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[EN] Agricultural economics Water Programming Models (WPM) has found that irrigators in water scarce areas have a rather inelastic response to water prices, making water pricing cost-ineffective towards water saving. We hypothesize that the predicted water saving performance of pricing is significantly underestimated by issues of model structure, due to the exclusion of deficit irrigation from the set of decision variables available to agents in conventional WPM. To test our hypothesis, we develop a model that integrates a continuous crop-water production function into a positive multi-attribute WPM, which allows us to assess agents¿ adaptive responses to pricing through deficit irrigation. The model is illustrated with an application to the El Salobral-Los Llanos irrigated area in Spain. Our results show that incorporating deficit irrigation as an adaptation option makes the water demand curve significantly more elastic as compared to an alternative model setting where deficit irrigation is precluded. We conclude that ignoring deficit irrigation can lead to a significant underestimation of the cost-effectiveness of water pricing towards water saving., The research leading to these results has received funding from the Program for the Attraction of Scientific Talent through the Project SWAN (Sustainable Watersheds: Emerging Economic Instruments for Water and Food Security), from the Biodiversity Foundation of the Spanish Ministry for Ecological Transition through the Project ATACC (Adaptacion ¿ Transformativa al Cambio Clim¿ atico en el Regadío) and from Programa Operativo FEDER Andalucía 2014-2020 through the project SEKECO (Evaluacion de estrategias de adaptacion a la sequía bajo el actual escenario de cambio climatico) Ref 1263831-R. This work was additionally supported by the ADAPTAMED (Design and evaluation of adaptation strategies to climate and global change in Mediterranean basins with intensive use of water for irrigation) national research project funded by the Spanish Ministry of Science and Innovation (RTI2018-101483-B-I00) with European FEDER funds.

The adaptation to the multiple facets of climate/global change challenges the conventional means of water system planning. Numerous demand and supply management options are often available, from which a portfolio of adaptation measures needs to be selected in a context of high uncertainty about future conditions. A framework is developed to integrate inputs from the two main approaches commonly used to plan for adaptation. The proposed “top–down meets bottom–up” approach provides a systematic and practical method for supporting the selection of adaptation measures at river basin level by comprehensively integrating the goals of economic efficiency, social acceptability, environmental sustainability, and adaptation robustness. The top-down approach relies on the use of a chain of models to assess the impact of global change on water resources and its adaptive management over a range of climate projections. Future demand scenarios and locally prioritized adaptation measures are identified following a bottom-up approach through a participatory process with the relevant stakeholders and experts. Cost-effective combinations of adaptation measures are then selected using a hydro-economic model at basin scale. The resulting adaptation portfolios are climate checked to define a robust program of measures based on trade-offs between adaptation costs and reliability. Valuable insights are obtained on the use of uncertain climate information for selecting robust, reliable, and resilient water management portfolios. Finally, cost allocation and equity implications are analyzed through the comparison of economically rational results (cooperative game theory) and the application of social justice principles.

[EN] Climate services are tools or products that aim to support climate-informed decision making for the adaptation to climate change. The market for climate services is dominated by public institutions, despite the efforts made by the European Commission to increase private enterprise in the market. The business model perspective has been proposed as a framework for enabling market growth through the development of appropriate business models for the provision of climate services. However, there is a lack of structured knowledge on how to approach climate service design and development from a business model standpoint. In this contribution, we first analyze the role of stakeholders in the design and development of climate services and identify opportunities for engaging users in the creation process. Afterwards, we explain our approach to climate service design and development using a business model perspective. To illustrate the proposed approach, we describe the co-creation of a climate service to support the adaptation to climate change of the urban water supply system in Valencia, Spain, and discuss the main findings and lessons learned from applying this approach., We acknowledge the European Research Area for Climate Services consortium (ER4CS) and the Agencia Estatal de Investigacion for their financial support to this research under the INNOVA project (Grant Agreement: 690462; PCIN-2017-066). This study has also been partially funded by the ADAPTAMED project (RTI2018-101483-B-I00) from the Ministerio de Ciencia, Innovacion y Universidades (MICIU) of Spain.

The replacement of flood-irrigation systems by drip-irrigation technology has been widely promoted with the aim of a more sustainable use of freshwater resources in irrigated agriculture. However, evidence for an irrigation efficiency paradox emphasizes the need to improve our understanding of the impacts of irrigation transformations on water resources. Here, we developed a distributed hydrological modeling approach to investigate the spatiotemporal effect of flood and drip irrigation on groundwater recharge. The approach recognizes differences in the water balance resulting from the localized application of water in surface drip-irrigated fields and the more extensive application of water in flood irrigation. The approach was applied to the semi-arid Mediterranean region of Valencia (Spain) and calibrated using a multi-objective framework. Multiple process scales were addressed within the framework by considering the annual evaporative index, monthly groundwater level dynamics, and daily soil moisture dynamics. Daily simulations from 1994 to 2015 suggested that, in our hydroclimatic conditions, (a) annual recharge is strongly related to annual rainfall, which had a four times higher impact on recharge than the type of irrigation practice, (b) flood-irrigated recharge tends to exceed drip-irrigated recharge by 10% at annual time scales, (c) however, recharge response to a particular precipitation event is smaller in flood irrigation than in drip irrigation, and (d) 8-18 rainfall events could generate more than half of the annual recharge in drip and flood irrigation, respectively. Our results highlight the importance of understanding the hydrological dynamics under different irrigation practices for supporting irrigation infrastructure policies., Water Resources Research, 57 (8), ISSN:0043-1397, ISSN:1944-7973

