Geometric overlapping coefcients for calculating the required emitters per plant in drip irrigation

[EN] The designer of irrigation systems must consider a complex combination of emitter type, emitter uniformity, hydraulics, topography, desired water distribution, crop salt tolerance, water requirements, water quality, fertilizer injection, soil salinity, cultural practices, and other site-specifc conditions. In contrast to the approaches applied for the hydraulic design of irrigation installations, there is not a clear, general and consolidated design criterion for calculating the number required emitters per plant. In most cases, given the wide spectrum of possible scenarios, only guideline recommendations can be found, and the fnal decision is often based on the subjective experience of the designer or grower. This paper aims at revising, clarifying and refning the existing published guidelines and methodologies for estimating the required emitters per plant in drip irrigation, focussing on the Montalvo approach. The agronomic design should satisfy, among others, two specifc conditions: (i) the emitters should wet at least a minimum threshold of the soil area (or volume) corresponding to the plant for ensuring a proper development of the roots; (ii) overlapping between emitter bulbs is required for merging wetted volumes and avoiding salt concentration near the root zone. Relying on this basis, a thorough theoretical geometric analysis of the overlapping between wet bulbs of contiguous emitters is carried out. As a result, Montalvo's overlapping coefcients are deduced here. This author assumes an identical net wetted area for all emitters in the laterals, but it can be stated that the overlapping areas between emitters difer in extreme emitters and interior emitters, as well as in confgurations with one lateral per plant row and two laterals per plant row. Therefore, this study proposes new formulations for the computation of the overlapping coefcient, which need to incorporate the number of emitters as an additional variable, as well as to distinguish between the presence of one or two laterals per plant row, and between grouped and non-grouped emitters. In one lateral per plant row, the original overlapping coefcient underestimates the net wetted area by one emitter and thus overestimates the theoretical number of required emitters. In the case of two laterals per plant row, the original overlapping coefcient overestimates the net wetted area in the interior emitters, and thus underestimates the theoretical number of required emitters per plant. The presented formulations are applied in diferent practical examples covering a wide range of scenarios. The results allow a general overview of the infuence of the soil type, the emitter fow rate, and the selected overlapping ratio in the number of required emitters per plant. The revision of guidelines and methods presented here, complemented with other experimental results and models of soil water dynamics under drip irrigation, might contribute to a better decision making of designers and feld engineers.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature.Martí, P.; González Altozano, P.; Gasque Albalate, M.; Turegano Pastor, JV.; Royuela, A. (2023). Geometric overlapping coefcients for calculating the required emitters per plant in drip irrigation. Irrigation Science. 1-20. https://doi.org/10.1007/s00271-023-00898-z120Al-Ogaidi AAM, Wayayok A, Rowshon MK, Fikri Abdullah A (2016) Wetting patterns estimation under drip irrigation Systems using an enhanced empirical model. Agric Water Manag 176:203–213. https://doi.org/10.1016/j.agwat.2016.06.002ASAE EP 405.1 1988 (R2019) Design and installation of microirrigation systems. American Society of Agricultural Engineers. USAAtkinson D (1983) The growth, activity and distribution of the fruit tree root system. Plant Soil 71:23–35. https://doi.org/10.1007/BF02182638Ayars J E, Hutmacher RB, Schoneman RA, Vail SS, Patton SH, Felleke D (1985) Salt distribution under cotton trickle irrigated with saline water. In: Drip/Trickle Irrigation in Action. Proc. Third Drip/Trickle Irrigation Congress, Fresno, California. Nov. 18–21, 1985. ASAE. Vol 2:666–672Ayars JE, Bucks DA, Lamm FR, Nakayama FS (2007) Introduction. In: Lamm FR, Ayars JE, Nakayama FS (eds) Microirrigation for crop production. Design, operation, and management. Elsevier, Amsterdam, pp 1–26Bar-Yosef B, Sagiv B, Markovitch T (1989) Sweet corn response to surface and subsurface trickle phosphorus fertigation. Agron J 81:443–447Benami A, Ofen A (1983) Irrigation engineering. Irrigation Engineering Scientific Publication, Haifa, IsraelBielorai H (1985) Moisture, salinity, and root distribution in drip irrigated grapefruit. In: Drip/Trickle Irrigation in Action. Proc. Third Drip/Trickle Irrigation Congress, Fresno, California. Nov. 18–21, 1985. ASAE Vol 2:562–567Black JDF, West DW (1974) Water uptake by an apple tree with various proportions of the root system supplied with water. In: Proceedings of the 2nd International Drip Irrigation Congress. California, USA. pp 32–433Clark GA, Haman DZ, Prochaska JF, Yitayew M (2007) General system design principles. In: Lamm FR, Ayars JE, Nakayama FS (eds) Microirrigation for crop production. Design, operation, and management. Elsevier, Amsterdam, pp 161–220del Vigo Á, Zubelzu S, Juana L (2020) Numerical routine for soil dynamics from trickle irrigation. Appl Math Model 83:371–385. https://doi.org/10.1016/j.apm.2020.01.058del Vigo Á, Juana L, Rodriguez-Sinobas L (2022) Modelo numérico de simulación de flujo de agua en el suelo afectado por la absorción de la raíz. 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Comput Electron Agric 178(11):105767. https://doi.org/10.1016/j.compag.2020.105767Keller J (1978) Trickle irrigation. Section 15-7. National Engineering Handbook. Soil Conservation Service. USDA, USAKeller J, Karmeli D (1974) Trickle irrigation design. Rainbird Sprinkler Manufacturing Corporation, Glendora, CaliforniaLevin I, Assaf R, Bravdo B (1979) Soil moisture and root distribution in an apple orchard irrigated by tricklers. Plant Soil 52:31–40. https://doi.org/10.1007/BF02197729Meiri A, Frenkel H, Mantell A (1992) Cotton response to water and salinity under sprinkler and drip irrigation. Agron J 84:44–50Montalvo T (2003) Riego localizado: diseño de instalaciones. Inter-técnica, SpainOzgur K, Payam K, Salim H, Bakhtiar K, Nazir K (2021) Modeling wetting front redistribution of drip irrigation systems using a new machine learning method: adaptive neuro- fuzzy system improved by hybrid particle swarm optimization – gravity search algorithm. Agric Water Manag 256:107067. https://doi.org/10.1016/j.agwat.2021.107067Pizarro F (1996) Riegos Localizados de alta frecuencia: goteo, microaspersión, exudación. Mundi-Prensa, SpainPlaut Z, Carmi A, Grava A (1988) Cotton growth and production under drip-irrigation restricted soil wetting. Irrig Sci 9:143–156. https://doi.org/10.1007/BF00262356Rodrigo J, Hernández JM, Pérez A, González JF (1997) Riego localizado. Mundi-Prensa, SpainRusso D (1987) Lettuce yield-irrigation water quality and quantity relationships in a gypsiferous desert soil. Agron J 79:8–14Schwankl LJ, Hanson BR (2007) Surface drip irrigation. In: Lamm FR, Ayars JE, Nakayama FS (eds) Microirrigation for crop production. Design, operation, and management. Elsevier, Amsterdam, pp 431–472Schwankl LJ, Edstrom J, Hopmans J, Andreu L, Koumanov K (1999) Microsprinklers wet larger soil volume; boost almond yield, tree growth. Calif Agric 53(2):39–43Schwartzman M, Zur B (1986) Emitter spacing and geometry of wetted soil volume. J Irrig Drain Eng 112(3):242–253. https://doi.org/10.1061/(ASCE)0733-9437(1986)112:3(242)Shiri J, Karimi B, Karimi N, Kazemi MH, Karimi S (2020) Simulating wetting front dimensions of drip irrigation systems: multi criteria assessment of soft computing models. J Hydrol 585:124792. https://doi.org/10.1016/j.jhydrol.2020.124792Šimůnek J, van Genuchten MT, Šejna M (2006) The HYDRUS software package for simulating the two- and three-dimensional movement of water, heat, and multiple solutes in variably-saturated media, Technical Manual Version 1.0 University of California Riverside. Riverside, CA, 3PC. Progress, Prague. Czech RepublicŠimůnek J, van Genuchten MT, Šejna M (2016) Recent developments and applications of the HYDRUS computer software packages. Vadose Zone J 15(7):1–25. https://doi.org/10.2136/vzj2016.04.0033USDA-NRCS (USDA-Natural Resources Conservation Service) (1984) Trickle irrigation, national engineering handbook. Section 15, Ch 7Waller P, Yitayew M (2016) Irrigation and drainage engineering. Springer International Publishing, Cham. https://doi.org/10.1007/978-3-319-05699-9Wang J, Chen R (2020) An improved finite element model for the hydraulic analysis of drip irrigation subunits considering local emitter head loss. Irrig Sci 38:147–162. https://doi.org/10.1007/s00271-019-00656-0Willoughby YP, Cockroft B (1974) Changes in root patterns of peach trees under tickle irrigation. In: Proceedings of the 2nd International Drip Irrigation Congress. California, USA. pp 439–44

