Hydrogeomorphology
Ehsan Alvandi
Abstract
In this research, Modeling the effects of management Actions to improve the status of water and soil resources of Tuyserkan watershed in mDSS software environment have been studied.For this purpose, first, the status of the watershed system was analyzed through the DPSIR approach.In order to predict ...
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In this research, Modeling the effects of management Actions to improve the status of water and soil resources of Tuyserkan watershed in mDSS software environment have been studied.For this purpose, first, the status of the watershed system was analyzed through the DPSIR approach.In order to predict the effects of each management activity from the indicators obtained from Four physical, social, economic and ecological criteria were used.Finally, in order to prioritize the proposed management activities, TOPSISand SAWtechniques have been used in the mDSS software environment.According to the results of the DPSIR approach, the most important pressures affecting the system Land use change,Capture and vegetation loss have been introduced.Also one of the most important effects on the status of the watershed system is the criteria for vegetation loss, reduced groundwater recharge and increased risk of flood damage.Finally, according to the results of the DPSIR approach, to improve the status of water and soil resources A set of solutions for biological rangeland improvement and biomechanical operations to store rainfall in the basin was proposed.According to the opinions of experts and environmental conditions of the region from a set of solutions for biological improvement of rangeland and biomechanical operations Seven management activities(Rangeland exclusion,Afforestation,Orchard development,Forage cultivation,Contour furrow,Pile seeding and Seeding)were selected to store rainfall.According to the results obtained from the prioritization of management activities in all proposed methods,Afforestation activity has the highest score and is in the initial priority and the activity of Contour furrow has the lowest score and Is in the final priority.
hydrogeology
Hadi Nayyeri; Mamand Salari; Zhila Chardawli
Abstract
The soil erosion issue and lands' degradation is one of the most important issues in natural sciences. Soil erosion is the predominant geomorphic process on many land surfaces. In order to assess the environmental and economic consequences of soil erosion, quantitative data are needed. In this research, ...
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The soil erosion issue and lands' degradation is one of the most important issues in natural sciences. Soil erosion is the predominant geomorphic process on many land surfaces. In order to assess the environmental and economic consequences of soil erosion, quantitative data are needed. In this research, soil erosion is studied with of morphometric parameters. For this aim, Gheshlagh river basin iin Kurdistan province, was studied. Areas with a rating of more than 2 that entered directly into the main river were plotted as sub-basins for morphometric calculations. These areas included 47 sub-basins. The number of 16 morphometric parameters were calculated to determine the morphometric conditions of the basin and were considered as the input layer. Then, the results of these parameters were aggregated by four multi-criteria decision models TOPSIS, VIKOR, SAW and CF. In all four, the northern sub-basins were classified as areas with low and very low susceptibility to erosion. These basins are often located in volcanic rocks. In a general view, according to all four models studied, the basins in the lithology of dark gray shale (Sanandaj shale). Their sensitivity to erosion have been classified from moderate to very high. the final results showed that the multi-criteria decision-making methods, by presenting a classification, divide the region into several classes in terms of the degree of erosion sensitivity, and the VIKOR method, due to the greater coefficient of variation, has more accurate than the others.
Mojgan Entezari; Tahere Jalilian
Volume 6, Issue 18 , June 2019, , Pages 19-38
Abstract
IntroductionLandslide as a natural hazard is very dangerous especially in mountainous areas. It results in loss of human life and property around the world. In spite of the progress in identifying, measuring, predicting, and landslide warning systems, the damage caused by landslides is still increasing ...
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IntroductionLandslide as a natural hazard is very dangerous especially in mountainous areas. It results in loss of human life and property around the world. In spite of the progress in identifying, measuring, predicting, and landslide warning systems, the damage caused by landslides is still increasing worldwide. Therefore, given the importance of the problem, the most important managerial goals include favorable sustainable development in watershed and urban management, and the prediction and controlling of landslide with the aim of reducing its dangers. Indeed, many landslide damages are caused due to not observing correct principles of residential development, dam construction, and construction of roads and facilities. Consequently, the identification of the areas prone to landslide has a great importance for executive organizations. Indeed, the mentioned organizations knowing the location of these areas, they should certainly prevent structure construction in these areas as much as possible. In addition, if it is necessary, they should consider required technical tips and arrangements with more precision. According to the cost of performance, prioritizing the sub basins is very important. Decision making methods is an effective tool to deal with issues that may be created and in this context it has a lot of use. In recent years, attention to the ranking methods in environmental studies have been increased, especially in natural hazards risk management. In this paper, considering the importance and efficiency of the non-ranked ELECTRE-1 method and its non-compensatory nature, we tried to apply this method in the prioritization of landslide risk assessment in six sub-watersheds at Kermanshah province based on the factors and indicators affecting a landslide. The main objectives of the current research were: (1) identifying the main factors affecting the landslides occurrence in the study area, (2) prioritization of the watersheds based on the risk of landslide occurrences, and (3) introducing critical watersheds regarding landslide occurrence.MethodologyThis method, like other decision-making models, is applicable to choosing the best option among others. And like the TOPSIS model, it prioritizes or ranks options by various criteria. In the ELECTRE-1 method, the weight of the criteria should also be calculated for each option.Landslide risk assessment options for the study period are Mahidshat basin, Deira, Kanekabod, Tajrakbadre, Kangir basin, and Chika basin.In general, there are various indicators for assessing the factors affecting the occurrence of landslides in the basins. According to the survey of location of the study area, of various factors affecting the occurrence of landslide, lithological factors, elevation, slope, slope direction, fault density, drainage density, congestion, land use, temperature, precipitation, and slip density were selected as effective factors.-ELECTREmodelFor the first time, it was developed by Roy (1968) in a situation where real criteria and limited privileged relationships were given. Due to the complexity and high volume of computations, the algorithm of the model was programmed in EXCEL software and the values of each step were obtained. Discussion and Conclusion In this research, a multi-criteria decision-making technique was used to map areas susceptible to landslide. To do so, the factors affecting the slope sensitivity to landslide were collected. Then, to apply ELECTERE I technique to rank the sensitivity of the selected sub watersheds to the landslide, the following steps were consecutively taken. 1) The Performance matrix was created to determine the weights of the criteria. 2) The Normalization and Non-normalization matrices were formed. 3) The Harmonious and Inharmonious matrices along with the Coordinated and Uncoordinated effective matrices were obtained. 4) The final Dominance matrix was calculated. The results suggested that among the selected sub watersheds, Mahidasht Rezevand basin ranked the first having the highest vulnerability to landslide occurrence. BadraTjrk and Chika basins respectively ranked the second and the third. Deira and Kanekabod basins shared the forth rank. Finally, Kangir basin was the least likely basin to suffer from landslide incident. The susceptibility maps of the studied basins together with field surveys confirmed the proper application of ELECTRE method for ranking the sub watersheds based on landside risk. Fig 2 indicates that over 36 percent of the landslides have occurred in the high risk area. The proposed method and findings of this study are invaluable for practitioners and future academic studies.