espanolEn este trabajo se desarrollo una red bayesiana (RB) para relacionar todos los efectos que la gestion forestal de base hidrologica introdujo en una parcela experimental tratada en comparacion con un testigo sin tratar. Se analizaron los ciclos del agua, del nitrogeno y del carbono asi como el riesgo de incendio a traves de un indicador de deficit de humedad del suelo. Los datos medidos en las parcelas se emplearon para calibrar y validar un modelo mecanicista basado en procesos. Con el modelo calibrado y validado se simularon 96 escenarios distintos de 50 anos de duracion con cuyos resultados se construyo la RB. Los resultados indican que la gestion forestal hidrologica es muy positiva pues mas agua y nutrientes fueron puestos a disposicion de la masa. El agua procede de una menor intercepcion, permitiendo un aumento de la evapotranspiracion, un ligero aumento de la percolacion profunda, sin efecto apreciable sobre la escorrentia superficial. Se incrementan tambien el contenido en carbono organico del suelo asi como la respiracion. El incremento en la disponibilidad de agua y nutrientes se traduce en un mayor LAI y productividad primaria asi como un descenso del riesgo de incendio. No se detectaron perdidas de nitrogeno en forma de lixiviados. EnglishIn this work a Bayesian network (RB) was built with the aim to relate those effects that the hydrological silviculture produced in an experimental plot in comparison with other one without any intervention. Water, Carbon and Nitrogen cycles as well as the forest fire risk using a soil moisture deficit index were included in the analysis. Experimental measurements were employed in the calibration and validation of a mechanistic model with the aim to study other 96 different scenarios of 50 year long and then to build the RB. According to the results, hydrology oriented forest management was very positive because of more water and nutrients were made available for the stand. This water comes from a reduction of the interception, allowing a higher evapotranspiration and a slightly higher deep percolation. Run off was undisturbed. Soil organic carbon content, soil respiration, LAI and gross primary production were increased too in the treated plot; however, the forest fire risk was reduced. Nitrogen leaching was no detected.

espanolLa convectividad de la lluvia es importante tanto desde el punto de vista de conservacion del suelo como en la genesis de recursos hidricos en zonas semiaridas, lo que supone que, en un contexto de selvicultura hidrologica, conocer su efecto en los procesos hidrologicos del bosque sea fundamental. Aqui se analiza el papel de la convectividad de la lluvia sobre la interceptacion, humedad del suelo, escorrentia y drenaje profundo en dos zonas climaticamente contrastadas del este de Espana, una prelitoral y otra continental. Se han considerado mas de 350 eventos de lluvia y se han clasificado segun el coeficiente de convectividad β. Estos datos se han acoplado con mediciones de los citados procesos hidrologicos. Los resultados indican un 8,7% de eventos convectivos en prelitoral frente a un 4,2% en continental, con un 38% de lluvia acumulada frente a un 11% en ambas zonas respectivamente. En prelitoral, solo se observa dinamismo en la humedad del suelo, el drenaje profundo y la escorrentia con este tipo de lluvias. Asi, solo 25 eventos (en 3 anos) produjeron escorrentia en el prelitoral (β=0,15) mientras que en la zona continental el numero se elevo a 149 (en 4 anos) y la convectividad no tuvo importancia (β=0,04). Las condiciones evaporativas durante la lluvia tambien tuvieron un impacto significativo en los resultados. EnglishConvective rainfall is important both from the point of view of soil conservation and in the provision of water resources in semi-arid zones, which means that, in a forest management context, knowing its effect on the hydrological processes of the forest is fundamental. Here we analyze the role of rain convection on interception, soil moisture, runoff and deep drainage in two climatically contrasted forest areas of eastern Spain, one pre-coastal and the other continental. More than 350 rainfall events have been considered and have been classified according to the coefficient of convection β. These data have been coupled with measurements of the aforementioned hydrological processes. The results indicate an 8.7% of convective events in the pre-coastal compared to a 4.2% in continental, with a cumulative rainfall of 38% compared to 11% in both zones, respectively. In pre-littoral, the only dynamism in soil moisture, deep drainage and runoff is observed with this type of rainfall. Thus, only 25 events (in 3 years) produced runoff in the pre-coastal (β = 0.15) while in the continental zone the number rose to 149 (in 4 years) and convection did not matter (β = 0.04). The evaporative conditions during the rain also had a significant impact on the results.

The Requena-Utiel aquifer in the Jucar River Basin (Mediterranean Spain) is mined mainly for the irrigation of vineyards (Denominación de Origen Utiel-Requena), and some olive and nut trees. It has been recently declared as in bad quantitative status by the Jucar River Basin Agency (Confederación Hidrográfica del Júcar, CHJ). Among the measures taken to control water abstraction, a pumping cap for the irrigation season (May-September) has been agreed between the CHJ and the groundwater user association. This limit depends on the cumulative precipitation from December to April (classifying the year in wet, normal or dry), although that irrigation amount is in any case below the crop requirements. Consequently, predicting the type of year beforehand is a piece of valuable information for the water users in order to optimally schedule groundwater pumping and foresee crop production.This study analyses the ability of seasonal meteorological forecasts from the Copernicus Climate Change Service (C3S) to anticipate the type of year in the agricultural areas of the Requena Utiel aquifer considering different periods ahead. The following seasonal forecasting services were used: ECMWF SEAS5, UKMO GloSEA5, MétéoFrance System, DWD GCFS, and CMCC SPS. Seasonal forecasts issued between November 1st and April 1st were downloaded and post-processed using a month-dependent linear scaling against historical records. Once post-processed, the skill of seasonal forecasts to predict the type of year has been evaluated for the 1995-2015 period, depending on the anticipation time.Results show that, on a broader view, the type of year cannot be safely anticipated before April 1st. However, we have identified that, for particular types of year and forecasting services, the anticipation time can be enlarged (e.g predicting wet years in December). Furthermore, we have found a direct relationship between the strength of the signal (number of ensemble members that predict the same type of year) and the forecasting skill, meaning that seasonal forecasts showing a strong signal, if properly identified, could offer valuable information months in advance to the beginning of the irrigation season.Acknowledgements:This study has received funding from the eGROUNDWATER project (GA n. 1921), part of the PRIMA programme supported by the European Union’s Horizon 2020 research and innovation programme. It has been also supported by the ADAPTAMED project (RTI2018-101483-B-I00), funded by the Ministerio de Economia y Competitividad (MINECO) of Spain and with EU FEDER funds.

