Clustering Groundwater Level Time Series of the Exploited Almonte-Marismas Aquifer in Southwest Spain

Groundwater resources are regularly the principal water supply in semiarid and arid climate areas. However, groundwater levels (GWL) in semiarid aquifers are suffering a general decrease because of anthropic exploitation of aquifers and the repercussions of climate change. Effective groundwater management strategies require a deep characterization of GWL fluctuations, in order to identify individual behaviors and triggering factors. In September 2019, the Guadalquivir River Basin Authority (CHG) declared that there was over-exploitation in three of the five groundwater bodies of the Almonte-Marismas aquifer, Southwest Spain. For that reason, it is critical to understand GWL dynamics in this aquifer before the new Spanish Water Resources Management Plans (2021–2027) are developed. The application of GWL series clustering in hydrogeology has grown over the past few years, as it is an extraordinary tool that promptly provides a GWL classification; each group can be related to different responses of a complex aquifer under any external change. In this work, GWL time series from 160 piezometers were analyzed for the period 1975 to 2016 and, after data pre-processing, 24 piezometers were selected for clustering with k-means (static) and time series (dynamic) clustering techniques. Six and seven groups (k) were chosen to apply k-means. Six characterized types of hydrodynamic behaviors were obtained with time series clustering (TSC). Number of clusters were related to diverse affections of water exploitation depending on soil uses and hydrogeological spatial distribution parameters. TSC enabled us to distinguish local areas with high hydrodynamic disturbance and to highlight a quantitative drop of GWL during the studied period

Piezometric and ground deformation relationship at Almonte-Marismas aquifer (Andalucía, Spain)

[EN] Groundwater is one of the most important hydric resources of the Spain territory. Nevertheless, heavy groundwater withdrawal generates severe consequences, being land subsidence one of them. The Interferometric Synthetic Aperture Radar (InSAR) technique have been recently exploited to detect and monitor aquifer related deformations. In the present work, relationship between piezometric levels drawdowns and land subsidence has been studied for the higher withdrawals areas within Almonte-Marismas aquifer system (which holds the Doñana Natural Space). Four datasets of radar satellite images, obtained from Sentine-1 satellite, have been processed using the InSAR technique in the period 2014 - 2020. Results show that in some of these areas, like those surrounding El Rocío and Matalascañas villages, the correlation between these two variables is high.[ES] El agua subterránea es uno de los recursos hídricos más importantes en el territorio español. La gran cantidad de agua que se retira de ellos puede tener graves consecuencias, entre las que destaca, en algunos acuíferos, la subsidencia del terreno. La técnica de interferometría radar (InSAR), ha sido desarrollada en las últimas décadas para detectar y monitorear las deformaciones relacionadas con los acuíferos. En este trabajo se estudia la posible relación existente entre la variación de los niveles piezométricos y el movimiento del terreno en zonas con grandes extracciones del acuífero Almonte-Marismas (sobre el que se ubica el Espacio Natural de Doñana). Para ello, se han analizado los datos de deformación del terreno obtenidos del satélite Sentinel-1 en el periodo 2014-2020 Los resultados muestran que, en alguna de estas zonas, como las cercanas a las poblaciones de El Rocío y Matalascañas, la correlación entre ambas variables es alta.Este trabajo es parte de las actividades subvencionadas dentro del Sistema Nacional de Garantía Juvenil (PEJ2018-002477), financiado por la Fundación Tripartita para la Formación en el Empleo, la iniciativa YEI (Youth Employment Initiative) y el Fondo Social Europeo (FSE). Los datos Copernicus Sentinel-1 se obtuvieron y procesaron en la plataforma GEP de la ESA en el marco del GEP Early Adopters Programme. Agradecemos al IGME y a la CHG por proporcionar los datos de piezometría, así como a la Junta de Andalucía por suministrar los datos meteorológicos.González-Jiménez, M.; Guardiola-Albert, C.; Aguilera-Alonso, H.; Béjar- Pizarro, M.; Herrera, G.; Ezquerro, P.; López-Vinielles, J.... (2021). Estudio de la relación entre la piezometría y la deformación del terreno en el acuífero Almonte-Marismas (Andalucía, España). En Proceedings 3rd Congress in Geomatics Engineering. Editorial Universitat Politècnica de València. 102-108. https://doi.org/10.4995/CiGeo2021.2021.12675OCS10210

