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Floods, droughts and climate variability – From early warning to early action

The main objective of the PhD thesis by Gabriela Guimarães Nobre is to improve the understanding on links between climate variability and weather-related impacts of both floods and droughts. This relationship is investigated from global to regional scales, and at different lead times, with the purpose of achieving an impact-based forecast that can guide the implementation of early actions effectively before a potential drought or flood materializes. 

 
Adaptive Strategies for Water Heritage

Since 2012, ICOMOS Netherlands has been exploring what can be learned from water-related heritage rooted in culture and nature. What insights can we derive from ancient water structures such as the dams of the Middle East or the qanats of arid regions; governance arrangements such as the water boards of the Netherlands; or, the ethico-spiritual frameworks of those of the Incas? How can these varied forms of water-related heritage teach and inspire future planners, architects, politicians, design engineers, and others as they address present and future water-related challenges? This is addressed in a new book.

 
Tritium as an Indicator of Modern, Mixed, and Premodern Groundwater Age

Categorical classification of groundwater age is often used for the assessment and understanding of groundwater resources. This new USGS report presents a tritium-based age classification system for the conterminous United States based on tritium (3H) thresholds that vary in space and time: modern (recharged in 1953 or later), if the measured value is larger than an upper threshold; premodern (recharged prior to 1953) if the measured value is smaller than a lower threshold; or mixed if the measured value is between the two thresholds. Inclusion of spatially varying thresholds, rather than a single threshold, accounts for the observed systematic variation in 3H deposition across the United States. Inclusion of time-varying thresholds, rather than a single threshold, accounts for the date of sampling given the radioactive decay of 3H. 

 
2019 Land Remote Sensing Satellite Compendium

Since about 2012, ever-increasing numbers of remote sensing satellites have been launched. This rapidly growing wave of new systems creates a need for a single reference for land remote sensing satellites that provides basic system specifications and linkage to assessments that may have been completed on existing systems. This volume is the first edition of a compendium, which is planned to be updated and released annually.

 
Isotopen in de hydrologie – free download

Special number 1 of the Netherlands Hydrological Association, on Isotopes in Hydrology (in Dutch: 'Isotopen in de hydrologie') has been made available as a free PDF file. It is a result of a NHV conference on the same topic. The publication was edited by Michael van der Valk, and the start of a series of NHV specials on different topics in hydrology.

 
Producing more interpretable recharge suitability maps

During the 10th International Conference on Managed Aquifer Recharge (ISMAR10), in Madrid, Spain, Galen Gorski, University of California, Santa Cruz, presented our (mainly his) work on the optimization of the suitability mapping process involved in selecting and allocating areas and locations that are potentially suitable for Managed Aquifer Recharge (MAR) projects, also known as Aquifer Storage and Recovery (ASR). Galen has developed an app, written in R using the Shiny web app development platform, that aims to visualize the sensitivity of the suitability to subjective choices during mapmaking. The presentation is available. This is part of our work on Management of Aquifer Recharge / Aquifer Storage and Recovery in Middle East countries, together with their governments and major universities.

 
GRACE storage change characteristics (2003–2016) over major surface basins and principal aquifers in the Conterminous United States

In a new paper, USGS colleagues characterized the changes in the Gravity Recovery and Climate Experiment (GRACE) monthly total water storage anomaly (TWSA) in 18 surface basins and 12 principal aquifers in the conterminous United States during 2003–2016. Regions with high variability in storage were identified. Ten basins and four aquifers showed significant changes in storage. Eight surface basins and eight aquifers were found to show decadal stability in storage. This study found that historically wetter regions (with more storage) are becoming wetter, and drier regions (with less storage) are becoming drier. Fourier analysis of the GRACE data showed that while all basins exhibited prominent annual periodicities, significant sub-annual and multi-annual cycles also exist in some basins. The storage turnover period was estimated to range between 6 and 12 months. This study provides new insights on several aspects of basin or aquifer storage that are important for understanding basin and aquifer hydrology. A new paper by our good friends Naga Manohar Velpuri, Gabriel B. Senay and others, in Remote Sensing.

 
Towards a Method of Participatory Planning in an Emerging Metropolitan Delta in the Context of Climate Change – new PhD thesis

Urbanizing deltas are subjected to pressures related to urban growth and climate change, within a context of uncertainty and unpredictability. Those pressures interact at multiple scales and temporalities, affecting the components of the systems, as well as the relations between them and with the environment. This complexity reveals the need for the society (including governments, institutions, civil organizations, academia, etc.) to enhance the adaptability of the system of the delta, in order to cope with changes without losing their substantial characteristics. The PhD thesis of Verónica Zagare is focused on the study of the complexity of self-organizing processes that emerge in metropolitan areas located in (or near) delta territories, in order to link climate adaptation with urban development from an actor-oriented perspective.

 
Groundwater around the world – free download

The book »Groundwater around the world« presents a unique and up-to-date summary of what is known about groundwater on our planet, from a global perspective and in terms of area-specific factual information. Unlike most textbooks on groundwater, it does not deal with theoretical principles, but rather with the overall picture that emerges as a result of countless observations, studies and other activities related to groundwater in all parts of the world. The focus is on showing the role and geographical diversity of groundwater—a natural resource of great importance in daily life, but poorly understood by the general public and even by many water sector professionals. As a result of a cooperation between author Jac van der Gun and Michael van der Valk | Hydrology.nl the book is now available as a free PDF file!

 
US stream flows reduced by groundwater pumping

Groundwater pumping has caused marked aquifer storage declines over the past century. In addition to threatening the viability of groundwater-dependent economic activities, storage losses reshape the hydrologic landscape, shifting groundwater surface water exchanges and surface water availability. A more comprehensive understanding of modern groundwater-depleted systems is needed as we strive for improved simulations and more efficient water resources management. Here, the authors of a new paper in Science begin to address this gap by evaluating the impact of 100 years of groundwater declines across the continental United States on simulated watershed behavior. Subsurface storage losses reverberate throughout hydrologic systems, decreasing streamflow and evapotranspiration. Evapotranspiration declines are focused in water-limited periods and shallow groundwater regions. Streamflow losses are widespread and intensify along drainage networks, often occurring far from the point of groundwater abstraction. Their integrated approach illustrates the sensitivity of land surface simulations to groundwater storage levels and a path toward evaluating these connections in large-scale models. 

 
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