Climate change is expected to have a significant impact on water resource systems, affecting both water quantity and quality. Among other probable impacts on raw water, the increase of sapid compounds such as geosmin and MIB (2-methylisoborneol) is one of the most challenging for urban water supply, as it alters both water taste and odour. Water managers and water utility companies need to anticipate events that increase the concentration of sapid compounds. Proper methods and tools are necessary to design adaptation strategies for future drinking water supply. In this research we analyse the drivers of MIB and geosmin growth, and study the consequence that an increasing occurrence and intensity of sapid compounds events will have on the required water treatments. The research has been developed for a Mediterranean reservoir used for water supply to the city of Valencia, the 3rd largest city in Spain. The methodology applies a chain of models that integrates water quantity and quality processes in the same modelling framework. The modelling framework includes climate models, hydrological and water resource management models at the basin scale, and a reservoir management and quality models. Key environmental variables were selected using statistical analysis and expert criteria. Fuzzy logic systems were then applied to predict MIB and geosmin concentration under different time periods and climate change scenarios. Two representative concentration pathways (RCP 4.5 and 8.5) and two-time horizons (short term 2020-2040, and mid term 2041-2070) were considered. Results show a significant increase of MIB and geosmin under climate change, especially during spring and summer. Concentrations of MIB would steadily rise until they double, reaching peaks of up to 0.50 µg/l by 2070 for all scenarios, while the World Health Organization maximum safe concentration is 0.01 µg/l. Geosmin concentrations also increase in all scenarios, reaching 0.05 µg/l by 2070. The microbiological data shows that benthic cyanobacteria Aphanocapsa delicatissima could be associated with MIB. Decreasing water storage, higher nitrate concentrations, and higher temperatures would stimulate MIB production, favoured by a likely increased of light penetration and resuspension of cyanobacteria present in the benthos of the reservoir. These environmental conditions appear mainly during drought events and force water treatment plants to change their processes to face the higher concentration of sapid compounds in raw water. AcknowledgementsThis study has been supported by the European Research Area for Climate Services programme (ER4CS) under the INNOVA project (Grant Agreement 690462) and the Agencia Estatal de Investigación (PCIN-2017-066), and by the ADAPTAMED project (RTI2018-101483-B-I00), funded by the Ministerio de Economia y Competitividad (MINECO) of Spain and with EU FEDER funds.

Irrigated agriculture is the major water consumer in the Mediterranean region. Improved irrigation techniques have been widely promoted to reduce water withdrawals and increase resilience to climate change impacts. In this study, we assess the impact of the ongoing transition from flood to drip irrigation on future hydroclimatic regimes in the agricultural areas of Valencia (Spain). The impact assessment is conducted for a control period (1971-2000), a near-term future (2020-2049) and a mid-term future (2045-2074) using a chain of models that includes five GCM-RCM combinations, two emission scenarios (RCP 4.5 and RCP 8.5), two irrigation scenarios (flood and drip irrigation), and twelve parameterizations of the hydrological model Tetis. Results of this modelling chain suggest considerable uncertainties regarding the magnitude and sign of future hydroclimatic changes. Yet, climate change could lead to a statistically significant decrease in future groundwater recharge of up -6.6% in flood irrigation and -9.3% in drip irrigation. Projected changes in actual evapotranspiration are as well statistically significant, but in the order of +1% in flood irrigation and -2.1% in drip irrigation under the assumption of business as usual irrigation schedules. The projected changes and the related uncertainties will pose a challenging context for future water management. However, our findings further indicate that the effect of the choice of irrigation technique may have a greater impact on hydroclimate than climate change alone. Explicitly considering irrigation techniques in climate change impact assessment might therefore be a way towards better informed decision-making.This study has been supported by the IRRIWAM research project funded by the Coop Research Program of the ETH Zurich World Food System Center and the ETH Zurich Foundation, and by the ADAPTAMED (RTI2018-101483-B-I00) and TETISCHANGE (RTI2018-093717-B-I00) research projects funded by the Ministerio de Economia y Competitividad (MINECO) of Spain including EU FEDER funds.

Perennial ryegrass (Lolium perenne) is the predominant forage crop in the equatorial highland zones of Colombia due to its high nutritional value and versatility to produce both milk and meat. This study aimed to determine the relationship between the relative depletion of usable soil water and the Ks values of canopy expansion and closure stomatal of perennial ryegrass, as well as to identify the threshold values of water stress. The experiment was carried out in pots under a controlled environment condition. These pots were arranged in a completely randomized manner. The experiment consisted of five treatments—including control treatment—of water deficits in the soil that progressively increased the depletion level as the crop cycle developed. This generated a wide range of conditions in the growth stages. For each treatment, four repetitions were performed Biomass production was significantly affected by water stress. The results show that the upper and lower thresholds of Ks were 0.28 and 1.3 of the depletion level (p) of the total available water (TAW) in the soil for the expansion of the canopy (CE), and 0.25 and 1.1 p of the TAW for stomatal closure (gs). Quadratic functions were fitted for both the CE (R2 = 0.72) and CS (R2 = 0.73); moreover, the Ks function of FAO-AquaCrop with positive shape factor (sf) was as follows: sf = 11, RMSE 0.22 for CE, and sf = 4.3, RMSE 0.19 for gs. Our results indicate that ryegrass is moderately sensitive to water stress. The differences found between the Ks function of FAO and the experimental data call for the need to use modeling with parameters adapted for each case.

