Net Inflow: An Important Target on the Path to Aquifer Sustainability     

J.J. Butler Jr.  G.C. Bohling  S.P. Perkins  D.O. Whittemore  G. Liu  B.B. Wilson 《Ground water》2023,61(1):56-65

Aquifers supporting irrigated agriculture are a resource of global importance. Many of these systems, however, are experiencing significant pumping-induced stress that threatens their continued viability as a water source for irrigation. Reductions in pumping are often the only option to extend the lifespans of these aquifers and the agricultural production they support. The impact of reductions depends on a quantity known as “net inflow” or “capture.” We use data from a network of wells in the western Kansas portions of the High Plains aquifer in the central United States to demonstrate the importance of net inflow, how it can be estimated in the field, how it might vary in response to pumping reductions, and why use of “net inflow” may be preferred over “capture” in certain contexts. Net inflow has remained approximately constant over much of western Kansas for at least the last 15 to 25 years, thereby allowing it to serve as a target for sustainability efforts. The percent pumping reduction required to reach net inflow (i.e., stabilize water levels for the near term [years to a few decades]) can vary greatly over this region, which has important implications for groundwater management. However, the reduction does appear practically achievable (less than 30%) in many areas. The field-determined net inflow can play an important role in calibration of regional groundwater models; failure to reproduce its magnitude and temporal variations should prompt further calibration. Although net inflow is a universally applicable concept, the reliability of field estimates is greatest in seasonally pumped aquifers.  相似文献   

Geologic sources and geographic distribution of sand tempers in prehistoric potsherds from the Mariana Islands     

William R. Dickinson  Brian M. Butler  Darlene R. Moore  Marilyn Swift 《Geoarchaeology》2001,16(8):827-854

Temper sands in prehistoric potsherds of the Mariana Islands include terrigenous detritus derived from Paleogene volcanic bedrock and calcareous grains derived chiefly from modern fringing reefs, but also in part from uplifted Neogene limestones overlying volcanic bedrock. Calcareous sands are nondiagnostic of island of origin, but volcanic sands and the terrigenous component of hybrid sands composed of mixed terrigenous and calcareous grain types can be traced to geologic sources on Saipan and Guam, the only occupied islands where volcanic bedrock is extensively exposed. Quartzose tempers of several types were derived exclusively from dacitic volcanic rocks on Saipan. Nonquartzose tempers of andesitic parentage derive from both Saipan and Guam, but abundance of orthopyroxene as well as clinopyroxene is diagnostic of Saipan andesitic tempers, the presence of olivine is diagnostic of selected tempers from Guam, and placer temper sands rich in heavy ferromagnesian minerals occur only in sherds on Guam. Temper analysis documents widespread ceramic transfer from Saipan to other islands throughout Mariana prehistory, and more restricted ceramic transfer from Guam to nearby Rota, although the origin of some andesitic temper types is petrographically indeterminate. © 2001 John Wiley & Sons, Inc.  相似文献   

Enstatite meteorite clasts in Almahata Sitta and other polymict ureilites: Implications for the formation of asteroid 2008 TC3 and the history of enstatite meteorite parent asteroids     

Cyrena Anne Goodrich  Hilary Downes  Richard Greenwood  Aidan J. Ross  Anna Maria Fioretti  Louise Alexander  Noriko T. Kita  Jon Butler  Michael J. Jercinovic  Peter Jenniskens  Muawia H. Shaddad 《Meteoritics & planetary science》2024,59(4):719-753

