A GIS-Based Support Vector Machine Model for Flash Flood Vulnerability Assessment and Mapping in China

Abstract

Flash floods are one of the natural disasters that threaten the lives of many people all over the world every year. Flash floods are significantly affected by the intensification of extreme climate events and interactions with exposed and vulnerable socio-economic systems impede regional development processes. Hence, it is important to estimate the loss due to flash floods before the disaster occurs. However, there are no comprehensive vulnerability assessment results for flash floods in China. Fortunately, the National Mountain Flood Disaster Investigation Project provided a foundation to develop this proposed assessment. In this study, an index system was established from the exposure and disaster reduction capability categories, and is based on analytic hierarchy process (AHP) methods. We evaluated flash flood vulnerability by adopting the support vector machine (SVM) model. Our results showed 439 counties with high and extremely high vulnerability (accounting for 10.5% of the land area and corresponding to approximately 100 million hectares (ha)), 571 counties with moderate vulnerability (accounting for 19.18% of the land area and corresponding to approximately 180 million ha), and 1128 counties with low and extremely low vulnerability (accounting for 39.43% of the land area and corresponding to approximately 370 million ha). The highly-vulnerable counties were mainly concentrated in the south and southeast regions of China, moderately-vulnerable counties were primarily concentrated in the central, northern, and southwestern regions of China, and low-vulnerability counties chiefly occurred in the northwest regions of China. Additionally, the results of the spatial autocorrelation suggested that the “High-High” values of spatial agglomeration areas mainly occurred in the Zhejiang, Fujian, Jiangxi, Hunan, Guangxi, Chongqing, and Beijing areas. On the basis of these results, our study can be used as a proposal for population and building distribution readjustments, and the management of flash floods in China.

An Operational Framework for Urban Vulnerability to Floods in the Guayas Estuary Region: The Duran Case Study

“…On the other hand, in the 1990s as part of a political campaign, the housing program called "Casa para Todos" was developed in what later was to become El Recreo (Table 3). This program included basic services for each house from the beginning of its implementation, however over time the number of families occupying many plots has increased, resulting in unplanned development in which the lack of technical drainage management, as well as waste and land filling at drainages sites has led to chronic flood events [73][74][75]. These conditions will be exacerbated during El Niño years and in the climate change scenarios.…”

Use of GIS Tools in Sustainable Heritage Management—The Importance of Data Generalization in Spatial Modeling

“…The processing functions include transforming, analyzing, aggregating, and generalizing. GIS software allows spatial analysis using a variety of methods, the most popular include: overlay analysis, spatial interpolation, spatial data exploration, hot spot analysis, or kernel density estimation; this type of research finds application in a number of areas, e.g., bathymetry [29], spatial planning [30], location selection [31,32], environmental protection and disaster reduction capability [33][34][35][36][37], spatial and distribution patterns [38][39][40][41], demography [42], as well as many others. Using GIS software, the data can be visualized using many cartographic visualization methods, such as: cartogram, cartodiagram, range method, dot map, etc.…”

Spatiotemporal Characteristics and Driving Force Analysis of Flash Floods in Fujian Province

“…After reviewing previous studies, research on flash floods has focused on the following aspects: First, the risk assessment of flash floods, which includes hazard and vulnerability assessment [12,13]. These research studies were mainly conducted at the county and provincial scales [14][15][16]. Second, flash flood mechanisms, including the process of occurrence, development, and influence [6,17].…”