[EN] Marginal semi-arid forests in areas currently affected by climate change are a challenge to forest management, which has to focus on key functional traits that can effectively contribute to resistance under extreme drought. We studied the effects of thinning in a marginal forest by quantifying functional responses relating to growth, carbon and water fluxes. Two experimental plots were established, one thinned in 2012 and the other one left as a control. The environmental conditions varied substantially during the 4-year study period, although dry years predominated. There were signs of dieback in the control with a decreasing inter-annual trend in LAI, as opposed to the treated plots, where LAI by the end of the study almost reached pre-thinning levels. Sap flow and transpiration were greatly enhanced by the treatment, with thinned trees transpiring 22.41 tree(-1) day(-1) in the growing season, about twice the control figures. The seasonal patterns of transpiration and soil moisture were uncoupled, indicating a contribution of deep groundwater to the former flux. In the control, limitations to water and carbon dynamics (canopy conductance) occurred at soil moisture values below 16%, whereas in the thinned trees these limitations appeared when soil moisture dropped below 10%. Overall, oaks' transpiration was enhanced with thinning to the point that stand-water use surpassed that of the control by the second half of the study period, averaging 24% of gross rainfall in both plots. Soil evaporation increased from 12 to 20% of gross rainfall after treatment in the overall period. The treatment had a profound watering effect in this marginal forest, led by fewer trees using the same amount of water as those in the untreated overstocked plot. This research may provide guidelines for ecohydrology-oriented silviculture in stands experiencing tree encroachment and transformation into shrublands that are more prone to global change-induced disturbances., This study is a component of the research projects HYDROSIL (CGL2011-28776-C02-02), SILWAMED (CGL2014-58127-C3-2) and CEHYRFO-MED (CGL2017-86839-C3-2-R), funded by the Spanish Ministry of Science and Innovation and the FEDER fund of the EU. The authors are grateful to the Valencia Regional Government (CMAAUV, Generalitat Valenciana) and ACCIONA for their support in allowing the use of the experimental forest La Hunde and for their assistance in the fieldwork.

Irrigation modernization, here defined as the replacement of traditional flood irrigation systems by pressurized drip-irrigation technology, has been widely promoted with the aim to move towards a more sustainable use of freshwater resources in irrigated agriculture. However, the scale sensitivity of irrigation efficiency challenged the predominantly positive value attributed to irrigation modernization and asked for an integrated evaluation of the technological change at various scales. The aim of this study is therefore to contribute to an improved understanding of the hydrological functioning in a landscape under irrigation modernization. We used local field observations to propose a regional scale modeling approach that allowed to specifically simulate the difference in water balance as a function of irrigation method and crop type. The approach focused on the modification of the spatial input data and had therefore the benefit of being relatively independent of the final choice of the hydrological model. We applied the proposed approach to the semi-arid agricultural area of Valencia (Spain), where regional information about the use of irrigation technologies and irrigation volumes at farm level were available. The distributed hydrological model Tetis was chosen to simulate the daily water balance from 1994 to 2015 for an area of 913 km2 at a spatial resolution of 200 m. Model simulations were based on a random selection of parameter values that were subsequently evaluated in a multi-objective calibration framework. Multiple process scales were addressed within the framework by considering the annual evaporative index, monthly groundwater level dynamics, and daily soil moisture dynamics for evaluation. Simulation results were finally analyzed with a focus on groundwater recharge, which is of particular interest for environmental challenges faced within the study area. Simulation results of groundwater recharge for the entire agricultural area indicated a considerable variability in annual recharge (values from 112 mm up to 337 mm), whereby recharge was strongly controlled by annual rainfall volumes. Annual recharge in flood-irrigated areas tended to exceed annual recharge in drip irrigated-areas except for years with above average rainfall volumes. The observed rainfall dependency could be explained by the fact that recharge in drip-irrigated areas almost exclusively occurred during rainy days, whereby a few heavy rainfall events could produce the majority of annual recharge. Our results indicated interesting differences but also commonalities in groundwater recharge for flood and drip irrigation, and therefore emphasized the importance of explicitly considering irrigation technology when modelling irrigated agricultural areas.

Water is the key element that modulates the provision of goods and services together with global/climate stressors affecting semiarid forests. In this sense, there is a need to improve the understanding and quantification of forest and water relationships as affected by forest management. This work addresses this issue by comparing net rainfall (Pn) redistribution into different belowground hydrological processes (BHP) in two forest types after a thinning treatment: a holm oak coppice (HU) and a post-fire Aleppo pine regeneration (CAL). The relative contribution (RI) of forest structure, antecedent soil moisture (θ st ), rainfall and meteorological conditions on the BHP was assessed through boosted regression trees models. In both sites, the RI of the forest structure itself was limited (, This study is a component of research projects: HYDROSIL (CGL2011-28776-C02-02), SILWAMED (CGL2014-58127-C3-2), CEHYRFO-MED (CGL2017-86839-C3-2-R) funded by the Spanish Ministry of Science and Innovation (Spain), FEDER funds (EU) and LIFE17 CCA/ES/000063 RESILIENTFORESTS. The authors are grateful to the Valencia Regional Government (CMAAUV), VAERSA, ACCIONA, the “Sierra Calderona” Natural Park and the communal authority of Serra, for their support in allowing the use of the experimental forest and for their assistance in carrying out the fieldwork. A.J. Molina is beneficiary of a “Juan de la Cierva” post-doctoral fellowship funded by the Spanish Ministry of Economy and Competitiveness. Appendix A

