Groundwater is a very important resource since water volumes stored underground are much larger compared with those located at the surface, such as rivers and lakes. Aquifers supply a high percentage of freshwater for human consumption as well as supplying economic activities like industry, agriculture, and livestock production. Among them, karst aquifers stand out due to their special hydrologic characteristics and behaviour. In karst aquifers, infiltration occurs faster in comparison with unconsolidated aquifers, due to high permeability features at the surface like dolines, karren, epikarst, and swallow holes that allow precipitating water to recharge the aquifer at higher rates. Nevertheless, these characteristics also increase the aquifer’s susceptibility to being affected by pollution generated by anthropogenic practices. With a low natural pollutant degradation capacity, karst systems mostly experience problems related with water quality rather than water quantity. At present, this represents a significant challenge because a high percentage of the world population is settled on karst areas and is solely dependent upon karst aquifers to fulfil their necessary water supply. A good example to represent this case is the Yucatan Peninsula. The Peninsula is a transboundary limestone platform, covering parts of Mexico, Belize, and Guatemala, whose characteristics do not allow surface streams to generate. Therefore, the karstic aquifer provides water for nearly 4.5 million inhabitants within Mexican territory; this estimation excludes water volumes used for economic activities. The anthropogenic impacts over this karst aquifer have generated problems for water intended for human consumption, furthered by weak environmental regulations that allow the disposal of wastewater without adequate treatment. In the Mexican state of Yucatan, roughly 10% of the population has access to public sewer services where wastewater is treated. Additionally, the use of fertilizers and pesticides is not regulated in agricultural areas, while pig farming is an increasing activity, which fails to keep the necessary standards for the proper disposal of pig slurry. Similar situations can be found around the world, thus the development of plans and strategies to preserve karst groundwater quality that aim to find a balance between resource protection and regional development is increasingly necessary. One important tool emerged to support decisions regarding groundwater protection: the groundwater vulnerability concept. However, due to the hydrologic differences among detritus and karst aquifers, the vulnerability concept, which was first promoted for the former aquifer type, necessitated the development of a specialized vulnerability method to consider the natural characteristics of karst landscapes. Nevertheless, due to the high heterogeneity and anisotropy present in karst systems several methodologies to estimate karst groundwater vulnerability have arisen. Current methodologies are theoretical approximations to differentiate areas where an assumed pollutant particle, released at the surface, is more likely to reach the aquifer due to the natural characteristics of the area. These methods have shown themselves to be useful in defining protection areas and in highlighting regions in which further studies can be performed. However, the high subjectivity and exclusion of anthropogenic influences as part of the analysis is a drawback for these methods. In order to estimate karst groundwater vulnerability for current and future scenarios, an integrated approach is highly necessary. Since most of the methods focus solely on the travel time of a theoretical pollutant from the surface towards groundwater or to a spring, inclusion of pollutants residence time and concentration as parameters to estimate vulnerability is of the uttermost importance. To reach this goal, it is necessary to investigate current intrinsic-based methods in terms of their applicability and regional congruence in order to highlight advantages and probable misclassifications among them and to propose improvements. Pollutant residence time and concentration can be estimated from modelling, which can highlight areas where pollution can represent a problem due to anthropogenic practices, such as wastewater disposal and water extraction fields influencing groundwater flow. Other problems to be contemplated are the data availability and the variable processes by which areas are classified as vulnerable or not. Evaluation of multiple criteria to define degrees of vulnerability is complicated, since several factors, such as subjectivity, data quality, scale, and regional conditions, will always be present. This work presents the results from the application of eight karst groundwater vulnerability methods to the Yucatan karst and outcomes from solute transport. Important considerations are explained in order to improve the workflow for intrinsic groundwater vulnerability assessment. Possible parameters, to be included as part of vulnerability analysis, are evaluated by modelling, demonstrating the importance of anthropogenic impacts for current vulnerability scenarios. Results obtained in this research are displayed as the basis for an Integrated Karst Aquifer Vulnerability (IKAV) method proposed as an alternative for vulnerability studies.

