Human populations, landforms, and landslide hazard in Guatemala

Background/Question/Methods

Guatemala, in Central America, is a mountainous country with high biological diversity. Approximately 11, 000, 000 people live in an area of 108,000 km². Agriculture is one of the most important economic activities and the traditional practice is shifting cultivation.  Land tenure problems, unsustainable wood harvesting and deforestation may be causing a greater use of marginal areas in steeplands, and an increase in the number of people living in the mountainous areas. While some global estimates indicate that between 10-39% of the world population live in mountains, Mexico and Central America have double those estimates with 76% of the population living in mountainous areas. Central America is an area prone to landslides and population dynamics may have a strong effect on landslide occurrence. The goal of this research is to estimate population density on Guatemalan ecosystems and landforms and their correspondence with overall landslide hazard. The objectives of this research were (1) to quantify population densities by landforms and ecosystems, and (2) to estimate the correspondence between landforms and landslide hazard, and between ecosystems and landslides hazard and population densities. We developed spatial models for population, landforms, ecosystem complexity, and landslide hazard and combined them using spatial analysis to quantify the spatial distribution of population across the different variables. We estimated the percentage of population by category and their population density.

Results/Conclusions

Most of the population in Guatemala lives in plains, lowlands and plateaus (74%) while only 26% of the population live in mountainous areas. Similar proportions were observed for areas of very low to medium ecosystem complexity (75% population) and high and very high ecosystem complexity (25% population). About 87% of the population are distributed in areas of very low to medium landslide hazard while 13% live in areas with very high landslide hazard. However, population density in very high landslide hazard areas is higher than lower landslide hazard areas. The combination of landforms and landslide hazard revealed that mountainous areas with higher landslide hazard had 39% more population density than similar areas with low landslide hazard. Low population densities tend to happen in highly complex ecosystems due mainly lack of accessibility, low agricultural productivity, and good conservation initiatives. Thirteen percent of the population concentrate areas with very high landslide hazard (10% of Guatemala), where great loss of life and property may happen when excessive rainfall occurs.