Current international projects in the Duero and Miño-Sil basins

[EN] This paper summarizes the research work that is being carried out within the framework of three international projects with a lifetime between 2022 and 2026: (1) LIFE-IP-Duero; (2) Supporting stakeholders for adaptive, resilience and sustainable water management; (3) IGCP- 730. (1) and (2) are developed in the Duero river basin and are funded by the European Commission meanwhile (3) is being developed in the Duero and Miño-Sil basins and is funded by the International Geosciences Programme (IGCP) of UNESCO.Peer reviewe

Responding to the challenges of Water and Global Warming: Environmental Hydrogeology and Global Change Research Group (HYGLO-Lab)

[EN] The current Global Warming of planet Earth is probably the most important geological phenomenon in the last 20,000 years of its history and for human race. This process is having nowadays notable effects on the climate, ecosystems and natural resources. Possibly the most important renewable geological resource is water. One of the most strategic phases of the water cycle is groundwater. Despite its low visibility, quantitatively (and qualitatively too) it is essential for life on Planet Earth. Foreseeable consequences on groundwater due to climate change and sea level rise will be very significant. Hydrogeology can provide answers to many of the questions that are beginning to be raised in relation to these impacts and their effects. Environmental hydrogeology is a way of understanding the set of disciplines mixed in Hydrogeology as a Science of Nature. The HYGLO-Lab Research Group of the IGME-CSIC National Center attempts, through its lines of research, with a double global and local component, to provide answers to some of these questions.Peer reviewe

European journalism observatory: An international consolidated platform for training and professional networks in the Faculty of Information Sciences

El objetivo principal de este proyecto Innova-Docenia era ampliar y consolidar una plataforma de formación internacional y consolidada, para alumnos y alumnas de la Facultad de Ciencias de la Información, como parte del European Journalism Observatory (EJO), fundado por el Instituto Reuters de la Universidad de Oxford. Se trataba de afianzar EJO Spain como plataforma de formación y escaparate de las acciones implementadas en España, donde la Universidad Complutense de Madrid se convertía en el socio español principal. El Observatorio Europeo de Periodismo (EJO), una red de instituciones independientes y sin ánimo de lucro del campo de la comunicación de 14 países, tiene como objetivo tender puentes entre la investigación y la práctica del periodismo en Europa y fomentar el profesionalismo y la libertad de prensa. Promueve el diálogo entre investigadores y profesionales de los medios. Acerca los resultados de la investigación a las personas que trabajan en los medios. Su objetivo es mejorar la calidad del periodismo, contribuir a una mejor comprensión de los medios y fomentar la libertad de prensa y la responsabilidad de los medios. Nació en 2004, como una red de varios socios europeos, coordinados por la Universidad de Lugano y la Universidad de Oxford. Fue diseñado para observar las tendencias en el periodismo y en los medios de comunicación, desde una perspectiva ética y deontológica muy amplia. Desde entonces, sus artículos, investigaciones y editoriales son publicados en las distintas páginas web de cada socio: https://es.ejo-online.eu/red-ej

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Soil-water system response in an anthropized mediterranean wetland during drying cycles: las Tablas de Daimiel National Park

