Alfonso Calera

• University of Castilla-La Mancha

Since the development of Water Footprint environmental indicator, significant research on blue and green crop water use and the respective water footprint estimations has been published. Such research is commonly approached using different methodologies that leverage tabulated values for crop development characterisation, while studies based on rem...

The significant climatic variability present in Latin America and the Caribbean (LAC) generate marked regional differences in needs, availability, and management of water resources for agriculture. The availability of large-scale technological tools for monitoring crops and environmental conditions within their surroundings, becomes imperative in s...

Aside from raising public awareness, gathering indicators on the sustainability of productive human sectors provides invaluable information in the administration of political decision-making (Giljum et al. 2008; Čuček et al. 2015). Among the environmental indicators available today, the water footprint approach brings to the agriculture sector the...

En esta publicación se describe el proceso y los hallazgos de un estudio centrado en analizar los factores que afectan a la variabilidad intraparcelaria de una explotación agrícola de almendros y así determinar los factores limitantes para poder ayudar en la toma de decisiones agronómicas. La variabilidad se describe mediante el uso de Mapas Zonale...

The irrigated area cultivated with almond trees (Prunus dulcis) has significantly increased in recent years worldwide. In Spain, the extension covered by irrigated almond orchards has doubled in the past 5 years, currently accounting for about 14% of the harvested almond area. The high water productivity of this crop jointly with the good market pe...

Indicators on the sustainability of productive human sectors help boosting societal awareness and provide remarkable information for political decision-making and resources management. Prominent examples of relevant environmental indicators currently available are those that form the footprint family. In agriculture, the water footprint approach pr...

Crop yield monitoring provides highly appreciated information by decision-makers and end-users, i.e., policymakers, insurance companies or professional farmers. Currently, the dense time series of remote sensing (RS) satellite images allow to accurately describe the spatial and temporal evolution of the canopy, providing valuable information for cr...

Remote sensing is a natural tool for mapping soil spatial differences, and it is widely used for digital soil mapping. The new generation of sensors, e.g., those carried by the twin Sentinel2 satellites, can describe crop canopy development with unprecedented high spatial and temporal resolution. These are excellent capabilities to describe the veg...

This study shows how remote sensing methods are used to support and provide means for improving agricultural water management (AWM) in Jordan through detailed mapping of irrigated areas and irrigation water consumption (IWC). Digital processing and classification methods were applied on multi-temporal data of Landsat 8 and Sentinel-2 to derive maps...

Ledflex is a fluorometer adapted to measure chlorophyll fluorescence at the canopy level. It has been described in detail by Moya et al. (2019), Photosynthesis Research. https://doi.org/10.1007/s11120-019-00642-9. We used this instrument to determine the effect of water stress on the fluorescence of a fescue field under extreme temperature and ligh...

Land use classification (LUC) is the process of providing information on land cover and the types of human activity involved in land use. In this study, we perform agricultural LUC using sequences of multispectral reflectance Sentinel-2 images taken in 2018. LUC can be carried out using machine or deep learning techniques. Some existing models proc...

En el acuífero Mancha Oriental, la Junta Central de Regantes de la Mancha Oriental, JCRMO, viene regulando desde el año 2018 las dotaciones unitarias promedio de agua de riego para cultivos como almendro, pistacho y olivo en función del valor que alcanza el NDVI en cada parcela durante el verano, en los meses de julio y agosto. Es un método que pre...

La óptima utilización de los recursos hídricos en agricultura requiere una estimación precisa de la demanda evaporativa de la atmósfera y de su distribución espacial. Esta es la evapotranspiración de referencia ETo, la que junto al parámetro coeficiente de cultivo (Kc) permite estimar las necesidades de riego de los cultivos. En este trabajo se abo...

El presente estudio expone una nueva metodología basada en la teledetección para estimar la huella hídrica sobre el proceso productivo de los cultivos agrícolas. Mediante un balance de agua en el suelo asistido por teledetección se estima de forma espacial y temporalmente distribuida la evapotranspiración ajustada de los cultivos y sus necesidades...

