Assessing Relevance of Tweets for Risk Communication

Although Twitter is used for emergency management activities, the relevance of tweets during a hazard event is still open to debate. In this study, six different computational (i.e. Natural Language Processing) and spatiotemporal analytical approaches were implemented to assess the relevance of risk information extracted from tweets obtained during the 2013 Colorado flood event. Primarily, tweets containing information about the flooding events and its impacts were analysed. Examination of the relationships between tweet volume and its content with precipitation amount, damage extent, and official reports revealed that relevant tweets provided information about the event and its impacts rather than any other risk information that public expects to receive via alert messages. However, only 14% of the geo-tagged tweets and only 0.06% of the total fire hose tweets were found to be relevant to the event. By providing insight into the quality of social media data and its usefulness to emergency management activities, this study contributes to the literature on quality of big data. Future research in this area would focus on assessing the reliability of relevant tweets for disaster related situational awareness

Principles and Applications of Data Science

Data science is an emerging multidisciplinary field which lies at the intersection of computer science, statistics, and mathematics, with different applications and related to data mining, deep learning, and big data. This Special Issue on “Principles and Applications of Data Science” focuses on the latest developments in the theories, techniques, and applications of data science. The topics include data cleansing, data mining, machine learning, deep learning, and the applications of medical and healthcare, as well as social media

Wetland Uranium Transport via Iron-Organic Matter Flocs and Hyporheic Exchange

Uranium (U) released from the M-Area at the Department of Energy Savannah River Site into Tims Branch, a seasonal wetland and braided stream system, is estimated to be 43,500 kg between 1965 and 1984. The motivation for this work is the uranium’s persistence in the wetland for decades, where it is estimated that 80% of the U currently remains in the Tims Branch wetland. U has begun to incorporate into wetland iron (Fe) and carbon cycles, associating with local Fe mineralogy and deposits of rich wetland organic matter (OM). The objective of this work is to characterize the chemical phases responsible for sequestration or mobilization of U, Fe, and C in a riparian wetland system and to understand the partitioning and lability of uranium incorporated into natural Fe and C cycles. Born from the observation of Fe-OM flocs under specific hydrologic conditions, it is hypothesized that the mobilization of Fe-OM flocs drive U transport from the wetland as U incorporates into the wetland cycles. This work first investigates the lateral distribution of U within the wetland and identifies key hotspots where U has accumulated due to hydrologic and geochemical controls. With knowledge of these hotspots, work sought to identify relationships of U to Fe and OM throughout the wetland in the water column and as a function of depth at the hotspots. Next, these relationships to Fe and OM were investigated further via parallel extraction of redox-preserved cores in oxic and anoxic atmospheres. This study determined that OM concentrations coupled with OM compound diversity heavily impact metal sequestration and availability in wetland sediments. Deep sediment layers with relatively non-labile OM accumulate metals naturally, as isotopic ratio evidence indicates that sequestration of natural U is occurring in addition to accumulation of anthropogenic depleted U. With an improved understanding of the metal inventories in the wetland, a seasonal study of metal transport allowed for initial estimates of seasonal U and Ni transport associated with Fe-OM flocs. Fluxes of U in Fe-OM flocs can be conservatively estimated to be of minimal risk to water quality, as worst-case assumptions and measurements pre- and post-storm determine that flocs would have mobilized only 132 kg U over the last 60 years. Currently, stream sediments are now hypothesized to be the primary driver of U transport from the wetland, but these U fluxes only amount to roughly 20 kg per year, based on stream flowrate data collection and stream water sampling

Essays on the Quantification and Propagation of Uncertainty in Climate Change Impact Assessments for Water Resource Systems

Sustainable water resources planning and management under climate change requires a proper treatment of uncertainties that emerge in an impacts analysis. A primary source of this uncertainty originates from the difficulties in projecting how anthropogenic greenhouse gas emissions will evolve over time and influence the climate system at regional and local scales. However, other sources of uncertainty, such as errors in modeling hydrologic response to climate and the influences of internal climate variability, compound the effects of climate change uncertainty and further obscure our understanding of water resources performance under future climate conditions. This work presents an approach to quantify the interactions, propagation, and relative contributions of different sources of uncertainty in a water resources impacts assessment under climate change. Hydrologic modeling uncertainty is addressed using Bayesian methods that can quantify both parametric and structural errors. Hydrologic uncertainties are propagated through an ensemble of climate projections to explore their joint uncertainty. A new stochastic weather generator is presented to develop a wide ensemble of climate projections that can extend beyond the limited range of change often afforded by global climate models and better explore climate risks. The weather generator also enables the development of multiple realizations of the same mean climate conditions, allowing an exploration of the effects of internal climate variability. The uncertainties from mean climate changes, internal climate variability, and hydrologic modeling errors are then integrated in two climate change analyses of a flood control facility and a multi-purpose surface reservoir system, respectively, to explore their separate and combined effect on future system performance. The primary goal of this work is to present methods that can better estimate the precision associated with future projections of water resource system performance under climate change, and through this provide information that can guide the development of adaptation strategies that are robust to these uncertainties

A Strategic Digital Transformation for the Water Industry

This book is a compilation of the knowledge shared and generated so far in the IWA Digital Water Programme. It is an insightful collection of white papers covering best practices, linking academic and industrial studies/insights with applications to give real-world examples of digital transformation. These White Papers are designed to help utilities, water professionals and all those interested in water management and stewardship issues to better understand the opportunities of digital technologies. This book covers a plethora of topics including: Instrumentation and data generation Artificial intelligence and digital twins The digital transformation and public health Mapping the digital transformation journey into the future With these topics, the aim is to present an all-encompassing reference for practitioners to use in their day-to-day activities. Through the Digital Water Programme, the IWA leverages its worldwide member expertise to guide a new generation of water and wastewater utilities on their digital journey towards the uptake of digital technologies and their integration into water services

Alternative Water Supply Systems

Owing to climate change related uncertainties and anticipated population growth, different parts of the world (particularly urban areas) are experiencing water shortages or flooding and security of fit-for-purpose supplies is becoming a major issue. The emphasis on decentralized alternative water supply systems has increased considerably. Most of the information on such systems is either scattered or focuses on large scale reuse with little consideration given to decentralized small to medium scale systems. Alternative Water Supply Systems brings together recent research into the available and innovative options and additionally shares experiences from a wide range of contexts from both developed and developing countries. Also covered are the technical, social, financial and institutional aspects associated with decentralized alternative water supply systems. These include systems for greywater recycling, rainwater harvesting, recovery of water through condensation and sewer mining