Tesis-Universidad Complutense de Madrid. - XXXIX, 457 p.The semiarid wetland area of Las Tablas de Daimiel National Park (TDNP) is located in central Spain. The peculiar mix of water qualities and geographical location conferred TDNP a special relevance among European wetland areas as an ecological refuge for singular waterfowl and plant species. This ecosystem linked to groundwater dynamics (former discharge area) was recognized as Biosphere Reserve by UNESCO and included in the Ramsar Agreement under the category of Wetlands of International Importance. Since the 1960s strong human intervention and disturbance has led to system denaturalization (ditching, damming, pollution, artificial drainage and flooding etc). Mainly due to excessive groundwater pumping for irrigation in the Mancha Plain region coupled to inherent climatic variability in semiarid Mediterranean environments, the wetland area was disconnected from the underlying aquifer system and now suffers from alternating flooding and drainage cycles. This process induces severe impacts and modifications in the ecological characteristics of the wetland, both in the biotic as well as the abiotic environment. From a hydrogeological point of view the hydraulic gradient shifted from upward to downward, turning TDNP into a recharge area. The most striking representative of human-induced degradation on TDNP physical-chemical structure is the process of peat cracking, subsidence and fire caused by desiccation. Artificial management aiming to sustain flooding conditions has also contributed to system disturbance and degradation turning the wetland into a regulated system of connected reservoirs which operates as an aquifer recharge area sustained through water transfers and groundwater pumping. One of the main limitations for suitable TDNP management has been the lack of precise knowledge of the physical and hydrological environments, particularly below the wetland surface. The understanding of the behaviour of the TDNP soil-water system during drainage periods has been the reason motivating this research. The two major goals have been: Hydrological-based physical-chemical characterization of the soil-water system Analysis of environmental and management implications and development of support tools for hydro-environmental planning. An integrated methodological approach has been followed to deal with system complexity and heterogeneity and the lack of detailed geological and hydrogeological knowledge. The subsurface system has been tackled through vadose zone (VZ) physical and chemical determinations and analyses. Soil chemistry was studied through descriptive statistics and multivariate analysis (principal component analysis and redundancy analysis) of 1:5 soil-water extracts and soil matrix samples. Intensive field and laboratory work has allowed for the determination of several soil physical parameters: texture, bulk density, saturated hydraulic conductivity, infiltration curves, water repellency, capillary wetting rate, and water retention and hydraulic conductivity curves. Special attention has been given to peat degradation characteristics following desiccation: hydrophobicity, shrinking and cracking properties, and combustion risk and propagation mechanisms. VZ physical-chemical characterization has led to the definition and mapping of soil functional types (SFT) regarding their hydraulic properties as water and solute transmitters and storage. Besides this, one-dimensional VZ water flow models in different soil profiles representing typical arrangement of SFT in TDNP have been successfully calibrated and validated using measured and estimated data. The interrelation between the surface water (SW) and groundwater (GW) environments has been inferred from a simple stepwise approach combining basic hydrochemical, hydrodynamic and isotopic data from a sampling network of monitoring points through clustering techniques and long-term time series analysis. A conceptual model of TDNP hydrological behaviour based on the interrelation between flooding, groundwater level and hydrochemistry, involving both spatial and temporal considerations in SW-GW interactions, is proposed. Environmental and management implications of soil and water physical-chemical characterization have been derived focusing on water availability and risk of groundwater contamination. Critical soil water contents for the development of soil hydrophobicity, reed (Phragmites australis) invasive expansion and peat combustion risk have been determined. Furthermore, usefulness of VZ water flow models as a management tool to simulate soil moisture progress and critical soil water contents reach during a drying scenario has been assessed. Eight SFT have been identified based on soil physical and chemical properties which are defined by different degrees of evolution, anthropization and edaphization. They belong to four major soil materials: charophyte layers (unconsolidated carbonated sediments biologically produced), clay, fluvial silt (fluvial deposits in rivers, ditches and drains) and organic (high organic matter content). A map of the average spatial distribution of SFT inside TDNP based on the information provided by more then 120 soil columns bored all around the Park is presented. The results show and that during drying periods TDNP becomes a highly saline and eutrophicated environment as inferred from both VZ and SW-GW chemical analyses. Median electrical conductivity (EC) in soil-water extracts of soil profiles is 3,280 S cm1, and median organic matter (OM) content in the soil matrix is 5.33%. Median EC values in SW range between 2,973 and 11,739 S cm-1 , and in GW between 677 and 15,383 S cm-1 . Median total organic carbon concentrations in some groundwater monitoring points reach over 9 mg l-1 . However, large variability is observed in the whole soil-water system conditioned by lithology, evaporation, vegetation, microtopography, soil degradation and anthropization (i.e. dams, pumps, ditches, water transfers and wastewater inflows). Physical properties of SFT show large variability reflecting high system heterogeneity. Lower bulk densities in organic SFT are associated to higher saturated hydraulic conductivities (Ks), infiltration capacities and OM contents, conditioning a less compact structure which enhances water transmissivity capacities. TDNP peats show extremely high Ks values [(2.2. 