The Central American Dry Corridor (CADC) is a sub-region in the isthmus that is relatively drier than the rest of the territory. Traditional delineations of the CADC’s boundaries start at the Pacific coast of southern Mexico, stretching south through Central America’s Pacific coast down to northwestern Costa Rica (Guanacaste province). Using drought indices (Standardized Precipitation Index, Modified Rainfall Anomaly Index, Palmer Drought Severity Index, Palmer Hydrological Drought Index, Palmer Drought Z-Index and the Reconnaissance Drought Index) along with a definition of aridity as the ratio of potential evapotranspiration (representing demand of water from the atmosphere) over precipitation (representing the supply of water), we proposed a CADC delineation that changes for normal, dry and wet years. The identification of areas that change their classification during extremely dry conditions is important because these areas may indicate the location of future expansion of aridity associated with climate change. In the same way, the delineation of the CADC during wet extremes allows the identification of locations that remain part of the CADC even during the wettest years and that may require special attention from the authorities.

Costa Rica’s Caribbean coastline is the result of a complex tectonic setting coupled with dynamic geological, climatological, hydrological and ecological processes. Despite their importance in risk prevention and in land use planning, geomorphological maps at detailed scales are scarce in Costa Rica. A geomorphology map of 210 km of the Caribbean coastline was produced at a scale of 1: 25,000 with a 1: 50,000 scale output map. Eleven landforms were mapped and described based upon their morphogenesis (i.e. tectonic, volcanic, fluvial and/or coastal). This work is an important base for coastal management, and is a compilation of the best existing knowledge of the Caribbean coast of Costa Rica.

Tropical cyclones are one of the most important causes of disasters in Central America. Using historical (1970–2010) tracks of cyclones in the Caribbean and Pacific basin, we identify critical path locations where these low-pressure systems cause the highest number of floods in a set of 88 precipitation stations in the region. Results show that tropical cyclones from the Caribbean and Pacific basin produce a large number of indirect impacts on the Pacific slope of the Central American isthmus. Although the direct impact of a tropical cyclone usually results in devastation in the affected region, the indirect effects are more common and sometimes equally severe. In fact, the storm does not need to be an intense hurricane to cause considerable impacts and damage. The location of even a lower intensity storm in critical positions of the oceanic basin can result in destructive indirect impacts in Central America. The identification of critical positions can be used for emergency agencies in the region to issue alerts of possible flooding and catastrophic events.

Introduction: La Cruz is located in northwestern Costa Rica, and it is characterized by a dry tropical climate with a well-defined dry season. This municipality has reported many impacts of hydrometeorological events during the last 45 years, mostly associated with wet events such as floods that affected roads, housing, and crops; as well as some droughts that have impacted the population and their livelihoods. Objective: The objective of this article is to provide information regarding possible future climate changes during the 21st century associated with a pessimistic emission scenario in the municipality of La Cruz in Guanacaste, Costa Rica. Methods: We used DesInventar database to identify the hydrometeorological impacts in La Cruz and classified them by month. Downscaled simulations from the Climate Model Intercomparison Project 5 (CMIP5) were used to simulate past and future changes (1979-2099) in temperature and precipitation. In addition, a hydrological model was used to calculate runoff projections from meteorological data. Results: Floods, and housing, roads and agricultural damages are the most recurrent impacts. In addition, some human deaths are reported during this time. Results show that a drier and warmer future will be characteristic of the climate in La Cruz in the 21st century, especially after 2040. Runoff is also expected to be reduced significantly following the meteorological trends. Conclusions: It is expected that higher aridity will be present in the future, affecting human and environmental systems. Introducción: La Cruz está localizada en el noroeste de Costa Rica, y está caracterizada por una estación seca bien definida y un clima tropical seco. Este cantón en los últimos 45 años ha reportado impactos de eventos hidrometeorológicos, en particular los húmedos como las inundaciones que han afectado viviendas, calles y cultivos, pero también algunas sequías han perjudicado a la población y sus actividades. Objetivo: El objetivo de este artículo es proveer información acerca de posibles cambios climáticos durante el siglo XXI asociados con un escenario pesimista de emisiones en el cantón de La Cruz en Guanacaste, Costa Rica. Métodos: Se utilizó la base de datos DesInventar para identificar los impactos y agruparlos según su mes de ocurrencia para relacionarlo con el régimen de precipitación. Simulaciones cambiadas de escala del Proyecto de Intercomparación de Modelos Climáticos 5 (CMIP5) fueron estados para simular cambios pasados y futuros (1979-2099) en temperatura y precipitación. Adicionalmente, un modelo hidrológico fue usado para calcular las proyecciones de escorrentía usando los datos meteorológicos. Resultados: Los resultados mostraron que un futuro más seco y caliente será característico del clima del siglo XXI, especialmente después del 2040. La escorrentía se espera que será reducida significativamente siguiendo las tendencias meteorológicas. Conclusiones: Algunos de los impactos más recurrentes históricamente son las inundaciones, daños a viviendas, calles y cultivos, sin embargo, también se han registrado algunas muertes en la zona. Se espera que una aridez mayor estará presente en el futuro, afectando sistemas humanos y ambientales.

