جستجوی مقالات مرتبط با کلیدواژه « مدیریت بحران » در نشریات گروه « آبخیزداری، بیابان، محیط زیست، مرتع »

Floods cause loss of life and financial losses every year, and their management is one of the essential elements of watershed management. In this research, an attempt is made to determine the flood susceptibility of the Sirwan watershed and finally the importance of various environmental factors in flood susceptibility based on historical flood events.

In this research, the maximum entropy model along with 13 topographical, hydrological, morpho-hydrological, geological, and environmental flood-affecting factors were used to model the flood susceptibility of the Sirwan watershed and determine the importance and percentage of participation of various factors in the state of flooding potential. A cellular computing unit (pixel) was chosen as the criterion for preparing the predictive factors and flood susceptibility maps. A total of 123 historical flood inundation events detected in the last decade were used as target variables in the model, of which 70% were considered for learning and the remaining 30% for validating the model results. To evaluate the performance of the model, the criterion of the area under the receiver operating characteristic curve was also used.

The results indicate that the accuracy of learning and validation were 98.2% and 97.3%, respectively, indicating the excellent performance of the model. Based on the visual interpretation of the flood susceptibility map, streams with a higher order near the watershed outlet, which are the conduits for the passage of the flow with a larger volume and are located in lower areas, often have a higher proneness to flood inundation. Based on the results of the relative importance test, the four factors of distance from the stream, topographic wetness index, drainage density, and land use were introduced as the most important factors in the modeling flood susceptibility, with of 17, 13, 12 and 10% participation, respectively. These results show that natural hydrological, morpho-hydrological and environmental factors (both natural and man-made) have a mutual effect in increasing flooding susceptibility. Based on the quantitative analysis of modeling, about 0.76% (5600 hectares) of the studied area is in the high and very high flood susceptibility class, which requires planning and flood management.

The high classification of flood susceptibility classes in the Sirwan watershed of Kurdistan province and the determination of the importance of environmental factors in the event of flooding make it possible for managers to take an effective preventive approach by planning relief facilities and infrastructure. To reduce the risk of flooding, flood crisis management in the Sirwan watershed should be defined based on the four main factors identified in this study. Application of the maximum entropy model in flood susceptibility analysis is suggested for flood management of watersheds.

Flooding and soil erosion are unfortunate hazards that cause huge and irreparable damage to the natural environment and man-made properties every year. Due to the importance of the agricultural sector in the country's economy and also the provision of food for the people of the society, for the sustainability of agriculture, special emphasis should be placed on the number of resources available in the agricultural sector and the factors affecting decision-making and allocation of resources. Although it is important to pay attention to the category of resilience in the agricultural sector, there are very few studies related to the improvement of resilience in the agricultural sector against floods and controlling soil erosion. Hence, the current research aims to identify ways to improve the resilience of agriculture against floods, while examining the importance of resilience, the effect of floods on agriculture and food security, and finally, ways to strengthen resilience in the agricultural sector dealing with floods and soil and water conservation. The results of this review research can be a scientific and key basis for researchers, executive officials, and managers of the country's agricultural sector. It will also help farmers consider different management methods to deal with all kinds of risks, especially floods and soil erosion.

Nowadays, it is necessary to use the facilities available in the communities to prevent all kinds of possible crises or to reduce the amount of damage. To deal with these crises, it is necessary to establish crisis management centers with the aim of carrying out preventive measures, crisis preparedness and response, providing relief to crisis areas, and temporary accommodation of victims. This study was conducted with the aim of locating the optimal areas for the construction of crisis management sites in the city of Babol.

In this study, effective criteria include of slope, slope direction, altitude, distance from commercial, medical, administrative, disciplinary, religious, educational use, distance from road and river in the location have been selected and weighted by experts with AHP method. After synchronizing all information layers, hierarchical analysis algorithms and fuzzy algorithms were applied to them in order to find the optimal location.

The results showed that, in AHP zoning, an area of ​​168 hectares, equivalent to 5.56 percent, has the best conditions for creating a crisis management site in the city of Babol. In fuzzy method, four operators in cloud of GAMA, Product, AND, OR were used. The AND operator had a better result than the other operators. In the operator, 103 hectares' area of the city equals 3.4 percent, is prone to creating a crisis management site.

