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Papers by José Manuel Nieto López

Research paper thumbnail of Estimación de parámetros hidrogeológicos en los acuíferos costeros del Bajo Guadalhorce (Málaga) mediante el análisis de la influencia de las mareas

Geogaceta, 2016

By the use of continuous data recording on two points of the Bajo Guadalhorce coastal sector (Mal... more By the use of continuous data recording on two points of the Bajo Guadalhorce coastal sector (Malaga province, southern Spain), located at 626 m and 985 m inland, it has been possible to verify a clear influence of tidal oscillations on the water table of the unconfined and the confined aquifers. Various methods to estimate aquifer transmissivity have been applied. The results depends on the method and, more important, on the storage coefficient (S) values. After the calculations it is possible to confirm that the time lag and tidal efficiency factor methods give coherent results with previous data, although with the time lag method the transmissivity values are an order of magnitude higher.

Research paper thumbnail of Variable Seepage Meter Efficiency in High-Permeability Settings

Water, Nov 21, 2020

The efficiency of seepage meters, long considered a fixed property associated with the meter desi... more The efficiency of seepage meters, long considered a fixed property associated with the meter design, is not constant in highly permeable sediments. Instead, efficiency varies substantially with seepage bag fullness, duration of bag attachment, depth of meter insertion into the sediments, and seepage velocity. Tests conducted in a seepage test tank filled with isotropic sand with a hydraulic conductivity of about 60 m/d indicate that seepage meter efficiency varies widely and decreases unpredictably when the volume of the seepage bag is greater than about 65 to 70 percent full or less than about 15 to 20 percent full. Seepage generally decreases with duration of bag attachment even when operated in the mid-range of bag fullness. Stopping flow through the seepage meter during bag attachment or removal also results in a decrease in meter efficiency. Numerical modeling indicates efficiency is inversely related to hydraulic conductivity in highly permeable sediments. An efficiency close to 1 for a meter installed in sediment with a hydraulic conductivity of 1 m/d decreases to about 60 and then 10 percent when hydraulic conductivity is increased to 10 and 100 m/d, respectively. These large efficiency reductions apply only to high-permeability settings, such as waveor tidally washed coarse sand or gravel, or fluvial settings with an actively mobile sand or gravel bed, where low resistance to flow through the porous media allows bypass flow around the seepage cylinder to readily occur. In more typical settings, much greater resistance to bypass flow suppresses small changes in meter resistance during inflation or deflation of seepage bags.

Research paper thumbnail of Preliminary Study of the Impact of Guadalhorce River Mouth Channeling (Málaga, Spain) on Groundwater and Related Wetlands

Environmental Earth Sciences, 2017

Research paper thumbnail of Considerations About Wastewater Reuse in Areas Subjected to Strong Pressures in the South of Spain

Asociacion Internacional de Hidrogeologos, Grupo Portugues International Association for Promotin... more Asociacion Internacional de Hidrogeologos, Grupo Portugues International Association for Promoting Geoethics Instituto Superior de Engenharia de Porto Asociacion Internacional de Hidrogeologos, Grupo Espanol

Research paper thumbnail of Hydro-environmental changes assessment after Guadalhorce River mouth channelization. An example of hydromodification in southern Spain

CATENA, 2020

The Guadalhorce River mouth (Málaga, Southern Spain) was channelized between 1997 and 2003 to red... more The Guadalhorce River mouth (Málaga, Southern Spain) was channelized between 1997 and 2003 to reduce flooding potential in adjacent densely populated sections of Málaga. The channel was bifurcated near the Mediterranean Sea, surrounding an isolated wetland complex composed of eight different ponds. Groundwaterlevel and wetland-stage data, combined with water-chemistry data from wells and wetlands, collected since 1977, have documented the hydrological and ecological responses to channelization. The results show that channelization has extended the tidal influence inland from the Mediterranean Sea through the Guadalhorce River and the subjacent coastal aquifers, producing a change in groundwater hydrodynamics. The isolation of the wetlands resulting from channelization has provoked a significant salinization of both surface water and groundwater, the extent of which varies among wetlands. These decadal-scale changes in water chemistry have promoted the appearance or increase of halophilic vegetation and have caused a shift from diving birds to predominantly shorebirds in some wetlands. Documentation of these unexpected ecosystem responses is a necessary first step for land managers who need to consider groundwater and surface water as a single resource, particularly in groundwater-dependent ecosystems along the densely populated and ecologically sensitive Mediterranean coastal areas.