Entre o Planalto de Guapiara e a Serra de Paranapiacaba ocorrem sistemas cársticos que estão sob constante pressão do avanço antrópicodas mais variadas naturezas, como mineração de rochas carbonáticas, silviculturas, agriculturas e a própria ocupação humana. Este estudo apresenta primeiramente um levantamento detalhado de aspectos geológicos e geomorfológicos do carste da região, baseado em fotointerpretação, geoprocessamento e trabalhos de campo. Os sistemas cársticos se desenvolvem de forma distinta em ambos os compartimentos geomorfológicos. No Planalto de Guapiara o carste é pouco expressivo com feições cársticas dispersas e raras em todos os corpos carbonáticos abordados. O relevo mais suavizado, com gradientes hidráulicos relativamente baixos e o pouco tempo de exposição das rochas carbonáticas não permitiram o desenvolvimento de umsistema cárstico pleno no planalto. Na Serra de Paranapiacaba, o relevo mais acidentado, associado a altos gradientes hidráulicos, carbonatos mais puros, e maior tempo de exposição das rochas carbonáticas, permite que as feições sejam mais concentradas e apresentem maior desenvolvimento em relação ao planalto. A partir dadeterminação da configuração do carste foi possível se determinar a vulnerabilidadee a delimitação de um zoneamento ambiental do sistema cárstico com a utilização de dois métodos: EPIK e KDI. Na região do Planalto de Guapiara a vulnerabilidade do carsteé baixa e a ocupação humana é mais expressiva, com poucos riscos ao sistema e à população que ali se estabeleceu. Na região da Serra de Paranapiacaba a presença de feições cársticas mais constantes e mais concentradas indica vulnerabilidade muito alta, porém a presença de Unidades de Conservação garante a preservação deste tipo de sistema e a baixa ocupação e interferência humana. Espera-se que este estudo venha a contribuir para políticas públicas de ordenamento territorial futuro, minimizando os eventuais impactos no carste da região. / Between the Guapiara Plateau and the Paranapiacaba Range there are karst systems that are under constant pressure from anthropic advancement of various natures, such as mining of carbonate rocks, forestry, agricultureand human settlement itself. This study presents a detailed survey of geologic and geomorphologic aspects based on photo interpretation, GIS and fieldwork observations. Karst systems develop differently in both geomorphological compartments. At the Guapiara Plateau is not very expressive with scattered and rare karst features in all carbonate bodies covered by this study. The most cushioned relief, with relatively low hydraulic gradients and the short time of exposure of the carbonate rocks did not allow the full development of a karst system at the plateau. At Paranapiacaba Range, the most rugged relief, associated with high hydraulic gradients, purer carbonates and longer exposure of the carbonate rocks, allows karst features to be more concentrated and greater development in relation to the plateau. From the determination of the karst setting was possible to determine the vulnerability and delimitation of an environmental zoning of karst system using two methods: EPIK and KDI. At the Guapiara Plateau the karst vulnerability is low and human settlement is more expressive, with little risk to the system and the people who settled there. At Paranapiacaba Range the presence of karst features is more constant and more concentrated so the vulnerability is very high, but the presence of protected areas to guarantee the preservation of this type ofsystem and the low occupancy and human interference . It is hoped that this study will contribute to public policies for future land use, minimizing any impacts on the karst region.

Entre o Planalto de Guapiara e a Serra de Paranapiacaba ocorrem sistemas cársticos que estão sob constante pressão do avanço antrópicodas mais variadas naturezas, como mineração de rochas carbonáticas, silviculturas, agriculturas e a própria ocupação humana. Este estudo apresenta primeiramente um levantamento detalhado de aspectos geológicos e geomorfológicos do carste da região, baseado em fotointerpretação, geoprocessamento e trabalhos de campo. Os sistemas cársticos se desenvolvem de forma distinta em ambos os compartimentos geomorfológicos. No Planalto de Guapiara o carste é pouco expressivo com feições cársticas dispersas e raras em todos os corpos carbonáticos abordados. O relevo mais suavizado, com gradientes hidráulicos relativamente baixos e o pouco tempo de exposição das rochas carbonáticas não permitiram o desenvolvimento de umsistema cárstico pleno no planalto. Na Serra de Paranapiacaba, o relevo mais acidentado, associado a altos gradientes hidráulicos, carbonatos mais puros, e maior tempo de exposição das rochas carbonáticas, permite que as feições sejam mais concentradas e apresentem maior desenvolvimento em relação ao planalto. A partir dadeterminação da configuração do carste foi possível se determinar a vulnerabilidadee a delimitação de um zoneamento ambiental do sistema cárstico com a utilização de dois métodos: EPIK e KDI. Na região do Planalto de Guapiara a vulnerabilidade do carsteé baixa e a ocupação humana é mais expressiva, com poucos riscos ao sistema e à população que ali se estabeleceu. Na região da Serra de Paranapiacaba a presença de feições cársticas mais constantes e mais concentradas indica vulnerabilidade muito alta, porém a presença de Unidades de Conservação garante a preservação deste tipo de sistema e a baixa ocupação e interferência humana. Espera-se que este estudo venha a contribuir para políticas públicas de ordenamento territorial futuro, minimizando os eventuais impactos no carste da região. / Between the Guapiara Plateau and the Paranapiacaba Range there are karst systems that are under constant pressure from anthropic advancement of various natures, such as mining of carbonate rocks, forestry, agricultureand human settlement itself. This study presents a detailed survey of geologic and geomorphologic aspects based on photo interpretation, GIS and fieldwork observations. Karst systems develop differently in both geomorphological compartments. At the Guapiara Plateau is not very expressive with scattered and rare karst features in all carbonate bodies covered by this study. The most cushioned relief, with relatively low hydraulic gradients and the short time of exposure of the carbonate rocks did not allow the full development of a karst system at the plateau. At Paranapiacaba Range, the most rugged relief, associated with high hydraulic gradients, purer carbonates and longer exposure of the carbonate rocks, allows karst features to be more concentrated and greater development in relation to the plateau. From the determination of the karst setting was possible to determine the vulnerability and delimitation of an environmental zoning of karst system using two methods: EPIK and KDI. At the Guapiara Plateau the karst vulnerability is low and human settlement is more expressive, with little risk to the system and the people who settled there. At Paranapiacaba Range the presence of karst features is more constant and more concentrated so the vulnerability is very high, but the presence of protected areas to guarantee the preservation of this type ofsystem and the low occupancy and human interference . It is hoped that this study will contribute to public policies for future land use, minimizing any impacts on the karst region.