Hydrometeorological Disaster Vulnerability Mapping in East Java Using Hierarchical Clustering

East Java Province is an area with a high increase in cases of hydrometeorological disasters every year with as many as 620 disaster cases occurring. The absence of information related to the level of vulnerability of an area to hydrometeorological disasters has resulted in the magnitude of the risk and impact of disasters that occur on humans as well as increasing damage to facilities and buildings. In this study, a website-based application is created that can map the level of vulnerability of an area to hydrometeorological disasters in East Java. In conducting the mapping, several criteria are needed to determine the vulnerability of an area. The criteria are taken from the hazard/threats and vulnerability criteria. Then the criteria data are grouped using the Centroid Linkage method. This method groups the data based on the level of similarity of the data that is processed by calculating the centroid (middle) distance between the clusters so that the distance of the two clusters that are at least minimal will be combined into a new cluster. The vulnerability level is divided into 3 clusters, namely low, medium, and high which are visualized on a map with a period from 2016 to 2020. Cluster testing is done by calculating the silhouette coefficient value and it is known that the average of each year is 0.370168.