Analysis of the causes of flooding in Samarinda City using spatial statistics: Geographically weighted regression

Abstract

This study discusses the analysis of the causes of flooding in Samarinda City using geographically weighted regression (GWR) method of spatial statistics. Samarinda City has an area that is prone to flooding. Floods in Samarinda City occur due to excess surface runoff and not being accommodated in the Mahakam watersheds so that water overflows. The factors that cause flooding in Samarinda City are natural factors such as high rainfall, the topography of the area, and the tides of the Mahakam watersheds. The second factor is humans, mainly due to the element of population growth followed by an increase in the need for infrastructure, housing, clean water facilities, education, and other community services. The results of spatial statistical analysis obtained that the best model was the GWR model with R2 of 0.92 and MSE value of 0.202. Based on these results, the concept of flood control in Samarinda City was divided into three parts, namely flood control in the upstream, middle and downstream areas. The upstream flood control concept could be implemented by repairing damaged watersheds conditions and increasing watersheds resistance. The concept of flood control in the middle area could be implemented by reducing flooding and reducing surface runoff. Meanwhile, the concept of flood control in the downstream area could be implemented by facilitating the flow of existing drainage done by increasing the capacity of the drainage channel water and protecting the flow in the channel from the influence of the tide of the Mahakam River.