Monitoring Land Surface Temperature (LST) from Landsat satellites has been shown to be effective in the estimation of crop water needs and modeling water use efficiency. Accurate LST estimation becomes critical in semiarid areas under water scarcity scenarios. This work shows the assessment of some well-known Single-Channel (SC) and Split-Window (S...

he FaST Navigator study (Nutrient management Algorithms, Valorisation of Inputs and greenhouse gas (GHG) Assessment – Tool for Optimization of Resources) sought to address one of the main challenges for the implementation of the FaST: the availability of operational models that are necessary to provide standardised and consistent advice on the use...

The irrigated area cultivated with almond trees (Prunus dulcis) has doubled in Spain in the past 5 years. Almond is becoming a very extended tree crop in Spain, due to the high response of this crop to water used jointly with the likewise good market perspectives. Thus, almond is a viable alternative to traditional crops, such as cereals and other...

Sustainable Development Goal (SDG) target 7.2 requests a substantial increase in the share of renewable energy in the global energy mix by 2030. Renewable energy production in all sectors has to be evaluated for its contribution to reach this target. Biomass for energy production has gained a bad reputation over the past years due to the "food vers...

Bioenergy represents the highest share of renewable energies consumed in the European Union and is still expected to grow. This could be possible by exploring bioenergy production on Marginal, Underutilised, and Contaminated lands (MUC) that are not used for agricultural purposes and therefore, present no competition with food/feed production. In t...

The Water Framework Directive in Europe requires extending metering and water abstraction controls to accurately satisfy the necessary water resource requirements. However, in situ measurement instruments are inappropriate for large irrigation surface areas, considering the high investment and maintenance service costs. In this study, Remote Sensin...

La presente Tesis Doctoral se centra en el desarrollo y evaluación de una metodología operativa que permita la modelización del rendimiento final en los cultivos de grano desarrollados en parcelas comerciales bajo una amplia variedad de condiciones ambientales, y de manejo de agua y nutrientes. Dado que unos de los principales factores que limitan...

This paper presents an operational methodology for the estimation of the harvest index (HI) in commercial fields planted with wheat crops (Triticum aestivum L.) using a Remote Sensing based approach. The approach proposed variants from the methodologies reported by Kemanian et al., (2007) and Sadras and Connor (1991) for the estimation of the HI us...

Irrigation water accounting (IWA) plays a key role in irrigation management in arid or semi-arid environments. Currently, water managers perform IWA through indirect or direct measurements such as statistical methods or flow meters. However, they have a high maintenance cost and great efforts must be done when large irrigated areas must be covered....

Downscaling techniques offer a solution to the lack of high-resolution satellite Thermal InfraRed (TIR) data and can bridge the gap until operational TIR missions accomplishing spatio-temporal requirements are available. These techniques are generally based on the Visible Near InfraRed (VNIR)-TIR variable relations at a coarse spatial resolution, a...

The advances achieved during the last 30 years demonstrate the aptitude of the remote sensing-based vegetation indices (VI) for the assessment of crop evapotranspiration (ETc) and irrigation requirements in a simple, robust and operative manner. The foundation of these methodologies is the well-established relationship between the VIs and the basal...

Accurate estimates of sensible (H) and latent (LE) heat fluxes and actual evapotranspiration (ET) are required for monitoring vegetation growth and improved agricultural water management. A large aperture scintillometer (LAS) was used to provide these estimates with the objective of quantifying the effects of surface heterogeneity due to soil moist...

The objective of the work is the calibration, validation and simulation of STICS model on wheat commercial plots using the remote sensing time series to map the variability of crop biomass and yield. Sentinel time series provide the Green Area Index (GAI-BV), field phenological observations and soil clay and organic matter for calibration; the mode...

This poster is part of a study about the comparison of laboratory and field continuum multispectral (400 – 2500 nm) and discrete remote (Sentinel2) measurements to estimate clay and organic matter on agriculture soils.

The sustainability of groundwater abstractions for irrigation practices must be monitored to achieve a long-term equilibrium in aquifers. The accounting of irrigation water requirements in river basin management plans is commonly and mainly calculated by combining the average multiannual irrigated surface estimates and the unitary crop water requir...

The Spanish General Directorate for Water hanging on the Ministry for the Ecological Transition (MITECO) is committed in the use of volumetric control for contrasting remote-sensing products as an imput for the hydrological planning process required by the Water Framework Directive (WFD). The results are temporal series maps of irrigated areas (sur...

