Juan José Durán

Advances in Research in Karst Media

The right to water use does not imply total sovereignty by some to the detriment of others over one of the most basic natural resources necessary to sustain life. Both developed and developing countries must find a workable balance for managing water resources. Water use decisions like those affecting Figeh Spring, Damascus, Syria, and Kharga Oases, Egypt, are controlled both by natural parameters, as well as human factors such as land use and population growth. Sustainable Water Development (SWD) is an internationally accepted program for balancing water use issues and goals among competing consumers.

A record of Pleistocene climate from a stalactite, Nerja Cave, southern Spain

A study of stable isotopes (N 18 O, N 13 C) of a uranium-series dated aragonitic stalactite from Nerja Cave (Malaga, southern Spain) was carried out in order to determine the conditions of deposition in isotopic equilibrium and non- equilibrium. We obtained a record of climate change from 190 000 to 160 000 years ago. A series of carbon (N 13 C) and oxygen (N 18 O) isotopes analyses have been carried out in parallel to the stalactite growth axis. Sampling was done in each growth layer. A curve of the secular N 18 O aragonite variations for the stalactite suggests cooler climate conditions

Mathematics of Planet Earth

1. Advances in classical statistics relevant to the geosciences.- 2. Frontier statistics.- 3. Compositional data analysis applied to geochemistry.- 4. Data assimilation in geosciences.- 5. Machine learning in geoscience applications.- 6. Spatiotemporal analysis: structural complexity and extreme behaviour. -7. Parameterization of soil systems at different scales.- 8. Fractals, chaos and complexity in the earth system.- 9. Remote sensing a changing world.- 10 Radar remote sensing for the detection, monitoring and modelling of ground instabilities.- 11. Geographic information systems/geoinformatics.- 12. Quantitative methods in geomorphology and land surface processes.- 13. Deformation modelling, geodynamics and natural hazards.- 14. Hydrogeology: From process understanding to improved predictions. - 15. Quantitative hydrology: working across scientific disciplines and time space scales.- 16. Quantitative environmental geology.- 17. Modelling of energy resources.- 18. New developments in oil and gas discovery modelling.- 19. Open session on mathematics of oil recovery.- 20 Geostatistical priors in inversion of geophysical and engineering data.- 21 Mineral and energy resources for planet earth: Evaluation, extraction and optimal management.- 22 Recent advances in quantitative methods applied to stratigraphy and paleontology.- 23 Geo-mathematical models of folds and folding.- 24. Mathematical geosciences and planetary geology.- 25. Mathematics of planet earth.- 26 Geoscience data models for practical interoperability. -27. Advances on stochastic non linear methods and inverse problems for dynamic models.

Presence of endocrine disruptors in freshwater in the northern Antarctic Peninsula region

The increasing human presence in Antarctica and the waste it generates is causing an impact on the environment at local and border scale. The main sources of anthropic pollution have a mainly local effect, and include the burning of fossil fuels, waste incineration, accidental spillage and wastewater effluents, even when treated. The aim of this work is to determine the presence and origin of 30 substances of anthropogenic origin considered to be, or suspected of being, endocrine disruptors in the continental waters of the Antarctic Peninsula region. We also studied a group of toxic metals, metalloids and other elements with possible endocrine activity. Ten water samples were analyzed from a wide range of sources, including streams, ponds, glacier drain, and an urban wastewater discharge into the sea. Surprisingly, the concentrations detected are generally similar to those found in other studies on continental waters in other parts of the world. The highest concentrations of micropollutants found correspond to the group of organophosphate flame retardants (19.60-9209ngL(-1)) and alkylphenols (1.14-7225ngL(-1)); and among toxic elements the presence of aluminum (a possible hormonal modifier) (1.7-127µgL(-1)) is significant. The concentrations detected are very low and insufficient to cause acute or subacute toxicity in aquatic organisms. However, little is known as yet of the potential sublethal and chronic effects of this type of pollutants and their capacity for bioaccumulation. These results point to the need for an ongoing system of environmental monitoring of these substances in Antarctic continental waters, and the advisability of regulating at least the most environmentally hazardous of these in the Antarctic legislation.

Soil Characteristics along a Transect on Raised Marine Surfaces on Byers Peninsula, Livingston Island, South Shetland Islands

This paper presents the results of a soil survey carried out in Byers Peninsula to characterize some of the main features of soils and processes involved in soil development in the largest ice-free area in the South Shetland Islands. Soils were sampled in four different sites at altitudes between 24 and 88 m a.s.l., along a transect of about 1.5 km in the southwestern sector of the peninsula. The sampling sites are located on different geomorphological units from the Holocene raised beaches to the pre-Holocene upper marine platforms. It was found that general soil properties and elemental composition differ among the distinctive edaphic environments that conform the soils on the platforms and on the raised beaches. From the platform to the beach, pH and electrical conductivity values decrease, as well as the clay and silt percentages. Increases in carbonate and sand contents were observed along the transect. The variability in some elements (K, Fe, Al, Ca, Sr) appears to be related to mineralogy and parent materials. In the studied soils, the main factors affecting soil development are related to cryogenic processes. Lixiviation and other weathering processes also play a role in soil evolution although their influence is restricted because water circulation is limited to the summer period.

