Development and Application of a Methodology for the Identification of Potential Groundwater Recharge Zones: A Case Study in the Virvini Micro-Basin, Tiraque, Bolivia

Abstract

Groundwater plays a vital role in human consumption and irrigation in many parts of Bolivia; yet, the absence of policies to regulate its extraction and protect groundwater recharge areas has led to a decline in water tables and threatened food security. Some municipal initiatives have been implemented to develop regulations, but the lack of reliable hydrogeological data (such as aquifer geometry, groundwater level data, location of potential groundwater recharge zones, and flow dynamics) hinders their effective implementation. The case study presented herein focuses on a municipal policy in Tiraque, Bolivia, aimed at protecting groundwater recharge zones, in addition to the need for a reliable methodology for their technical identification. The EARLI approach (an acronym for “Enhanced Algorithm for Recharge based on the Rainfall and Land cover Inclusion”) is suggested as a participatory-simplified multi-criteria decision method to address the absence of hydrogeological data. This approach was adjusted to the basin’s specific conditions, including local vegetation communities and their influence on infiltration, and was applied as a pilot study in the Virvini micro-basin. The EARLI model emphasizes the spatial distribution of rainfall as an input indicator for potential recharge in addition to the biophysical characteristics of the catchment area. The methodology successfully mapped the degree of groundwater recharge potential and was validated by traditional hydrogeological models, field infiltration measurements, and the local community’s application of the tool. Therefore, the results of this study provide the necessary technical bases for groundwater-integrated management in Tiraque.

Keywords

• groundwater recharge
• groundwater protection
• vegetation/groundwater relations
• decision making
• socio-hydrogeology
• Bolivia