0.9)·104 cm d-1] due to secondary porosity and swelling capacity. Average infiltration capacities in dry SFT range between 159 cm d-1 in clay to over 2,000 cm d-1 in peat, with all organic materials exceeding 1,000 cm d-1. Only two organic SFT (peat and edapizhed charophytes) show soil water repellency conditioned by amount and type of OM, soil water content and drying conditions. Peats develop extreme soil water repellency after oven-drying at 105 °C, a laboratory condition not far from reality given the high topsoil temperatures observed in the field. A threshold 45% OM content and 9-22 vol% critical soil water content range have been defined for soil water repellency development in TDNP peats. Desiccation decreases peat total porosity making it shrink and giving rise to cracks and hollows which constitute preferential flow paths for both air and infiltrating waters. High soil temperatures and low water contents promote exponential increase in cracks and hollows number, dimension and extension in short time (i.e. less than one year), reaching up to half meter wide and two meters deep. Soil water content and organic fraction are the main controlling properties for smouldering fires ignition and spread. Fire irreversibly modifies soil physical properties, increasing the risk of solute mobilisation and, thus, groundwater pollution. During drying periods, the combination of large SW and soil nutrient contents with high water transmissivity capacities in the VZ of the left TDNP margin where higher degree of SW-GW interactions have been observed, conditions groundwater pollution. Anthropic management (soil compacting by heavy machinery, recirculation of low quality groundwater, reed reaping, water transfers or smouldering fire extinction) increases the risk of releasing stored nutrients. As organic soils are widespread in the left TDNP margin area, it is likely that increased SW-GW interactions in this area are enhanced by soil physical degradation. Preferential flow paths through peat cracks and hollows in S and SE areas constitute freeways for water and solute transport. Fluvial silts in ditches, which store large amounts of nutrients and OM, as well as low permeability Tertiary levels, hold perched poor-quality groundwater levels connected to deeper layers. The closing effect of the dams and the functioning of the system as an artificial recharge pond causes that the overall effect of management measures during drying periods is solute accumulation in the VZ. Besides this, the extent of SW-GW interactions condition a higher risk that groundwater pollution is spread through the groundwater flow that percolates from TDNP to deeper aquifer layers and meets the regional flow towards pumping irrigation areas. Increased understanding of the TDNP physical-chemical environment has allowed for the development of tools to support Park management during a system dry out. The classification and mapping of SFT involves an enhancement of current knowledge of the physical environment and will contribute to management actions planning. It has allowed to delimit areas showing homogeneous behaviour and, thus, modelling time as well as monitoring systems expenses can be optimized. VZ water flow simulations under different climatic and management scenarios can, for example, help to foresee the development of soil moisture conditions suitable for reed overgrowth (36-51 vol% in charophytes and 21-30 vol% in peat) and peat combustion risk (below 23 vol%). This way, management actions could be less dependent on improvisation and their impact to the physical system minimized. Modelling can be complemented with a monitoring network of soil moisture and temperature sensors at different depths. With these sensors underground cracks and hollows development or surface water inflows arrival could be detected and monitored in real time. The huge amount of compiled data on soil and water physical-chemical properties is in itself a valuable management tool. Qualitative and quantitative characteristics of drying processes in the Park can be used as input data for different eco-hydrological modelling approaches suitable for managing needs. To summarize, the two main objectives previously mentioned have been successfully achieved through an integrated methodological approach of VZ and SW-GW study tackling with system complexity, heterogeneity and lack of geological and hydrogeological knowledge. In order to build more accurate flux and transport hydrological models further research on local geological characteristics (i.e. geophysical studies) and hydrological and hydrochemical dynamics in flooding periods is still required. Besides this recommendation, there is still a need to quantify impacts influence and degree of disturbance on soil and water physical-chemical properties. Also the knowledge of shrinking characteristics and piping development in Mediterranean semiarid peatlands should be improved. Hopefully, the information provided in this research will contribute to support and enhance management actions in Las Tablas de Daimiel National Park.Instituto Geológico y Minero de España, EspañaDepartamento de Edafología, Universidad Complutense de Madrid, EspañaPeer reviewe