Research paper thumbnail of The Bajo Buadalhorce coastal aquifers (Málaga, Spain): five decades of human induced evolution

BOLETÍN GEOLÓGICO Y MINERO

This work makes a synthesis of the hydrogeological knowledge acquired from different works from t... more This work makes a synthesis of the hydrogeological knowledge acquired from different works from the decade of 1970 in the Bajo Guadalhorce detrital, coastal aquifers. Hydrodynamic, hydrochemical and geophysical studies were done in the frame of the aforementioned works to determine the hydrogeological properties of these aquifers. Besides, the drilling of research piezometers was carried out in the framework of some of these studies. This information allowed to study the spatial and temporal behavior of groundwater table and some chemical components of the groundwater of these aquifers, as well as to estimate some parameters as hydraulic conductivity or transmissivity. Overexploitation of aquifers was also studied, because marine intrusion situations were detected over the years. However, some studies carried out in the decade of 2010 have remarked a noticeable difference in the hydrodynamic and hydrochemical state of aquifers, due to intense changes in land use during the end of th...

Research paper thumbnail of Características hidroquímicas de humedales salinos andaluces situados en distintos contextos hidrogeológicos

Research paper thumbnail of Hydrodynamic and hydrochemical evolution of the Bajo Guadalhorce Valley alluvial aquifer (Málaga, S Spain) in the last 40 years

&... more <p>Groundwater flowing through coastal aquifers is increasingly impacted by human pressures as consequence of a growing demand on drinking water, tourism and agriculture, among others. Thus, groundwater availability very often depend on its quality since water salinization and pollution are the main challenges for water management because of seawater and freshwater interaction. Therefore, it is crucial to monitor the availability of groundwater and its quality under changing scenarios where this water resource can be specially threatened.</p><p>This study aims to assess the spatial distribution and time evolution of groundwater levels and hydrochemistry of the alluvial aquifer of the Bajo Guadalhorce Valley (Málaga, S Spain) for the evaluation of its quantitative and qualitative status. To that, groundwater level, electrical conductivity and Cl<sup>-</sup> and SO<sub>4</sub><sup>2-</sup> concentrations of water have been measured in a field sampling campaign carried out in the alluvial aquifer of the Bajo Guadalhorce Valley (Málaga, S Spain) in April 2017. Additionally, historical data from the last 40 years have been compiled.</p><p>Results show that groundwater generally flow towards the Guadalhorce River, where gaining relationship remains more…

Research paper thumbnail of Estimación de parámetros hidrogeológicos en los acuíferos costeros del Bajo Guadalhorce (Málaga) mediante el análisis de la influencia de las mareas

Geogaceta, 2016

By the use of continuous data recording on two points of the Bajo Guadalhorce coastal sector (Mal... more By the use of continuous data recording on two points of the Bajo Guadalhorce coastal sector (Malaga province, southern Spain), located at 626 m and 985 m inland, it has been possible to verify a clear influence of tidal oscillations on the water table of the unconfined and the confined aquifers. Various methods to estimate aquifer transmissivity have been applied. The results depends on the method and, more important, on the storage coefficient (S) values. After the calculations it is possible to confirm that the time lag and tidal efficiency factor methods give coherent results with previous data, although with the time lag method the transmissivity values are an order of magnitude higher.

Research paper thumbnail of Variable Seepage Meter Efficiency in High-Permeability Settings

Water, Nov 21, 2020

The efficiency of seepage meters, long considered a fixed property associated with the meter desi... more The efficiency of seepage meters, long considered a fixed property associated with the meter design, is not constant in highly permeable sediments. Instead, efficiency varies substantially with seepage bag fullness, duration of bag attachment, depth of meter insertion into the sediments, and seepage velocity. Tests conducted in a seepage test tank filled with isotropic sand with a hydraulic conductivity of about 60 m/d indicate that seepage meter efficiency varies widely and decreases unpredictably when the volume of the seepage bag is greater than about 65 to 70 percent full or less than about 15 to 20 percent full. Seepage generally decreases with duration of bag attachment even when operated in the mid-range of bag fullness. Stopping flow through the seepage meter during bag attachment or removal also results in a decrease in meter efficiency. Numerical modeling indicates efficiency is inversely related to hydraulic conductivity in highly permeable sediments. An efficiency close to 1 for a meter installed in sediment with a hydraulic conductivity of 1 m/d decreases to about 60 and then 10 percent when hydraulic conductivity is increased to 10 and 100 m/d, respectively. These large efficiency reductions apply only to high-permeability settings, such as waveor tidally washed coarse sand or gravel, or fluvial settings with an actively mobile sand or gravel bed, where low resistance to flow through the porous media allows bypass flow around the seepage cylinder to readily occur. In more typical settings, much greater resistance to bypass flow suppresses small changes in meter resistance during inflation or deflation of seepage bags.

