Juan Giraldez

Juan Giraldez
University of Cordoba (Spain) | UCO

About

280
Publications
36,284
Reads
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5,426
Citations
Citations since 2016
49 Research Items
2824 Citations
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
Introduction
Skills and Expertise

Publications

Publications (280)
Chapter
The rainfall is one of the most important water sources of the planet. However, when the raindrops arrive at the soil surface, they can induce some problems, like destruction and detachment of aggregates, formation of surface crusts and generation and dispersal of sediments. The main aspects of these problems have been well known by men since the o...
Article
Full-text available
Understanding the natural and anthropogenic drivers that influence erosion and sediment transport is a key prerequisite for adequate management of river basins, where, especially in tropical catchments, there are few direct measurements or modeling studies. Therefore, this study analyzed the effect of human-induced land-use changes and natural ENSO...
Article
The interaction between hydrology, terrain, and vegetation, is an essential element in understanding complex landscapes, and in forecasting their evolution under climate change. In Mediterranean Europe, few studies have been performed on the interrelation between them. In this study, soil moisture, vegetation, and water table dynamics were measured...
Article
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Drought is an important natural hazard that is expected to increase in frequency and intensity as a consequence of climate change. This study aimed to evaluate the impact of future changes in the temperature and precipitation regime of Spain on agricultural droughts, using novel static and dynamic drought indices. Statistically downscaled climate c...
Article
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Hydrometeorological data sets are usually incomplete due to different reasons (malfunctioning sensors, collected data storage problems, etc.). Missing data do not only affect the resulting decision-making process, but also the choice of a particular analysis method. Given the increase of extreme events due to climate change, it is necessary to impr...
Article
Detailed knowledge of soil moisture (θ) is crucial for implementing appropriate soil and crop management decisions and assuring crop productivity and soil functioning. θ measurement is challenging in the stony soils of traditional olive orchards where the operationality of common sensors is often compromised and fine scale variability of soil prope...
Article
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The early and accurate detection of drought episodes is crucial for managing agricultural yield losses and planning adequate policy responses. This study aimed to evaluate the potential of two novel indices, static and dynamic plant water stress, for drought detection and yield prediction. The study was conducted in SW Spain (Córdoba province), cov...
Article
Understanding differences in the agro‐hydrologic performance of Vertisols under conventional tillage (CT) and direct drill (DD) requires a thorough knowledge of the soil hydraulic properties. We measured water retention on 54 undisturbed topsoil (0–0.05 m) samples collected at the CT and DD plots from a long‐term experiment. Water retention was sig...
Article
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This chapter presents the monitoring and research of groundwater resources and natural recharge in the Doñana Natural Area. The subchapter "Monitoring networks for Groundwater Resources and Recent Management Issues of the Doñana" deals with the history and current state of the official monitoring networks for piezometry and hydrochemistry. In the s...
Article
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Drought prediction is crucial, especially where the rainfall regime is irregular, such as in Mediterranean countries. A new combined drought indicator (CDI) integrating rainfall, soil moisture and vegetation dynamics is proposed. Standardized precipitation index (SPI) is used for evaluating rainfall trends. A bucket-type soil moisture model is empl...
Book
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The main objective of this report is the orderly and classified compilation of the written and oral documentation that has been obtained on how the natural recharge to aquifers in Spain is evaluated, both on the peninsular and on the insular part. To do this, we start from an analysis of the state of scientific and technological knowledge of the re...
Article
The disintegration of rocks into soil plays an important role in geomorphological processes, such as the evolution of hillslopes and river valleys. Nevertheless, the factors and processes controlling the physical weathering of rock particles are poorly understood. In this study, the surface and subsurface distribution of rock fragments abundance an...
Article
Environmental flow determination is important for the management of rivers and reservoirs. This parameter allows us to calculate the water supply of basins and minimize environmental impacts associated with water harvesting. In the past, research has been performed to determine environmental flows in rivers of Antioquia. However, the results did no...
Article
Full-text available
Drought prediction is critical, especially where rainfall regime is irregular, such as in Mediterranean countries. A new combined drought indicator (CDI) is proposed that integrates rainfall, soil moisture and vegetation dynamics. Standardized precipitation index (SPI) is used for evaluating rainfall trends. A bucket-type soil moisture model is use...
Article
Particles on soil‐mantled hillslopes are subject to downslope transport by erosion processes and vertical mixing by bioturbation. Both are key processes for understanding landscape evolution and soil formation, and affect the functioning of the critical zone. We show here how the depth‐age information, derived from feldspar‐based single grain post‐...
Article
Full-text available
