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Volume 1, Issue 3 (10-2014)
Today, urban and regional issues related to sustainable development is a key challenge for policy-makers, planners and specialists in various disciplines. Geomorphologic studies can be useful and effective in analyzing and deriving acceptable means to assess the growth and development of the city, and to set criteria to determine the directions of urban development. Landslides range of motions not only affect the human structures such as roads, rail lines and residential areas, but also lead to casualties. Tehran metropolis mountainous basins, including Kan, Vesk, Farahzad, Darake, Velenjak, Darband, Golabdare, Darabad, Sorkheh-Hesar, and Sohanak due to the lithology, geologic structure, weathered sediments, steep slope, rainfall and poor urban development are considered as one of the places where landslides are a range of geomorphologic processes can be studied. At this research, using Fuzzy and AHP methods and by the use 8 factor variables such as lithology, elevation, slope, aspect, annual rainfall, maximum daily rainfall, distance from fault and drainage system. the map of landslide zonation hazard in mountainous areas of the city is prepared to determine risky strips. After the standardization of the criteria for the occurrence of landslides and using frequency ratio method and fuzzy model and functions, Landslide hazard zonation maps was prepared for evaluating from the fuzzy sum, fuzzy product and fuzzy gamma operator 0.8 and 0.9. Then the final map of landslide zonation, obtained from the above-mentioned method matched with the map of urban regions in mountainous areas. In this way the constructed region have been distinguished from very high and very low hazard zonation. Lithological studies showed that most of the basin areas covered by Karaj Formation. About 45/7 percent of units with sliding movement in areas with "rock crystal tuff and tuff lytic green, with the layers of limestone" (unit Et2) of the intermediate tuff formation occurred. Cross of faults distance map with landslide density map showed that about 33/1 percent of landslides occurred within 200 m of the fault lines and 78/4 percent of landslides occurred within 500 m of drainage network. Most sliding movements (60/2 percent) in the range of 1900 to 2500 meters altitude and about 35/3 percent of this type of range of motion in height of 1500 to 1900 meters occurred. This area is about 81/6 percent of sliding movements in slopes between 15 and 40 degrees (26/8 to 83/9 percent) and about 17/6 percent on slopes less than 15 degrees (26.8 percent) occurred. In the aspect, sliding movements of the basin, mainly in the south-western slopes (about 23/2 percent), the South (about 17/5 percent), West (about 16/6 percent) and Southeast (about 77/1 percent), northwest (about 33/1 percent) occurred. About 88/9 percent of sliding movements in areas with average annual rainfall of 244 to 280 mm occurred. According to the zoning map, 12 percent of mountainous basins area (approximately 10,057 acres) is in the zone of very high risk, 33 percent (approximately 27,723 acres) is in high risk areas, 20.5 percent (approximately 17,143 acres) in the moderate risk zone, 30/ 7 percent (approximately 25,672 acres) in area and 3.8 percent of the total area of the basin, low risk (approximately 3172 acres) located in low risk areas. The results showed that approximately 5.2 hectares (about 0/05 percent) of the urban in zones with a huge landslide, about 51/5 acre (approximately 1 percent) in zones with high landslide risk and about 821 acres (equivalent to 25/16 percent) in the medium risk landslide zones are located and developed. The final results indicate that some mountainous regions of Tehran Metropolis are apt to landslide with middle to high risk. (Apart from strengthening the vulnerable area) avoiding these areas is an important solution to decrease damages caused by landslide.
Volume 9, Issue 1 (5-2022)
Investigation of Construction Wastes Release in Roadside Using AHP
Introduction
Although construction waste is an integral part of municipal waste, due to the differences between this waste and waste and environmental issues, a suitable model should be designed for optimal productivity and acquisition of resources. The increasing volume of urban materials and rubbish, especially the rubbish from the destruction of their construction and worn-out urban textures, has created many problems in large cities, as well as environmental problems that have arisen due to unprincipled and unprofessional disposal of these materials. Has attracted these materials. Research shows that the amount of this waste is equal to 10 to 15% of the total materials used in construction operations. This amount is much higher than what is estimated by the estimators.
Data and research method
In Iran and other developing countries, construction and construction waste is a major part of municipal waste, which in addition to high costs for its disposal, also has adverse consequences on the environment. The volume of this garbage is so much that now this issue has become a social and environmental problem not only in Iran but also in developed countries due to the limitation of natural resources and preservation of national capital for future generations as well as environmental protection And it is necessary because with proper management and efficient planning and reducing the volume of construction waste, not only the waste of natural resources and national capital is prevented, but also additional and ancillary costs are reduced and it is economically beneficial.
In this study, first, the effective criteria in selecting the burial site in the study area are determined. These criteria are reviewed and used by various standards, including standards related to the Environmental Protection Organization, the Ministry of Interior and international standards, as well as by reviewing resources and studies on the process of locating landfills in the country and abroad and by examining the conditions of the region. The study and the influencing factors are compiled in the study area. The layers related to each criterion in the relevant table will be prepared, processed and converted from the relevant organizations. The method of this dissertation is applied-modeling in terms of purpose, because on the one hand, the concepts and rules related to the field of knowledge are carefully analyzed, and on the other hand, the relationships between these concepts and rules are evaluated and determined by experts. In this study, there is a need to use the decision theory method to evaluate and investigate the status of construction waste disposal along roads to increase trust and confidence in decision making.