Forests play a determinant role in the hydrologic cycle, with water being the most important ecosystem service they provide in semiarid regions. However, this contribution is usually neither quantified nor explicitly valued. The aim of this study is to develop a novel hydro-economic modelling framework for assessing and designing the optimal integrated forest and water management for forested catchments. The optimization model explicitly integrates changes in water yield in the stands (increase in groundwater recharge) induced by forest management, and the value of the additional water provided to the system. The model determines the optimal schedule of silvicultural interventions in the stands of the catchment in order to maximize the total net benefit in the system. Canopy cover and biomass evolution over time were simulated using growth and yield allometric equations specific for the species in Mediterranean conditions. Silvicultural operation costs according to stand density and canopy cover were modelled using local cost databases. Groundwater recharge was simulated using HYDRUS, calibrated and validated with data from the experimental plots. In order to illustrate the presented modelling framework a case study was carried out in a planted pine forest (Pinus halepensis Mill.) located in south-western Valencia province (Spain).The optimized scenario increased groundwater recharge. This novel modelling framework can be used in the design of a “payment for environmental services” scheme in which water beneficiaries could contribute to fund and promote efficient forest management operations. This article is protected by copyright. All rights reserved.

[EN] Soil organic carbon pools have an important role in the maintenance of ecosystems as a source of energy for soil microorganisms. Soil biological and biochemical properties are essential for the decomposition of organic matter. These soil properties can be affected by thinning, which is considered sustainable when the soil properties are maintained or improved. We studied the effects of selective thinning and shrub clearing, performed with an ecohydrological approach, in a marginal Holm oak forest in a semiarid area on soil properties. The effects of thinning (T) were compared with an untreated area (control, C). Fine woody debris was ground into mulch onto the thinned area. Forest floor and mineral soil properties were analyzed between five months and seven years after the thinning. In the forest floor, gravimetric water content (GWc(ff)) and water soluble organic carbon (WSOCff) were analyzed and compared between T and C. In mineral soil, GWC(ms), soil organic carbon (SOC), WSOCms, soil basal respiration (BR), soil microbial biomass carbon (MBC) and soil enzymes (acid phosphatase (Acid PA) and urease (URE)) were analyzed. In the early stage, the results showed slightly higher SOC and WSOms in T likely due to fine woody debris left on the forest floor. However, seven years after the thinning the effects of the thinning on all the studied variables were negligible. All variables showed high spatial-temporal variability. Our results suggest that selective thinning and shrub clearing in the studied site do not affect negatively soil properties when woody debris is left on the forest floor., This study is a component of research projects: HYDROSIL (CGL2011-28776-C02-02) and SILWAMED (CGL2014-58+127-C3-2), RESILIENT-FORESTS (LIFE17 CCA/ES/000063) and CEHYRFO-MED (CGL2017-86839-C3-2-R) funded by the Spanish Ministry of Science and Innovation, and the FEDER fund and the EU. The authors are grateful to the Valencia Regional Government (CMAAUV, Generalitat Valenciana) for it supports in allowing the use of the experimental forest. We thank Joana Oliver for her laboratory and technical assistance and Dr. Rafael Herrera for valuable comments on the manuscript.

[EN] Semi-arid forests are water limited environments considered as low-productive. As a result, these forests usually end up unmanaged and abandoned, with the subsequent wild fire risk increasing, water yield decreasing and a general diminishing of the forest resilience. Hydrological-oriented silviculture could be a useful alternative that increases management possibilities by combining forest productivity and water yield. However, the slight water yield increase after forest management together with the low forest productivity, could make this option insufficient for semi-arid forests, and other goods and services should be included and quantified. In this sense, the present study analyzes to what extent semi-arid forest management for water yield results effective and profitable at catchment scale, and how does it improve when it is combined with other benefits such as biomass production and fire risk diminishing. To that end, the effects of forest management of semi-arid Aleppo pine post-fire regeneration stands are analyzed in terms of water yield (TETIS-VEG model), fire risk (KDBY index and FARSITE) and biomass production, at catchment scale. Regarding to water yield, the results confirmed the slight effect of forest management on its increase (average increase of 0.27 +/- 0.29 mm yr(-1)), at the same time that highlighted the role of the upper catchment area as an important water contributor. The management produced 4161.6 Mg of biomass, and decreased in 27 +/- 17% and 25.6 +/- 14.1% the fire risk and fire propagation, respectively. Finally, a simple economic estimation of the management profitability is carried out by means of comparing the Benefit/Cost ratio of the managed and unmanaged scenarios. Both scenarios were always above the unity when just considering water as benefit, although the unmanaged scenario produced a higher ratio, as no management costs are expended. Contrarily, when wildfire was also included into the evaluation, the situation is overturned for wildfires equal or higher than 1.5 day duration, where the forest management is shown as the most convenient alternative., This study is a component of the research projects: INTEGRA (CGL2011-28776-0O2), E-HIDROMED (CGL2014-58127-C3) and CEHYRFO-MED (CGL2017-86839-C3-2-R) funded by the Spanish Ministry of Science and Innovation and FEDER funds, and LIFE17 CCA/ES/000063 RESILIENTFORESTS. The authors are grateful to the Valencia Regional Government (CMAAUV, Generalitat Valenciana), the VAERSA staff, the Natural Park staff and the communal authority of Serra (specially Juanjo Mayans) for their support and allowing the use of the Natural Park experimental forest.

With population growth, climate change, and increasing forest disturbance, understanding the complex relationships between forests and water is key to sustaining future forest resources, aquatic habitat, and water supplies. Research into forest and water interactions continues to expand our understanding of ecohydrological processes and our ability to assess the hazards associated with natural and human-related forest disturbances.