Development of a Low-Cost Open-Source Platform for Smart Irrigation Systems

Nowadays, smart irrigation is becoming an essential goal in agriculture, where water and energy are increasingly limited resources. Its importance will grow in the coming years in the agricultural sector where the optimal use of resources and environmental sustainability are becoming more important every day. However, implementing smart irrigation is not an easy task for most farmers since it is based on knowledge of the different processes and factors that determine the crop water requirements. Thanks to technological developments, it is possible to design new tools such as sensors or platforms that can be connected to soil-water-plant-atmosphere models to assist in the optimization and automation of irrigation. In this work, a low-cost, open-source IoT system for smart irrigation has been developed that can be easily integrated with other platforms and supports a large number of sensors. The platform uses the FIWARE framework together with customized components and can be deployed using edge computing and/or cloud computing systems. To improve decision-making, the platform integrates an irrigation model that calculates soil water balance and wet bulb dimensions to determine the best irrigation strategy for drip irrigation systems. In addition, an energy efficient open-source datalogger has been designed. The datalogger supports a wide range of communications and is compatible with analog sensors, SDI-12 and RS-485 protocols. The IoT system has been deployed on an olive farm and has been in operation for one irrigation season. Based on the results obtained, advantages of using these technologies over traditional methods are discussed

Study of the Soil Water Movement in Irrigated Agriculture

In irrigated agriculture, the study of the various ways water infiltrates into the soils is necessary. In this respect, soil hydraulic properties, such as soil moisture retention curve, diffusivity, and hydraulic conductivity functions, play a crucial role, as they control the infiltration process and the soil water and solute movement. This Special Issue presents the recent developments in the various aspects of soil water movement in irrigated agriculture through a number of research topics that tackle one or more of the following challenges: irrigation systems and one-, two-, and three-dimensional soil water movement; one-, two-, and three-dimensional infiltration analysis from a disc infiltrometer; dielectric devices for monitoring soil water content and methods for assessment of soil water pressure head; soil hydraulic properties and their temporal and spatial variability under the irrigation situations; saturated–unsaturated flow model in irrigated soils; soil water redistribution and the role of hysteresis; soil water movement and drainage in irrigated agriculture; salt accumulation, soil salinization, and soil salinity assessment; effect of salts on hydraulic conductivity; and soil conditioners and mulches that change the upper soil hydraulic properties and their effect on soil water movement

Enhancing quality of service in IoT through deep learning techniques

When evaluating an Internet of Things (IoT) platform, it is crucial to consider the quality of service (QoS) as a key criterion. With critical devices relying on IoT technology for both personal and business use, ensuring its security is paramount. However, the vast amount of data generated by IoT devices makes it challenging to manage QoS using conventional techniques, particularly when attempting to extract valuable characteristics from the data. To address this issue, we propose a dynamic-progressive deep reinforcement learning (DPDRL) technique to enhance QoS in IoT. Our approach involves collecting and preprocessing data samples before storing them in the IoT cloud and monitoring user access. We evaluate our framework using metrics such as packet loss, throughput, processing delay, and overall system data rate. Our results show that our developed framework achieved a maximum throughput of 94%, indicating its effectiveness in improving QoS. We believe that our deep learning optimization approach can be further utilized in the future to enhance QoS in IoT platforms