Soil-water system response in an anthropized mediterranean wetland during drying cycles: las Tablas de Daimiel National Park

Tesis-Universidad Complutense de Madrid. - XXXIX, 457 p.The semiarid wetland area of Las Tablas de Daimiel National Park (TDNP) is located in central Spain. The peculiar mix of water qualities and geographical location conferred TDNP a special relevance among European wetland areas as an ecological refuge for singular waterfowl and plant species. This ecosystem linked to groundwater dynamics (former discharge area) was recognized as Biosphere Reserve by UNESCO and included in the Ramsar Agreement under the category of Wetlands of International Importance. Since the 1960s strong human intervention and disturbance has led to system denaturalization (ditching, damming, pollution, artificial drainage and flooding etc). Mainly due to excessive groundwater pumping for irrigation in the Mancha Plain region coupled to inherent climatic variability in semiarid Mediterranean environments, the wetland area was disconnected from the underlying aquifer system and now suffers from alternating flooding and drainage cycles. This process induces severe impacts and modifications in the ecological characteristics of the wetland, both in the biotic as well as the abiotic environment. From a hydrogeological point of view the hydraulic gradient shifted from upward to downward, turning TDNP into a recharge area. The most striking representative of human-induced degradation on TDNP physical-chemical structure is the process of peat cracking, subsidence and fire caused by desiccation. Artificial management aiming to sustain flooding conditions has also contributed to system disturbance and degradation turning the wetland into a regulated system of connected reservoirs which operates as an aquifer recharge area sustained through water transfers and groundwater pumping. One of the main limitations for suitable TDNP management has been the lack of precise knowledge of the physical and hydrological environments, particularly below the wetland surface. The understanding of the behaviour of the TDNP soil-water system during drainage periods has been the reason motivating this research. The two major goals have been: Hydrological-based physical-chemical characterization of the soil-water system Analysis of environmental and management implications and development of support tools for hydro-environmental planning. An integrated methodological approach has been followed to deal with system complexity and heterogeneity and the lack of detailed geological and hydrogeological knowledge. The subsurface system has been tackled through vadose zone (VZ) physical and chemical determinations and analyses. Soil chemistry was studied through descriptive statistics and multivariate analysis (principal component analysis and redundancy analysis) of 1:5 soil-water extracts and soil matrix samples. Intensive field and laboratory work has allowed for the determination of several soil physical parameters: texture, bulk density, saturated hydraulic conductivity, infiltration curves, water repellency, capillary wetting rate, and water retention and hydraulic conductivity curves. Special attention has been given to peat degradation characteristics following desiccation: hydrophobicity, shrinking and cracking properties, and combustion risk and propagation mechanisms. VZ physical-chemical characterization has led to the definition and mapping of soil functional types (SFT) regarding their hydraulic properties as water and solute transmitters and storage. Besides this, one-dimensional VZ water flow models in different soil profiles representing typical arrangement of SFT in TDNP have been successfully calibrated and validated using measured and estimated data. The interrelation between the surface water (SW) and groundwater (GW) environments has been inferred from a simple stepwise approach combining basic hydrochemical, hydrodynamic and isotopic data from a sampling network of monitoring points through clustering techniques and long-term time series analysis. A conceptual model of TDNP hydrological behaviour based on the interrelation between flooding, groundwater level and hydrochemistry, involving both spatial and temporal considerations in SW-GW interactions, is proposed. Environmental and management implications of soil and water physical-chemical characterization have been derived focusing on water availability and risk of groundwater contamination. Critical soil water contents for the development of soil hydrophobicity, reed (Phragmites australis) invasive expansion and peat combustion risk have been determined. Furthermore, usefulness of VZ water flow models as a management tool to simulate soil moisture progress and critical soil water contents reach during a drying scenario has been assessed. Eight SFT have been identified based on soil physical and chemical properties which are defined by different degrees of evolution, anthropization and edaphization. They belong to four major soil materials: charophyte layers (unconsolidated carbonated sediments biologically produced), clay, fluvial silt (fluvial deposits in rivers, ditches and drains) and organic (high organic matter content). A map of the average spatial distribution of SFT inside TDNP based on the information provided by more then 120 soil columns bored all around the Park is presented. The results show and that during drying periods TDNP becomes a highly saline and eutrophicated environment as inferred from both VZ and SW-GW chemical analyses. Median electrical conductivity (EC) in soil-water extracts of soil profiles is 3,280 S cm1, and median organic matter (OM) content in the soil matrix is 5.33%. Median EC values in SW range between 2,973 and 11,739 S cm-1 , and in GW between 677 and 15,383 S cm-1 . Median total organic carbon concentrations in some groundwater monitoring points reach over 9 mg l-1 . However, large variability is observed in the whole soil-water system conditioned by lithology, evaporation, vegetation, microtopography, soil degradation and anthropization (i.e. dams, pumps, ditches, water transfers and wastewater inflows). Physical properties of SFT show large variability reflecting high system heterogeneity. Lower bulk densities in organic SFT are associated to higher saturated hydraulic conductivities (Ks), infiltration capacities and OM contents, conditioning a less compact structure which enhances water transmissivity capacities. TDNP peats show extremely high Ks values [(2.2. 