جستجوی مقالات مرتبط با کلیدواژه « Weighted Linear Combination » در نشریات گروه « آبخیزداری، بیابان، محیط زیست، مرتع »

Population growth with the growth of urban communities has been increased consumer demand and waste production. Waste collection and transportation, as the most expensive element in the waste management system, is so important that a slight change in the cost of management process will reduce the related costs in the waste management system. Among these, transfer stations, as facilities that reduce the costs of collection and transportation, are particular importance. The aim of this study is to select a suitable site for the construction of a waste transfer station and then prioritize suitable options in Karaj. The innovation of this research is in the number of criteria and sub-criteria used for locating and prioritizing options. After setting the major criteria and sub-criteria related to the location of the waste transfer station in this city, their maps were prepared. A total of 3 criteria and 14 sub-criteria were used in this study, then the prepared maps were standardized to a range of [0, 1] and the weight of each criterion and sub-criterion was determined using the pairwise comparison method. The weighted linear combination method was used to prepare the suitability map. The results showed that the major criteria for choosing the transfer station were the boundaries and distances, followed by the physical criteria of land and land use. Then 10 options were selected as the final option and 2 criteria of future development plans and land price were also added to the research and the options were prioritized using the TOPSIS method and the most suitable option with an area of more than 4 hectares was selected in 4 regions. The approach used in this research can be used in other cities.

Wind erosion and dust storms are among the most important natural hazards and have negative impacts on environment and people. The Hamoun international wetland- located in the southeast of Iran and southwest of Afghanistan, at the estuary of the Helmand River – due to the severe droughts during the last three decades has become the main source of soil erosion. The purpose of this study is to investigate the sensitivity of wind erosion in the Iranian section of the Hamoun wetland as the Hamoun wildlife refuge. Byliterature reviewing and using experts’ knowledge, 15 effective criteria in the phenomenon of wind erosion were determined and weighted by using AHP method. The weights analysis showed that among the criteria, vegetation cover with 0.13 had the highest weight. Using satellite images related to November 2021, the SAVI vegetation index was prepared as an index of the amount of vegetation cover.  To prepare the soil criteria maps, 135 pints of surface soil were taken and transferred to the lab. After determining the criteria value in each sample, the map of each criterion was prepared using the IDW method. The criteria were standardized using the FUZZY method, and then combined by applying the calculated weights and using the weighted linear combination method to prepare the wind erodibility model. The prepared model was classified into five erodibility classes. To assess model accuracy, the wind erosion threshold speed was calculated by installing a portable wind tunnel device at 40 sites. The resulting figures were classified into five levels according to the erodibility classes, and compared with the corresponding erosion class of the wind tunnel sites.  An overall accuracy of 81% for the prepared model shows capability of this model to prepare an accurate wind erosion model.

The Balouchi Black bear as an endangered subspecies, has a limited distribution in Iran, including the provinces of Kerman, Sistan and Baluchestan and Hormozgan. In this study, multi-criteria evaluation method was used to model the suitability of the land as a habitat of the black bear. For this purpose, by literature reviewing and experts’ knowledge, the most important criteria for evaluating the suitability of the land as black bear habitat were identified, were standardized by fuzzy and Boolean methods and criteria weights were determined using the hierarchical analysis process (AHP) method. The highest weight is related to slope criterion. Criteria and constraints maps were prepared by satellite image interpretation and available data. Results have shown 0-20% vegetation cover crown with 6945673 ha has the highest portion in study area. The study criteria and constraints were overlaid using the Weighted Linear Combination (WLC) method and the land suitability model was produced for the Balouchi black bear. In habitat suitability map, 261615 ha were identified with very high habitat suitability for black bear. Field studies and overlaying areas with the highest habitat suitability on the suitability maps of the used criteria, show that these areas mostly include mountainous areas with wild date (Daz) and farm land date. The results of this study with producing 81% total accuracy show the capability of multi-criteria evaluation methods by producing suitability maps with considering the importance of habitat evaluation criteria in modeling the suitability black bear habitat and the possibility of trade-off the criteria which causes criteria with more importance, support lower importance criteria.