Enhancing child safety with accurate fingerprint identification using deep learning technology

Utilizing deep learning algorithms to differentiate the fingerprints of children can greatly enhance their safety. This advanced technology enables precise identification of individual children, facilitating improved monitoring and tracking of their activities and movements. This can effectively prevent abductions and other forms of harm, while also providing a valuable resource for law enforcement and other organizations responsible for safeguarding children. Furthermore, the use of deep learning algorithms minimizes the potential for errors and enhances the overall accuracy of fingerprint recognition. Overall, implementing this technology has immense potential to significantly improve the safety of children in various settings. Our experiments have demonstrated that deep learning significantly enhances the accuracy of fingerprint recognition for children. The model accurately classified fingerprints with an overall accuracy rate of 93%, surpassing traditional fingerprint recognition techniques by a significant margin. Additionally, it correctly identified individual children's fingerprints with an accuracy rate of 89%, showcasing its ability to distinguish between different sets of fingerprints belonging to different children

Riego de precisión para la eficiencia hídrica en la agricultura Mediterránea

Tesis por compendio[EN] The present Doctoral Thesis is framed around the three axes of the efficient irrigation: water distribution system selection, determination of irrigation water needs and plant water status assessment. The experiment detailed in Chapter II is focused on the selection of the drip irrigation system better adapted to the peculiarities of citrus crops. The possible advantages of subsurface drip irrigation and the installation of irrigation laterals with higher density of emitters per plant were evaluated. Specifically, in the study was assessed the performance of the mandarin (Citrus clementina, Hort. Ex Tan. 'Arrufatina') under a surface (SI) and subsurface drip irrigation (SSI) with 7 (SI7, SSI7) or 14 emitters (SI14, SSI14) per plant, as well as a third SS treatment (SSIA), identical to SSI7 but equipped with an additional drip line buried between the tree rows. Treatments were assessed in terms of yield, fruit composition, water productivity (WP) and water savings. Results showed that, on average, water savings were 23.0% in the SSI treatment compared to the SI treatment without significant differences in either yield or fruit composition. SSIA was the treatment with the lowest irrigation volumes and the highest yield. Chapter III proposes a methodology for estimating irrigation water needs for mandarins based on the use of capacitance water content probes (e.f. FDR). The calculation procedure is defined in three sequential parts: i) soil water content thresholds determination adapted to plants requirements for different phenological stages; ii) standardizing measurements from capacitance probes by using a hydrological simulation software to minimize equipment uncertainty; and finally iii) an extrapolation procedure for adapting critical soil water content thresholds to different soil conditions. Validating this strategy in a citrus orchard (Citrus clementina, Hort. Ex Tan. 'Arrufatina') a water saving of 26% was reached without significant differences in yield and increasing the WP by 33%. In the experiments described in the Chapter IV a leaf turgor pressure sensor (Yara ZIM-probe) was evaluated as plant water status indicator in order to further asses the possibility to implement water status determinations in a more holistic irrigation scheduling approach. This technology, through a patch of an intact leaf and a pressure transductor, provides a signal (Pp) which is inversely correlated with the turgor pressure. The first experiment was made in Persimmon trees (Diospyros kaki L.f.). The turgor pressure sensor was assessed in an experimental plot with different irrigation doses and rootstocks with different drought tolerance [Diospyros lotus (L) and Diospyros virginiana (V)]. The information provided by the sensor was compared with concomitant measurements of midday stem water potential (¿stem) and trunk diameter variations. Three states of leaf turgor associated with specific plant water status were established from the study of the Pp signal evolution together with the ¿stem. Persimmon trees exhibited the inversed Pp curve phenomena under water stress (maximum values at night). Using the information from the sensors, it was possible to differentiate plant water status between rootstocks, pointing L as the most sensitive to the water deficit. The second experiment was made in mandarin (Citrus clementina, Hort. Ex Tan. 