[EN] The present work aims to take a closer look at the behavior of two releases of the Keetch Byram droughtindex (KBDI) under different forest management strategies in Mediterranean conditions. Since theseversions of the index were demonstrated to be insensitive to the changes in water balance caused bydifferent thinning treatments, a new KBDI-based index sensitive to silviculture operations was developed.This new approach enabled us to simulate the benefits achieved from a thinning operation in terms offorest fire risk reduction. Abatements of 22.5% and 26.4% in KBDI were obtained for the 2009 and 2010high-risk forest fire periods, respectively, due to thinning. The reductions observed in the short-term didnot disappear in a long term. A plot thinned 10 years ago showed KBDI reductions of 12.5% and 6.7% withrespect to a non-managed plot (control treatment) in the same period. Finally, in order to make possibleapplication of the new index to other stands, coefficients of the index were based on well-known andeasy to get tree-related and physiological variables., This study is part of the research project: "CGL2011-28776-C02-02, Hydrological characterization of forest structures at plot scale for an adaptive management, Hydrosil", funded by the Spanish Ministry of Science and Innovation and FEDER funds.

[EN] Hydrology-oriented forest management sets water as key factor of the forest management for adaptation due to water is the most limiting factor in the Mediterranean forest ecosystems. The aim of this study was to apply Bayesian Network modeling to assess potential indirect effects and trade-offs when hydrology-oriented forest management is applied to a real Mediterranean forest ecosystem. Water, carbon and nitrogen cycles, and forest fire risk were included in the modeling framework. Field data from experimental plots were employed to calibrate and validate the mechanistic Biome-BGCMuSo model that simulates the storage and flux of water, carbon, and nitrogen between the ecosystem and the atmosphere. Many other 50-year long scenarios with different conditions to the ones measured in the field experiment were simulated and the outcomes employed to build the Bayesian Network in a linked chain of models. Hydrology-oriented forest management was very positive insofar as more water was made available to the stand because of an interception reduction. This resource was made available to the stand, which increased the evapotranspiration and its components, the soil water content and a slightly increase of deep percolation. Conversely, Stemflow was drastically reduced. No effect was observed on Runof due to the thinning treatment. The soil organic carbon content was also increased which in turn caused a greater respiration. The long-term effect of the thinning treatment on the LAI was very positive. This was undoubtedly due to the increased vigor generated by the greater availability of water and nutrients for the stand and the reduction of competence between trees. This greater activity resulted in an increase in GPP and vegetation carbon, and therefore, we would expect a higher carbon sequestration. It is worth emphasizing that this extra amount of water and nutrients was taken up by the stand and did not entail any loss of nutrients., This study is a component of research projects: HYDROSIL (CGL2011-28776-C02-02), SILWAMED (CGL2014-58127-C3-2) and CEHYRFO-MED (CGL2017-86839-C3-2-R) funded by the Spanish Ministry of Science and Innovation and FEDER funds. The authors are grateful to the Valencia Regional Government (CMAAUV, Generalitat Valenciana), ACCIONA for their support in allowing the use of the experimental forest and for their assistance in carrying out the fieldwork.

[EN] Water-oriented forest management is an urgent need in semiarid catchments. In the case of low-biomass forests and shrublands, the magnitude, efficiency and temporal duration of thinning effects on rainfall partitioning needs further attention. This work studies the effects of juvenile thinning and shrub clearing on stemflow (Stf), throughfall (Thr) and interception (It) in two low-biomass forests (CAL: post-fire Aleppo pine saplings with 74% of basal area, BA, removed; and HU: evergreen oak coppice with 41% of BA removed), as well as the relative contribution of the event meteorology. The effects are compared with a control plot during the first 3¿4¿years. Stf rate (%) decreased with density and, on a tree scale, it was enhanced by the treatment only in the bigger oaks. Event Thr increased from 55 to 81% and from 68 to 86% of gross rainfall (Pg) for CAL and HU respectively after thinning, resulting in about 15% less intercepted Pg. High evaporative conditions and an open (ventilated) forest structure led to high It rates in the controls when comparing with other studies, thus making the treatments more efficient in net precipitation (Pn) gain (Pg intercepted decreased 17% or 2.3% per unit of LAI or BA removed respectively). In general, depths (mm) were mostly explained (>75%) by the rainfall characteristics of the event (e.g. amount, duration, intensity), with a limited contribution from forest structure (e.g. cover, LAI) and event meteorology (e.g. temperature, wind speed, vapor pressure deficit). On the contrary, when expressed as rates (% of Pg), forest structure and event-meteorology gained importance (explaining 25¿65%), especially in the drier site (CAL). In this site, the low gain in Pn (~25¿mm per year on average) was offset with no temporal dampening during the span of this study, as observed in the wetter site (HU), where plant growth tended to mitigate the effect of the treatment by the end of the study. The results presented here make a contribution to a better understanding of the effects of water-oriented forest management in low-biomass semiarid forests., This study is a component of research projects: HYDROSIL (CGL2011-28776-C02-02), SILWAMED (CGL2014-58127-C3-2) and CEHYRFO-MED (CGL2017-86839-C3-2-R) funded by the Spanish Ministry of Science and Innovation and the FEDER fund of the EU. The authors are grateful to the Valencia Regional Government (CMAAUV, Generalitat Valenciana), Serra municipality, VAERSA and ACCIONA for their support in allowing the use of the experimental forest and for their assistance in carrying out the fieldwork.