Zehkalut in Jiroft, is one of the arid lands in the country, has been facing desertification problem in recent years, due to the improper exploitation of natural resources. As desertification has become a serious problem in this region, it seems necessary to use models for rehabilitation and biological restoration of the degraded areas, based on environmental conditions and ecological potential. The main aim of this study is to provide a model to determine an appropriate method of reclamation and rehabilitation of desert (desertification) considering all environmental factors for successful implementation of projects. A model for desert reclamation using Fuzzy AnalyticalHierarchy Process (FAHP) model has offered in this research. For this purpose, opinions of experts to determine the effective criteria and their priorities were evaluated by using Delphi method and pairwise comparisons. Then, by developing Fuzzy decision-making matrix and using weighted linear combination method, the coefficient of significance of the criteria was determined. Final land suitability map for land reclamation of the area was produced by applying the coefficient of significance of each criterion to the classified map of the same criterion and integrating the maps using a fuzzy gamma operator. Results showed that reclamation of degraded areas could be done only in margins of the watercourses by planting compatible and native tree species. This area include the lands that are predicted to be used with the utmost caution in biological operations, to justify the costs incurred. The results show the ability of the Fuzzy AnalyticalHierarchy Process and GIS in assessing land suitability for reclamation considering a group decision-making approach.

Forecasting models of Land Use/ Cover changes are the main resources for managers and policy-makers in order to develop a sustainable land management plan. Changes of Orchard-lands have an effect on water resources as well as soil permeability. Thus simulation of this land use changes, in areas where there is a shortage of water resources, can provide more information about the occurred changes during a specified time scales along current management. The present study was carried out to simulate and predict the spatial-temporal changes of the orchard by 2026. For this purpose, Geomod method was used to simulate spatial changes of the orchard. Due to the lack of ability of this model in temporal simulation, Markov chain analysis method was used to solve the mentioned problem with the error proportional of 0.012. Orchard was extracted using Landsat 5, 7, and 8 satellite data after necessary corrections as well as SVM in 1987, 2000, and 2013. Then, to understand the impact of each of the criteria used to change this type of land use, instead of Delphi methods, logistic regression, Fuzzy standardization and, after all, WLC were used. The ROC index was used to validate the model. The results showed, this model has a good performance to simulate spatial changes because of area under Curve 0.91 for both of the 2000 and 2013. In the 26-years period, there are 294 hectares of orchard development, and the hybrid model showed that this land use will increase to 304 hectares till 2026.

The Birjand plain is located in the south Khorasan province and its area is about 3425 square Kilometers. This plain has no significant surface water resources due to the inappropriate climatic conditions and evaporation intensity. The flow of water flow is seasonal or periodic and weak and there are some narrow rivers with a constant flow in other parts of the river network. Therefore, groundwater resources are the most important water resources that maybe used in this region. Groundwater has a substantial role in economic activities and saving water in underground reservoirs requires a lower economic investment. However, the increasing demand and excessive extraction of water has caused shortages in the alluvial aquifers in all plains of the province and consequently this has led to a substantial drop in the level of water in the aquifers. Since the rain in this is negligible and at times it leads to destructive floods, the operation of artificial feeding of ground water can be an appropriate method for optimum usage of floods and ground water stability. Selecting the criteria and suitable method is of great importance for the operation of artificial feeding. In this study, the analytical hierarchical process and weighted linear combination has been used. By choosing the Birjand plain as a case study, the slope, fault, flooding potential, land use, settlements and water quality criteria have been considered for selecting the appropriate places for artificial feeding. The artificial feeding ability map is divided into 5 categories according to natural features. The results indicated that 148.93 square Kilometers are in the very unsuitable category, 339.73 square Kilometers are in the unsuitable category, 453.49 square Kilometers are in the medium suitable category, 222.83square Kilometers are in the suitable category and 142.53 square Kilometers are in the very suitable part of the studied area.

Unplanned urban development imposes significant pressure on land resources and land use structures and brings about many negative socio-economic and environmental consequences. Therefore, comprehensive studies should be applied to support urban land use management in the world and especially in developing countries. In Iran, like many other developing countries, urban development is fast and often unharnessed. Tehran province is the main focus of urban sprawl, in which strong economic state and allocation of facilities and infrastructures encourage mass migration of people and cause unplanned construction and changes in spatial structure of the region. In this study, an integrated approach towards urban land suitability assessment in Tehran province including social – economic and ecological aspects has been implemented. The employed method and the developed model can be considered as an efficient sample of achieving sustainable urban development and regulating the physical development in Iran. In this research, a Weighted Linear Combination Method was conducted in a Geographical Information System considering 15 criteria, including social–economic and ecological factors. For weighting the criteria, the Analytic Hierarchy Process was used including opinions of ten experts. At the end, a land suitability map was produced showing suitable area for urban development. These areas include six arenas with suitable extent and desirable suitability in southern part of the province that can be used by urban planners and spatial decision makers. As the results are systematic and reproducible, they can be regarded as means of collaboration and consensus making among urban developers and decision makers.