Hydrometeorological hazards have historically affected Central America and significantly impacted the isthmus. However, the spatial distribution of those impacts is heterogeneous and depends on several factors, such as storm trajectories and community vulnerability. To address the spatial distribution of impacts related with historical events, Honduras was used as a case study. This paper was aimed at identifying the municipalities most impacted by the hydrometeorological events and at studying their correlation with socioeconomicvariables. Impacts recorded from 1919 to 2012 were collected from the DesInventar and EM-DAT databases. Data was georeferenced using a Geographical Information System and the information was disaggregated atlocal government scale. Spearman spatial correlation were calculated between physical variables and socioeconomic indices. The municipalities that reported more impacts included La Ceiba, Choluteca, Francisco Morazán and Yoro. Three hazards were found and the most important regarding impacts: cold fronts or outbreaks, tropical cyclones and easterly waves. The first type was more common during boreal winter, while the last two hazards were normally found during boreal spring-summer-autumn. Population and poverty were the social variables with the highest correlation with impacts. The analysis showed that spatial distribution of impacts related with hydrometeorological causes cannot be explained solely by climate causes. Therefore, other variables, such as socioeconomic should also be considered in analyses of these types of impact.

Introduction: Warming is already significant in Central America and the Caribbean and may be magnified even further in the future. A decrease in the precipitation is projected, increasing also regional aridity. Objective: To study observed and projected latitudinal gradients for precipitation and temperature in three Southern Caribbean locations of Central America: Bluefields (Nicaragua), Limón (Costa Rica) and Bocas del Toro (Panamá) and to characterize their future changes and determine if there are differences or similarities in a north-south direction. Methods: Monthly precipitation (P) and temperature (T) data from General Circulation Models from 1979 to 2099, were downloaded from the WRF repository. Data from the selected models from the repository were subjected to a delta-type statistical downscaling to bring them to a resolution of 1 x 1 km. These models are part of the latest generation of the Coupled Model Intercomparison Project-Phase 6 used by the Intergovernmental Panel on Climate Change. The ground-truth data necessary for bias correction were obtained from the ERA5 reanalysis. Monthly P and T data were downloaded from 1979 to 2014 at different native spatial resolutions and climatologies at 1 x 1 km spatial resolution at global scales were obtained from WorldClim data. Results: Scenarios show that some regions would go from very humid to humid, based on strong reductions in precipitation and warming at the end of the 21st century. This expected increase in the aridity is going to have impacts on ecology and ecosystem services, agriculture, human consumption due to a water availability reduction per capita and hydroelectric generation. Conclusions: Generation of high spatial Climate Change scenarios is necessary because Central America is a region characterized by significant topographic complexity, land use variety and spatial occurrence of hydrometeorological disasters. This intrinsic variability suggests that local risk management and planning strategies must be designed with a highly specific approach to each locality or region. This implies that, even in areas geographically near to each other, the measures taken may not necessarily be transferable due to differences in climate projections, as it was found for the three nearby communities in the Southern Central American Caribbean coastal region.