Research paper thumbnail of Preliminary Study of the Impact of Guadalhorce River Mouth Channeling (Málaga, Spain) on Groundwater and Related Wetlands

Environmental Earth Sciences, 2017

Research paper thumbnail of Considerations About Wastewater Reuse in Areas Subjected to Strong Pressures in the South of Spain

Asociacion Internacional de Hidrogeologos, Grupo Portugues International Association for Promotin... more Asociacion Internacional de Hidrogeologos, Grupo Portugues International Association for Promoting Geoethics Instituto Superior de Engenharia de Porto Asociacion Internacional de Hidrogeologos, Grupo Espanol

Research paper thumbnail of Hydro-environmental changes assessment after Guadalhorce River mouth channelization. An example of hydromodification in southern Spain

CATENA, 2020

The Guadalhorce River mouth (Málaga, Southern Spain) was channelized between 1997 and 2003 to red... more The Guadalhorce River mouth (Málaga, Southern Spain) was channelized between 1997 and 2003 to reduce flooding potential in adjacent densely populated sections of Málaga. The channel was bifurcated near the Mediterranean Sea, surrounding an isolated wetland complex composed of eight different ponds. Groundwaterlevel and wetland-stage data, combined with water-chemistry data from wells and wetlands, collected since 1977, have documented the hydrological and ecological responses to channelization. The results show that channelization has extended the tidal influence inland from the Mediterranean Sea through the Guadalhorce River and the subjacent coastal aquifers, producing a change in groundwater hydrodynamics. The isolation of the wetlands resulting from channelization has provoked a significant salinization of both surface water and groundwater, the extent of which varies among wetlands. These decadal-scale changes in water chemistry have promoted the appearance or increase of halophilic vegetation and have caused a shift from diving birds to predominantly shorebirds in some wetlands. Documentation of these unexpected ecosystem responses is a necessary first step for land managers who need to consider groundwater and surface water as a single resource, particularly in groundwater-dependent ecosystems along the densely populated and ecologically sensitive Mediterranean coastal areas.

Research paper thumbnail of The Bajo Buadalhorce coastal aquifers (Málaga, Spain): five decades of human induced evolution

BOLETÍN GEOLÓGICO Y MINERO

This work makes a synthesis of the hydrogeological knowledge acquired from different works from t... more This work makes a synthesis of the hydrogeological knowledge acquired from different works from the decade of 1970 in the Bajo Guadalhorce detrital, coastal aquifers. Hydrodynamic, hydrochemical and geophysical studies were done in the frame of the aforementioned works to determine the hydrogeological properties of these aquifers. Besides, the drilling of research piezometers was carried out in the framework of some of these studies. This information allowed to study the spatial and temporal behavior of groundwater table and some chemical components of the groundwater of these aquifers, as well as to estimate some parameters as hydraulic conductivity or transmissivity. Overexploitation of aquifers was also studied, because marine intrusion situations were detected over the years. However, some studies carried out in the decade of 2010 have remarked a noticeable difference in the hydrodynamic and hydrochemical state of aquifers, due to intense changes in land use during the end of th...

Research paper thumbnail of Características hidroquímicas de humedales salinos andaluces situados en distintos contextos hidrogeológicos

Research paper thumbnail of Hydrodynamic and hydrochemical evolution of the Bajo Guadalhorce Valley alluvial aquifer (Málaga, S Spain) in the last 40 years

&... more <p>Groundwater flowing through coastal aquifers is increasingly impacted by human pressures as consequence of a growing demand on drinking water, tourism and agriculture, among others. Thus, groundwater availability very often depend on its quality since water salinization and pollution are the main challenges for water management because of seawater and freshwater interaction. Therefore, it is crucial to monitor the availability of groundwater and its quality under changing scenarios where this water resource can be specially threatened.</p><p>This study aims to assess the spatial distribution and time evolution of groundwater levels and hydrochemistry of the alluvial aquifer of the Bajo Guadalhorce Valley (Málaga, S Spain) for the evaluation of its quantitative and qualitative status. To that, groundwater level, electrical conductivity and Cl<sup>-</sup> and SO<sub>4</sub><sup>2-</sup> concentrations of water have been measured in a field sampling campaign carried out in the alluvial aquifer of the Bajo Guadalhorce Valley (Málaga, S Spain) in April 2017. Additionally, historical data from the last 40 years have been compiled.</p><p>Results show that groundwater generally flow towards the Guadalhorce River, where gaining relationship remains more…