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Application of entropy weighting method for urban flood hazard mapping

Malekinezhad Hossein, Sepehri Mehdi, Pham Quoc Bao, Hosseini Seyed Zeynalabedin, Meshram Sarita Gajbhiye, Vojtek Matej, Vojteková Jana

Acta Geophysica

2021

Vol. 69, no. 3

841--854

Flooding is one of the most frequently occurring natural hazards worldwide. Mapping and assessment of possible flood hazards are critical components of the evaluation and mitigation of flood risk. In this study, six flood-related indices, i.e., slope, elevation, distance to discharge channel, runof volume, street-drainage network intersection, index of the development and persistence of the drainage network (IDPR), were used to assess the flood hazard. The entropy weighting method was used for assigning the weights to flood-related indices and combining them to prepare urban food hazard mapping in Hamadan city. The produced map showed that nearly 20% of the study area (14.7 km2 ) corresponded to very high susceptibility to flooding, 19.4% (143 km2 ) to high susceptibility and 20.3%, 20.7% and 19.6% regard the moderate, low and very low susceptibility to flooding, respectively. Finally, two methods were used to evaluate the accuracy of the produced food susceptibility map. The frst method is related to assessing the behavior of the map by making and propagating error in foodrelated indices and used model (entropy weighting method), and the second method is superimposing method. The results showed that by making and propagation of error, the behavior of producing food susceptibility mapping, the produced map has a robust behavior either in ranking importance of flood-related indices and percentage of food susceptibility areas. On the other hand, regarding the result of the superimposing method, the accuracy of the flood susceptibility map was 72%, which also suggests an acceptable result.

Integration of interval rough AHP and fuzzy logic for assessment of food prone areas at the regional scale

Sepehri Mehdi, Malekinezhad Hossein, Jahanbakhshi Farshid, Ildoromi Ali Rerza, Chezgi Javad, Ghorbanzadeh Omid, Naghipour Elham

Acta Geophysica

2020

Vol. 68, no. 2

477--493

This study was conducted to prepare a food susceptibility map in northwest of Hamadan Province, Iran. For this purpose, six criteria related to food (i.e., distance to discharge channel, slope (%), elevation, soil texture and land use, topographic wet index, and check dams) were chosen. Then, based on the role of these criteria on degree of food susceptibility, were weighted both in the context of inter-weighting (fuzzy logic) and outer-criteria (Interval Rough Analytic Hierarchy Process). Finally, by combining these primary weights by weight overlay method in GIS, the food susceptibility mapping was prepared in the study area. The resulted map based on K-means clustering and Silhouette function was divided into 9 clusters, whereas the lower clusters show low susceptibility to food and vice versa. To assess the accuracy of the produced map, 102 food observation points were overlaid on the clustered food susceptibility map. The results showed that among these 102 food points, 66 points are located in the clusters 8 and 9 and 3 points are located on cluster 7. These values show that the produced food susceptibility mapping has a high accuracy.

Assessment of food hazard mapping in urban areas using entropy weighting method: a case study in Hamadan city, Iran

Sepehri Mehdi, Malekinezhad Hossein, Hossein Seyed Zeynalabedin, Reza Ildoromi Ali

Acta Geophysica

2019

Vol. 67, no. 5

1435--1449

Flood is one of the major natural disasters which cause enormous casualties and damages particularly in urban areas. In urban areas, studies on food hazards have been accompanied by tensions for various reasons, including complexity of urban levels, diferent spatial modeling indices, lack of accurate hydrological data, and precise modeling of land surface simulations. This paper used a Constrained Delaunay Triangular Irregular Network to model fne urban surfaces (based on the detailed ground sampling data), and subsequently discusses fve indicators regarding the dangers of food, namely (1) elevation, (2) slope, (3) distance to discharge channels, (4) index of development and persistence of the drainage network (IDPR), and (5) infiltration rate. In the next step for food hazard mapping, the combination of geographical information systems and the entropy weight method as the multi-criteria decision analysis was used to combine the indicators. The proposed methodology was used for Hamadan city that is located in the central part of Hamadan Province in Iran where several foods occur annually. The food hazard mapping indicates that approximately 15.83% of the total study area is classifed as very highly hazardous, 31.72% as hazardous, 20.11% as moderate, 16.02% as minor, and 16.32% as the least hazardous. Finally, superimposition and receiver operating characteristic (ROC) curve methods were used to verify the accuracy of the obtained food hazard map. In terms of superimposition and ROC curve, the accuracy of the model was approximately 70% and 73%, respectively.