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1.
Janez TURK 《山地科学学报》2012,9(3):322-330
A lot of paleoenvironmental surveys have been carried out in the Alpine region to elucidate glacier extension during the Last Glacial or the Würmian (115 - 12 ka BP). However, the evidence of past glaciations differs greatly between Western and Eastern Alps, while contrast between Southern and Northern Alps is not evident. The main purpose of this paper is to interpret variability of humidity during the last interglacial-glacial cycle in the Alpine region, based on results of various surveys performed in the Alpine region. Results show that distribution of moisture throughout the Alps was most even during the Late Würmian, while precipitation was mainly concentrated in the (North)Western Alps during the Early Würmian and in the (North)Western and along all the Southern Alps during the Middle Würmian. The Eastern Alps were rather dry during both episodes. Such moisture distribution can be explained by paths of prevailing winds. Moisture distribution is directly linked with atmospheric and oceanic circulation. 相似文献
2.
Local characteristics of Postojna Cave climate, air temperature, and pressure monitoring 总被引：1，自引：0，他引：1
In Postojna Cave, air temperature and pressure monitoring has been conducted since July 21, 2008. Air pressure in the cave at three monitoring sites fluctuates synchronically with outside air pressure. Temperature data for Postojna 1 and 3 show good correlation with outside climate conditions for the period 2009?C2010. The temperature at Postojna 1 was increasing constantly from March to May 2009, while at Postojna 2, it was decreasing. Postojna 1 has a seasonal trend in accordance with outer trend, while seasonal trend at Postojna 2 is just contrary to outside trend. Microclimate studies at Postojna 2 show local variability, especially in winter, and exhibit special microclimate conditions that may be due to ventilation of unknown passages in the back. 相似文献
3.
Cave air temperature, carbon dioxide concentrations in the cave air and external air temperature were analysed at several locations in Postojna Cave over the course of six holiday periods in 2009–2011. The results show that a 1-day increase in visitor numbers from 200 to 3,500 raised the cave air temperature by a maximum of 0.5 °C. The air temperature increases are within the annual range of cave air temperature variations. A fivefold increase in visitor numbers resulted in a carbon dioxide concentration that was at least twice as high as normal. The carbon dioxide concentration increased from 450 to 1,750 ppm (December 2009–January 2010). After 10 days of peak period visits, both the CO2 concentration and the temperature returned almost to the pre-holiday values. The gradual increase in mean annual air temperature in the cave (2004–2010) is not related to the number of visitors but to outside climate conditions. 相似文献
4.
?rna Jama is the coldest section of cave within the Postojna Cave System. Mean annual air temperatures at the ?rna Jama 2 site are 5.6 °C (2015) and 5.7 °C (2016), and at the ?rna Jama 3 site 7.1 °C (2015) and 7.2 (2016), whereas the mean external air temperature was 10.3 °C (2015) and 10.0 °C (2016). In Lepe Jame, the passage most heavily visited by tourists, the mean cave-air temperature is 10.7 °C (2014–2017). ?rna Jama exhibits winter and summer temperature regimes. During warm periods (Tcave < Tout), it acts as a cold air trap, exchanging no air with the outside atmosphere. Under such conditions the cave-air temperature shows no short-term diurnal temperature oscillations. Cave-air temperature is significantly stable and affected only by elevation of the groundwater table, which is associated with precipitation. During cold periods (Tcave > Tout), ventilation takes place and dense, cold, outside air sinks into ?rna Jama because of the favourable cave entrance morphology. Recent ?rna Jama air temperature data (2014–2017) indicate a < 0.5 °C higher temperature than that recorded in historical data since 1933. ?rna Jama is the most appropriate place within the Postojna Cave System to study long-term climatic changes. There are hardly any tourist visits to the cave, and human impacts on the cave climate are essentially reduced. 相似文献
5.
The physicochemical parameters of the sulphide spring water from a 500?m deep artesian borehole in Sovra Valley (Slovenia) are stable, with very little variation: temperature, 9.2 ± 0.0 °C; pH 7.70 ± 0.11; specific electrical conductivity, 777 ± 8 μS/cm; and dissolved oxygen, 0.19 ± 0.11 mg/l. The water from the borehole is hard, rich in sulphates, and has a notable concentration of sulphide, while it is low in chlorides. Communities of phototrophs were analysed at the oxygenic ecocline at the outflow from the borehole, and from further downstream. Caloneis tenuis, Frustulla vulgaris, Gomphonema sp., Navicula radiosa, Oscillatoria sp., and Tribonema vulgare successfully thrive exclusively at the outflow from the borehole under sub-optimum conditions for the majority of phototrophs. Downstream from the borehole, where the hydrogen sulphide degasses, autotrophic biofilms were dominated by different diatoms. The Bray–Curtis similarity index confirms the distinctive phototrophic communities along the oxygenic ecocline downstream from the sulphidic spring. The sulphidic ecocline downstream from the spring is indicative of the composition of phototrophic communities, as some species appear only downstream from the spring. An ecocline downstream from the borehole of the sulphidic spring was reflected also in the bacterial indicator groups. This study brings novel insights to the limited knowledge in the field of oxygenic phototrophy related to sulphidic springs. 相似文献
6.
