Quantitative analysis of non-cooperative transboundary river basins

Le partage de l’eau dans des bassins versants transfrontaliers est un problème complexe, en particulier lorsqu’il n’y a pas de tradition de coopération entre les pays riverains dans d’autres domaines non liés à l’eau tels que le commerce. De plus, à mesure que les ressources en eau se développent et que le changement climatique est une nouvelle source de risque, le manque d’informations partagées quant aux débits hydrologiques et aux décisions humaines et institutionnelles sur la gestion des ressources rend de plus en plus difficile la distinction entre facteurs naturels et anthropiques dans le dérèglement d’un régime hydrologique. Des tentatives de récupération de données hydrologiques dans des régions difficiles d’accès ont été réalisées avec succès en utilisant la télédétection. Mais l’application de cette technique pour la modélisation des systèmes d’eau (notamment pour caractériser des infrastructures ou des comportements d’usagers) reste difficile puisqu’elle nécessite d’importantes observations et interactions avec les gestionnaires de la ressource sur le terrain. La portée de la plupart des techniques de modélisation est également limitée par leur incapacité à gérer la multitude d’institutions en charge des ressources en eau, ou l’impact de leurs intérêts spécifiques et souvent opposés sur la ressource en elle-même. Pendant des décennies, ce manque de données détaillées et de techniques de modélisation appropriées a conduit de nombreuses études sur des bassins versants internationaux non gérés de façon concertée à rester qualitatives ou conceptuelles. Cette incapacité à comprendre et à quantifier de manière indépendante les causes de changements hydrologiques est particulièrement frustrante pour des décideurs politiques. Dans le bassin du Yarmouk, par exemple, qui est partagé entre la Syrie, la Jordanie et Israël, le débit annuel moyen correspond aujourd’hui à moins de 15 % de celui qui a précédé la période de développement, et ce malgré la signature d’accords bilatéraux entre la Syrie et la Jordanie (1987) et entre la Jordanie et Israël (1994). Cette situation a conduit les pays riverains à développer chacun leur propre théorie, contestée, concernant l’effondrement du débit du Yarmouk. En prenant ce bassin comme étude de cas, cette thèse de doctorat vise à analyser quantitativement des changements hydrologiques dans des bassins versants transfrontaliers, non gérés de façon concertée, complexes institutionnellement, et aménagés à l’excès. Cet objectif passe par deux activités de recherche principales : (i) le suivi de la retenue d’eau de petits barrages dans des zones inaccessibles – comme première étape à la caractérisation d’un système multi-réservoirs ; et la simulation et l’analyse de scénarios, dans le but d’étudier de manière quantitative des changements hydrologiques dans un bassin versant. Les résultats indiquent que des facteurs naturels et anthropiques sont responsables de la chute du débit du Yarmouk et évaluent leur contribution à cet effet en combinant télédétection, simulation multi-agent et analyse de scénarios.Sharing waters in a transboundary river basin is challenging, especially when there is no tradition of cooperation between riparian countries in other, non water-related, issues such as trade. Moreover, as water resources are being developed and climate change is a new source of risk, the lack of shared information on hydrological flows and human/institutional decisions on resources management implies that it is increasingly difficult to distinguish between natural and anthropogenic factors affecting a flow regime. Attempts to retrieve hydrological data in hardly accessible areas have successfully been made using remote sensing. But the use of this technique for water systems modeling efforts, and particularly for characterizing infrastructure or understand water user behaviors, remains challenging as it requires extensive on-the-ground observations and interactions with water resources managers. The scope of most modeling techniques is also limited by their inability to handle the multiplicity of institutions dealing with water, or the impact of their specific and often competing interests on water resources. For decades, this lack of detailed data and suitable modeling techniques has led many studies on non-cooperatively managed international river basins to remain qualitative or conceptual, and has therefore frustrated policy makers for not being able to independently understand and quantify the causes of hydrological changes. In the Yarmouk River basin, for example, which is shared between Syria, Jordan and Israel, the annual outflow now corresponds to less than 15% of that of pre-development era, despite the signature of bilateral agreements between Syria and Jordan (1987), and between Jordan and Israel (1994). This state of affairs has led riparian countries to develop their own, contested, narratives regarding the collapse of the Yarmouk flow. Taking the Yarmouk basin as a case-study, this Ph.D. thesis consequently aims at quantitatively analyzing past hydrological changes in non-cooperatively managed, institutionally complex, over-built, transboundary river basins. This objective goes through two main research activities: (i) the monitoring of small reservoirs’ storage in inaccessible areas, as a start to characterize a multi-reservoir system; and (ii) the simulation and analysis of scenarios to quantitatively study changes in a river basin. Results reveal that the contributions of natural and anthropogenic factors to explain the decline of the Yarmouk flows can be identified and then assessed using remote sensing, multi-agent simulation, and scenario analysis

Proceedings of the European Conference on Agricultural Engineering AgEng2021

This proceedings book results from the AgEng2021 Agricultural Engineering Conference under auspices of the European Society of Agricultural Engineers, held in an online format based on the University of Évora, Portugal, from 4 to 8 July 2021. This book contains the full papers of a selection of abstracts that were the base for the oral presentations and posters presented at the conference. Presentations were distributed in eleven thematic areas: Artificial Intelligence, data processing and management; Automation, robotics and sensor technology; Circular Economy; Education and Rural development; Energy and bioenergy; Integrated and sustainable Farming systems; New application technologies and mechanisation; Post-harvest technologies; Smart farming / Precision agriculture; Soil, land and water engineering; Sustainable production in Farm buildings

