The estimation of flood area based on a few selected and weighted parameters: Case study of the Nangka river basin, Balikpapan (Indonesia)

In several previous studies on flood analysis and estimation, there was no clear rationale for why different researchers used a different combination of parameters in the determination of flood zones. Such research results raise the question of how to select a few dominant parameters without reducing the objectivity of the analysis. This research proposes the standardization of parameters selection by using Pareto Analysis in screening a few vital flood parameters from numerous parameters that prevail in certain areas. The selection of the right dominant parameters is the key to achieving the analysis goal and it will also simplify the analysis processes. This flood zone estimation study uses a combination of Pareto Analysis, Analytic Hierarchy Process (AHP) and Geographic Information System (GIS). The results of the study include a flood zonation map. The study area can be classified by its level of vulnerability as follow: very low vulnerability zones (0.003 km2), low vulnerability zones (5.588 km2), medium vulnerability zones (11.876 km2), high vulnerability zones (8.629 km2), and very high vulnerability zones (2.198 km2). The validation shows that the estimation of the most vulnerable zone is consistent with field validation and the flood event history of several locations in the study area. As a result, the developed model can provide an accurate flood zonation map, enabling stakeholders to take appropriate mitigation measures for different areas.