News
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. 

 
Strategic use of groundwater-based solutions for drought risk reduction and climate resilience in Asia and beyond

Groundwater is a de-facto source of water during drought and emergencies. In a broader perspective, the traditional short-term strategy of using groundwater to combat water deficits during drought needs revisiting. The objective of a new paper is to examine the relevance and options for developing and adopting such groundwater-based natural infrastructure solutions in DRR strategies. While addressing emergency situations, such solutions may also serve to enhance the sustainable use and management of groundwater as a strategic resource for long-term drought risk reduction as well as enhancing the resilience of farming systems and groundwater dependent cities and natural ecosystems. 

 
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.

 
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.

 
« StartPrev12345678910NextEnd »

Page 1 of 29