The effect of non-uniform solar radiation over opposing hillslopes leads to aspect-controlled vegetation patterns in semi-arid ecosystems. It creates a differentiation in soil properties and vegetation characteristics. In mid- to high-latitudes where available soil moisture is a limiting factor for vegetation growth, slopes with polewardfacing aspect tend to develop denser vegetation cover that provides more erosion protection than on the equatorward-facing hillslopes. The variation in erosion rates across opposing hillslopes causes the topographic asymmetry of hillslopes over long timescales. The magnitude of this asymmetry is measured by the hillslope asymmetry index (HAI), a metric given as the ratio of the median slope angles of opposite hillslopes. In this study, we present a novel approach to investigate the relationships of HAI with climatological, geomorphic, and ecologic variables at a global scale. Here, we analyzed these relationships using DEM data to compute HAI for 80 different catchments across the world, in which aspect-controlled vegetation has been reported in the literature. We used the CHILD landscape evolution model (LEM), which uses the continuity equation for water, sediment, and biomass, in order to investigate the control of climatological, geomorphic, and ecologic variables on the development of hillslope asymmetry. Preliminary results show that latitude and mean topographic gradient are the two dominant factors affecting hillslope asymmetry due to their vital role in controlling vegetation density through the modulation of incoming solar radiation. These results improve our understanding on how different climatic variables and geographic properties affect the magnitude of hillslope asymmetry and their implications on landform evolution modelling.