MDPI has published two issues on groundwater in arid and semi-arid areas in Geosciences [...]

GroundwaterEarly View Book Review Book Review: Urban Groundwater John M. Sharp Jr., Corresponding Author John M. Sharp Jr. [email protected] Department of Earth and Planetary Sciences, University of Texas at Austin, 2275 Speedway Stop C9000, Austin, Texas, 78712-1722 USASearch for more papers by this author John M. Sharp Jr., Corresponding Author John M. Sharp Jr. [email protected] Department of Earth and Planetary Sciences, University of Texas at Austin, 2275 Speedway Stop C9000, Austin, Texas, 78712-1722 USASearch for more papers by this author First published: 26 December 2023 https://doi.org/10.1111/gwat.13381Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Reference Howard, K. 2023. Urban Groundwater. The Groundwater Project, Guelph, Canada. https://gw-project.org/books/urban-groundwater/ (accessed December 4, 2023). Google Scholar Early ViewOnline Version of Record before inclusion in an issue ReferencesRelatedInformation

A glossary of key terms and concepts in hydrogeology and closely related fields, including hydrology, geology, soils, engineering, biology, public administration, law, economics, and others.

Aridland springs maintain groundwater-dependent habitats for aquatic and terrestrial species. San Solomon Spring (Texas, USA) is part of a regional karst spring complex in the Chihuahuan Desert that supports several species of federal and state conservation interest. However, drought, climatic variability, and groundwater abstraction threaten discharge and water quality. In the surrounding Delaware Basin, expansion in unconventional oil and gas development using hydraulic fracturing may increase demands on aquifers that also provide flows to the springs. A critical knowledge gap limiting habitat conservation and sustainable groundwater abstraction is that the flow system is not well understood. While the source of most spring discharge is from a Pleistocene-recharged regional flow system, evidence suggests that a modern local flow component provides fresh water influx. However, the exact sources, mechanisms, and timing of localized recharge are unknown. To address these questions, this study combined long-term in-situ spring water quality monitoring (specific conductance, turbidity, and temperature) data with weather station-corrected 4 km gridded precipitation data to quantify the lag response at San Solomon Springs to mesoscale storm events and to delineate potential local recharge zones. Between April 2011 and March 2012, 26 event-flow responses were documented, with an average lag of 43 days between storm event and spring response. Response time varied depending on storm magnitude, spatial extent, and antecedent soil moisture conditions. Cross-correlation analysis of spatially distributed precipitation indicated zones of potential local recharge in the mountain block/mountain front zones and alluvial channels issuing from the Davis Mountains. Some local flow paths appear to cross known watershed boundaries, suggesting that groundwater abstraction in sensitive capture zones should be managed carefully to maintain spring flows and conserve habitats.

The Edwards aquifer system is one of the great karstic aquifer systems of the world. It supplies water for more than 2 million people and for agricultural, municipal, industrial, and recreational uses. The Edwards (Balcones Fault Zone) Aquifer in the San Antonio, Texas, area was the first to be designated a sole source aquifer by the Environmental Protection Agency in 1975. The Edwards Aquifer also hosts unique groundwater, cave, and spring ecosystems. This 27-chapter memoir reviews the current state of knowledge, current and emerging challenges to wise use of the aquifer system, and some of the technologies that must be adopted to address these challenges.

The Edwards Aquifer along the Balcones fault zone is in a rapidly growing, urbanizing area. Urbanization creates major hydrogeological impacts, generally increasing impervious cover and flooding intensity, water demands, groundwater recharge, and temperatures both above and below the land surface; covering springs and small streams; altering the porosity and permeability fields; and contaminating groundwater, surface water, and soils. Urbanization also alters topography, natural flora, and the local climate. Several of these effects have either been documented or predicted for the Edwards Aquifer. Groundwater recharge from leaky utility systems and irrigation return flow is significant, particularly during times of low rainfall. The hydraulic properties of the epikarst, particularly the permeability field, can be highly modified. Aquifer water quality remains excellent, but increased anthropogenic chemical nitrate and chloride concentrations, and occasional bacteriological contamination have been observed. The eventual effects of these changes on the aquifers' unique ecosystems is not known. Urbanization and urban sprawl are projected to increase, which will continue to alter the Edwards Aquifer system physically, chemically, and biologically. Understanding of these changes, their causes, and their effects is necessary to addressing the critical and growing environmental and water-resources issues of urban areas in the coming century.

