diagnosed to be suitable for dry land cultivation (S1), while 8% had average suitability (S2) and 73% were unsuitable (N2). The findings also show that the mountainous terrain has the ability to be used as pasture. Despite being mountainous the hills have the availability be become pastures as well. And all the upper terraced land has the potential for dry land and irrigated agriculture if the water supplies are provided.