The data analysis tools of this research are SPSS, Expert Choice and Matlab for conducting the research. In the research process, after data collection, the next step involves data analysis. Cronbach's alpha coefficient was used to evaluate the reliability of the localization tools of the research components. In order to describe the data, the mean and standard deviation of the research data have been used.
The four-step process of multi-criteria decision-making process and fuzzy logic calculations to investigate the dumping of construction debris along roadsides is as follows:
Step 1 - Modeling causal relationships based on similarity to the ideal solution
Step 2 - Parallel comparisons and determining the weight of causal relationships based on the evaluation of decision options between the criteria for assessing the status of construction debris on the sidewalks,
Step 3 - Prioritize Based on Causal Relationships Based on Evaluation of Decision Options
Step 4 - Fuzzy Prioritization and Final Analysis Investigation of Construction Waste Disposal Status
Result and Discussion
The most important results of the study of the dumping of construction debris along the roadsides are that,
1- The most important criterion in the cluster "Environmental factors of construction waste disposal" with code (A), "Soil pollution in the city" with code (AB) with fuzzy network weight of 0.096; And
2- The most important criteria in the cluster "Applications of GIS in urban management of construction debris disposal" with code (B), "Urban green space management" with code (BA) with fuzzy network weight equal to 0.191; And "Urban management related to health" with code (BB) with fuzzy network weight equal to 0.120; Were calculated. on the other hand,
3- The most important criterion in the cluster "Economic factors of construction waste disposal" with code (C), "Construction waste management training cost" with code (CD) with fuzzy network weight equal to 0.123; Prioritized,
conclusion
The results of the present study can be said that, after reviewing the theoretical foundations of the research and reviewing the research background, it was found that due to research gaps in the fields of economic factors of construction waste disposal, GIS applications in urban management, construction waste disposal, environmental factors, Utilization of a combined fuzzy multi-criteria decision-making methodology to investigate the status of construction debris dumping along roadsides; It is possible to realize the innovation of the present research in filling the mentioned research gaps.
Key words: Construction Debris, Civil Waste Management, Multi-Criteria Decision Making, Karaj.
Volume 10, Issue 1 (5-2023)
Introduction
A flood is a natural disaster caused by heavy rainfall, which causes casualties and damage to infrastructure and crops. Trend of floods in the world increasing due to climate change, changing rainfall patterns, rising sea levels in the future, and in addition, population growth and urban development and human settlements near river have caused floods to become a threat to humans. One of the most important and necessary tasks in catchments is to prepare flood risk maps and analyze them. In recent decades, researchers have been using remote sensing techniques and geographic information systems to obtain flood risk maps in an area. Due to the numerous floods that have occurred in the Neka river catchment, it is necessary to conduct a study entitled zoning of flood sensitivity in Neka river catchment for more effective management in this area.
Materials and methods
Study area: Neka river catchment area with an area of 1922
To study the flood zoning of the area using a multi-criteria decision model, 1: 25000 maps of the surveying organization and a digital elevation model with a resolution of 12.5 meters (Alos Palsar) were extracted. In order to study the flood risk in Neka river, 4 criteria of height, distance from the river, land use and slope have been used. In the present study, modeling and preparation of flood risk zoning map in 4 stage including descending valuation, normalization of each class, normalized index weight and integration of criteria has been done by the following linear weighting method. Performing linear weighting operations depends on the weighted average of a number of selected parameters in the opinion of the expert. According to the weight assigned to each criterion based on the expert opinion, each of the criteria was multiplied by the assigned weight and at the end the criteria were added together and the final zoning map was obtained.
Results and Discussion
In this study, using a multi-criteria decision-making system model, a flood risk zoning map in the Neka river catchment was prepared. According to the weight assigned to each criterion based on expert opinion, the final risk probability map has a value between 0.02 to 0.2, which is ultimately divided into 5 classes in terms of flood risk. Value range 0.02 to 0.06 component of very low risk zone, range 0.08 to 0.11 component of low-risk zone, range 0.11 to 0.13 component of medium-risk zone, range 0.13 to 0.16 component of high-risk zone, and finally domain 0.16 to 0.20 components of the area with very high risk potential have been obtained. According to the final divisions in the flood risk zoning map of the catchment area, a safe area means areas where the probability of flooding is very low and close to zero, and in contrast, the area with a high and very high risk potential for flooding has the probability of high-risk floods. According to the final flood risk zoning map, about 982
Conclusion
The results obtained from the model indicates that the highest risk of flooding points are located in the western parts of the Neka catchment area and the end of the catchment area that reach the city of Neka. According to the research findings, the most important factors in increasing the risk of floods were the slope in this area and the distance from the drainage network. According to the results of the model, a large area of the basin is a component of high risk zone, that means the Neka river watershed has a high potential for floods. Evidence and documented reports show that the Neka river Basin has experienced several floods in the last two decades. The major part of the occurrence of floods is due to the natural conditions of the basin, thus it is necessary to reduce flood damage by changing the locations of various land uses based on flood vulnerability maps. Using multi-criteria decision making method can be used to prepare flood risk zoning maps in basins that do not have hydrometric data; It is also a more cost-effective method in terms of time. One of the important issues in the final result of this model is due to the weight of the layers, which should be used by experts, who are familiar with the region and this method and adapt to field evidence.
Keyworlds: Flood, Multi-criteria decision making system(MCDA), Hazard zoning, Nekarod, Natural hazard.
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