Soil quality is usually assessed through the measurement of selected soil properties. However, in spite of the diversity of the chosen properties, use of the soil water retention curve, like the pressure head or the specific water capacity at the inflection point, provides relevant information of degradation or improvement of soil. The main aim of...
Article
Este trabajo pretende dar un impulso a la modernización educativa mediante un esfuerzo colaborativo dirigido por los propios estudiantes. Mediante la combinación de las Tecnologías de la Información y la Comunicación (TIC) y las nuevas redes sociales usadas frecuentemente por los estudiantes (Twitter, Periscope, Youtube, Instagram, Pinterest por ci...
Article
Alternative management practices such as no‐tillage compared to conventional tillage are expected to recover or increase soil quality and productivity, even though all of these aspects are rarely studied together. Long‐term field experiments (LTEs) enable analysis of alternative management practices over time. This study investigated a total of 251...
Article
Soil erosion is intense on steep slopes, where many olive orchards are located in Mediterranean areas. The adoption of cover crops is a promising soil and water conservation practice for these areas. Nevertheless, there has not been enough information to be able to advise farmers on the selection of plant species. The purpose of this report is to a...
Article
Efficient monitoring of soil moisture is becoming increasingly important. To understand soil–plant–water dynamics, we evaluate the potential of using a multiple‐coil‐array electromagnetic induction instrument and inversion software to map soil moisture beneath an olive tree. On twelve different days, we collected apparent electrical conductivity (E...
Article
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In spite of recent progresses in evaporation estimate through advanced models and laboratory experiments, the drying process of bare soils through its successive stages remains difficult to predict. A study which addresses evaporation modeling in natural bare soils is presented. It relies upon hydro-meteorological measurements performed in a plot w...
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A 3-year experiment compared in an olive orchard the effect of different cover crops’ composition on runoff, water erosion, diversity of annual plants, and arthropod communities which could provide an alternative to conventional management based on tillage (CT). The cover crops evaluated were a seeded homogeneous grass (GC), a seeded mix of ten dif...
Chapter
Full-text available
Although precise weighing lysimeters are mostly installed for agricultural purposes in crop-producing areas, these instruments are also useful in areas of ecological interest where soil and aquifer recharge-discharge processes need to be better understood. In September 2015 a high precision meteo-lysimeter was installed in a coastal dune of the Doñ...
Conference Paper
Full-text available
The Geological and Mining Institute of Spain (IGME) has initiated a project of continuous measurement of natural recharge in the Doñana National Park, in which a high precision meteo-lysimeter, was installed. The main objective of the study is to quantify the recharge in dune belts, and to estimate its dependence on regional climate trends. The lys...
Article
Vegetal covers protect the soil against erosion in agricultural systems. In marginal olive farms, spontaneous grass covers are preferred due to their low cost, despite their high spatial and temporal heterogeneity which limits their efficiency. Although the impact of different managements, soil conditions or cover crops species has been evaluated a...
Article
To evaluate the agronomic value of animal manure, we quantified the effects of pedo-climatic, crop and management factors on crop productivity, N use efficiency, and soil organic matter, described with simple indicators that compare manures with mineral fertilizers. We selected 80 European long-term field experiments that used bovine farmyard manur...
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Hydrological signatures are indices that help to describe the behavior of catchments. These indices can also be used to transfer information from gauged to ungauged catchments. In this study, different approaches were evaluated to determine volumetric runoff coefficients in 18 small/ medium experimental gauged catchments of the Iberian Peninsula an...
Article
This paper analyses soils-related policies in Europe and in selected member states and regions. Our approach breaks down policy packages at European, national and regional levels into strategic objectives, operational objectives, policy measures and expected impacts, and assesses the relationships between these elements and soil stakes. Four major...
Article
Vertisols are well suited for rainfed agriculture in water-limited environments as a result of their unique water transfer and retention characteristics. Despite their importance, the agro-hydrological behavior of these soils under seasonally dry climates is not yet fully understood. We collected water retention data for a Vertisol, measured from s...
Article
Full-text available
Gully erosion is an important erosive process in Mediterranean basins. However, the long-term dynamics of gully networks and the variations in sediment production in gullies are not well known. Available studies are often conducted only over a few years, while many gully networks form, grow, and change in response to environmental and land use or m...
Article
Since prehistoric times, farmers have faced the challenge of balancing the demand for increasing food production from existing soil resources with conservation of these resources. Land use change from natural vegetation to agricultural land and intensification of agricultural soil management are closely linked to increased rates of soil erosion. Th...
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When confronted with a great piece of art or research, one often wonders about what made it possible, what method was used by its author, in part so one can try to emulate it in one's own activities. Upon the retirement of Garrison Sposito after a long and very distinguished career, we considered that, as former doctoral students of Gary's, we were...
