| چکیده انگلیسی مقاله |
Introduction Any height of river water that overflows and covers the lands around the river and causes damage to economic and financial facilities is called a flood. Flood is one of the natural disasters that causes many injuries and damages every year. The first measure to reduce the flood risk is to control the flood at its source, i.e. the watershed sub-basins. Of course, to do this, it is necessary to identify the flood-prone areas of the basin. In this sense, areas with high flood production potential should be identified. In this research, we are looking to first use multi-criteria decision-making models to focus on the zoning of vulnerability to flood risk in Andimshek city, and then considering that natural gas is currently the most used fuel and it is a source of energy and the occurrence of accidents in these lines causes human and financial losses. In this research, an attempt has been made to determine the location and amount of gas lines in high-risk and vulnerable areas against floods. It is expected that, according to the results, accidents during floods will be prevented. Materials and Methods The current research is of an applied type and its research method is an analysis based on the integration of data analysis, geographic information system, and the use of multi-criteria analysis techniques. ENVI, Ecognition, Arc GIS, Idrisi, and Excel software were used for image processing and data analysis. To investigate the flood risk, first, the effective factors (dem, slope, aspect, distance from the river, distance from the road network, distance from gas lines, distance from residential areas, land use, and geology) were identified according to the natural and human conditions of the region. In the next step, the layers of information related to each of the factors were prepared in the environment of the geographic information system, and the evaluation and standardization of the standard maps were done together using the fuzzy method. The weighting of the examined factors was done according to the CRITIC method and the final analysis, using the multi-criteria methods of MABAC, CODAS, and Vikor. Results and Discussion According to the output of the studied algorithms, the high-risk and very high-risk zones occupy the largest area of the city. so that in order; According to the CODAS model, 30 and 27%, according to the output of the MABAC model, 32 and 28%, and according to the zoning map of the Vikor model, 27 and 36 hectares of the range area are in the high-risk and very high-risk category. Therefore, it can be said that the results of this study indicate the high risk of Andimshek City in terms of flood risk occurrence. In addition, it can be acknowledged that the results of the examination of the outputs obtained from the investigated methods indicate that a high percentage of the city's gas lines and facilities are at risk. So, according to the results of CODAS and MABAC multi-criteria decision-making models, 386 km (equivalent to 44% of gas lines) is in the high-risk area and 285 km (equivalent to 32% of gas lines) is in the very high-risk area, and based on the map from the Vikor model, 398 km (equivalent to 45% of the gas lines) is in the high-risk area and 427 km (equivalent to 49% of the gas lines) is in the very high-risk area. Conclusion According to the obtained results, it can be stated that due to the presence of steep slopes in the northern part, as well as the high area in the south, south-west, and south-east slopes, the land use situation and the presence of transit roads and the existence of plains with a slope of 0 to 5%, the slope criteria, distance from communication roads, land use and lithology are known as important criteria involved in the occurrence of floods in Andimshek city. In addition, according to the results of the current research, it seems that the risk caused by a possible flood in the gas transmission pipelines of this city can lead to many human and financial losses. Therefore, it is suggested that to prevent the possibility of accidents on gas lines (including water washing in the flow of pipelines after a flood and the exposure of gas lines, flooding of gas facilities due to floods, destruction of access roads and buildings of pressure reduction stations, broken pipes, and even explosions and fires), measures should be taken to strengthen gas lines and facilities at the city level. |