Spatial-Temporal Trend Analysis of Rainfall Erosivity and Erosivity Density of Tropical Area in Air Bengkulu Watershed, Indonesia

Abstract There have been many studies on rainfall erosivity and density (ED). However, it was not widely developed in Indonesia as a tropical country has unique precipitation patterns. They are indicators for assessing the potential risk of soil erosion. The Air Bengkulu Watershed is undergoing severe land degradation due to This study aimed analyze spatial-temporal ED based monthly data (mm). used consisted 19 weather stations during period 2006–2020 which sparsely distributed over watershed. analysis done by using Arnold's equation. Then, trend tested parametric non-parametric statistics, analysed with linear regression equation, Spearman's Rho Mann Kendall's tests. spatial distribution both algorithms inverse distance weighted (IDW) method geographic information system (GIS). Unlike previous research findings, long-term average revealed general increase decreasing trend, whereas found be non-significant when indices were observed. these results indicate range from 840.94 MJ · mm −1 ha h , 552.42 472.09 that November month followed December April most susceptible months Therefore, upstream area region shows various anthropogenic activities must managed properly taking into account environment more stringent measures should water conservation activities.