Article
Soil properties can exhibit strong spatial variation, even at the small catchment scale. Especially soil carbon pools in semi-arid, mountainous areas are highly uncertain because bulk density and stoniness are very heterogeneous and rarely measured explicitly. The effect of topographic and vegetation variables, on stoniness, bulk density and soil c...
Article
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Mediterranean olive trees traditionally grow under rainfed conditions, on poor soils with steep slopes. Rainfall is mainly concentrated during autumn and winter and is characterized by intense rain pulses, separated by dry periods. The use of electromagnetic induction (EMI) techniques in these olive orchards might be questioned since EMI surveys ar...
Article
Knowledge of spatio-temporal soil-water content (SWC) variability in agricultural fields is useful for improving crop management. Spatial patterns of SWC can be characterized using temporal stability analysis of difficult-to-obtain data from high spatial density and temporal frequency. Soil apparent electrical conductivity (ECa) measurements with h...
Article
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The snow pack of Sierra Nevada, southern Spain, melts during spring and early summer, feeding ancestral irrigation channels in the region known as the Alpujarra. This simulation study compares the traditional irrigation water supply, based on proportional division, with the actual supply, based on up-downstream priority, in one watershed in the Alp...
Article
Full-text available
Gully erosion is an important erosive process, especially in Mediterranean basins. However, the longterm dynamics of gully networks and the variation of sediment production in gullies is not well known. Available studies are often done over a few years only, while many gully networks form, grow, and change in response to environmental and land use...
Article
Full-text available
Understanding soil spatial variability is needed to delimit areas for precision agriculture. Electromagnetic induction sensors (EMI) which measure the soil apparent electrical conductivity (ECa) reflect soil spatial variability. The objectives of this work were to see if a temporally stable component could be found in ECa, and to see if temporal st...
Article
Olive cultivation is a widespread land use in Mediterranean climates. The proper implementation of soil and water conservation practices in groves requires detailed knowledge governing hydrological processes. In this work topsoil moisture dynamics under wet and dry conditions and across a small catchment was investigated in the inter row (IR) and d...
Conference Paper
Full-text available
Analysis of storm rainfall-runoff data is essential to improve our understanding of catchment hydrology and to validate models supporting hydrological planning. In a context of climate change, statistical and process-based models are helpful to explore different scenarios which might be represented by simple parameters such as volumetric runoff coe...
Article
During the last decades, electromagnetic induction has become one of the most popular soil sensing techniques for mapping apparent electrical conductivity (ECa), which is used as a proxy for other soil properties. However, the contributions of different soil physical and chemical properties to ECa are interrelated and depend on soil water content a...
Article
Individual soil water balances have been computed using detailed soil moisture measurements at different locations under the canopies of olive trees and at the adjacent inter-row areas within an experimental catchment. During rain pulses increments of profile soil water storage were slightly higher beneath tree canopies than in the open spaces. Dee...
Article
Although soil erosion is one of the main threats to agriculture sustainability in many areas of the world, its processes are difficult to measure and still need a better characterization. The use of iron oxides as sediment tracers, combined with erosion and mixing models opens up a pathway for improving the knowledge of the erosion and redistributi...
Conference Paper
Full-text available
Soil formation depends on bedrock, climate, relief, vegetation and time. Bioturbation and colluvial soil re-location are important and significant processes that affect the mechanisms and rate of bedrock weathering. The estimation of the relative fraction of bedrock grains which has been mixed in the soil and transported either vertically or latera...
Conference Paper
Full-text available
In this work, rainfall-runoff data and physical attributes from small rural catchments located in the Iberian Peninsula (Portugal and Spain) were examined in order to compare the representative values of runoff coefficients using three different approaches: i) statistical analysis of rainfall-runoff data and their quantiles (Dhakal et al., 2012); i...
Conference Paper
The rational use of soil requires the selection of management practices to take profit of the beneficial functions of plant growth, water and nutrient storage, and pollutants removal by filtering and decomposition without altering its properties. However, the first evidence of important and widespread erosion peaks can generally be found with the a...
Conference Paper
Soil resources in many parts of Europe are being degraded due to non-sustainable land and soil management practices. During the past decennia, best management practices (BMPs) have been developed in order to maintain or restore soil health. However, the adoption rate in practice is rather low. Amongst other reasons, these practices might lack on-fa...
Conference Paper
Los procesos de generación del exceso de lluvia y de escorrentía superficial, y de arranque, transporte y depósito de sedimentos en un cultivo alomado han sido caracterizados con medidas de caudales, concentraciones de sedimentos y trazadores de suelos basados en óxidos de hierro. Para una mejor interpretación de los resultados, y sus implicacione...