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1.
This study analyzes the relationship between Aerosol Optical Depth (AOD) obtained from Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) and ground-based PM10 mass concentration distribution over a period of 5 years (2008–2012), and investigates the applicability of satellite AOD data for ground PM10 mapping for the Croatian territory. Many studies have shown that satellite AOD data are correlated to ground-based PM mass concentration. However, the relationship between AOD and PM is not explicit and there are unknowns that cause uncertainties in this relationship. The relationship between MODIS AOD and ground-based PM10 has been studied on the basis of a large data set where daily averaged PM10 data from the 12 air quality stations across Croatia over the 5 year period are correlated with AODs retrieved from MODIS Terra and Aqua. A database was developed to associate coincident MODIS AOD (independent) and PM10 data (dependent variable). Additional tested independent variables (predictors, estimators) included season, cloud fraction, and meteorological parameters — including temperature, air pressure, relative humidity, wind speed, wind direction, as well as planetary boundary layer height — using meteorological data from WRF (Weather Research and Forecast) model. It has been found that 1) a univariate linear regression model fails at explaining the data variability well which suggests nonlinearity of the AOD-PM10 relationship, and 2) explanation of data variability can be improved with multivariate linear modeling and a neural network approach, using additional independent variables.  相似文献   

2.
With the use of the optimised three-step BCR sequential-extraction procedure it was possible to assess the mobility of selected elements in soil profiles from Croatian and Slovakian karst terrains. The soils in the Croatian karst were enriched in Cr, Ni, V, Mn, Cu, Cd and Mo, while soils from the Slovak Karst had high Pb and Zn concentrations. It was determined that the elements were most readily mobilised from the topsoil and the degree of mobility decreased with depth. Cr and Ni were mainly bound to the residual fraction, and Pb in the oxidisable fraction. Cu mobility was high in samples treated with agrochemicals throughout the soil profile.  相似文献   

3.
三峡工程库区移民迁建区地质灾害与防治   总被引:1,自引:1,他引:1  
殷跃平 《地质通报》2002,21(12):876-880
三峡工程移民总人口达120万人,移民迁建区地质条件复杂,地质环境容量极为有限,人地关系紧张,移民安置难度大。本文将三峡工程移民迁建区地质工作归结为地质条件的复杂性、地质工作的阶段性、地质认识的局限性、地质问题的长期性4个方面,并对三峡库区地质灾害临测预警工程的建设内容和运行方式进行了初步探讨。三峡库区地质灾害预警工程将按照“中央领导,分省负责,县为基础”的方针,在群测群防体系和专业技术体系相结合的基础上,以国家、省市和县区3级地质环境监测站为依托,采用现代化的计算机网络技术和群测群防手段,对库区以滑坡为主的地质灾害进行分批分级监测,三峡库区地质灾害预警工程将分4个阶段实施。最后,就三峡工程移民迁建区地质灾害防治工作提出了建议。  相似文献   

4.
Durability is one of the most important engineering properties of weak and clay-bearing rocks. Weathering can induce a rapid change in rock material from initial properties to soil-like properties. The sensitivity of a rock type against weatherability is usually described by a durability parameter, such as the slake durability index. However, marl resistance is not detected satisfactorily by the durability indices by using slake durability test as suggested by ISRM for two wetting–drying cycles. The results of this study are obtained from samples of compact or laminated eocene marls from region of Dalmatia, Croatia. The samples were subjected to 4 cycles of slake durability, point load tests, determination of dry density, determination of carbonate content and absorption of water. The scatter of data suggests that strength probably has no influence on the durability of marls. On the other hand a separate group of marl samples have a second-cycle slake durability index higher than approximately 85%, and the durability of these samples is classified as “medium-high” to “high”, although the visual inspection of samples after testing, suggests that they should have “medium” to “low” durability classification. According to obtained results these samples of marl fulfil the criterions for the durability classification: a carbonate content lower than approximately 65%, a dry density lower than 2.4 Mg/m3, and values of water absorption higher than 5%.  相似文献   