The BIOPLAT-EU project will promote and support the uptake of sustainable bioenergy projects on marginal, underutilized and contaminated lands (MUC lands). These lands cannot be used for food production or for recreational and conservation purposes, but in some cases, they still retain the potential to produce biomass for non-food purposes. Moreove...

This paper explored the ability of remote sensing (RS) and meteorological data to map the variability of yield/biomass in cultivated wheat (Triticum aestivum). The methodology integrated a time series of RS-based vegetation indices (VI) into a simple model based on the water productivity. Thus, the study analyzed if the biophysical parameters deduc...

The objective of this paper was to determine the water use efficiency (WUE) and light use efficiency (LUE) values of garlic (Allium sativum L.) and to analyze the normalization of these efficiencies for the atmospheric conditions. We analyzed the use of daily reference evapotranspiration (ETo) and the vapor pressure deficit (VPD) for these purposes...

Temporal series maps of irrigated areas, and the corresponding irrigation water requirements based on remote sensing, is a recognized tool contributing to water governance at different scales, from water user associations to whole river basin districts. These thematic cartographies offer a first estimation of the crop irrigation requirements, and a...

Evapotranspiration (ET) is the second largest component of the water cycle in arid and semiarid environments, and, in fact, more than 60% of the precipitation on earth is returned to the atmosphere through it. MOD16 represents an operational source of ET estimates with adequate spatial resolution for several applications, such as water resources pl...

Water policies have been implemented worldwide to face water stress. However, the existence of water users' groups with opposite interests and different political power clout results in the plain failure or low effectiveness of water policy reforms. A better understanding of users' perceptions regarding policy outcomes is important to avoid the fai...

We propose the use of temporal series of remote-sensing images (RS) for the characterization of the dynamics of the crop canopy throughout the growing and development cycle. Crop phenology, meteorological data, and normalized difference vegetation index (NDVI) were obtained during the period 2008 to 2016 for commercial fields planted with wheat. Th...

In this paper, we present the results of our study on the operational application of the reflectance-based crop coefficient for assessing table grape irrigation requirements. The methodology was applied to provide irrigation advice and to assess the irrigation performance. The net irrigation water requirements (NIWR) simulated using the reflectance...

This paper explores the ability of Remote Sensing data from space platforms combined with available meteorological parameters to monitor crop biomass accumulation at satellite scale in a direct, operational way, exploiting the temporal information from time series of multispectral images. We describe a methodology to estimate biomass growth by inte...

Mapping irrigated surfaces and the crops growing on these surfaces by using Remote Sensing is a well known first relevant step to contribute to water governance at different scales ranging from farm, irrigation scheme and, by scaling-up, to the whole river basin. These maps provide a first estimation of the spatially distributed water flows about e...

This work proposes a methodology that uses remote sensing (RS) images to obtain optimum nitrogen crop uptake (N uptake ) maps, for the all pixels in the image included in the field during the entire growing season. The N uptake was determined from relationship between critical nitrogen concentration (Nc) and biomass where biomass was estimated by a...

Intensive agriculture has the objective to increase nutrients use efficiency. Nitrogen (N) is a key nutrient for crops and the estimations of crop N status allow adjusting the fertilization levels to crop requirements, while reducing the environmental costs and optimizing the benefits for farmers. In this work the N status of wheat in a commercial...

Biomass production is a diagnosis tool for the evaluation of the effect of climate, crop genomic and management. The differences in biomass accumulation are necessary for the assessment of the fertilization necessities in the strategies for variable nitrogen doses. Remote sensing-based data provide a direct observation of the differences in canopy...

Irrigated agriculture is a key activity for the long-term survival of human-environmental systems and the assessment of agricultural sustainability has been gaining increasing relevance. In spite of several proposals developed, there is not a holistic approach that can be generally applied to assess sustainability of irrigated agricultural areas. I...

The experiences gathered during the past 30 years support the operational use of irrigation scheduling based on frequent multi-spectral image data. Currently, the operational use of dense time series of multispectral imagery at high spatial resolution makes monitoring of crop biophysical parameters feasible, capturing crop water use across the grow...

Water use efficiency (WUE) at ecosystem level (WUEEC) can be expressed through the ratio between net ecosystem CO2 exchange (NEE) and evapotranspiration (ET). The fact that WUE at leaf scale depends on changes in atmospheric demand or daily pattern of leaf exposure to the sun, it exhibits high variation within the canopy and does not allow an adequ...

