(Physical Density Map for Determining Flood Risk Elements in Kota Belud Area, Sabah, Malaysia)

Flooding is a natural disaster that annually impacts human lives, socio-economic disruptions, and environmental destruction. There are three critical components to interpreting flood risk: Hazard, vulnerability, and exposure. Exposure in this context refers to elements that are exposed or at risk of experiencing losses and have their level of vulnerability. The record of flood incidents in this area is increasing, especially after the Ranau Earthquake 2015. This increase in incidents affects livelihoods as the local community relies on agricultural yields such as rice cultivation for income generation, in addition to the presence of public facilities such as hospitals, government offices, and schools. Therefore, identifying the risky elements in this area is crucial to minimising the flood risk that may affect the region. The main objective of this study was to identify the elements at risk from flood disaster threats in the Kota Belud area of Sabah. Risk elements can be identified explicitly or implicitly. Explicit risk elements are identified through the presence of buildings and the types of road networks in the study area, while implicit risk elements are analysed through field surveys. A Physical Density Map (PDM) is then generated from the building footprints and road network map to illustrate the risk elements at a regional scale. This map is created by converting building polygons into points, calculating them based on square kilometres, and combining them with road network information. This method is also an alternative approach to depicting population distribution in areas where data availability and accessibility are limited. The analysis results show that high physical density risk elements are located near major rivers such as Sungai Kadamaian, Sungai Wariu, Sungai Gurong-gurong, Sungai Tempasuk, and Sungai Abai. This study is precious as a pioneering study in interpreting flood risk in this area. It has the potential to be extended to other areas to manage and reduce damages and losses to properties, infrastructure, or public utilities.