'Arrufatina'). Similarly, Pp values were compared with ¿stem measurements. In this case, the curves practically did not suffer inversions when the plant water status was inadequate, but an increase in the minimum and maximum Pp values was recorded at night and at noon, respectively. There was a good correlation between the concomitant hourly spot measurements of ¿stem and Pp that were taken at midday during two drought periods (coefficient of determination, r2 = 0.40 - 0.74). The analysed strategies and technologies have demonstrated that water use efficiency can be optimized at the plot level. Consumptive water use can be reduced using subsurface irrigation systems, achieving net savings in water consumption. By estimating the irrigation dose by means of capacitance soil water content probes, the efficiency in the application of the irrigation is improved and the water losses due to deep percolation are reduced, minimizing the leaching of nutrients and with it, the risk of aquifer contamination. In any case, it would be advisable to study the viability of these proposals in the global and integral context of water resources management at watershed and irrigation district level.[ES] La presente Tesis Doctoral se enmarca en torno a los tres ejes que requiere cualquier riego para considerarse eficiente: 1) selección del sistema de distribución de agua, 2) determinación de las necesidades de riego y 3) control del estado hídrico de la planta. El ensayo detallado en el Capítulo II se centró en la selección del sistema de riego por goteo que mejor se adaptara a las particularidades del cultivo de los cítricos. Se estudió la respuesta productiva de mandarino (Citrus clementina, Hort. Ex Tan. 'Arrufatina') en función de diversos sistemas de riego superficial (SI) y subterráneo (SSI) con 7 (SI7, SSI7) y 14 emisores (SI14, SSI14) por planta dispuestos en doble línea, así como un tercer tratamiento subterráneo (SSIA), idéntico a SSI7, pero equipado con una línea adicional subterránea situada entre filas de árboles. Los resultados mostraron que el ahorro de agua empleando el sistema SSI, en comparación con SI, puede llegar a ser del 23% sin mermas en la producción ni en la calidad de la fruta, incrementando por lo tanto la WP. El sistema SSIA fue el tratamiento que empleó menor volumen de agua de riego y obtuvo mayor rendimiento productivo. En el Capítulo III se propone una metodología de cálculo de las necesidades de riego para mandarinos basada en el uso de sondas de humedad de tipo capacitivo (e.f. FDR). El procedimiento de cálculo se define en tres fases secuenciales: i) determinación de umbrales de humedad de suelo adaptados a los requerimientos de las plantas en distintas fases fenológicas; ii) estandarización de las lecturas de las sondas capacitivas mediante un programa de simulación hidrológica que permita reducir los efectos de la variabilidad intrínseca de los equipos; y, por último, iii) un procedimiento para extrapolar los umbrales de humedad definidos en el trabajo a cualquier parcela con distintas características edáficas. La validación de esta estrategia en una parcela de cítricos (Citrus clementina, Hort. Ex Tan. 'Arrufatina') supuso un ahorro de agua del 26% sin reducciones significativas en la producción, mejorando la WP un 33%. En los ensayos descritos en el Capítulo IV se realiza la evaluación de los sensores de turgencia de hojas (Yara ZIM-probe) como indicadores del estado hídrico de la planta. Un primer experimento se realizó en caqui (Diospyros kaki L.f.), evaluando los sensores de turgencia en un ensayo de campo con distintas dosis de riego y portainjertos con diferente tolerancia a la sequía [Diospyros lotus (L) y Diospyros virginiana (V)]. La información que proporcionaba el sensor se comparó con medidas de potencial hídrico de tallo al mediodía solar (¿stem) y variaciones del diámetro del tronco. La evolución del Pp junto con los valores de ¿stem, permitió establecer tres estados de turgencia asociados a estados hídricos concretos. Los árboles insuficientemente regados con ¿stem por debajo de los -0.8 MPa, mostraron curvas Pp con signos de inversión (valores máximos durante la noche). Así mismo, con la información procedente de los sensores, fue posible diferenciar el estado hídrico entre patrones, señalando a L como el portainjerto más sensible al déficit hídrico. El segundo experimento se realizó en mandarino (Citrus clementina, Hort. Ex Tan. 'Arrufatina'). Del mismo modo, los valores de Pp se compararon con las medidas de ¿stem. En este caso, las curvas prácticamente no sufrieron inversiones cuando el estado hídrico de la planta era inadecuado, pero sí se determinó un aumento de los valores de Pp mínimos y máximos registrados por la noche y al mediodía, respectivamente. Así mismo, se realizaron dos ciclos de medidas horarias que mostraron que existe una buena correlación entre Pp y ¿stem (coeficiente de determinación, r2 = 0.40 - 0.74). Las estrategias y tecnologías investigadas han demostrado que es posible optimizar la eficiencia del uso del agua en parcela. Con la implementación de sistemas de riego subterráneo se puede reducir el uso consuntivo de agua, obteniendo ahorros netos en el consumo hídrico. Mediante la estimación de la dosis de riego a través de sensores de humedad, se mejora la eficiencia en la aplicación del riego y se reducen así las pérdidas por percolación profunda, minimizando el lavado de nutrientes y, con ello, el riesgo de contaminación de los acuíferos. En todo caso, sería recomendable estudiar la viabilidad de estas propuestas en el contexto global e integral de la gestión de los recursos hídricos a nivel de un distrito de riego y cuenca hidrográfica.