The experiences gathered during the past 30 years support the operational use of irrigation scheduling based on frequent multi-spectral image data. Currently, the operational use of dense time series of multispectral imagery at high spatial resolution makes monitoring of crop biophysical parameters feasible, capturing crop water use across the grow...

This study analysed the effect of row direction on photosynthetically active radiation (PAR) absorption (APAR) and the fraction of PAR absorbed (fPAR) on both a daily and hourly temporal scale in vertical shoot positioned trellised vineyards. The analysis included experimental data and model simulations. The data of fPAR and APAR were acquired in c...

The main goal of this research was to estimate the actual evapotranspiration (ETc) of a drip-irrigated apple orchard located in the semi-arid region of Talca Valley (Chile) using a remote sensing-based soil water balance model. The methodology to estimate ETc is a modified version of the Food and Agriculture Organization of the United Nations (FAO)...

El Instituto de Investigaciones Agropecuarias, a través de su Centro Regional de Investigación Intihuasi, conjuntamente con el Gobierno Regional de Coquimbo, a través del Fondo de Innovación para la Competitividad (FIC), pusieron en marcha el proyecto denominado “Desarrollo de un Centro de Análisis para la Agricultura de Riego (CAPRA) para mejorar...

Advancements on Earth Observation science and technology in the last decades have made possible the operative use of dense time series of multispectral imagery at high spatial resolution [5-30 m] to monitor crop development across its growing season at a suitable scale. These time series of images, jointly with meteorological data are able to provi...

This research presents an algorithm developed for calibrating the soil water balance model (SWB) in terms of total available water in the soil root zone (TAW) assimilating actual evapotranspiration (ET) data. After calibration, the TAW value is used to estimate the actual ET and water stress processes at canopy scales. This methodology also allows...

En el proyecto “Estudio de innovación para un uso más eficiente del agua en el regadío mediante herramientas basadas en la red SIAR, teledetección y SIG”, el Ministerio de Agricultura, Alimentación y Medio Ambiente (MAGRAMA) pone a disposición de los usuarios vía WebSIG, y en el ámbito espacial de la Península Ibérica (años 2014 – 2015), los produc...

La distribución espacial de la biomasa del cultivo dentro de una parcela y el análisis de su variabilidad en términos de suelo y manejo proporciona información relevante para un mejor manejo agronómico, que permita ajustar los input de agua y nutrientes a las demandas del cultivo. Series temporales de imágenes multiespectrales permiten registrar la...

Water in sufficient amounts and quality is essential for meeting both human and ecological needs. Most water used by mankind is destined for agriculture, and demand is steadily growing. Under this pressure, water management faces significant environmental problems. In the case of groundwater, these difficulties are exacerbated by intensive, unregul...

En este trabajo se presenta el seguimiento de los flujos de energía en un cultivo de vid bajo riego, obtenidos a partir del modelo de balance de energía METRIC (Allen et al., 2007b). Este modelo resulta operativo al utilizar un método de calibración interna definido a partir de la selección de píxeles con valores extremos dentro de la escena. De es...

1- Introduccion. Objetivos del trabajo El conocimiento previo a la aplicacion del riego de las necesidades hidricas o evapotranspiracion de los cultivos (ET c ), contribuye a la mejora en su gestion. Actualmente, la metodologia mas extendida para su estimacion es mediante la relacion evapotranspiracion de referencia (ET o ), determinada mediante es...

We present and evaluate an experimental relationship between the fraction of ground cover (FV) and multispectral vegetation indices (VI) derived from medium resolution images (Landsat 5-TM) in vertical shoot trellised vineyards. The results indicate a strong linear relationship between FV and the Normalized Difference Vegetation Index (NDVI) and So...

Water scarcity is a growing concern for global agriculture, many irrigated areas have experienced in recent years a reduction in water availability due both to its decrease and an increase in demand for water for domestic and industrial use. Future scenarios, due to climate change could intensify the problems of water scarcity and irrigation requir...

In this work, the induction and reversion of a water stress in a vineyard was followed by several indexes calculated from reflectance and fluorescence measurements at leaf scale. Control (irrigated plants) and deficit (no-irrigated plants) were simultaneously monitored. After the deficit treatment, irrigation was applied to follow the water stress...

