Geo-Spatial Analysis in Hydrology

Geo-spatial analysis has become an essential component of hydrological studies to process and examine geo-spatial data such as hydrological variables (e.g., precipitation and discharge) and basin characteristics (e.g., DEM and land use land cover). The advancement of the data acquisition technique helps accumulate geo-spatial data with more extensive spatial coverage than traditional in-situ observations. The development of geo-spatial analytic methods is beneficial for the processing and analysis of multi-source data in a more efficient and reliable way for a variety of research and practical issues in hydrology. This book is a collection of the articles of a published Special Issue Geo-Spatial Analysis in Hydrology in the journal ISPRS International Journal of Geo-Information. The topics of the articles range from the improvement of geo-spatial analytic methods to the applications of geo-spatial analysis in emerging hydrological issues. The results of these articles show that traditional hydrological/hydraulic models coupled with geo-spatial techniques are a way to make streamflow simulations more efficient and reliable for flood-related decision making. Geo-spatial analysis based on more advanced methods and data is a reliable resolution to obtain high-resolution information for hydrological studies at fine spatial scale

Estuarine geomorphodynamic assessment of environmental change and stressor impacts: a geographic information systems and remote sensing (geoinformatic) modelling approach for sustainable management of southeast Australian coastal ecosystems

Increased habitation and global warming is posing growing threats to the coastal zone and estuarine settings through direct and indirect environmental and anthropogenic modification of sensitive coastal systems and their relevant catchments. It is essential to understand the impact of the different stressors on the coastal environment under current conditions and within the historical record in order to predict future responses of estuaries and coastal wetlands. Short-term remote sensing and GIS modelling and field assessment have made a significant contribution to our knowledge on estuarine and coastal wetland dynamism within the last few decades. This thesis assesses the potential impacts of anthropogenic modifications, climatic factors and sea level rise on estuarine eco-geomorphic intertidal sedimentary landforms and their associated coastal wetlands in southeastern Australia based on three estuarine systems on the south coast of NSW: the estuarine Comerong Island, Wandandian deltaic estuary, and Towamba estuary. The thesis’ short-term evaluation approach shows that the degradation levels on estuarine platforms are dependent on catchment development, sediment characteristics, ecosystem stability and sea level rise inundation. During anticipated climate change and rising sea level conditions, estuaries depend on their sediment source areas, especially on modifications to their river catchment. Catchments with high anthropogenic modification levels, like the dam infrastructure in the Shoalhaven River catchment, influence sediment availability and transportation with clear impacts on eco-geomorphic coastal platform losses. In contrast, mostly unmodified but high-sloped catchments, such as the Towamba example, may have other negative effects on the estuary since the sediments are poorly sorted and coarser noncohesive quartz-dominated particles cause the geomorphic landforms and associated ecosystems to be more vulnerable to erosion and lead to less stable vegetation. Regions with small moderately modified catchments, such as the Wandandian site, allow ideal geomorphic processes to occur. Here, sediment is weathered slowly and moved downstream naturally to a secure inner estuarine deltaic setting where fine sandy/silty particles accumulate and provide more geomorphic stability. Associated vegetation assemblages ensure the progradation and steady growth of the deltaic eco-geomorphic system. The thesis assessment shows the eco-geomorphic-dynamism of the Towamba estuary, which has a mostly unmodified catchment surface (only 14% anthropogenic modifications), has grown a total of 0.17 km2 since 1949. This growth rate indicates that the Towamba estuary future scenarios will mostly be filled at the completion of the 21st Century. In comparison, the partially modified (22.1%) catchment has prograded the Wandandian deltaic shorelines resulting in the total growth of 0.24 km2 during the study period (1949-2016). However, results on Comerong Island show significant changes in the spatial extent, elevation, and shorelines with total net losses of 0.3 km2 over the investigated timespan (1949-2014). Changes included northern accretion (0.4 km2), and western, middle and southern erosion (0.7 km2) of the island. The thesis emphasises the dynamic character of the estuarine eco-geomorphic system, particularly using Normalised Difference Vegetation Index (NDVI) as a vegetation canopy assessment approach. This approach illustrates the significant correlations between vegetation and climatic and geomorphic influences at the study sites, indicating that these factors are the main drivers of vegetation canopy disturbance on intertidal sedimentary landforms during the 21st Century. Locally, map-algebra expression shows the spatial distribution of the NDVI identifies areas that need to be managed in relation to the causes and drivers. This modelling confirms the LiDAR-DEMs-driven character of the existing situations to their influencing factors, which also control the estimated future-scenarios and illustrate clear inundatable landform zones at the study sites by 2100. Results indicate that the rise of sea level will have tremendous effects on the coastal eco-geomorphic systems, particularly wetlands, throughout southeastern Australia and equivalent systems overseas by the end of this century. This thesis develops possible mitigation and adaptation strategies and sustainable solutions that might be utilized to minimize the indirect devastating consequences of climate change and anthropogenic modifications, particularly damming rivers, which cause direct sedimentation problems as implied by the Tallowa Dam case study. The thesis shows that intertidal sedimentary landforms will have a future negative or positive vegetarian response according to their evolving morphological character. Within a short-term timescale, the whole eco-geomorphic system will interact with many environmental and anthropogenic variables (particularly sedimentation rates) to evolve its own character over a longer timescale. Therefore, the long term assessment approach can be directed by having a better understanding of the existing situation and accurately identifying the past drivers. Future projections indicate that indirect anthropogenic-induced global warming will have a great effect on estuaries and coastal wetlands in the 21st Century. This research helps to provide an important framework for quantifying the current situation, future stressors and vulnerability responses during any intensification of natural and artificial coastal hazards, which may be of concern to the general public and environmental scientists who are currently focusing their attention on the best way to preserve estuaries and their wetland ecosystems at the current stage of global warming and human settlement