5.
Amphorae sherds from the Laecanius workshop of Roman Istria (10–5 B.C. and 78 A.D.), Croatia, were studied by integrating archaeological and geological techniques including fabric analysis, thin‐section petrography, X‐ray diffractometry (XRD), and heavy mineral analysis. The fabric of the sherds showed distinctive characteristics, permitting their classification and allocation into nine fabric groupss. Petrography revealed that quartz is the dominant clastic component, whereas carbonate is common as temper; XRD provided information on firing temperatures that ranged between 750 and 900°C. The sherds contain diverse heavy mineral suites with generally high epidote and garnet proportions; zircon is occasionally important. Garnet/epidote ratios and the presence of diagnostic species (pyroxene, hornblende) showed systematic variations that coincided with similar variations in fabric characteristics. Heavy mineral signatures of amphorae produced in other workshops proved essential in differentiating them from Laecanius sherds. A comparative heavy mineral analysis of terra rossa samples from the vicinity of the workshop indicated that terra rossa was the major source for the paste. Differences observed in the heavy mineral composition of the sherds and terra rossa were interpreted by the spatial heterogeneity of the latter and the mixing of the paste with sandy temper. Fresh Adriatic sponge spicules in the majority of Laecanius sherds and the temper‐derived, generally immature heavy mineral assemblages suggest that sandy deposits from the Adriatic were used for the clastic temper. © 2006 Wiley Periodicals, Inc.  相似文献   

6.
7.
Rural diversification in Croatia is well advanced because many rural families have been able to find work in secondary and tertiary activities without the need to migrate to the towns. Many rural settlements have now attained an urban character although there are regional variations, including a contrast between the continental zone with a relatively high level of commitment to agriculture and the coastal areas, with pronounced ‘deagrarisation’ where the ports and tourist resorts are well developed and the natural resource conditions for agriculture are poor. These variations are examined at the municipality level with reference to two key indicators: the share of nonagricultural population and the share of workers in the total active population. Four categories of socio-economic transformation are recognised: more urbanised, urbanised, less urbanised and rural. The main regional differences between the continental and coastal areas are confirmed with the latter showing a relatively high level of socio-economic transformation through the prominence of more highly urbanised municipalities. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

8.
As both Middle-European and Mediterranean country, the Republic of Croatia is composed of several regional units. Every single natural and geographical unit is not specific only in terms of its general natural features, but also by its role in linking Croatia with the rest of the world. Additional peculiarity of these geographic units is their complementary value, which gives good prerequisites for successful economic development of the country.In Pannonian section of Croatia prevail natural features close to those in other Central-European countries. Namely, this section of Croatia participates in Danube catchment area, linking Croatia with the rest of Central Europe. Dinaric Alps are typical mountainous area; in north-western part of the range (i.e. in the region of Gorski Kotar) they are very narrow, making thus possible a comparatively easy communication between Pannonian part of Croatia and the Adriatic coast. Coastal region of Croatia — stretching along the most of (north)eastern coast of the Adriatic — is predominantly characterised by Mediterranean natural features. Due to its size and share in total area of the country, territorial waters of the Adriatic sea can be accepted as the fourth natural and geographic unit of Croatia.  相似文献   

9.
Croatia, through its geographic position, is a Mediterranean/Adriatic and Central European/Danube state. As an Adriatic coastal state, it has a long maritime tradition, which is apparent in its well-developed shipping (2.4 million GT), the high-quality ship-building industry (among the top six in the world) and through its numerous sea ports, of which many were established in ancient times. The leading national port is Rijeka, which is at the same time an important transit port for Austria, Hungary, Slovakia and the Czech Republic.The exceptionally indented Croatian Adriatic coast with its attractive archipelagos and favorable climatic and oceanographic conditions in the coastal sea offers very advantageous conditions for comprehensive tourist utilization. This is particularly true of nautical tourism, which is complimented by a larger number of constructed and well-equipped yachting ports/marinas on the coast and islands.  相似文献   