[CA] La present Tesi Doctoral s'emmarca al voltant de tres eixos que requerix qualsevol reg per a considerar-se eficient: 1) selecció del sistema de distribució d'aigua, 2) determinació de les necessitats de reg i, 3) control de l'estat hídric de la planta. L'assaig detallat al Capítol II es centrà en la selecció del sistema de reg per degoteig que millor s'adaptara a les particularitats del cultiu dels cítrics. S'estudià la resposta productiva del mandarí (Citrus clementina, Hort. Ex Tan. 'Arrufatina') en funció dels diversos sistemes de reg superficial (SI) i subterrani (SSI) amb 7 (SI7, SSI7) i 14 emissors (SI14, SSI14) per planta disposats en doble línia, així com un tercer tractament subterrani (SSIA), idèntic a SSI7, però equipat amb una línia addicional subterrània col·locada entre fileres d'arbres. L'efecte dels tractaments s'avaluà en xifres de producció, qualitat de la fruita, productivitat de l'aigua (WP) i estalvi d'aigua. Els resultats mostraren que l'estalvi d'aigua amb el sistema SSI poden arribar a ser del 23% en comparació amb SI, sense minves en la producció ni en la qualitat de la fruita, incrementant per tant la WP. El sistema SSIA fou el tractament que emprà menys volum d'aigua de reg i obtingué un major rendiment productiu. Al Capítol III es proposa una metodologia de càlcul de les necessitats de reg per a mandarins basada en l'ús de sondes d'humitat de tipus capacitiu (e.f. FDR). El procediment de càlcul es definix en tres fases seqüencials: i) determinació de límits d'humitat de sòl adaptats als requeriments de les plantes en diverses fases fenològiques; ii) estandardització de les lectures de les sondes capacitives mitjançant un programa de simulació hidrològica que permet reduir els efectes de la variabilitat intrínseca dels equips; i, per últim, iii) un procediment per a extrapolar els límits d'humitat definits al treball a qualsevol parcel·la amb diferents característiques edàfiques. La validació d'aquesta estratègia en una parcel·la de cítrics (Citrus clementina, Hort. Ex Tan. 'Arrufatina') suposà un estalvi d'aigua del 26% sense reduccions significatives en la producció, millorant la WP un 33%. Als assajos descrits al Capítol IV es realitza l'avaluació dels sensors de turgència de fulles (Yara ZIM-probe) com a indicadors de l'estat hídric de la planta. Un primer experiment es realitzà en caqui (Diospyros kaki L.f.), avaluant els sensors de turgència en un assaig de camp amb diverses dosis de reg i portaempelts amb diferent tolerància a la sequera [Diospyros lotus (L) i Diospyros virginiana (V)]. La informació que proporcionava el sensor es comparà amb mesures de potencial hídric de tija al migdia solar (¿stem) i variacions del diàmetre de tronc. L'estudi determinà que l'anàlisi visual de les corbes dels valors diaris de Pp és un bon indicador de l'estat hídric de la planta. L'evolució de Pp juntament amb els valors de ¿stem, permeté establir tres estats de turgència associats a estats hídrics concrets. Els arbres insuficientment regats amb ¿stem per baix dels -0.8 MPa, mostraren corbes Pp amb signes d'inversió (valors màxims durant la nit). Així mateix, amb la informació procedent dels sensors fou possible diferenciar l'estat hídric entre patrons, assenyalant a L com el portaempelt més sensible al dèficit hídric. El segon experiment es realitzà en mandarí (Citrus clementina, Hort. Ex Tan. 'Arrufatina'). Els valors de Pp es compararen amb les mesures de ¿stem. En aquest cas, les corbes pràcticament no sofriren inversions quan l'estat hídric era inadequat, però sí es determinà un augment dels valors de Pp mínims i màxims registrats a la nit i al migdia, respectivament. Així mateix, es realitzaren dos cicles de mesures horàries que mostraren que existix una bona correlació entre Pp i ¿stem (coeficient de determinació, r2 = 0.40 -0.74 ). Les estratègies i tecnologies investigades han demostrat que és possible optimitzar l’eficiència de l’ús de l’aigua en parcel·la. Amb la implementació de sistemes de reg subterrani es pot reduir l’ús consumptiu d’aigua, obtenint estalvis nets en el consum hídric. Amb l’estimació de la dosi de reg mitjançant sensors d’humitat, es millora l’eficiència en l’aplicació del reg i es reduix així les pèrdues per percolació profunda, minimitzant el llavat de nutrients, i amb això, el risc de contaminació dels aqüífers. En tot cas, seria recomanable estudiar la viabilitat d’aquestes propostes al context global i integral de la gestió dels recursos hídrics a nivell de districte de reg i conca hidrogràfica.Martínez Gimeno, MA. (2020). Riego de precisión para la eficiencia hídrica en la agricultura Mediterránea [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/149394TESISCompendi