This paper aims to present the use of a remote sensing-based soil water balance to estimate holm oak woodland evapotranspiration (ET). The model is based on the assimilation of MODIS reflectance-based vegetation indices in the dual crop coefficient methodology. A daily water balance was performed on the root zone soil to estimate plant water stress...

The conflict between spatial and temporal resolution of satellite systems, as well as the frequent presence of clouds in the images, has been a traditional limitation of remote sensing in the optical domain. Nevertheless, most of the conceptual tools and algorithms developed classically in remote sensing are based on the input of a series of cloud-...

The spatio-temporal estimates of evapotranspiration (ET) have been traditionally addressed applying the water balance (WB) model of the root zone using the FAO-56 approach. The WB model is a prognostic approach of obtaining estimates of the ET and soil moisture on a daily basis. The reflectance based basal-crop coefficient Ksbrf in the WB model is...

This paper aims to evaluate the use of a remote sensing-driven soil water balance to estimate irrigation water requirements of wheat. The applied methodology is based on the approach of the dual crop coefficient proposed in the FAO-56 manual (Allen et al., 1998), where the basal crop coefficient is derived from a time series of remote sensing multi...

Scientific expertise on irrigated agriculture or hydrological modelling has achieved advance models with tested results. However, real connexions between this knowledge and its applications, and water end-users (either water managers on the field, or water policy makers) need a meeting point. According with the main aim of Global Monitoring for Env...

Farming services based on satellite imagery are useful for managerial and decision making processes, and helpful for optimizing some of the inputs of the crop activity (e.g. water, fertilizers). Pasture management is increasingly making use of satellite observations when evaluating the state of the resources. In both cases, user requirements about...

The experiment presented and discussed in this paper attempts to understand the relationships between vegetation cover measurements and soil moisture estimations, to improve soil moisture calculations based on the FAO56 water balance, also known as the Kc-ET0 (crop coefficient-reference evapotranspiration) approach. The experiment provided a detail...

A two-source energy balance model that separates surface fluxes of the soil and canopy was applied to a drip-irrigated vineyard in central Spain, using a series of nine Landsat-5 images acquired during the summer of 2007. The model partitions the available energy, using surface radiometric temperatures to constrain the sensible heat flux, and compu...

La integración SiAR-Satélite obtenida mediante el presente trabajo por HidroMORE, ofrece productos de calidad a regantes y gestores del mundo del agua en relación a las necesidades hídricas de los cultivos y otras variables intermedias derivadas del balance hídrico. Así, enlazando por un lado la extensa y numerosa red SiAR compuesta de estaciones a...

Se estima la evapotranspiración y las necesidades de riego de los cultivos (Regadíos de primavera, Regadíos de verano, Alfalfa, Dobles cosechas y Leñosos de regadío) en el ámbito del acuífero Mancha Oriental, para tres años con distintas condiciones meteorológicas 2005, 2009 y 2010. Para ello, se utiliza el modelo hidrológico asistido por satélite...

This paper shows the application of a water balance based on remote sensing that integrated a Landsat 5 series from 2009 in an area of 1,300 km 2 in the Duero Basin (Spain). The objective was to simulate the daily soil water content (SWC), actual evapotranspiration, deep percolation and irrigation rates. The accuracy of the application is tested in...

A two-source energy balance model (TSM) has been applied over a drip-irrigated vineyard using soil and canopy radiometric temperature measured during the summer of 2007 in Central Spain. Flux estimations from the model compared well with semi-hourly and daytime values obtained by an eddy covariance flux tower installed at the same location during t...

This paper evaluates the capability of the reflectance-based crop coefficient coupled with a water balance model to estimate crop evapotranspiration (ET) and soil water depletion on rain-fed grapes. A grape orchard located in southeast Spain was studied during the 2009 growing season. Model results were evaluated by comparison with ET measured by a...

The approach presented here is based on the capability to derive the actual vegetation conditions in terms of a "transpiration coefficient" from remote sensing imagery. This "reflectance-based basal crop coefficient" (Kcb-vi), derived from multi-temporal remote sensing time series, is assimilated directly in a model that combines the FAO-56 dual cr...