Hydrogeological and Environmental Investigations in Karst Systems

This paper presents preliminary results from two karst systems belonging to the ‘‘Jurassic Karst’’ observatory in the French Jura Mountains. The sites are characterized by localized and diffuse recharge. Physicochemical monitoring was performed at the karst outlet (springs), as well as in the unsaturated zone (cave and epikarstic spring). During two contrasting flood events, water level, temperature, electrical conductivity, dissolved organic carbon, turbidity, and dissolved oxygen were recorded at high frequency and compared. These preliminary results allow to propose a conceptual model for both sites. It was possible to distinguish specific autogenic and allogenic recharge mechanisms and to characterize the respective contribution of the saturated and unsaturated zones.

Fractal Modelling of Karst Conduits

Three kinds of porosity and permeability, rock matrix porosity, fracture porosity and conduit porosity, must be considered when creating spatially distributed mathematical models of karst systems. These components are responsible for the two kinds of karst flows that can be observed in nature and that must be reproduced by the mathematical models: the slow flow that takes place through the matrix of porous and small fractures and the fast flow through large fractures and conduits. Although the three components present fractal characteristics, the aim of this work is the fractal behaviour of the karst conduits. Two aspects of the karst conduits are considered: their geometry and their topology. The geometry is defined by the sections of the conduits and their tortuosity while the topology is given by the network characteristics of the conduits (connectivity, spatial density and three-dimensional distribution in space). This work deals with the calculation of the fractal dimensions of the different characteristics and how the fractal dimension can be used for morphometric characterization of karst networks, for simulating three-dimensional networks of karst conduits and for calculating the volume of conduits and thus the total conduit porosity of the karst system. The karst system of Sierra de las Nieves in Malaga province (Southern Spain), a high relief karst where the endokarst is very well developed and has given birth to super-caves, is used to illustrate the methodology.

Fractal Modeling and Estimation of Karst Conduit Porosity

The three-dimensional distribution of karst conduits in a karst aquifer is the main source of its heterogeneity and anisotropy. It also has a strong effect on peak spring discharge, and in the form of the karstic hydrograph, chemograph, and thermograph. The direct access to the conduits is only possible by speleological exploration and cave mapping, which provides a very valuable information for karst modeling. However, this information is biased because the speleologists can only explore a limited part of the conduit network: they can only map conduits of a minimum diameter, the speleological exploration can take many years in order to explore all the leads that appear in a network system and parts of the network are not accessible. In order to estimate conduit porosity we can take advantage of the fractal character of nature. The volume of conduits larger than a given diameter can be estimated in a particular volume of rock. This is done by extrapolating a power law that has been fitted to experimental data. The power law distribution of the volume of conduit voids larger than a particular diameter is related with the fractal behavior of a network of karst conduits. This fact was also used for simulating a three-dimensional network of karst conduits by a stochastic process of diffusion limited aggregation. The procedure is illustrated in the Sierra de las Nieves karst aquifer in the province of Malaga, Southern Spain. Karst conduit porosity can be used for generation of numerical models of karst systems, and for the mathematical modeling of flow in karst aquifers.

Karst massif susceptibility from rock matrix, fracture and conduit porosities: a case study of the Sierra de las Nieves (Málaga, Spain)

The potential contamination of a karst massif from surface sources can be evaluated and represented in a susceptibility map. In the case of a carbonate aquifer, the susceptibility assessment must take into account their very complex and heterogeneous nature. The complexity originates in the presence of three types of porosity: matrix rock, fracture and conduit porosity. This paper presents a method for karst susceptibility mapping by estimating the three porosity types and evaluates their integration in a single susceptibility index. Matrix rock porosity is measured in the laboratory from samples collected in the field and is well correlated with lithology. Fracture porosity is estimated from fracture mapping and field measurements of secondary fracture porosity. Geostatistical methods are used to obtain continuous fields of rock matrix porosity and fracture porosity. Conduit porosity is calculated from a power model fitted to speleological cave mapping data. However, because of the scarcity and sampling bias of conduit data, probabilistic models are conjectured. A fourth porosity factor evaluated is the detritic filling of karst depressions. The integration of the different porosities in a single susceptibility factor gives a quantitative map that is reclassified to provide a qualitative, easy to interpret susceptibility index map of the karst system. Porosity estimation may also be of interest in recharge estimation and mathematical modelling of flow and transport in karst systems. The case study used to illustrate this approach is the Sierra de las Nieves karstified rock mass, a high relief Mediterranean karst in the province of Málaga in southern Spain.

Synthesis of Groundwater Recharge of Carbonate Aquifers in the Betic Cordillera (Southern Spain)

This paper presents a synthesis of the results and the evaluation methods of recharge in 51 carbonate aquifers of the Betic Cordillera. The average infiltration coefficient is 38 %, with a standard deviation of 12 %. The method of evaluation of recharge most applied is soil water balance, which served to take the first steps in groundwater management in Spain. Other widely used methods are water balance of the aquifer, chloride mass balance, and empirical methods such as APLIS. In eastern areas of the Cordillera, where the semiarid conditions are more overt, distributed models are used to assess recharge and calibrate it with data from the piezometric level evolution. In general, the annual recharge rates obtained appear higher when correlated with the annual rainfall. Thus, the data presented in this work contribute to a correct evaluation of renewable resources associated with the carbonate aquifers of the region. The high capacity of recharge and good quality of water for different uses, and especially to supply the population, makes these aquifers essential in the face of strong demand. Moreover, the data presented should be of special interest for future comparisons involving recharge assessments and different scenarios of climate change and changes in land use.