Risk-Based Decision-Support Groundwater Modeling for the Lower San Antonio River Basin,Texas, USA     

Linzy K. Foster  Jeremy T. White  Andrew T. Leaf  Natalie A. Houston  Aarin Teague 《Ground water》2021,59(4):581-596

A numerical surface-water/groundwater model was developed for the lower San Antonio River Basin to evaluate the responses of low base flows and groundwater levels within the basin under conditions of reduced recharge and increased groundwater withdrawals. Batch data assimilation through history matching used a simulation of historical conditions (2006-2013); this process included history-matching to groundwater levels and base-flow estimates at several gages, and was completed in a high-dimensional (highly parameterized) framework. The model was developed in an uncertainty framework such that parameters, observations, and scenarios of interest are envisioned stochastically as distributions of potential values. Results indicate that groundwater contributions to surface water during periods of low flow may be reduced from 6% to 25% with a corresponding 25% reduction in recharge and a 25% increase in groundwater pumping over an 8-year planning period. Furthermore, results indicate groundwater-level reductions in some hydrostratigraphic units are more likely than in other hydrostratigraphic units over an 8-year period under drought conditions with the higher groundwater withdrawal scenario.  相似文献   

Macroalgal mats in Langstone harbour     

P.G. Soulsby  D. Lowthion  M. Houston 《Marine pollution bulletin》1983,14(5):202

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The Identification and Evaluation of Benthic Macroinvertebrate Assemblages in an Industrialised estuary—Southampton Water, UK, using a longterm, low-level sampling strategy     

M. Houston  D. Lowthion  P. G. Soulsby 《Marine environmental research》1983,10(4):189-207

A long-term, low-intensity sampling strategy has been applied to the benthic infauna of Southampton Water, UK to determine patterns of faunal distribution in relation to water quality influences. The estuary receives domestic and industrial discharges including a large oil refinery and associated petro-chemical industries.The data has been subject to classification and ordination techniques and three faunal assemblages identified, one characterising an area with high hydrocarbon and copper sediment values.Spatial and temporal variations have been identified- emphasising the need for a long-term approach to demonstrate the dominant faunal patterns in an area receiving a variety of discharges. The approach is economic in use of resources but compatible with the objectives of monitoring surveys.  相似文献   

Modeling of tropical cyclone winds and waves for emergency management   总被引：5，自引：0，他引：5  

Amal C. Phadke  Christopher D. Martino  Kwok Fai Cheung  Samuel H. Houston   《Ocean Engineering》2003,30(4):5039-578

This paper compares three commonly used parametric models of tropical cyclone winds and evaluates their application in the wave model WAM. The parametric models provide surface wind fields based on best tracks of tropical cyclones and WAM simulates wave growth based on the wind energy input. The model package is applied to hindcast the wind and wave conditions of Hurricane Iniki, which directly hit the Hawaiian Island of Kauai in 1992. The parametric wind fields are evaluated against buoy and aircraft measurements made during the storm. A sensitivity analysis determines the spatial and spectral resolution needed to model the wave field of Hurricane Iniki. Comparisons of the modeled waves with buoy measurements indicate good agreement within the core of the storm and demonstrate the capability of the model package as a forecasting tool for emergency management.  相似文献   

Evaporation in the Atacama Desert: An empirical study of spatio-temporal variations and their causes   总被引：3，自引：0，他引：3  

John Houston   《Journal of Hydrology》2006,330(3-4):402-412

The Atacama Desert is hyper-arid, and areas where adequate moisture exists for evaporation are spatially highly restricted. Nevertheless, water resources exist and their evaluation requires knowledge of this elusive but important component of the hydrological cycle. Evaporation may occur in four typical areas: rivers and associated riparian zones, localized springs, large playas and extensive areas of bare soil after infrequent precipitation events. Transpiration is locally possible where moisture is sufficiently close to the surface to allow phreatophytes or scarce grass cover to grow, but virtually no information is available for quantification. Pan evaporation data from 11 stations for the period 1977–1991 is analyzed and complemented by analysis of an evaporation study conducted in the Salar de Atacama during 1987/1988. The results show that pan evaporation, and hence maximum potential evaporation may be considered largely a function of maximum temperature and elevation as well as density of the evaporating fluid. Actual evaporation is limited by available moisture and diminishes rapidly as the level of soil moisture saturation drops below the soil surface, extinguishing at ca. 2 m depth. Evaporation is greatest during the summer, but at higher elevations convective cloudiness develops during January and February reducing evaporating rates at a time when significant precipitation may occur. Inter-annual variations in pan evaporation are considerable and weakly correlated with ENSO, but variations in actual evaporation are damped by comparison. Regression equations are developed which have widespread applicability and may be used to estimate evaporation in areas where no site-specific data exists.  相似文献   