Exploring sediment dynamics in coastal bays by numerical modelling and remote sensing

Coastal bays and salt marshes are buffer zones located at the interface between land and ocean, and provide ecologically and commercially important services worldwide. Unfortunately, their location makes them vulnerable and sensitive to sea-level rise (SLR), reduced sediment loads and anthropogenic modifications of the shoreline. Sediment budget and sediment availability are direct metrics for evaluating the resilience of salt marshes and coastal bays to various stressors (e.g. SLR). Salt marshes requires adequate sediment inputs to maintain their elevation with respect to sea level. Understanding sediment trajectories, sediment fluxes and sediment trapping capacities in different geomorphic unit facilitates efficient restorations and coastal management. In this research I used remote sensing, field observations and numerical modelling in the Plum Island Sound in Massachusetts, USA, to explore mechanisms controlling sediment dynamics and their feedbacks with SLR. The analysis of remote-sensed suspended sediment concentrations (SSC) reveals that a 5-year record (2013-2018) is sufficient to capture a representative range of meteorological and tidal conditions required to determine the main drivers of SSC dynamics in hydrodynamically-complex and small-scale coastal bays. The interplay between river and tidal flows dominated SSC dynamics in this estuary, whereas wind-driven resuspension had a more moderate effect. The SSC was higher during spring because of increased river discharge due to snowmelt. Tidal asymmetry also enhanced sediment resuspension during flood tides, possibly favoring deposition on marsh platforms. Together, water level, water-level rate of change, river discharge and wind speed were able to explain > 60% of the variability in the main channel SSC, thereby facilitating future prediction of SSC from these readily available variables. To determine the fate of cohesive sediments and spatial variations of trapping capacity in the system, a high-resolution (20 m) numerical model coupled to a vegetation module was developed. The results highlight the importance of the timing between sediment inputs and tidal phase and show that sediment discharged from tidal rivers deposit within the rivers themselves or in adjacent marshes. Most sediment is deposited in shallow tidal flats and channels and is unable to penetrate farther inside the marshes because of the limited water depths and velocities on the marsh platform. Trapping capacity of sediment in different intertidal subdomains decreases logarithmically with the ratio between advection length and the typical length of channels and tidal flats. Moreover, sediment deposition on the marsh decreases exponentially with distance from the channels and marsh edge. This decay rate is a function of settling velocity and the maximum value of water depth and velocity on the marsh platform. Bed sediment compositions were generated to further explore feedbacks between SLR, sediment dynamics and morphological changes. The results show SLR increases tidal prism and inundation depth, facilitating sediment deposition on the marsh platform. At the same time, SLR enhances ebb-dominated currents and increases sediment resuspension, reducing the sediment-trapping capacity of tidal flats and bays, leading to a negative sediment budget for the entire system. This bimodal distribution of sediment budget trajectories will have a profound impact on the morphology of coastal bays, increasing the difference in elevation between salt marshes and tidal flats and potentially affecting intertidal ecosystems. The results also clearly indicate that landforms lower with respect to the tidal frame are more affected by SLR than salt marshes. Therefore, Salt marshes, shallow bays, tidal flats, and barrier islands are inherently and physically connected systems, and evaluating the effect of SLR on salt marshes should involve all these units