The anomalous polymict ureilite Almahata Sitta (AhS) fell in 2008 when asteroid 2008 TC₃ disintegrated over Sudan and formed a strewn field of disaggregated clasts of various ureilitic and chondritic types. We studied the petrology and oxygen isotope compositions of enstatite meteorite samples from the University of Khartoum (UoK) collection of AhS. In addition, we describe the first bona fide (3.5 mm-sized) clast of an enstatite chondrite (EC) in a typical polymict ureilite, Northwest Africa (NWA) 10657. We evaluate whether 2008 TC₃ and typical polymict ureilites have a common origin, and examine implications for the history of enstatite meteorite asteroids in the solar system. Based on mineralogy, mineral compositions, and textures, the seven AhS EC clasts studied comprise one EH_a3 (S151), one EL_b3 (AhS 1002), two EH_b4-5 (AhS 2012, AhS 26), two EH_b5-6 or possibly impact melt rocks (AhS 609, AhS 41), and one EL_b6-7 (AhS 17), while the EC clast in NWA 10657 is EH_a3. Oxygen isotope compositions analyzed for five of these are similar to those of EC from non-UoK collections of AhS, and within the range of individual EC meteorites. There are no correlations of oxygen isotope composition with chemical group or subgroup. The EC clasts from the UoK collection show the same large range of types as those from non-UoK collections of AhS. The enstatite achondrite, AhS 60, is a unique type (not known as an individual meteorite) that has also been found among non-UoK AhS samples. EC are the most abundant non-ureilitic clasts in AhS but previously were thought to be absent in typical polymict ureilites, necessitating a distinct origin for AhS. The discovery of an EC in NWA 10657 changes this. We argue that the types of materials in AhS and typical polymict ureilites are essentially similar, indicating a common origin. We elaborate on a model in which AhS and typical polymict ureilites formed in the same regolith on a ureilitic daughter body. Most non-ureilitic clasts are remnants of impactors implanted at ~50–60 Myr after CAI. Differences in abundances can be explained by the stochastic nature of impactor addition. There is no significant difference between the chemical/petrologic types of EC in polymict ureilites and individual EC meteorites. This implies that fragments of the same populations of EC parent bodies were available as impactors at ~50–60 Myr after CAI and recently. This can be explained if materials excavated from various depths on EC bodies at ~50–60 Myr after CAI were reassembled into mixed layers, leaving relatively large bodies intact to survive 4 billion years. Polymict ureilites record a critical timestep in the collisional and dynamical evolution of the solar system, showing that asteroids that may have accreted at distant locations had migrated to within proximity of one another by 50–60 Myr after CAI, and providing constraints on the dynamical processes that could have caused such migrations.  相似文献   

Field Investigation of a New Recharge Approach for ASR Projects in Near‐Surface Aquifers          下载免费PDF全文

Gaisheng Liu  Steven Knobbe  Edward C. Reboulet  Donald O. Whittemore  Falk Händel  James J. Butler Jr. 《Ground water》2016,54(3):425-433

Aquifer storage and recovery (ASR) is the artificial recharge and temporary storage of water in an aquifer when water is abundant, and recovery of all or a portion of that water when it is needed. One key limiting factor that still hinders the effectiveness of ASR is the high costs of constructing, maintaining, and operating the artificial recharge systems. Here we investigate a new recharge method for ASR in near‐surface unconsolidated aquifers that uses small‐diameter, low‐cost wells installed with direct‐push (DP) technology. The effectiveness of a DP well for ASR recharge is compared with that of a surface infiltration basin at a field site in north‐central Kansas. The performance of the surface basin was poor at the site due to the presence of a shallow continuous clay layer, identified with DP profiling methods, that constrained the downward movement of infiltrated water and significantly reduced the basin recharge capacity. The DP well penetrated through this clay layer and was able to recharge water by gravity alone at a much higher rate. Most importantly, the costs of the DP well, including both the construction and land costs, were only a small fraction of those for the infiltration basin. This low‐cost approach could significantly expand the applicability of ASR as a water resources management tool to entities with limited fiscal resources, such as many small municipalities and rural communities. The results of this investigation demonstrate the great potential of DP wells as a new recharge option for ASR projects in near‐surface unconsolidated aquifers.  相似文献   

NMR Logging to Estimate Hydraulic Conductivity in Unconsolidated Aquifers          下载免费PDF全文

Rosemary Knight  David O. Walsh  James J. Butler Jr.  Elliot Grunewald  Gaisheng Liu  Andrew D. Parsekian  Edward C. Reboulet  Steve Knobbe  Mercer Barrows 《Ground water》2016,54(1):104-114

Nuclear magnetic resonance (NMR) logging provides a new means of estimating the hydraulic conductivity (K) of unconsolidated aquifers. The estimation of K from the measured NMR parameters can be performed using the Schlumberger‐Doll Research (SDR) equation, which is based on the Kozeny–Carman equation and initially developed for obtaining permeability from NMR logging in petroleum reservoirs. The SDR equation includes empirically determined constants. Decades of research for petroleum applications have resulted in standard values for these constants that can provide accurate estimates of permeability in consolidated formations. The question we asked: Can standard values for the constants be defined for hydrogeologic applications that would yield accurate estimates of K in unconsolidated aquifers? Working at 10 locations at three field sites in Kansas and Washington, USA, we acquired NMR and K data using direct‐push methods over a 10‐ to 20‐m depth interval in the shallow subsurface. Analysis of pairs of NMR and K data revealed that we could dramatically improve K estimates by replacing the standard petroleum constants with new constants, optimal for estimating K in the unconsolidated materials at the field sites. Most significant was the finding that there was little change in the SDR constants between sites. This suggests that we can define a new set of constants that can be used to obtain high resolution, cost‐effective estimates of K from NMR logging in unconsolidated aquifers. This significant result has the potential to change dramatically the approach to determining K for hydrogeologic applications.  相似文献   

