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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. 

 
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.

 
Soluciones Basadas en la Naturaleza para la gestión del agua en España

A new report about nature-based water management solutions in Spain shows that natural infrastructure can a cost-effective the basis for water security. It consolidates recommendations and provides a sound basis for moving forward with scaling up nature-based solutions for water security in Spain. Ensuring water security is a complex, although not intractable challenge, that is too large for any single institution to take on: it calls for collective action with the participation of public and private sector, as well as local, national, multilateral and civil society organizations and individuals.

 
Decision Making under Deep Uncertainty

This book focuses on both the theory and practice associated with the tools and approaches for decision-making in the face of deep uncertainty. It explores approaches and tools supporting the design of strategic plans under deep uncertainty, and their testing in the real world, including barriers and enablers for their use in practice. The book broadens traditional approaches and tools to include the analysis of actors and networks related to the problem at hand. It also shows how lessons learned in the application process can be used to improve the approaches and tools used in the design process.

 
Effects of multi-layering in a classical pumping test

To demonstrate several techniques for the analysis of pumping tests in confined aquifers Vedat Batu (1998) presents Example 4-6 on page 160–161 of his book «Aquifer Hydraulics». The pumping well (Q = 540 m3/d) and the two observation wells (r = 25 m and r = 75 m) are fully penetrating. Resulting transmissivities and storativities of the various methods are found between T = 174 and 260 m2/d, and between S = 0.000135 and S = 0.000666. All methods show a rather poor fit, mainly because the measured drawdown rate during the first 30 minutes is clearly higher than in the later period of the test. A much better fit can be obtained when the data of both observation wells are analyzed with the MLU software and a two-aquifer (analytical) model is used.

 
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.

 
Bridging the floods − The role of social learning for resilience building in urban water services

The development of cities is increasingly threatened by a worldwide water crisis. Urban water services (including drinking water, sanitation and drainage) are facing complex and multiple pressures, which are becoming increasingly frequent and severe. These pressures include floods, and the depletion, pollution and degradation of water resources and their associated ecosystems. These diverse pressures fall mainly within the domains of flood risk and water resources management: two working fields that are divided by different institutional structures, approaches and practices. Social learning is becoming increasingly popular as an approach that has the potential to “bridge” these silos, and ultimately, contribute to building resilience in urban water services. However, empirical analyses on this issue are rare and fragmented. In her PhD thesis, Åse Johannessen fills this gap. Her results identify challenges to the integration of the identified silos, what resilience means for urban water services, and the key elements of social learning that can support or inhibit urban water resilience.

 
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