Economic instruments can be used to control groundwater nitrate pollution due to the intensive use of fertilizers in agriculture. In order to test their efficiency on the reduction of nitrate leaching, we propose an approach based on the combined use of production and pollution functions to derive the impacts on the expected farmer response of these instruments. Some of the most important factors influencing nitrate leaching and crop yield are the type of soil and the climatic conditions. Crop yield and nitrate leaching responses to different soil and climaticconditions were classified by means of a cluster analysis, and crops located in different areas but with similar response were grouped for the analysis. We use a spatial economic optimization model to evaluate the potential of taxes on nitrogen fertilizers, water prices, and taxes on nitrate emissions to reduce nitrate pollution, as well as their economic impact in terms of social welfare and farmers' net benefits. Themethod was applied to theMancha Oriental System(MOS) in Spain, a large area with different soil types and climatic conditions.We divided the study area into zones of homogeneous crop production and nitrate leaching properties. Results how spatially different responses of crop growth and nitrate leaching, proving howthe cost-effectiveness of pollution control instruments is contingent upon the spatial heterogeneities of the problem., The study has been supported by the European Community 7th Framework Project GENESIS (226536) on groundwater.

The role of forests on the provision and regulation of non-marketed ecosystem services is well known (Thorsen et al. 2014). This is especially important in areas like the Mediterranean, where protective forests play a major role against soil erosion and degradation, landscape quality and stabilization of the hydrological cycle. Socio-economic and cultural changes affecting rural society from the 1960s have produced a demographic decline, and with it, an abandonment of rural activities, leading to an expansion and densification of forest and scrub. Forest encroachment may decrease the streamflow from upper catchments (Gallart and Llorens 2004); this study reports a decrease in average annual flow of major Spanish rivers between 37 and 59%, partly explained by the densification of upstream forests, and increasing interception loss. Moreover, some Mediterranean basins (e.g. Segura and Jucar in Spain) present very serious problems of water scarcity, because of a combination of low/irregular rainfall and high rates of evapotranspiration, that has resulted in overuse of groundwater resources (Estrela et al. 2000a, b). These problems may even endanger urban water supply (approx. 15% of the total water supply in Spain). In addition, the Mediterranean region is already suffering some significant impacts of the climate change, such as longer dry seasons, or lower soil moisture content (Giorgi and Lionello 2008; Garcia-Ruiz et al. 2011). All these issues have raised concern about the importance of forests and water interactions in the Mediterranean (Birot et al. 2011).

A pressurized irrigation network may operate in two ways, namely, on demand and organized under operating sectors. In the first case, the user decides when to irrigate, and the pumping station has to meet the discharge and pressure head requirements of the group of users that is demanding water at any time. In the second case, the operating hydrants at a given moment are previously established, which permits identification of scenarios related to lesser energy consumption. In this work, a new model was developed that identifies such scenarios. The optimization process is carried out by means of simulated annealing (SA). The model was applied to an example and the result obtained was compared with the same network operating on demand and sectorized using the criterion of hydrant elevation with respect to the pumping station. The scenario adopted for SA saved 11.8% and 15.5% in energy consumption compared with the two other scenarios, and decreased the installed power requirement by 38.3% and 21.6%, respectively.

[EN] This paper develops a participatory methodology to integrate farmer’s vision in the design of an adaptation strategy to global change in the Jucar River basin. It aims at answering three questions: How farmers perceive climate change impacts; which adaptation measures they consider; and how they assess these measures. Participatory workshops with different actors were held in two areas (La Ribera and La Mancha Oriental). This methodology has allowed identifying the local impacts and consequences of global change, and the difficulties of the adaptation processes to climate change scenarios. [ES] El presente trabajo desarrolla una metodología participativa para integrar la visión de los agricultores en el diseño de una estrategia de adaptación al cambio global en la cuenca del Júcar. Responde a tres preguntas: cómo perciben los agricultores los impactos del cambio climático, qué medidas de adaptación identifican, y cómo las valoran. Se desarrolló mediante talleres participativos con actores de dos zonas de la cuenca (La Ribera y La Mancha Oriental). Además de identificar los impactos locales del cambio global, se analizan las dificultades de adaptación percibidas por los agricultores.

The present work aims at approaching the study of the performance and uncertainty associated with an irrigation scheduling method based on a soil-water balance. On a daily time step, a water-balance-based irrigation scheduling model has been developed. A Monte Carlo simulation of the irrigation scheduling model is developed using a series of actual daily weather data of evapotranspiration and precipitation and bootstrapping stochastic technique to resampling them. Performance evaluation measurements and their uncertainty are studied by means of several parameters: reliability, resiliency, vulnerability, total irrigation water allocation, total water loosed by deep percolation, and actual evapotranspiration/potential evapotranspiration rate along the growing season. The behaviors of 12 different types of soils (between coarse-textured soils and fine-textured soils) are compared using pedotransfer functions. Total available water (TAW) is the most important hydraulic property of the soil as far as irrigatio...

The present work aims at taking us closer to the study of the influence of the spatial configuration of the irrigated zone on the unit cost (€/ha) of a layout irrigation network design. The layout ...

Traditional irrigation zones in the east of Spain have been denoted by the high level of parcellation. The layout of the irrigation network design in highly parcelled territories presents an important degree of difficulty, the previous experience of the designer in this task being crucial in the final result. In this work, a new heuristic algorithm for layout of the irrigation network design is presented. We start from a classical graph theory algorithm (Dijkstra’s algorithm) used for solving the shortest path spanning tree problem. This algorithm is modified to assign weights to the arcs and plot limits are used as if they were the arcs of a graph. The algorithm is implemented on a geographical information system, thus creating an application that automatically generates the layout of the irrigation network design. The only necessary initial data are the origin of the network (supply point) and the hydrants (delivery points). The advantage of this heuristic is that the subjectivity introduced for the des...