The output of the models designed by the hierarchical method and fuzzy logic were different. The reason for this difference was considering the criteria with the same weight in the fuzzy model and considering the layers with different weights in the AHP model. The output results of the AHP model, which was a combination of standardized information layers using the opinions of experts, were more accurate due to the involvement of expert opinions.

The present study was conducted to make a brief prioritization based on a combined index for flood potential, water stress, rainfall erosivity index and drought severity at province scale in Iran. To accomplish this, the initial country-wide available data were initially collected. The raw data were mined and then standardized to neglect differences in units and magnitudes. The standardized data were ultimately analyzed using geometric mean. According to the results, Khozestan, Alborz and Kermanshah Provinces with respective combined indices of 0.61, 0.59 and 0.58 stood at the first priority in viewpoint of water and erosion indicators. Furthermore, the results of the study showed that southwestern provinces of the country were the most sensitive areas owing to high probability of extreme events and as a result, high amount of water resources loss and erosion potential. So that, implementation of soil and water resources management strategies in aforesaid provinces seems to be vital.

Groundwater resources have shrunk noticeably in arid and semi-arid areas in recent decades. Therefore, determination of the most important problems of the aquifers and the best management strategies is important. The purpose of this study is to identify in the causes of the imbalance of groundwater in the Abarkuh Plain aquifer, in the Yazd Province. To attain this, the criteria and sub-criteria of groundwater problems were determined using Analytical Hierarchy Process (AHP) method in the Expert Choice software. Then, aquifer management strategies were designed using the same process (AHP method). The results indicated that agriculture, with a relative weight of 76.00% compared to industry and domestic water is the most effective consuming sectors in creating the aquifer imbalance. The most important agents in this sector were over-exploitation of the aquifer (22.50%), competition in agricultural water utilization (20.10%), irrigation systems (14.50%), cultivation patterns (12.50%), cultivated land area (8.20%), illegal irrigation wells (6.00%), and the development of high water demand industries (4.50%). Furthermore, the most important solutions for crisis management were irrigation system reform and cultivation pattern correction. To acheive these solutions, management strategies including equipping the wells with the volumetric counters, prevention of illegal pumping, separation of drinking from sanitation water, and development of the low water-consuming industries are suggested.

     Rapid population growth and ever-increasing demand for food lead to increase the exploitation of natural resources compared to the previous period and the continuation of this trend could lead to negative consequences and environmental crises, threatening human security and ecosystems. Therefore, this study was conducted to investigate the status of natural resources in West of Kurdistan Province and the role of defense actions on natural resources crisis management. The population of this study consisted of the villagers of West of Kurdistan Province (N = 133837). The sample size was calculated to be 220 using Cochran's formula. The data were collected using a questionnaire. The face and content validity of the questionnaire was confirmed by panel of experts and the reliability of instrument was confirmed by conducting a pre-test and calculating a Cronbach's alpha coefficient more than 0.70 for different sections of the questioner. The data analysis was performed using SPSs20 software. The findings showed that from the perspective of 95% of respondents, the degradation of natural resources is evaluated at a high level. The results also showed that the defense actions including passive defense and the level of satisfaction from defense operating actions had a significant negative effect on the degradation of natural resources in the study area. Also, the results showed that 41.7% of the variations of the natural resources degradation was explained by defense activities.

Recognizing the susceptible areas for natural hazards is one of the primary steps in natural resources management and Development program schematizations. Assessing existing and future of disaster states can facilitate the design of disaster management organizations. Liquefaction is an important geotechnical phenomenon that usually takes place in saturated loose sandy soils due to increasing pore water pressure and decline soil resistivity. In this research liquefaction hazard potential in west of the Golestan province was evaluated. After processing data and base maps in GIS environment، SWM model was used for producing hazard maps with (20×20m) pixel size، for existing condition. Considering alterations in future water level and seismic acceleration، 7 different scenarios were developed، and hazard maps for these scenarios were obtained. Then area percent around five towns in hazard classes was calculated. The results of statistical comparison show that significance different exist between the hazard classes in different scenarios. The results indicates that the minimum and maximum Liquefaction hazards after earthquake event respectively occurs in 1 and 8 scenarios in Bandar-Torkaman and Bandar-Gaz areas that are in proximity of surface earthquake center and Caspian Sea coasts.