Palaeohydraulics of a tabular,cross-stratified sand in the Brampton Esker,Ontario     

Houston C. Saunderson  Alan V. Jopling 《Sedimentary Geology》1980,25(3):169-188

Several hydraulic techniques were used to estimate the flow depth (0.3 m) associated with the deposition of a tabular set (micro-delta) of cross-stratified sand in the Brampton esker. The competency of the flow, deduced from both the grain size and structural characteristics of the set, gave a value of approximately 0.65 m/sec for the palaeo-velocity of the flow. Estimates of palaeo-depth and velocity facilitated calculation of the Froude and Reynolds numbers, about 0.38 and 1.24 · 10⁵, respectively. Extrapolation of other parameters included bed shear stress τ₀ (4.50 N/m²), shear velocity U_* (0.067 m/sec), dimensionless Chezy coefficient C/√g (9.7), slope of the energy gradient S(0.00153), Darcy-Weisbach friction factor f(0.085), Manning roughness coefficient n(0.027) and discharge of bed-material load (19 metric tons/day/m). The figures cited are reasonable estimates only. The occurrence of regressive ripples in the bottomset of the micro-delta aided in the hydraulic interpretation. These flow characteristics are only representative of the final stages of deposition at one location on the flank of the esker. The core of the esker was probably deposited under different hydraulic conditions.  相似文献   

Characteristics of the top ten snowstorms at First-Order Stations in the U.S.     

Tamara G. Houston  Stanley A. Changnon 《Natural Hazards》2009,48(1):101-113

Snowstorms can produce varying degrees of damage depending on the amount and intensity of the snowfall over a given amount of time. Concurrent weather conditions such as freezing rain and high winds often exacerbate the amount of damage received. In order to assess the frequency of potentially damaging conditions during climatologically significant snowstorms, the top ten snowstorms (TTS) at individual First-Order Stations in the eastern two-thirds of the conterminous U.S. were determined, and the hourly weather conditions during each event were analyzed. The results show that TTS have occurred as early as September and as late as June, with January being the peak month of occurrence. Hourly precipitation totals during TTS were 2.3 mm or less 88% of the time. Seven percent of TTS were classified as a blizzard with over half of the blizzards occurring in the West North Central region. The most common concurrent weather condition during a TTS was fog followed by blowing snow. Regionally, heavy snow events in the Northeast had relatively higher precipitation amounts, colder temperatures, higher winds, and more fog and blowing snow than any other region.  相似文献   

Development of an augen gneiss terrain     

Scott B. Smithson  Donald J. Murphy  Robert S. Houston 《Contributions to Mineralogy and Petrology》1971,33(3):184-190

Augen gneisses and related migmatites commonly form extensive areas in deep crystalline terrains and are interlayered with horizons of undoubted metasedimentary rocks. Augen gneiss, migmatite, and hornblende gneiss near McMurdo Sound, Antarctica, is interlayered with calcareous metasedimentary rocks on all scales and passes gradationally into quartzo-feldspathic gneiss. Numerous discontinuous lenses and layers of metasedimentary rocks in augen gneiss have been disrupted by transposition of layering and form tectonic inclusions. Calc-silicate layers have reacted with the surrounding rocks and become partially amphibolitized. Field evidence suggests that augen gneiss formed from quartzo-feldspathic gneiss by local metasomatism that accompanied strong deformation and smoothed out original metasedimentary differences. Locally partial melting took place. The final result is a sequence of augen gneiss, hornblende gneiss, and migmatite with thin amphibolite lenses and layers. The metasedimentary rocks are correlated with lower grade limestones and calcareous arenites including graywackes 125 km to the south. The quartzo-feldspathic gneiss would thus represent highly metamorphosed graywacke and sandstone. Augen gneiss and quartzo-feldspathic gneiss have similar chemical compositions, but augen gneiss seems to be somewhat more mafic. The composition of augen gneiss is more mafic than average continental shield surface rock and less mafic than the average crustal rock. Evidence indicates that augen gneiss and related rocks formed by homogenization of rocks that were originally sedimentary and its composition may reflect the bulk composition of material supplied to the crust earlier in the earth's history.  相似文献   

Creating a thinking space for the rising stars of Australian urban geography     

Dallas Rogers  Libby Porter  Wendy Steele  Donna Houston 《The Australian geographer》2019,50(2):141-143

The Institute of Australian Geographers Urban Study Group and Australian Geographer present the first essay in our Leading Insights/Thinking Space partnership. We discuss Dr Natalie Osborne's 2018 essay, flag Dr Marilu Melo's 2019 essay and talk about creating a thinking space for the rising stars of Australian urban geography.  相似文献