Analysis GIS for Flood Problem in the Big City: A Case Study in Pekanbaru City, Riau Province, Indonesia

Abstract

Pekanbaru City, Riau Province, Indonesia located at 0°25'29.20"- 0°39'15.22" N and 101°20'43.39"- 101°34'25.60" E. This research aims to study the common causes of flooding in Pekanbaru city with a good geological condition. Research in the flood area of the city of Pekanbaru using primary and secondary data; geological, geomorphological, rainfall, and land use data. Information about this earth system combined with geographic information system (GIS) analysis using a small unmanned aerial vehicle (UAV) / drones including Geographic Positioning Systems (GPS) combined with online coordinate systems that can help spatial analysis to determine the level of vulnerability of flood disasters by producing a visual mapping model. The study shows that 4 locations were found vulnerable to being affected by flooding when it rained. The flood impact in those areas happened because those locations are in a geomorphological system with a low topographic area, the natural river system that controls the water to the main river, and a poor water escape-system / drainage. The geomorphological analysis showed two geomorphological units, i.e., lowland denudational and lowland structural with river flow-pattern that is dendritic, sub-dendritic, and parallel. Rainfall is quite high in 2018 with 2621.5 mm and caused flood-prone areas, which are divided into three categories: Non-vulnerable area (64.575%), Medium Vulnerable area (23,386%), and Vulnerable area (12,039%) from the entire of the research area.