Optimización de la gestión de redes de riego a presión a diferentes escalas mediante Inteligencia Artificial

Factors such as climate change, world population growth or the competition for the water resources make freshwater availability become an increasingly large and complex global challenge. Under this scenario of reduced water availability, increasing droughts frequency and uncertainties associated with a changing climate, the irrigated agriculture sector, particularly in the Mediterranean region, will need to be even more efficient in the use of the water resources. In Spain, many irrigation districts have been modernized in recent years, replacing the obsolete open channels by pressurized water distribution networks towards improvements in water use efficiency. Thanks to this, water use has reduced but the energy demand and the water costs have dramatically increased. Thus, strategies to reduce simultaneously water and energy uses in irrigation districts are required. This thesis consists of nine chapters, which include several models to optimize the management of the irrigation districts and increase the efficiency of water and energy use.Factores tales como el cambio climático, el crecimiento de la población mundial o la competencia por los recursos hídricos hacen que la disponibilidad de agua se esté convirtiendo en un desafío global cada vez más grande y complejo. En este escenario de reducción de la disponibilidad de agua, aumento de la frecuencia de las sequías y de las incertidumbres asociadas a un cambio climático, el sector de la agricultura de regadío, en particular en la región mediterránea, tendrá que ser aún más eficiente en el uso de los recursos hídricos. En España, muchas comunidades de regantes se han modernizado en los últimos años, sustituyendo los obsoletos canales abiertos por redes de distribución de agua a presión con el objetivo de mejorar la eficiencia en el uso del agua. Gracias a esto, el uso del agua se ha reducido, pero la demanda de energía y los costos del agua se han incrementado drásticamente. Por lo tanto, se requieren estrategias para reducir simultáneamente el uso de agua y energía en las comunidades de regantes. Esta tesis consta de nueve capítulos que incluyen varios modelos para optimizar la gestión de las comunidades de regantes y aumentar la eficiencia en el uso del agua y la energía

Assessment of fruit growth response to water stress in a super-high-density olive orchard: monitoring, physiological mechanisms and potential use to schedule irrigation.

