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Although future climate change will significantly affect New Zealand's climate, how regional climates will be changed remains highly uncertain. As a consequence, pre‐screening sensitivity analysis is recommended for climate‐sensitive activities. A ‘bottom‐up’ approach intended to serve this purpose in the context of non‐irrigated pasture is developed and demonstrated in the Hawke's Bay context. This is achieved using a simple daily water balance model to simulate near‐surface hydrological processes and empirical relationships between transpiration and pasture dry matter production. The Hawke's Bay case study indicates that the methodology has merit and is worthwhile pursuing nationally (with refinements). 相似文献
124.
Some 2088 lightning-caused forest fires that occurred between 1960 and 1971 in northern Idaho are described and analyzed relative to the properties of pattern, central tendency, and spatial variability. Pattern analysis reveals that randomness characterizes both the distribution of total fires and of annual mean areal centers. A model is proposed relating the latitudinal and longitudinal behavior of mean areal centers to shifts in storm tracks and resultant adjustments in fuel-moisture conditions. Rank correlation analysis reveals that northwest shifts in mean areal centers are associated with higher fuel-moisture conditions whereas southeast movements in mean areal centers are related to reduced fuel-moisture conditions. No significant differences were revealed in the variability of the annual standard distances of fire distribution, nor was there any association between temperature and azimuthal adjustments in mean areal centers. 相似文献
125.
Elevation, timber type, size and density of stand, position on slope, and slope aspect were assessed as to their effects upon the location of 2088 lightning-caused forest fires in a 1.4 million-hectare tract of northern Idaho. χ2 analysis revealed that relative fire frequency was greatest between 1050 and 1650 m on the upper 1/3 of those slopes which lie perpendicular to dominant storm tracks and which are covered with Hemlock, Alpine Fir and Spruce. 相似文献
126.
Phillip M. Fowler 《自然地理学》2013,34(1):88-95
Surficial spatial variation in air photo linears is evaluated as a mineral search methodology having potential in differentiating between ore-bearing and non-ore-bearing areas. Linear density, bearing, length, and pattern were compared in equal sized plots of mineralized and adjacent non-mineralized ground in each of 10 study areas. Variance and discriminant analysis indicate that the variables of density and pattern are useful in the prediction and classification of areas as either mineralized or non-mineralized. 相似文献
127.
Christopher S. Fowler 《Urban geography》2016,37(1):1-25
Neighborhoods and neighborhood change are often at least implicitly understood in relation to processes taking place at scales both smaller than and larger than the neighborhood itself. Until recently our capacity to represent these multiscalar processes with quantitative measures has been limited. Recent work on “segregation profiles” by Reardon and collaborators expands our capacity to explore the relationship between population measures and scale. With the methodological tools now available, we need a conceptual shift in how we view population measures in order to bring our theories and measures of neighborhoods into alignment. I argue that segregation can be beneficially viewed as multiscalar; not a value calculable at some “correct” scale, but a continuous function with respect to scale. This shift requires new ways of thinking about and analyzing segregation with respect to scale that engage with the complexity of the multiscalar measure. Using block-level data for eight neighborhoods in Seattle, Washington, I explore the implications of a multiscalar segregation measure for understanding neighborhoods and neighborhood change from 1990 to 2010. 相似文献
128.
A. C. Fowler 《地球物理与天体物理流体动力学》2013,107(2):99-140
Abstract We reconsider the problem of formulation of a model for polythermal glaciers, focussing attention in particular on the temperate zone where ice and water can coexist at the melting temperature. The energy equation for the ice-water mixture in this zone introduces a moisture flux, and a constitutive law for this flux is required. By analogy with the flow through a porous medium, we use Darcy's law (i.e. the second momentum equation of a two-phase flow model with “porous” geometry), and then require a mechanical constitutive relation relating the water pressure p w to the average ice pressure p i . Experience in two phase flows suggests that p w =p i may be problematical, and experience in soil mechanics suggests it is inaccurate. A constitutive relation is therefore presented based on work of Nye (1976), and its effect on the well-posedness of the model is examined. Considerations of the sort presented here have clear relevance in the formulation of similar problems in other geophysical situations, notably mantle convection. 相似文献
129.
Josep M Bayona Amanda Monjonell Juan Carlos Miquel Scott W Fowler Joan Albaigs 《Organic Geochemistry》2002,33(12):1338
Three particle interceptor traps were moored from June to September 1996 along the SE coast of Milos Island (Aegean Sea), in an area known for its extensive seabed geothermal activity. The settling particles collected differed between sites not only in quantity but also in their geochemical composition. In the area directly influenced by warm water vents, the vertical flux of particulate material was almost one order of magnitude higher than that observed at the reference sites 6.5 km away from the vents, with a higher contribution of biogenic material in the former. The neutral lipid fractions exhibited a significant zooplankton biomarker signature (e.g. cholesterol and wax esters), followed by those of microalgal and terrigenous remains. The biogeochemical cycle of sterols included the formation of steroidal ketones, thiols and stanols, the latter two particularly associated with the venting activity. Moreover, the aliphatic and aromatic hydrocarbons in the particles from the venting area reflected a locally enhanced maturity of the organic matter. Although part of the material collected in the traps may have been exported in the vent waters, the higher fluxes observed in the vicinity of the hydrothermal plumes are mainly the result of an assemblage of zooplankton which, in turn, may contribute significantly to the sedimentation, through fast sinking faecal pellets, of the petrogenic hydrocarbons possibly generated in the vents. 相似文献
130.
W. J. Emery C. Fowler J. Maslanik Stephanie Pfirman 《Marine pollution bulletin》1997,35(7-12):345-352
Sea ice has been reported to contain contaminants from atmospheric and nearshore sediment resuspension processes. In this study successive passive microwave images from the 85.5 GHz channels on the Special Sensor Microwave Imager (SSM/I) were merged with drifting buoy trajectories from the International Arctic Buoy Program to compute Arctic sea ice motion in the Russian Arctic between 1988 and 1994. Smooth daily motion fields were averaged to prepare monthly maps making it possible to compute the 7-year mean and mean seasonal ice motions as well as principal components of directional variability of sea ice motion for the entire Arctic and surrounding basins. These mean motion vectors are used to simulate the advection of contaminants deposited on or contained within the sea ice and subsequently transported into the Arctic Ocean in order to predict both their mean trajectories and dispersal over time. The 3-year displacement of contaminants from a number of Russian sites and one American site display various behaviours from substantial displacement and dispersal to almost no movement. This computational procedure could be applied to realtime SSM/I and ice buoy data to provide detailed, all-weather, vector motion maps of ice circulation to predict the path and dispersal of any new substance introduced to the sea ice and transported into the Arctic or Antarctic ocean surface. 相似文献