Inundações em múltiplas escalas na América do Sul : de áreas úmidas a áreas de risco

South America hosts some of the major river systems on Earth, often associated with large floodplains that are inundated every year, such as the Pantanal and many Amazon wetlands. Interfluvial wetland complexes are also found across the continent, with particular geomorphic settings and unique savanna or grassland vegetation. South American wetlands can provide distinctive ecosystem services such as biodiversity supporting, food provision and flood attenuation. On the other hand, humans have settled around wetlands for millennia, benefiting from all resources they provide, and have adapted to its flood regime as well adapted its landscape, defining what has been called human-water systems. Yet, an increasing number of South American people have been negatively affected by extreme floods. Moving from continental to local scales, this thesis invites the readers to a journey across major South American wetland systems and their unique hydrological dynamics, under the light of the satellite era and the breakthrough advances on hydrologic-hydrodynamic modeling in the last decades. This work is founded on the proposition of a continental wetland research agenda, and based on a comparative hydrology approach. Floods are studied through both natural wetland processes and hazard dimensions. The first part presents a set of studies on the Amazon basin wetlands, from the development of 1D and 2D models to simulate hydrological processes in contrasting wetland types in the Negro river basin to the basin-wide intercomparison of 29 inundation products and assessment of long-term inundation trends. While most wetland studies have been conducted over the central Amazon floodplains, major knowledge gaps remain for understanding the hydrological dynamics of interfluvial areas such as the Llanos de Moxos and Negro savannas, where the inundation is less predictable and shallower. The second part of the thesis leverages satellite-based datasets of multiple hydrological variables (water levels, total water storage, inundation extent, precipitation and evapotranspiration) to address the hydrology of 12 large wetland systems in the continent. It shows the major differences among river floodplains and interfluvial wetlands on the water level annual amplitude, time lag between precipitation and inundation, and evapotranspiration dynamics. Finally, the third part addresses the flood hazard component of human-wetland interactions through large-scale assessments of flood hazard dynamics and effects of built infrastructure (dams) on flood attenuation. The dynamics of the great 1983 floods, one of the most extreme years ever recorded in the continent, is assessed with a continental hydrological model. Then, the capabilities of continental models to simulate the river-floodplain-reservoir continuum that exists across large river basins are assessed with case studies for major river basins affected by human intervention (Itajaí-Açu and upper Paraná river basins in Brazil). While this thesis enlightens some relevant hydrological processes regarding South American floods and their positive and negative effects to human societies and ecosystems in general, major knowledge gaps persist and provide great research opportunities for the near future. The launching of many hydrology-oriented satellite missions, and an ever-growing computational capacity, make the continental hydrology agenda related to wetlands and floods a great research topic for the upcoming years.A América do Sul abriga alguns dos maiores sistemas hídricos do planeta, frequentemente associados a grandes planícies de inundação, como o Pantanal e várias áreas da Amazônia. Áreas úmidas (AU’s) interfluviais são também encontrados no continente, com características geomorfológicas particulares, e vegetações de savana e gramíneas únicas. As AU’s da América do Sul provêm diversos serviços ecossistêmicos, como suporte à biodiversidade, provisão de alimento e atenuação de cheias. Humanos têm se estabelecido ao redor de AU’s por milênios, se beneficiando dos recursos providos por elas. Eles se adaptaram ao seu regime de inundação, e adaptaram sua paisagem, definindo o que tem sido chamado de sistemas sociedade-água. Por outro lado, um número crescente de pessoas têm sido negativamente afetado por cheias extremas. Da escala continental à local, esta tese convida o leitor a uma jornada através de importantes AU’s da América do Sul e suas particulares dinâmicas de inundação, sob a luz da era dos satélites e dos grandes avanços em modelagem hidrológica-hidrodinâmica das últimas décadas. Este trabalho é baseado na proposta de uma escala continental de pesquisa sobre AU’s, e é baseado em uma abordagem de hidrologia comparativa. Inundações são estudadas em múltiplas dimensões, de processos de AU’s naturais à questão do perigo para humanos. A primeira parte apresenta uma série de estudos sobre as AU’s da bacia amazônica, desde o desenvolvimento de modelos 1D e 2D para simular processos hidrológicos em tipos contrastantes de AU’s na bacia do Rio Negro, até a intercomparação de 29 produtos de inundação e avaliação de tendências de inundações de longo prazo para a escala da bacia amazônica. Enquanto a maioria dos estudos de AU’s foi conduzida nas várzeas do rio Amazonas, importantes lacunas do conhecimento permanecem para a compreensão da dinâmica hidrológica de áreas interfluviais como Llanos de Moxos e as savanas do rio Negro, onde a inundação é menos previsível e mais rasa. A segunda parte da tese utiliza dados oriundos de satélites relacionados a múltiplas variáveis hidrológicas (níveis d’água, armazenamento total de água, extensão de áreas inundadas, precipitação e evapotranspiração) para estudar a hidrologia de 12 grandes sistemas de AU’s do continente. São destacadas as grandes diferenças entre planícies de inundação e AU’s interfluviais em termos de amplitude anual de níveis d’água, defasagem entre precipitação e inundação, e dinâmica de evapotranspiração. Por fim, a última parte da tese aborda o componente de perigo de inundação das interações sociedade-água através de avaliações em grande escala da dinâmica de inundação e dos efeitos de infraestruturas construídas (como barragens) na atenuação de cheias. A dinâmica das grandes cheias de 1983, um dos anos mais extremos já registrados no continente, é avaliada com um modelo hidrológico continental. Depois, a capacidade de modelos continentais para simular o continuum entre rios, planícies de inundação e reservatórios que existe em grandes bacias hidrográficas é avaliada com estudos de casos para importantes bacias afetadas pela intervenção humana (bacia dos rios Paraná e Itajaí-Açu). Enquanto esta tese avança a compreensão de relevantes processos hidrológicos relacionados a inundações na América do Sul em múltiplas escalas, bem como seus efeitos positivos e negativos nas sociedades humanas e ecossistemas em geral, importantes lacunas do conhecimento persistem e fomentam importantes oportunidades de pesquisa futuras. O lançamento de várias missões satelitais orientadas a hidrologia, e uma cada vez mais crescente capacidade computacional, faz da agenda continental de hidrologia relacionada a AU’s e inundações um grande tópico de pesquisa para os próximos anos