Olive fruit growth has an important effect on the final yield, and thus, it is important to study its response to water stress, and to know how olive fruits grow under no water restriction. The present PhD. Thesis centered on the fruit growth, and the factors that influence it, such as the root system distribution, the leaf gas exchange and the water relations between fruits and leaves as well as on the utility of continuous measurements of fruit diameter variations. Therefore, in Chapter 2 we assessed the influence of the increment of drip lines (from one to two drip lines per tree row) on the belowground and aboveground vegetative and on the fruit growth, during two irrigation seasons. We also estimated leaf stomatal conductance from sap flux measurements, and simulated photosynthesis (Chapter 3). From the simulated photosynthesis, we compared its accumulated values with growth, both vegetative growth (leaf area and number of internodes in current-year stems) and fruit growth (fruit dry weight and oil content). As fruit growth is not only influenced by photosynthesis, but also by the water relations, we assessed the influence of water stress on the water relations between fruits and leaves, and its influence on fruit growth (Chapter 4). Additionally, we performed pressure-volume curves with olive fruits from well irrigated and deficit irrigated treatments. Finally, we evaluated the usefulness of fruit dendrometers, and the indexes derived from its measurements, to assess tree water status and to schedule irrigation (Chapter 5). The results presented in this PhD. Thesis improve the knowledge on the factors involved in fruit growth and present a first step towards the use of fruit dendrometers in olive trees. Additionally, these results are important for the development of future studies on the olive fruit growth physiology

Advances in Monitoring Dynamic Hydrologic Conditions in the Vadose Zone through Automated High-Resolution Ground-Penetrating Radar Images and Analysis

This body of research focuses on resolving physical and hydrological heterogeneities in the subsurface with ground-penetrating radar (GPR). Essentially, there are two facets of this research centered on the goal of improving the collective understanding of unsaturated flow processes: i) modifications to commercially available equipment to optimize hydrologic value of the data and ii) the development of novel methods for data interpretation and analysis in a hydrologic context given the increased hydrologic value of the data. Regarding modifications to equipment, automation of GPR data collection substantially enhances our ability to measure changes in the hydrologic state of the subsurface at high spatial and temporal resolution (Chapter 1). Additionally, automated collection shows promise for quick high-resolution mapping of dangerous subsurface targets, like unexploded ordinance, that may have alternate signals depending on the hydrologic environment (Chapter 5). Regarding novel methods for data inversion, dispersive GPR data collected during infiltration can constrain important information about the local 1D distribution of water in waveguide layers (Chapters 2 and 3), however, more data is required for reliably analyzing complicated patterns produced by the wetting of the soil. In this regard, data collected in 2D and 3D geometries can further illustrate evidence of heterogeneous flow, while maintaining the content for resolving wave velocities and therefore, water content. This enables the use of algorithms like reflection tomography, which show the ability of the GPR data to independently resolve water content distribution in homogeneous soils (Chapter 5). In conclusion, automation enables the non-invasive study of highly dynamic hydrologic processes by providing the high resolution data required to interpret and resolve spatial and temporal wetting patterns associated with heterogeneous flow. By automating the data collection, it also allows for the novel application of established GPR data algorithms to new hydrogeophysical problems. This allows us to collect and invert GPR data in a way that has the potential to separate the geophysical data inversion from our ideas about the subsurface; a way to remove ancillary information, e.g. prior information or parameter constraints, from the geophysical inversion process

A novel nomadic people optimizer-based energy-efficient routing for WBAN

In response to user demand for wearable devices, several WBAN deployments now call for effective communication processes for remote data monitoring in real time. Using sensor networks, intelligent wearable devices have exchanged data that has benefited in the evaluation of possible security hazards. If smart wearables in sensor networks use an excessive amount of power during data transmission, both network lifetime and data transmission performance may suffer. Despite the network's effective data transmission, smart wearable patches include data that has been combined from several sources utilizing common aggregators. Data analysis requires careful network lifespan control throughout the aggregation phase. By using the Nomadic People Optimizer-based Energy-Efficient Routing (NPO-EER) approach, which effectively allows smart wearable patches by minimizing data aggregation time and eliminating routing loops, the network lifetime has been preserved in this research. The obtained findings showed that the NPO method had a great solution. Estimated Aggregation time, Energy consumption, Delay, and throughput have all been shown to be accurate indicators of the system's performance