Development of an Integrated Strategy for Karst Aquifer Vulnerability Assessment (IKAV)
Project type
Doctoral Research Project
Funding
Consejo Nacional de Ciencia y Tecnología (CONACYT), México
Duration
03.2015 - 04.2019
Cooperation partners
Universidad Autónoma de Yucatán (UADY)
Centro de Investigación Científica de Yucatán (CICY)
Comisión Nacional del Agua (CONAGUA), Organismo de Cuenca Península de Yucatán
Background
Yucatán State (39,524 km2) is settled over the limestone platform of Peninsula de Yucatán. As a well-developed karst, the area holds cavities, conduits and sinkholes of variable size. Sinkholes (cenotes) density varies spatially from areas with several cenotes per square kilometer to several kilometers between cenotes. Yucatán topography is mostly flat, elevation ranges from centimeters along the coast to approximately 30 meters above sea level at the base of a hill area located at the southern part of the State. Surface flow is non-existent due to the considerable karstification and low slopes, being rainwater infiltrated at fast rates through fissures and cracks. Groundwater is the only source for human consumption (2,097,175 inhabitants at 2015) and also for agriculture and other economic activities.
Due to intrinsic features like flatness of the surface and hardness of the limestone, waste water sewage systems are almost inexistent. Although new urban developments are encouraged to implement sewage, nowadays only a roughly 10% of the Yucatan population is covered with this service. Disposal of waste water is mostly done by artisanal septic tanks, where waste water experience residence times of a few hours, percolating into the vadose zone and reaching the shallow groundwater. Additionally, in urban areas rain water is infiltrated directly to groundwater by boreholes located along the streets, acting as concentrated flow points. Being Merida city, the most populated settlement with 970,377 inhabitants (2015) and a population density of 858 inh/km2, the continuous waste water infiltration has created a pollution plume contaminating the upper 20 meters of the available fresh water below the capital city but occurrence of this phenomena in other cities sub-surface has not been measured.
Pollution risk which Yucatán faces nowadays urges the necessity to evaluate solutions and strategic approaches to secure appropriate groundwater quality. The lack of surface flow on the region makes the Yucatan aquifer the sole source for water supply but also a receptor of waste water stressing the necessity of an integrated groundwater vulnerability approach to help water managers and decision makers into sustainable protection strategies.
Objectives
The aim of this research is the development of an integrated vulnerability approach for karst areas. Inclusion of global change factors is highly necessary for a more realistic approach either for actual or future scenarios. To understand the pollution threat, concentration of pollutants (e.g. nitrates) and their residence time in the system must be included in a vulnerability analysis.
Some of the necessary steps to understand and evaluate the Yucatán case are:
- Application and analysis of current intrinsic vulnerability methods on the study area;
- Determine the pollution plume extent using geophysical methods to analyze the precipitation/pollution relationship;
- Development and validation of a new integrated method.
Dissertation
- Miguel Alonzo Moreno Gomez (2021)
Development of an integrated methodology to estimate groundwater vulnerability to pollution in karst areas. Dissertation, Technische Universität Dresden, 2021
Publications (selection)
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Moreno-Gómez, M., Martinez-Salvador, C., Moulahoum, A.-W., Liedl, R., Stefan, C., Pacheco, J. (2019)
First steps into an integrated karst aquifer vulnerability approach (IKAV). Intrinsic groundwater vulnerability analysis of the Yucatan karst, Mexico. Water, 11(8): 1610. doi: 10.3390/w11081610 -
Martinez-Salvador, C., Moreno-Gómez, M., Liedl, R. (2019)
Estimating Pollutant Residence Time and NO3 Concentrations in the Yucatan Karst Aquifer; Considerations for an Integrated Karst Aquifer Vulnerability Methodology. Water, 11(7): 1431. doi: 10.3390/w11071431 -
Moreno-Gómez, M., Liedl, R., Stefan, C. (2019)
A new GIS-based model for karst dolines mapping using LiDAR; application of a multidepth threshold approach in the Yucatan karst, Mexico. Remote Sensing, 11(10): 1147. doi: 10.3390/rs11101147 - Moreno Gomez, M., Pacheco, J., Liedl, R., Stefan, C. (2018)
Evaluating the applicability of European karst vulnerability assessment methods to the Yucatan karst, Mexico. Environ Earth Sci. 77:682. doi: 10.1007/s12665-018-7869-5
Researcher
Dr. Miguel Moreno