Graph theoretical analysis of braided rivers

PhDBraided rivers are one of the most complex and unpredictable natural systems on Earth. Found worldwide, they are easily identified from above by their distinctive morphology (a large network of interlinked channels divided by interspersed sedimentary deposits). Their propensity to dramatically adjust their form during flood events impacts upon millions of people who interact with them. However, their size and the intensity of processes that are active during these episodes of morphological change have presented considerable barriers to the measurement, understanding, prediction and management of braided river behaviour. This research has begun to resolve these issues through the successful development of a new theoretical framework for the study of braided river evolution based on graph theory (a branch of mathematics concerned with network structure and function). Leveraging a recent upsurge in open-access Earth observation data provision, it is now possible to extract network representations of braided rivers globally from satellite imagery. A workflow for the extraction of braided river networks from multi-spectral remotely sensed imagery is described herein, with these networks providing the basis for graph analysis. A key question in network research is how to define functional units, which in the context of braided rivers are reaches. Defining reaches has previously been done arbitrarily, which likely negates key controls that determine the spatial scales over which braided river morphologies evolve. This research proposes a new, physically-based approach to defining reaches in braided rivers that accounts for spatial scaling and network structure. Evolution of braided river morphologies at the reach-scale or greater occurs over timescales that range from event-based change to long-term trajectories of change in the whole braided channel network. Analysis of the topological evolution of a braided channel network is presented to show spatio-temporal variation in connectivity and how this relates to braided river morphodynamics.This work has been funded by a Queen Mary University of London Strategic PhD Studentship in River Science and supported by the Erasmus Mundus Doctorate Program SMART (http://www.riverscience.eu) funded by the Education, Audio-visual and Culture Executive Agency (EACEA) of the European Commission

Pareamento bacia-lagoa usando modelagem hidrológica-hidrodinâmica e sensoriamento remoto

