Specifics of landslide processes in Guatemala: apsect of the terrain and wind circulation during hurricanes

Abstract:

Specific relationship between slope aspect and wind circulation during hurricane events exists for Guatemala. Analysis of hurricanes Mitch (1998) and Stan (2005) showed that eastern, southeastern and southern slopes are more subjected to landslides processes than other slope orientations. This conclusion is based on landslide data obtained immediately after hurricane occurences and satellite data on wind circulation during hurricane events. Because Guatemala is located between Atlantic and Pacific "swarms" of hurricane tracks, typical argument based on the strong right side impact of hurricanes cannot be applied here. We analyzed series of satellite based wind circulation data related to Mitch and Stan and established strong association between eastern, southeastern and southern wind directions and landslide affected areas. This is reflection of the local wind circulation during hurricane events at elevations 800 hPa. This is in agreement with previous meteorologic studies in the region by Portig (1965). It is possible that similar relationship is true for the rest of Central American region. If this is a case then future studies can develop a regional model that can be used as a tool in landslide assessment and hazard mapping on a regional level. However, data quality is a key factor in this type of analysis.