A New Temperature-Vegetation Triangle Algorithm with Variable Edges (TAVE) for Satellite-Based Actual Evapotranspiration Estimation

The estimation of spatially-variable actual evapotranspiration (AET) is a critical challenge to regional water resources management. We propose a new remote sensing method, the Triangle Algorithm with Variable Edges (TAVE), to generate daily AET estimates based on satellite-derived land surface temperature and the vegetation index NDVI. The TAVE captures heterogeneity in AET across elevation zones and permits variability in determining local values of wet and dry end-member classes (known as edges). Compared to traditional triangle methods, TAVE introduces three unique features: (i) the discretization of the domain as overlapping elevation zones; (ii) a variable wet edge that is a function of elevation zone; and (iii) variable values of a combined-effect parameter (that accounts for aerodynamic and surface resistance, vapor pressure gradient, and soil moisture availability) along both wet and dry edges. With these features, TAVE effectively addresses the combined influence of terrain and water stress on semi-arid environment AET estimates. We demonstrate the effectiveness of this method in one of the driest countries in the world—Jordan, and compare it to a traditional triangle method (TA) and a global AET product (MOD16) over different land use types. In irrigated agricultural lands, TAVE matched the results of the single crop coefficient model (−3%), in contrast to substantial overestimation by TA (+234%) and underestimation by MOD16 (−50%). In forested (non-irrigated, water consuming) regions, TA and MOD16 produced AET average deviations 15.5 times and −3.5 times of those based on TAVE. As TAVE has a simple structure and low data requirements, it provides an efficient means to satisfy the increasing need for evapotranspiration estimation in data-scarce semi-arid regions. This study constitutes a much needed step towards the satellite-based quantification of agricultural water consumption in Jordan

A New Temperature-Vegetation Triangle Algorithm with Variable Edges (TAVE) for Satellite-Based Actual Evapotranspiration Estimation

The estimation of spatially-variable actual evapotranspiration (AET) is a critical challenge to regional water resources management. We propose a new remote sensing method, the Triangle Algorithm with Variable Edges (TAVE), to generate daily AET estimates based on satellite-derived land surface temperature and the vegetation index NDVI. The TAVE captures heterogeneity in AET across elevation zones and permits variability in determining local values of wet and dry end-member classes (known as edges). Compared to traditional triangle methods, TAVE introduces three unique features: (i) the discretization of the domain as overlapping elevation zones; (ii) a variable wet edge that is a function of elevation zone; and (iii) variable values of a combined-effect parameter (that accounts for aerodynamic and surface resistance, vapor pressure gradient, and soil moisture availability) along both wet and dry edges. With these features, TAVE effectively addresses the combined influence of terrain and water stress on semi-arid environment AET estimates. We demonstrate the effectiveness of this method in one of the driest countries in the world—Jordan, and compare it to a traditional triangle method (TA) and a global AET product (MOD16) over different land use types. In irrigated agricultural lands, TAVE matched the results of the single crop coefficient model (−3%), in contrast to substantial overestimation by TA (+234%) and underestimation by MOD16 (−50%). In forested (non-irrigated, water consuming) regions, TA and MOD16 produced AET average deviations 15.5 times and −3.5 times of those based on TAVE. As TAVE has a simple structure and low data requirements, it provides an efficient means to satisfy the increasing need for evapotranspiration estimation in data-scarce semi-arid regions. This study constitutes a much needed step towards the satellite-based quantification of agricultural water consumption in Jordan

COST Action 733. Harmonization and application of weather type classifications for European regions. Final scientific report

Freely available via Official URL link

Water resources of wadi systems of Southern Saudi Arabia

This study is a water resources assessment of two wadi systems in the southern Arabian Shield using seismic refraction, electrical resistivity (VES) and borehole geophysical techniques, pumping tests and ground water quality data and an examination of artificial recharge. Wadi Baysh (flowing southwest to the Red Sea) and Wadi Habawnah (flowing east to the Rub Al Khali) have similar catchment areas (approximately 10000 km2) and are underlain by igneous and metamorphic rocks but contrast in their hydrological cycles. The mean annual rainfall of Wadi Baysh is 350 mm while Wadi Habawnah receives 150 mm. The mean annual water discharges of Wadi Baysh and Wadi Habawnah are 75 and 10 mcm respectively. Hydrochemical classification, evolution of groundwater and its suitability for agricultural and domestic usage were studied in both wadis. In the upper and middle parts of both wadis the solute concentrations reach 1200 mg/l whereas in the lower parts solute concentrations range between 2000 and 3500 mg/l. Both wadis show high average values of transmissivity and storativity determined from pumping tests and grain size analysis. The geophysical surveys confirmed that the unconfined aquifer thickness is less than 42 m in both wadis. The seismic velocities of the aquifers range between 536 and 1817 ms-1 while the resistivities range between 23 and 125 ohm-m in both wadis. The igneous and metamorphic bedrock resistivity range between 3400 and 10260 ohm-m. The sediment has a high potential for water supply in the middle and lower parts of both wadis. The transverse resistance of the saturated part of the aquifers is used for correlation with the hydraulic transmissivity in which a computed empirical function may be applicable to similar aquifers in other Arabian Shield wadis. This study introduces a plan for the surface and subsurface storage that should help to manage the perennial yield and minimise the mining yield. The analysis reveals that building small reservoirs in both wadis is economically justifiable