0.9)·104 cm d-1] due to secondary porosity and swelling capacity. Average infiltration capacities in dry SFT range between 159 cm d-1 in clay to over 2,000 cm d-1 in peat, with all organic materials exceeding 1,000 cm d-1. Only two organic SFT (peat and edapizhed charophytes) show soil water repellency conditioned by amount and type of OM, soil water content and drying conditions. Peats develop extreme soil water repellency after oven-drying at 105 °C, a laboratory condition not far from reality given the high topsoil temperatures observed in the field. A threshold 45% OM content and 9-22 vol% critical soil water content range have been defined for soil water repellency development in TDNP peats. Desiccation decreases peat total porosity making it shrink and giving rise to cracks and hollows which constitute preferential flow paths for both air and infiltrating waters. High soil temperatures and low water contents promote exponential increase in cracks and hollows number, dimension and extension in short time (i.e. less than one year), reaching up to half meter wide and two meters deep. Soil water content and organic fraction are the main controlling properties for smouldering fires ignition and spread. Fire irreversibly modifies soil physical properties, increasing the risk of solute mobilisation and, thus, groundwater pollution. During drying periods, the combination of large SW and soil nutrient contents with high water transmissivity capacities in the VZ of the left TDNP margin where higher degree of SW-GW interactions have been observed, conditions groundwater pollution. Anthropic management (soil compacting by heavy machinery, recirculation of low quality groundwater, reed reaping, water transfers or smouldering fire extinction) increases the risk of releasing stored nutrients. As organic soils are widespread in the left TDNP margin area, it is likely that increased SW-GW interactions in this area are enhanced by soil physical degradation. Preferential flow paths through peat cracks and hollows in S and SE areas constitute freeways for water and solute transport. Fluvial silts in ditches, which store large amounts of nutrients and OM, as well as low permeability Tertiary levels, hold perched poor-quality groundwater levels connected to deeper layers. The closing effect of the dams and the functioning of the system as an artificial recharge pond causes that the overall effect of management measures during drying periods is solute accumulation in the VZ. Besides this, the extent of SW-GW interactions condition a higher risk that groundwater pollution is spread through the groundwater flow that percolates from TDNP to deeper aquifer layers and meets the regional flow towards pumping irrigation areas. Increased understanding of the TDNP physical-chemical environment has allowed for the development of tools to support Park management during a system dry out. The classification and mapping of SFT involves an enhancement of current knowledge of the physical environment and will contribute to management actions planning. It has allowed to delimit areas showing homogeneous behaviour and, thus, modelling time as well as monitoring systems expenses can be optimized. VZ water flow simulations under different climatic and management scenarios can, for example, help to foresee the development of soil moisture conditions suitable for reed overgrowth (36-51 vol% in charophytes and 21-30 vol% in peat) and peat combustion risk (below 23 vol%). This way, management actions could be less dependent on improvisation and their impact to the physical system minimized. Modelling can be complemented with a monitoring network of soil moisture and temperature sensors at different depths. With these sensors underground cracks and hollows development or surface water inflows arrival could be detected and monitored in real time. The huge amount of compiled data on soil and water physical-chemical properties is in itself a valuable management tool. Qualitative and quantitative characteristics of drying processes in the Park can be used as input data for different eco-hydrological modelling approaches suitable for managing needs. To summarize, the two main objectives previously mentioned have been successfully achieved through an integrated methodological approach of VZ and SW-GW study tackling with system complexity, heterogeneity and lack of geological and hydrogeological knowledge. In order to build more accurate flux and transport hydrological models further research on local geological characteristics (i.e. geophysical studies) and hydrological and hydrochemical dynamics in flooding periods is still required. Besides this recommendation, there is still a need to quantify impacts influence and degree of disturbance on soil and water physical-chemical properties. Also the knowledge of shrinking characteristics and piping development in Mediterranean semiarid peatlands should be improved. Hopefully, the information provided in this research will contribute to support and enhance management actions in Las Tablas de Daimiel National Park.Instituto Geológico y Minero de España, EspañaDepartamento de Edafología, Universidad Complutense de Madrid, EspañaPeer reviewe