Regional characterisation of hard‐bottom nursery habitat for juvenile Caribbean spiny lobster (Panulirus argus) using rapid assessment techniques     

Rodney D. Bertelsen  Mark J. Butler IV  William F. Herrnkind  John H. Hunt 《新西兰海洋与淡水研究杂志》2013,47(1):299-312

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Characteristics of beaver ponds on deltas in a mountain environment     

David R. Butler 《地球表面变化过程与地形》2012,37(8):876-882

Many beaver ponds in the Rocky Mountains, that have been described in the literature, are in‐channel ponds that are relatively small and short‐lived. This paper describes floodplain beaver ponds on low‐gradient deltas in glacial finger lakes in Glacier National Park, Montana. These ponds are distinctly larger, probably fed by hyporheic flow, and stable and long‐lived. Ponds examined were, with one exception, 44 years old. Glacial discharge is present in each valley where beaver ponds occupy low‐gradient deltas, and this discharge likely sustains pond water level over the course of the summer. As glaciers recede and disappear, deltaic beaver ponds dependent on hyporheic flow may be negatively affected. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Water temperature dynamics in High Arctic river basins   总被引：2，自引：0，他引：2  

Phillip J. Blaen  David M. Hannah  Lee E. Brown  Alexander M. Milner 《水文研究》2013,27(20):2958-2972

Despite the high sensitivity of polar regions to climate change and the strong influence of temperature upon ecosystem processes, contemporary understanding of water temperature dynamics in Arctic river systems is limited. This research gap was addressed by exploring high‐resolution water column thermal regimes for glacier‐fed and non‐glacial rivers at eight sites across Svalbard during the 2010 melt season. Mean water column temperatures in glacier‐fed rivers (0.3–3.2 °C) were lowest and least variable near the glacier terminus but increased downstream (0.7–2.3 °C km^–1). Non‐glacial rivers, where discharge was sourced primarily from snowmelt runoff, were warmer (mean: 2.9–5.7 °C) and more variable, indicating increased water residence times in shallow alluvial zones and increased potential for atmospheric influence. Mean summer water temperature and the magnitude of daily thermal variation were similar to those of some Alaskan Arctic rivers but low at all sites when compared with alpine glacierized environments at lower latitudes. Thermal regimes were correlated strongly (p < 0.01) with incoming short‐wave radiation, air temperature, and river discharge. Principal drivers of thermal variability were inferred to be (i) water source (i.e. glacier melt, snowmelt, groundwater); (ii) exposure time to the atmosphere; (iii) prevailing meteorological conditions; (iv) river discharge; (v) runoff interaction with permafrost and buried ice; and (vi) basin‐specific geomorphological features (e.g. channel morphology). These results provide insight into the potential changes in high‐latitude river systems in the context of projected warming in polar regions. We hypothesize that warmer and more variable temperature regimes may prevail in the future as the proportion of bulk discharge sourced from glacial meltwater declines and rivers undergo a progressive shift towards snow water and groundwater sources. Importantly, such changes could have implications for aquatic species diversity and abundance and influence rates of ecosystem functioning in high‐latitude river systems. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Distribution and properties of soft weathered bedrock at ≤ 1 m depth in the contiguous United States     

Jonathan A. Wald  Robert C. Graham  Phillip J. Schoeneberger 《地球表面变化过程与地形》2013,38(6):614-626

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MODAL ANALYSIS OF AIRPHOTO LINEARS,CENTRAL IDAHO     

Phillip M. Fowler  William B. Hall  Patricia A. Pober 《自然地理学》2013,34(1):71-81

Approximately 3,000 airphoto linears from an 8,300 km² area of central Idaho are plotted, classified for azimuthal orientation, counted for frequency, and measured for length. Dominant linear orientations, weighted for length, are compared to equivalent central tendency measures for joints, dikes, and foliation. Variations in linear density are also compared to differing lithologies. Statistical analysis reveals the following: (1) the dominant lineation mode is statistically independent of the dominant foliation mode; (2) no statistically significant difference exists between the dominant lineation mode and the average directional mode of dikes; (3) no statistically significant difference exists between the dominant lineation mode and the average directional mode of joints; (4) linear frequency is statistically independent of lithology. Visual comparison of raised relief maps with the isopleth map of directionally dominant linears reveals a pronounced correspondence between those areas exhibiting strong structural control over landforms and highs on the isopleth surface.  相似文献