[ES] El balance hídrico, y especialmente la recarga por percolación profunda de un suelo, puede ser modificado a nivel de parcela mediante el manejo de la masa. Extendido a nivel de cuenca debemos esperar que dicha modificación afecte al conjunto del ciclo hidrológico. Sin embargo, el primer paso es la cuantificación del efecto que produce sobre el balance de agua el manejo silvícola de la masa con fines hidrológicos a nivel de parcela. Para ello se diseñó un experimento en una parcela de Pinus halepensis en la que se realizaron aclareos de distinta intensidad. El ciclo del agua se monitorizó midiendo la temperatura, humedad relativa, pluviometría dentro y fuera de la masa, el contenido de agua del suelo y la transpiración. Para cuantificar el volumen de agua que atraviesa la zona de raíces se calibró y validó el modelo HYDRUS-1D, el cual resuelve las ecuaciones de flujo en medios porosos saturados y no saturados. Los resultados demuestran que la recarga conseguida mediante el manejo de la masa puede ser modificada, consiguiendo valores de recarga netamente superiores en las parcelas tratadas. Sin embargo reducciones por debajo del 50% la fracción de cabida cubierta (FCC) no producen mejora en la recarga. Se comprueba que el régimen de precipitaciones tiene un efecto importante en el valor de la recarga. Dado que se trata de parcelas llanas en las que no se evidenció escorrentía, el estudio debe ser ampliado a laderas en donde este componente del ciclo presente una mayor importancia.

[ES] El Manejo Forestal Adaptativo (MFA) en entornos semiáridos tiene como objetivo adaptar el bosque a la escasez de agua mediante una regulación artificial de la estructura y la densidad del mismo. En el presente trabajo se aplica el MFA a una masa marginal de Quercus ilex con el fin de optimizar los recursos hídricos y tratando de evitar a su vez el posible impacto negativo derivado de una pérdida excesiva de suelo y nutrientes. La masa se encuentra en la Cuenca Mediterránea, dentro del Monte Público de La Hunde, Valencia (E de España), donde dos parcelas contiguas, control y tratamiento, de 1800 m2 cada una, fueron establecidas. La orientación (NO), pendiente (30 %) y densidad (861 árboles por ha) fueron las mismas en ambas parcelas. La parcela tratamiento fue aclarada en Mayo del 2012, reduciendo la densidad de 861 a 414 árboles por ha. La parcela control no fue aclarada. Los efectos del aclareo en los ciclos hidrológico y biogeoquímico fueron caracterizados en ambas parcelas y comparados entre sí. Los resultados indicaron un efecto temprano del aclareo que optimiza el ciclo hidrológico. Se encontró un incremento significativo de la transpiración, escorrentía cortical y humedad del suelo en la parcela tratada. Por el contrario, no se observaron efectos ni en la escorrentía superficial ni en la trascolación. De la misma forma, el MFA parece no afectar significativamente al ciclo biogeoquímico del bosque, ya que no se encontraron diferencias significativas en el contenido de C, N y P en el agua de ambas parcelas. La removilización de nutrientes parece verse afectada por el resalveo. La parcela tratada muestra una menor eficiencia en el uso de los nutrientes, probablemente derivada de una mayor disponibilidad de agua. Con estos resultados, podemos afirmar que la aplicación de un adecuado MFA posibilita la optimización del ciclo hidrológico sin dañar significativamente el ciclo de los nutrientes. De la misma forma, además de la satisfacción de las necesidades hídricas y nutricionales del ecosistema, el MFA incrementa la disponibilidad de agua para el resto de la cuenca.

[EN] The agricultural sector faces the challenge of ensuring food security without an excessive burden on the environment. Simulationmodels provide excellent instruments for researchers to gainmore insight into relevant processes and best agricultural practices and provide tools for planners for decision making support. The extent to which models are capable of reliable extrapolation and prediction is important for exploring new farming systems or assessing the impacts of future land and climate changes. A performance assessmentwas conducted by testing six detailed state-of-the-artmodels for simulation of nitrate leaching (ARMOSA, COUPMODEL, DAISY, EPIC, SIMWASER/STOTRASIM, SWAP/ANIMO) for lysimeter data of the Wagna experimental field station in Eastern Austria, where the soil is highly vulnerable to nitrate leaching. Three consecutive phases were distinguished to gain insight in the predictive power of themodels: 1) a blind test for 2005 2008 in which only soil hydraulic characteristics, meteorological data and information about the agricultural management were accessible; 2) a calibration for the same period in which essential information on field observations was additionally available to the modellers; and 3) a validation for 2009 2011 with the corresponding type of data available as for the blind test. A set of statistical metrics (mean absolute error, root mean squared error, index of agreement,model efficiency, root relative squared error, Pearson's linear correlation coefficient) was applied for testing the results and comparing the models. None of the models performed good for all of the statistical metrics. Models designed for nitrate leaching in high-input farming systems had difficulties in accurately predicting leaching in low-input farming systems that are strongly influenced by the retention of nitrogen in catch crops and nitrogen fixation by legumes. An accurate calibration does not guarantee a good predictive power of the model. Nevertheless all models were able to identify years and crops with high- and low-leaching rates., This research was made possible by the GENESIS project of the EU 7th Framework Programme (Project No. 226536; FP7-ENV-2008-1). We are grateful for the experimental data provided by Joanneum Raum (Graz, Austria). The modelling team of Democritus University of Thrace would like to thank Per-Erik Jansson (Royal Institute of Technology, Stockholm, Sweden) for his valuable help during the application of Coup Model.

Location-allocation algorithms allow for situating services in an efficient way in zones where the demand is dispersed across the area. In the present work, the minisum location-allocation algorithm is used to optimize the placement multioutlet hydrants, which are needed to supply irrigation to the region. The objective function aims to minimize the total access costs of the service. Because the total number of hydrants is the same as what currently exists the results can be compared with the presented solution. The proposed model reduces the total distance run to access the service, from 16,177 m to 13,560 m (16.17%), and the objective function (proportional to the cost) by 28.95%. © 2012 American Society of Civil Engineers.