Lessons learnt from semi-arid wetland degradation. Las Tablas de Daimiel National Park

18 p. Incluye versión abreviada en castellanoThe Tablas de Daimiel National Park wetland developed in an area characterized by the cyclic nature of droughts, excessive aquifer exploitation and an evident aridification trend driven by climate change. The park and its surroundings have been exploited since prehistoric times and they are currently deeply anthropized to the point that both the physical survival of the wetland as well as its ecological function entirely depend on human action. A severe drought between 2006 and 2009 together with the drawdown of the water table caused the dry out of the system, reed overgrowth, disappearance of cut-sedge and sub-aquatic Chara spp. meadows and a smouldering peat fire. During this same period surface water, soil and groundwater were sampled for physical, hydrological and hydrochemical characterization. Upon drainage, the system functions as an artificial recharge system and becomes eutrophic showing large nutrient and salt content in soils and water. High water transmissivity capacities in the unsaturated zone and anthropic park management (soil compacted by heavy machinery, recirculation of low quality groundwater, reed reaping, water transfers, etc.) condition groundwater pollution. Increased knowledge of the physical-environment has allowed us to build a conceptual model of the surface water – groundwater interactions and to develop management tools to support the park management during a system dry out. Amongst these actions, we propose an unsaturated flow model for soil moisture simulation than can be used to predict critical soil water content for reed overgrowth or peat combustion risk.Instituto Geológico y Minero de España, Españ

Estimating extremely large amounts of missing precipitation data

Published paperAccurate estimation of missing daily precipitation data remains a difficult task. A wide variety of methods exists for infilling missing values, but the percentage of gaps is one of the main factors limiting their applicability. The present study compares three techniques for filling in large amounts of missing daily precipitation data: spatio-temporal kriging (STK), multiple imputation by chained equations through predictive mean matching (PMM), and the random forest (RF) machine learning algorithm. To our knowledge, this is the first time that extreme missingness (>90%) has been considered. Different percentages of missing data and missing patterns are tested in a large dataset drawn from 112 rain gauges in the period 1975–2017. The results show that both STK and RF can handle extreme missingness, while PMM requires larger observed sample sizes. STK is the most robust method, suitable for chronological missing patterns. RF is efficient under random missing patterns. Model evaluation is usually based on performance and error measures. However, this study outlines the risk of just relying on these measures without checking for consistency. The RF algorithm overestimated daily precipitation outside the validation period in some cases due to the overdetection of rainy days under time-dependent missing patterns.Área de Geología Ambiental y Geomatemáticas, Instituto Geológico y Minero de España, EspañaEscuela Técnica Superior de Ingenieros de Minas y Energía, Universidad Politécnica de Madrid, Españ