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911.
Katherine J. Knierim Anna M. Nottmeier Scott Worland Drew A. Westerman Brian R. Clark 《Hydrogeology Journal》2017,25(6):1779-1793
Hydrologic budgets to determine groundwater availability are important tools for water-resource managers. One challenging component for developing hydrologic budgets is quantifying water use through time because historical and site-specific water-use data can be sparse or poorly documented. This research developed a groundwater-use record for the Ozark Plateaus aquifer system (central USA) from 1900 to 2010 that related county-level aggregated water-use data to site-specific well locations and aquifer units. A simple population-based linear model, constrained to 0 million liters per day in 1900, provided the best means to extrapolate groundwater-withdrawal rates pre-1950s when there was a paucity of water-use data. To disaggregate county-level data to individual wells across a regional aquifer system, a programmatic hierarchical process was developed, based on the level of confidence that a well pumped groundwater for a specific use during a specific year. Statistical models tested on a subset of the best-available site-specific water-use data provided a mechanism to bracket historic groundwater use, such that groundwater-withdrawal rates ranged, on average, plus or minus 38% from modeled values. Groundwater withdrawn for public supply and domestic use accounted for between 48 and 74% of total groundwater use since 1901, highlighting that groundwater provides an important drinking-water resource. The compilation, analysis, and spatial and temporal extrapolation of water-use data remain a challenging task for water scientists, but is of paramount importance to better quantify groundwater use and availability. 相似文献
912.
在前人研究基础上,依托露头和钻井资料,以沉积相分析为核心,结合四川盆地构造演化,采用单因素分析多因素综合法,以"组"为单元编制了奥陶纪岩相古地理图。奥陶纪四川盆地及邻区总体呈现西高东低的古地理格局,自西向东发育滨岸相、混积潮坪相、局限台地相、开阔台地相和斜坡相—盆地相。从岩相古地理视角对成藏条件的分析表明:奥陶系五峰组沉积期四川盆地主体属于局限海环境,发育了一套优质烃源岩,此外,与奥陶系临近的上覆志留系龙马溪组和下伏寒武系筇竹寺组烃源岩在有断层沟通的情况下可提供有效气源;奥陶系碳酸盐岩总体致密,白云石化、表生溶蚀和裂缝的存在是储层形成的关键因素,对应发育了桐梓组—红花园组颗粒滩白云岩储层、岩溶储层和宝塔组裂缝储层等三类储层;奥陶系发育下部(下生上储)和上部(上生下储)两套成藏组合,具有较好的勘探潜力。 相似文献
913.
Spatial pattern of grassland aboveground biomass and its environmental controls in the Eurasian steppe 总被引:1,自引:0,他引:1
Vegetation biomass is an important component of terrestrial ecosystem carbon stocks. Grasslands are one of the most widespread biomes worldwideplaying an important role in global carbon cycling. Thereforestudying spatial patterns of biomass and their correlations to environment in grasslands is fundamental to quantifying terrestrial carbon budgets. The Eurasian steppean important part of global grasslandsis the largest and relatively well preserved grassland in the world. In this studywe analyzed the spatial pattern of aboveground biomass(AGB)and correlations of AGB to its environment in the Eurasian steppe by meta-analysis. AGB data used in this study were derived from the harvesting method and were obtained from three data sources(literatureglobal NPP database at the Oak Ridge National Laboratory Distributed Active Archive Center(ORNL)some data provided by other researchers). Our results demonstrated that:(1) as for the Eurasian steppe overallthe spatial variation in AGB exhibited significant horizontal and vertical zonality. In detailAGB showed an inverted parabola curve with the latitude and with the elevationwhile a parabola curve with the longitude. In additionthe spatial pattern of AGB had marked horizontal zonality in the Black Sea-Kazakhstan steppe subregion and the Mongolian Plateau steppe subregionwhile horizontal and vertical zonality in the Tibetan Plateau alpine steppe subregion.(2) Of the examined environmental variablesthe spatial variation of AGB was related to mean annual precipitation(MAP)mean annual temperature(MAT)mean annual solar radiation(MAR)soil Gravel contentsoil p H and soil organic content(SOC) at the depth of 0–30 cm. NeverthelessMAP dominated spatial patterns of AGB in the Eurasian steppe and its three subregions.(3) A Gaussian function was found between AGB and MAP in the Eurasian steppe overallwhich was primarily determined by unique patterns of grasslands and environment in the Tibetan Plateau. AGB was significantly positively related to MAP in the Black Sea-Kazakhstan steppe subregion(elevation 3000 m)the Mongolian Plateau steppe subregion(elevation 3000 m) and the surface(elevation ≥ 4800 m) of the Tibetan Plateau. Neverthelessthe spatial variation in AGB exhibited a Gaussian function curve with the increasing MAP in the east and southeast margins(elevation 4800 m) of the Tibetan Plateau. This study provided more knowledge of spatial patterns of AGB and their environmental controls in grasslands than previous studies only conducted in local regions like the Inner Mongolian temperate grasslandthe Tibetan Plateau alpine grasslandetc. 相似文献
914.