Furdek M Vahčič M Ščančar J Milačič R Kniewald G Mikac N 《Marine pollution bulletin》2012,64(2):189-199
In this work, data on the level of organotin compounds (OTCs) in seawater and mussels collected along the entire Croatian Adriatic Coast are presented. The samples were collected in 2009 and 2010 at 48 locations representing different levels of maritime activities, including marinas, ports and reference sites. Butyltins (BuTs) were found in all analyzed samples, representing >97% of OTCs, and ranged from 0.46 to 27.98 ng Sn L(-1) in seawater and from <6 to 1675 ng Sn g(-1) in mussels. The results indicate a recent input of TBT, with the highest concentrations of BuTs found in the marinas. It appears that the Adriatic coast is still polluted with TBT despite the fact that TBT-containing antifouling paints have been banned in Croatia since 2008. It is questionable how much TBT pollution decreased since 2005, when a high incidence of imposex was established in the same area. 相似文献
7.
Martin Knez Janja Kogovšek Hong Liu Janez Mulec Metka Petrič Nataša Ravbar Tadej Slabe 《Environmental Earth Sciences》2012,67(1):273-283
In Kunming area (6.8 mio population), two big interventions are in progress: construction of a new airport, the 23 km2 area of which will extend across karst terrain northeast of the city, and extensive uptake of water from karst aquifers for drinking and agricultural use. In the study, an interdisciplinary approach was utilized to demonstrate the need for holistic karstology studies prior to performing extensive interferences in the karst environment. This study included survey of surface karst features and microscopic analyses of rock samples in the area of the new airport location, accompanied by hydrogeological studies and microbiological analyses of two karst drinking water sources in its vicinity (Qinglongdong, Huanglongdong). Results showed the specific characteristics of the subsoil stone forest that indicated a high level of karstification. The direction and characteristics of groundwater flow from the sinking Qiaotou Stream at the margin of the new airport area toward the Huanglongdong Spring were defined with a single tracer test. Additional information about hydrogeological characteristics of the karst aquifer was obtained by individual measurements of physical and chemical parameters of the springs and sinking stream. Selected chemical and bacteriological parameters showed substantial pollution of both springs due to various types of human activities in the catchments. The results of the study pointed to the necessity of taking immediate measures for the springs’ protection and showed the importance of interdisciplinary research when planning anthropogenic activities in the karst. 相似文献
8.
The CO2 concentration of the air in Postojna Cave (400–7900 ppm) is found to be induced by CO2 sources (human respiration contributing?~?20,000–58,000 ppm per breath, outgassing of dripwater and water seeping from the vadose zone/epikarst with a pCO2 values of 5000–29,000 ppm, and underground Pivka River having pCO2 at 2344–4266 ppm) and CO2 dilution (inflow of outside air with a CO2 concentration of?~?400 ppm). Measurements show that sinking Pivka River has the lowest CO2 concentration among plausible CO2 sources but still continuously exceeds the surrounding cave air CO2 concentration. During the winter months, intensive ventilation reduces the cave air CO2 concentration to outside levels (~?400 ppm), even in the centre of the cave system. CO2 dilution is less pronounced in summer (CO2(min)?≈?800 ppm), since the ventilation rate is not as strong as in winter and the outside air that enters the cave through breathing holes and fractures is enriched with soil CO2. During spring and autumn, the daily alternation of the ventilation regime with a smaller rate of air exchange results in yearly cave air CO2 peaks of up to?~?2400 ppm. Some dead-end passages can be much less affected by ventilation, resulting in a cave air CO2 concentration of up to 7900 ppm. The strongest diurnal CO2 peaks due to human respiration were recorded during the spring holidays (increase of up to 1300 ppm day?1), compared to considerably smaller summer peaks despite peak visits (increase of?~?600 ppm day?1). 相似文献
9.
Janez Perko 《Computational Geosciences》2018,22(6):1423-1432
In this paper, we describe a single-relaxation-time (SRT) lattice Boltzmann formulation, which can be effectively applied to anisotropic advection-dispersion equations (AADE). The formulation can be applied to space and time variable anisotropic hydrodynamic dispersion tensor. The approach utilizes diffusion velocity lattice Boltzmann formulation which in the case of AADE can represent anisotropic diagonal and off-diagonal elements of the dispersion matrix by the coupling of advective and diffusive fluxes in equilibrium function. With this approach, AADE can be applied to the SRT lattice Boltzmann formulation using the same equilibrium function and without any changes to collision step nor in the application of boundary conditions. The approach shows good stability even for highly anisotropic dispersion tensor and is tested on selected illustrative examples which demonstrate the accuracy and applicability of the proposed method. 相似文献
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