A gestão de recursos hídricos tornou-se cada vez mais complexa devido ao rápido crescimento sócio-econômico e as mudanças ambientais nas bacias hidrográficas nas últimas décadas. Modelos computacionais são importantes ferramentas de suporte na gestão de recursos hídricos e tomada de decisões devido a sua funcionalidade, provendo informações importantes sobre os principais processos físicos, químicos e biológicos, e permitindo melhorar o entendimento desses processos, os quais ocorrem em diferentes escalas espaciais e temporais. Na presente tese, o objetivo foi compreender o funcionamento hidrológico do sistema integrado bacia hidrográfica - lagoa, e os efeitos na hidrodinâmica do lago, utilizando como suporte o acoplamento da modelagem hidrológica - hidrodinâmica, e o uso de técnicas de sensoriamento remoto para o monitoramento de parâmetros de qualidade da água (e.g., clorofilaa, temperatura da superfície d’água e níveis da água). A área de estudo é a bacia hidrográfica da Lagoa Mirim, localizada no sul do Brasil, possuindo uma área total de 58.000 km2 (56% no Uruguai e o restante no Brasil). Foram propostos e testados modelos empíricos para estimativa de clorofila-a emumlago raso subtropical, baseados em imagens do sensor MODIS e técnicas estatísticas. Além disso, foi desenvolvido e avaliado o acoplamento da modelagem hidrológica-hidrodinâmica de grande escala e o sensoriamento remoto. O modelo hidrológico distribuído de grande escala MGBIPH acoplado com o modelo hidrodinâmico IPH-ECO foi utilizado para simular a bacia hidrográfica e os principais componentes hidrodinâmicos da Lagoa Mirim. O modelo mostrou bom desempenho quando comparado com observações de vazões, além de dados provenientes de sensoriamento remoto, através de altimetria espacial. As simulações mostraram importantes aspectos sobre a estrutura de fluxo, campos de velocidade e níveis d’água na lagoa, assim como a influência de grandes rios, forçantes externas como o vento (intensidade e direção) e o impacto do estressor antrópico (retiradas para irrigação) no sistema. As simulações permitiram avaliar aspectos relacionados com as variações espaciais e temporais (diurna, mensal, sazonal e inter-anual) da temperatura da superfície da água, a dinâmica dos fluxos de calor (sensível e latente) e os efeitos de eventos meteorológicos de pequena escala como frentes frias, os quais têm um impacto significativo sobre a temperatura superficial da água e os fluxos de calor na lagoa. Quanto aos modelos empíricos para estimativa de clorofila-a a partir do MODIS, os resultados mostram que um simples e eficiente modelo desenvolvido a partir de análise de regressão múltipla, apresentou ligeiras vantagens sobre os modelos de redes neurais artificiais, modelos multiplicativos não paramétricos e modelos empíricos (e.g., Appel, Kahru, FAI e O14a) usualmente utilizados na estimativa de Chl-a em ambientes aquáticos. Resultados também indicam que é inapropriado generalizar um único modelo desenvolvido a partir do conjunto total de dados, para estimar concentrações de Chl-a na lagoa, o que corrobora a heterogeneidade espacial na distribuição de Chl-a e as diferenças entre regiões (litoral e pelágica). A modelagem hidrológica-hidrodinâmica de grande escala apoiada por informação de sensoriamento remoto, mostrou ser uma abordagem promissora para o entendimento da estrutura e funcionamento de lagoas rasas de grande porte e longo prazo, úteis para a gestão integrada dos recursos hídricos.The last decade, the water resource management is being complex due to the rapid socioeconomic development and environmental changes in river basins. Computations models are important support tools in water resource management and make decision providing important information and allowing a better comprehension of the physical, chemical and biologic processes, which occur in di erent temporal/spatial scales. In this thesis, the objective was to understand the hydrological functioning of the integrated basin- lake system and its e ects on hydrodynamics, using hydrodynamic - hydrodynamic modeling and water quality monitoring (e.g., chlorophyll-a, water surface temperature and water levels) from remote sensing techniques. The study area is the Lake Mirim basin, located between Brazil and Uruguay (basin total area 58.000 km2). Empirical models were proposed and tested to chlorophyll-a estimation in a shallow subtropical lake, based on MODIS imagery and statistics techniques. In addition, we developed and assessed the coupling of large scale hydrological/hydrodynamic modeling and remote sensing techniques. The large-scale distributed hydrological model MGB-IPH coupled with the hydrodynamic model IPHECO were used to simulate the river basin and the hydrodynamic components of the Lake Mirim. The coupled model showed good performance when compared to in-situ measurements and satellite altimetry data. The simulations showed important aspects relate to flow structure, velocity fields and lake water levels, as well as the influence of large rivers, external forcing as such the wind (intensity and direction), and the impact of anthropogenic stressors (irrigation withdrawals) in the system. The simulations allowed assessing the spatial and temporal variations (diurnal, monthly, seasonal and inter-annual) in the water surface temperature, heat fluxes dynamics (sensible and latent) and the e ects of short time-scale events, as such cold fronts passages over the lake, which cause strong impacts on the water surface temperature and heat fluxes in the lake. Regarding the empirical models developed to chlorophyll-a estimation from MODIS imagery, the results showed that a simple and e cient model developed from multiple regression analysis, performed best in comparison with artificial neural network models, non-parametric multiplicative models, and empirical models (e.g., Appel, Kahru, FAI and O14a) common used in the Chl-a estimation in aquatics environments. Results also indicated that is inappropriate to generalize a single model developed from the total datasets to estimates Chl-a in the lake, which corroborates the spatial heterogeneity (Chl-a distribution) and the di erences among regions (littoral and pelagic). The synergy between large-scale hydrological-hydrodynamic modeling, in situ measurements and remote sensing techniques provided a promising approach to improve the comprehension of the structure and ecosystem functioning of large shallow lakes in long-term time scale, useful to water resources management