Marcinków(Lower Silesia, ?nie?nik Masiff,south-western Poland) has been a well-known mining centre since the mid-15 th century. Mineral extraction ended in 1949 with the ores of Pb, Ag, Cu and occasionally Au, U or graphite mined there. The mine is surrounded by metamorphic graphite and mica schist. It is not open to the public and no bats have been recorded living in. The aim of this study was the mycological analysis of the air, the rock surface and the water of the disused ore mine of Marcinków.Additionally, the chemical composition of rocks and water, and microclimate conditions of the adit were determined. Fungi were identified using a combination of phenotypic and molecular methods.Six taxa of fungi were cultured from the indoor air samples of the adit, whereas the outdoor air samples contained only five taxa. On the other hand, nine taxa were isolated from both the rocky walls and the water.The Aspergillus group was present only on the rocks and in the water, whereas Cladosporium herbarum,Dumontinia tuberosa, Epicoccum nigrum, Hirsutella sp., were found exclusively in the air. The mycobiota found in the ore mine were mostly similar to those recorded in other mines and natural caves. However,it should be noted that the internal microclimate and chemical compounds of the rocks. 相似文献
915.
Gabriel Granco Marcellus Marques Caldas Jason Scott Bergtold Ana Claudia Sant’Anna 《GeoJournal》2017,82(1):63-80
Within the past decade, the sugarcane ethanol industry in Brazil has increased its production capacity to meet rising domestic demand for ethanol. However, to achieve this growth the industry has had to expand into new frontiers in the Brazilian Cerrado, specifically in the states of Goiás and Mato Grosso do Sul, which is now the second largest producing area of ethanol in Brazil. We argue that the expansion into the Brazilian Cerrado is a result of the interactions between the increase in demand, governmental policies, infrastructure, and factors that have prevented traditional sugarcane producing regions from meeting the increasing demand for ethanol. This paper analyzes the policies that have shaped the sugarcane industry in Brazil and the expansion of the industry across the country. The policies and issues examined include those that led to the concentration and consolidation of the sugarcane industry in the state of São Paulo and the consequences of this consolidation; the influence of governmental policies on the decision-making process of producers and industry; the state-level policies designed to expand the industry into Goiás and Mato Grosso do Sul states; infrastructure development; and the Sugarcane Agroecological Zoning policies. Through this study we conclude that the ethanol industry identified the Cerrado states as an opportunity for investment, given the good agricultural conditions for producing sugarcane, affordable land prices and favorable state-level fiscal incentive policies. In addition, there is a need for further regional development policies as the interaction between the sugarcane sector and regional government is likely to continue into the future. 相似文献
916.
Shaun Rmer Henrik Breuning‐Madsen Thomas Balstrm Anna‐Elisabeth Jensen 《Geoarchaeology》2006,21(1):113-124
Archaeological sites dating to the Ertebolle period of the Mesolithic have been recorded below a thin layer of marine sands in a reclaimed bay on northern Falster Island in Denmark. The finds seemed randomly distributed throughout the bay; there was no obvious pattern related to the modern landscape. However, by coring through the veneer of marine sands and mapping the pattern of the underlying Late Quaternary deposits, the authors were able to reconstruct the Mesolithic landscape and thereby explain the distribution of archaeological sites. This approach allows archaeologists to focus subsurface exploration in geomorphic settings, such as former fjords and coastlines that have a high potential for yielding prehistoric sites. © 2006 Wiley Periodicals, Inc. 相似文献
917.
Table of Contents
Table of Contents 相似文献918.
A Note on Velocity Spectra in the Marine Boundary Layer 总被引:1,自引:1,他引:0
Spectra of longitudinal and vertical velocity have been studied at a marine site, östergarnsholm, in the Baltic Sea during a period of six days with near-neutral or slightly unstable conditions, when the wave state gradually changed from pure wind sea to strong swell having approximately the same direction as the wind. During the pure wind sea phase, spectra are shown to adhere closely to general forms for the neutral atmospheric surface layer obtained from a new theory. As soon as the wave age goes slightly beyond that representative of pure wind sea conditions, the spectra deviate in shape from the ideal forms. The spectral modification appears to start at a frequency typical of the swell component. As the wave age increases, it progresses in frequency as a downscale cascade, which is particularly prominent in the spectrum of the vertical component but which is also observed in the longitudinal component. In addition, there is a strong effect in the low-frequency part of the spectra. It is interpreted as an indirect effect of large-scale inactive turbulence, which becomes progressively more important as wave-age increases. It is found that the ratio of the spectrum of the vertical component and the spectrum of the corresponding longitudinal component attains the theoretically predicted value of 4/3 for cases of developing sea (gale force wind) for frequencies above approximately 4 Hz but never much exceeds unity for cases with swell. It is argued that this is an indication of local anisotropy and that the inertial-dissipation method for determination of the momentum flux is inappropriate in the case of mixed seas or swell. 相似文献
919.
920.
Comparison Between Eddy-Correlation and Inertial Dissipation Methods in the Marine Atmospheric Surface Layer 总被引:2,自引:2,他引:0
A comparison of momentum fluxes determined by the eddy-correlation method(ECM) and the inertial dissipation method (IDM) has been performed using longterm measurements over the sea. The measurements were made on the island ofÖstergarnsholm in the middle of the Baltic Sea. The results show that a`classical' form of the inertial dissipation method, i.e., assuming that the transportterms are negligible, and using an effective value for the Kolmogorov constant of0.55, can be used with a mean relative difference between the two methods of about15% for -1 < z/L < 0.5 (z being height and L the Obukhov length). The IDMmethod works best for high wind speeds and neutral conditions. For low windspeeds (U < 6 m s-1) the relation between the two methods is morecomplex. IDM then gives higher values than ECM on the average (about 20%),especially for swell conditions, indicating the need for an imbalance function inthe turbulent kinetic energy budget. Calculations of the effective Kolmogorovconstant, a, suggest a dependence upon the wave age, a increasing with increasing wave age, where the value 0.59 fits the data well for saturated waves. 相似文献