Significance of river infiltration to the Port-au-Prince metropolitan region: a case study of two alluvial aquifers in Haiti

Abstract

Mountain block recharge (MBR) mechanisms are an important component of the water budget for many alluvial aquifers worldwide. The MBR dynamics are complex, difficult to constrain, and quantification is highly uncertain. These challenges are magnified in data-scarce study areas, including the Cul-de-Sac and Leogane plains, two of Haiti’s largest alluvial aquifers, which are flanked by the Massif de la Selle mountain block. The associated groundwater supplies the regional metropolitan area of Port-au-Prince (RMPP) and it is facing increasing pressure, requiring improved understanding of the aquifer system to guide management and protection. This report introduces the aquifers and investigates the significance of river infiltration from flows originating from the mountain block. The approach to derive important insight on recharge included analysis of broad datasets on piezometry, isotopes, hydrochemistry, and streamflow. The findings indicate that river infiltration is a major source of recharge to the alluvial aquifers. Grise and Blanche river infiltration may account for >80% of recharge to the Cul-de-Sac aquifer, exhibiting temporal variation correlated to climate events such as cycles of the El Niño/La Niña Southern Oscillations. Momance and Rouyone river infiltration may account for >50% of recharge to the Leogane aquifer. The results direct attention to the Massif de la Selle carbonate aquifer system, where bulk recharge is estimated to be four times greater than both alluvial aquifers. The Massif not only supplies the RMPP with ~65% of its water supply from karst springs, but its streamflow also recharges the alluvial aquifers that supply the balance of RMPP supply.

Assessing Impacts of Land Subsidence in Victoria County, Texas, Using Geospatial Analysis

“…The groundwater data for Victoria County were used to produce potentiometric maps. These maps are a valuable tool used by hydrogeologists to deduce useful information such as the groundwater flow direction and hydraulic conductivity variations [43][44][45]. After initial data processing, the potentiometric surface maps were prepared using the inverse distance weighting (IDW) interpolation method in ArcGIS Pro to illustrate the groundwater level variations in the County from 2000 to 2021.…”

Topical Collection: Advancements in hydrogeological knowledge of Haiti for recovery and development

“…The understanding of temporal recharge dynamics is improved through these papers, which show the importance of larger precipitation events and El Niño Southern Oscillation (ENSO) climatic cycles for both the bedrock and alluvial aquifer systems. Groundwater storage, flow dynamics and water quality in the alluvial aquifers have a close relation to the river systems that have carved out and infilled the basins (Adamson et al 2022b;Arnaud et al 2022). The cost-efficient geophysical methods outlined by Miner et al (2022a) The discontinuous carbonate and karst bedrock aquifers absorb most of the country's recharge and feed thousands of springs and hundreds of water systems throughout the country.…”

“…The findings support insights into what may be considered one of Haiti's most important and least studied aquifer systems. Adamson et al (2022b) synthesize and analyze piezometric, stream flow, stable isotope and chloride data to evaluate river infiltration recharge to the Plaine du Cul-de-Sac and Plaine de Leogane alluvial aquifers. The results advance the conceptual understanding of the aquifers and the importance of the Massif de la Selle mountain block and its watersheds for recharge to the alluvial aquifers.…”

“…Many of Haiti's alluvial aquifers do not receive significant quantities of recharge from direct precipitation, in part because of their low elevations and high evapotranspiration (Adamson et al 2022b;Adamson et al 2022a;Arnaud et al 2022). Infiltration of rivers and inflow from mountain bedrock aquifers are interpreted as key sources of recharge for the Plaine du Nord, Plaine du Cul-de-Sac, Plaine de Leogane and Plaine de Gonaïves, and perhaps other alluvial aquifers in Haiti.…”