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341.
This paper presents a scheme describing low flow formation processes in areas with different environmental conditions, including the impact of the selection and explanatory power of predictors for a probabilistic model based on the Logit model. The research was carried out using 29 daily streamflow gauges located in the Lublin region of southeastern Poland for the hydrological period 1976–2018. Analysis resulted in two distinct low flow schemes. In the lowland rivers, low flows occur during the warm season and are related to evaporation exceeding precipitation. In the upland rivers, hydrogeological factors related to water levels in the local Cretaceous aquifers determine the occurrence of low flows. This differentiation affects the quality of the predictive models. For lowland rivers, models based on the climatic water balance with a monthly shift have a better fit, while these models used for upland rivers are characterized by an approximately 10% decrease in accuracy. For upland rivers, the combined CtHt models without shifts produce the best model fit. The generalized precision of the Logit models is around 80%–90%. 相似文献
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Toward very high horizontal resolution NWP over the alps: Influence of increasing model resolution on the flow pattern 总被引:1,自引:0,他引:1
Michał Z. Ziemiański Marcin J. Kurowski Zbigniew P. Piotrowski Bogdan Rosa Oliver Fuhrer 《Acta Geophysica》2011,59(6):1205-1235
The increasing resolution of contemporary regional numerical weather prediction (NWP) models, reaching horizontal grid sizes
of O(1 km), requires robust and reliable dynamical cores, working well beyond the approximation of quasi-horizontal flows. That
stimulates an interest in an application for NWP purposes of dynamical cores based on the anelastic, or — more generally —
sound-proof flow equations, and characterized by appropriate robustness and reliability. The paper presents results from testing
the dynamical core of EULAG, the anelastic research model for multi-scale flows, as a prospective NWP dynamical core. The
model simulates the semi-realistic frictionless and adiabatic flow over realistic steep Alpine topographies, employing horizontal
grid sizes of 2.2, 1.1, and 0.55 km. The paper demonstrates not only the numerical robustness of EULAG, but also studies the
influence of the varying horizontal resolution on the simulated flow. Results show that the increased horizontal resolution
increases orographic drag on the flow. While the general flow pattern remains the same, increased resolution influences the
flow on scales from hundreds of kilometers to meso-gamma scales. The differences are especially apparent in the near-surface
layer of 1.5 to 3 km deep, and in the distribution and amplitudes of the orographically-induced gravity waves. 相似文献
345.
In this paper, a feasibility of anelastic approach for numerical weather prediction (NWP) is examined. The study concerns
the anelastic nonhydrostatic model EULAG as a prospective candidate for the new dynamical core of a high-resolution NWP model.
Such an application requires a series of benchmark tests to be performed. The study presents the results of dry idealized
two-dimensional linear and non-linear tests. They include evolution of cold and warm density currents in neutrally stratified
atmosphere, inertia-gravity waves in short and long channels, as well as mountain gravity waves for a set of different flow
regimes. Detailed comparison of the results with the reference solutions, based mainly on the results of compressible models,
indicates a high level of conformity for all of the experiments. It verifies the anelastic approach as strongly consistent
with the compressible one for a broad class of atmospheric problems. It also corroborates the robustness of EULAG numerics,
an essential requirement of dynamical core of NWP model. 相似文献
346.
The background nickel (Ni) concentrations in the sediments of two sub‐mountain reservoirs (Dobczyce and Czorsztyn) situated in the Carpathian Flysh (southern Poland) were evaluated. Ni concentrations (15.6–83.1 µg g?1 dry wt.) in both reservoir sediments were affected mainly by the high background content of Ni in the surrounding watershed. Distribution of elevated Ni concentrations mostly revealed an impact of long‐range transport influenced by the flow of the main tributary. Ni spatial pattern was mainly influenced by mineral compounds of Fe, Mn, and Al, and to a lesser degree by organic matter content and silt and clay fractions of the sediments of both investigated reservoirs. Spatial distribution was additionally modified by hydrological conditions (flood events and course of the old river‐bed). In both reservoirs, substantial portions of Ni were bound to potentially immobile phases, i.e., moderately reducible and residual phases (64–82% in total). Laboratory experiments showed that changes in pH affected Ni leaching from the sediment to a small degree (at pH ~3 up to 19.9%). Our results indicated that Ni in these reservoirs has low mobility and, therefore, poses a low toxicological risk to aquatic organisms. 相似文献
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Several samples of peat from 6 bogs located in southern Poland were investigated for occurrence and distribution types of biomarkers present in their extractable organic matter fraction. It was found that there are inputs from two different sources of organic compounds differing in their characteristics and origin: (1) recent immature peat organic matter deposited in situ which is the source of all polar functionalized compounds, most of n-alkanes, and acyclic isoprenoids, and (2) mature fossil fuels, most probably bituminous coals from the Upper Silesia Coal Basin of vitrinite reflectance equivalent values of 0.9–1.1%. The latter compounds were most probably transported with fly ash to bogs from nearby settlements utilizing such fuel in domestic ovens. This group includes pentacyclic triterpenoids (hopanes and moretanes), minor amounts of n-alkanes, and numerous alkyl naphthalenes and alkyl phenanthrenes. All these compounds show distributions and values of geochemical ratios characteristic for mature organic matter confirming there ex situ origin. 相似文献
349.
Tomasz Kamiński 《Singapore journal of tropical geography》2023,44(1):58-74
In a polycentric world, cities increasingly bear responsibility for implementing climate policies. To do so, they establish transnational city networks (TCNs), which produce ambitious imaginaries of the future of cities, such as ‘smart cities’ or ‘resilient cities’, based on ecological knowledge. This paper analyses Southeast Asian (SEA) cities’ participation in TCNs. First, this paper presents city networks operating in SEA. Then, drawing on a case study of Quezon City, this paper shows how SEA cities often position themselves in the network as knowledge consumers rather than (co)producers and prefer to learn from cities in the Global North. This research also shows how TCNs—with limited success—seek to counter this neo-colonial knowledge flow model. The paper contributes to the literature on TCNs, arguing that the ongoing North–South imbalance needs to be addressed if networks are to promote viable models of future SEA cities. Identifying the patterns of knowledge flows inside TCNs, this study argues that networks should assist cities in imagining possible city futures beyond the experiences of the select world and global cities. TCNs should pay more attention to supporting their SEA members in looking ‘outwards’ to comparable cities worldwide rather than merely ‘upwards’ to global and mega-cities. 相似文献
350.