ABSTRACT The Edwards aquifers are typically faulted, karstified, and transmissive. Water quality is generally excellent; the hydrochemical facies is mostly a calcium bicarbonate water with total dissolved solids (TDS) <500–1000 mg/L. Exceptions to this result from both natural and anthropogenic factors. In the Edwards Plateau, mixing of the formation water with underlying water from the Trinity aquifers or Permian rocks increases salinity to the west. Along the Balcones fault zone, the southern and eastern borders of the Edwards (Balcones Fault Zone) Aquifer are demarcated by a bad-water line where salinity rises to over 1000 mg/L. Detailed studies show that this line is a band, because salinities in the aquifer are not uniform with depth. The bad-water (or saline-water) zone is relatively stable over time, and six hydrochemical facies were identified, which are created by different combinations of dissolution of evaporite and other minerals, mixing with basinal brines, dedolomitization, and cross-formational flow from underlying formations. Flow in this zone is restricted, the waters are reducing, and recent studies suggest that microbes play important chemical and physical roles. The bad-water zone has sufficient water in storage and sufficient permeability so that desalination could be a future water-source option.

The crystalline-rock aquifer system of the Llano Uplift (Central Texas, USA) hosts an important local water resource that has been relatively little studied. The Uplift is a structural dome of Precambrian granitic and metamorphic rocks. Late Paleozoic normal faulting and fractures, decompressive fractures, weathering, lithology, and rock fabric control the aquifer properties. Data from driller reports (over 2,000 wells) show that wells in granites have higher median yields than wells in metamorphic rocks. There is a weak correlation of well yield with regolith thickness, and median regolith thickness is greater over granites than over metamorphic rocks. Fracture permeability, which is very heterogeneous, is the major control. Wells are shallow (generally <100 m depth), but more recent wells have been drilled more deeply. Permeability data imply decreased open-fracture density and aperture with depth, although sample bias is a consideration. Diamond drill cores show that many near-surface fractures with significant aperture are filled by rock fragments from weathered surrounding rocks and that fracture skins are thinner and contain iron oxides in a more reduced state with depth. Fracture skins can be porous, with porosity ranging to over 10%. There is a need to compare crystalline-rock aquifer systems to assess weathering, tectonics, fractures, and mineralogy/petrology to assess the characteristics of these systems, which are critical water resources in large areas of the world.

GroundwaterVolume 57, Issue 5 p. 819-823 Historical Note/ Jean-Baptiste Paramelle and The Art of Finding Springs by Patricia Bobeck, Corresponding Author Patricia Bobeck bobeckpa@gmail.com Present address: Geotechnical Translations, PO Box 161391, Austin, TX 78716-1391; bobeckpa@gmail.comCorresponding author: University of Texas Department of Geological Sciences, 1 University Station, C1100 Austin, TX 78712-0254; bobeckpa@gmail.comSearch for more papers by this authorJohn M. Sharp Jr., John M. Sharp Jr. jmsharp@jsg.utexas.edu University of Texas Department of Geological Sciences, 1 University Station, C1100 Austin, TX 78712-0254Search for more papers by this author by Patricia Bobeck, Corresponding Author Patricia Bobeck bobeckpa@gmail.com Present address: Geotechnical Translations, PO Box 161391, Austin, TX 78716-1391; bobeckpa@gmail.comCorresponding author: University of Texas Department of Geological Sciences, 1 University Station, C1100 Austin, TX 78712-0254; bobeckpa@gmail.comSearch for more papers by this authorJohn M. Sharp Jr., John M. Sharp Jr. jmsharp@jsg.utexas.edu University of Texas Department of Geological Sciences, 1 University Station, C1100 Austin, TX 78712-0254Search for more papers by this author First published: 30 June 2019 https://doi.org/10.1111/gwat.12897Citations: 1 Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume57, Issue5September/October 2019Pages 819-823 RelatedInformation