Let's get connected: A new graph theory-based approach and toolbox for understanding braided river morphodynamics

Our understanding of braided river morphodynamics has improved significantly in recent years, however, there are still large knowledge gaps relating to both long‐term and event‐based change in braided river morphologies. Furthermore, we still lack methods that can take full advantage of the increasing availability of remotely sensed datasets that are well suited to braided river research. Network analysis based on graph theory, the mathematics of networks, offers a largely unexplored toolbox that can be applied to remotely sensed data to quantify the structure and function of braided rivers across nearly the full range of spatiotemporal scales relevant to braided river evolution. In this article, important commonalities between braided rivers and other types of complex network are described, providing a compelling argument for the wider uptake of complex network analysis methods in the study of braided rivers. We provide an overview of the extraction of graph representations of braided river networks from remotely sensed data and detail a suite of metrics for quantitative analysis of these networks. Application of these metrics as new tools for multiscale characterization of braided river planforms that improve upon traditional, spatially averaged approaches is discussed and potential approaches to network‐based analysis of braided river dynamics are proposed, drawing on a range of different concepts from braided river research and other network sciences. Finally, the potential for using graph theory metrics to validate numerical models of braided rivers is discussed

Remote Sensing of the Aquatic Environments

The book highlights recent research efforts in the monitoring of aquatic districts with remote sensing observations and proximal sensing technology integrated with laboratory measurements. Optical satellite imagery gathered at spatial resolutions down to few meters has been used for quantitative estimations of harmful algal bloom extent and Chl-a mapping, as well as winds and currents from SAR acquisitions. The knowledge and understanding gained from this book can be used for the sustainable management of bodies of water across our planet

Amazon hydrology from space : scientific advances and future challenges

As the largest river basin on Earth, the Amazon is of major importance to the world's climate and water resources. Over the past decades, advances in satellite-based remote sensing (RS) have brought our understanding of its terrestrial water cycle and the associated hydrological processes to a new era. Here, we review major studies and the various techniques using satellite RS in the Amazon. We show how RS played a major role in supporting new research and key findings regarding the Amazon water cycle, and how the region became a laboratory for groundbreaking investigations of new satellite retrievals and analyses. At the basin-scale, the understanding of several hydrological processes was only possible with the advent of RS observations, such as the characterization of "rainfall hotspots" in the Andes-Amazon transition, evapotranspiration rates, and variations of surface waters and groundwater storage. These results strongly contribute to the recent advances of hydrological models and to our new understanding of the Amazon water budget and aquatic environments. In the context of upcoming hydrology-oriented satellite missions, which will offer the opportunity for new synergies and new observations with finer space-time resolution, this review aims to guide future research agenda toward integrated monitoring and understanding of the Amazon water from space. Integrated multidisciplinary studies, fostered by international collaborations, set up future directions to tackle the great challenges the Amazon is currently facing, from climate change to increased anthropogenic pressure