10.
The aim of the present work was to investigate links between the low-field magnetic susceptibility (MS) and chemical and mineral composition of sediments from several Croatian and Slovenian rivers, as well as to determine possible anthropogenic influence on these sediments. MS measurements are a fast and simple method, which serves as a proxy for the estimation of pollution in different environmental systems. The investigated rivers are predominantly unpolluted rivers from Croatian and Slovenian karstic and flysch areas, which belong to the Adriatic or the Black Sea watersheds: the Dragonja, the Mirna, the Ra?a, the Ri?ana, the Reka, the Rak, the Cerkni?nica, the Unec and the Ljubljanica rivers. It was assumed that, due to their mostly unpolluted status, they could serve as a database for natural MS background values for this region. For comparison, several rivers and a lake from the Celje old metallurgic industrial area (Slovenia) were also investigated: the Savinja, the Hudinja, the Voglajna rivers and Slivni?ko Lake. They form a sub-basin of the Sava River drainage basin. Sediments of the clean karstic and flysch rivers showed extremely low MS values, with mass susceptibility values ranging from 0.58 × 10?7 to 5.11 × 10?7 m3/kg, and isothermal remanent magnetism (IRM) values ranging from 0.71 to 7.88 A/m. In the Celje industrial area, river sediments showed much higher MS values, with mass susceptibility values ranging from 1.31 × 10?7 to 38.3 × 10?7 m3/kg, and IRM values ranging from 0.91 to 100.42 A/m. The highest MS value was found in the Voglajna River at Teharje-?tore, a point which showed a significant number of anomalies of toxic metals in earlier investigations. Semiquantitative determination of relations between grain size and concentration of magnetite was performed using the Thompson-Oldfield method. X-ray diffraction (XRD) mineralogical analysis showed that sediments of the Celje area have mostly quartz as major mineral, with relatively small amount of carbonate minerals, while in sediments of karstic rivers carbonate minerals prevail. Statistically significant correlations were obtained between MS and Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Ba in the Slovenian karstic region and between MS and Cr, Fe, Co, Ni and Zn in flysch drainage basins. On the contrary, no correlation of MS and Hg content was obtained.  相似文献   

11.
Recently discovered dinosaur bones in submerged near-shore deposits of southwest Istria include one vertebra, one femur, and two rib fragments. They all show well-developed vascularization. The large amounts of primary bone tissue in the vertebral and femoral compacta as well as in one rib fragment suggest that they belong to sub-adult animals which were growing rapidly. The structure of a second rib fragment differs in that it consists of secondary bone. The absence of lines of arrested growth is evident in all investigated bones. This suggests a sustained manner of bone deposition.  相似文献   

12.
The position of Croatia on the border of larger geographic wholes (Central Europe, the Mediterranean, the Balkans) makes it a transitional region for these larger areas. However, the Pannonian region of Croatia, as the largest part of its national territory, places it in the ranks of the Central European states. The long historical ties of the Croatian lands with the Austrian and Hungarian centers of Central European power also confirm Croatia's affiliation with Central Europe. The cultural, civilization, religious and other characteristics, which today ease Croatia's communications with Central European countries, are unavoidable. With state independence, Croatia acquired the political sovereignty vital for its Central European orientation and was liberated from the problems of the Balkans, although it is still struggling for its territorial integrity. Croatian statehood was realized soon after the reunification of Germany, which in fact renewed the concept and content of Central Europe. This fact opened many questions tied to the rivalry and political balance of the European powers, which is also connected to the geopolitical position of Croatia.  相似文献   

13.
Eastern coast of the Adriatic Sea consists of karstified carbonates. It belongs to the well-known Dinaric karst region. The coast is extremely indented and there are 718 islands with numerous rock crags and reefs. Some of the inhabited islands use their own water resources for public water supply, or plan to do it in the future. Since karst rocks are extremely permeable, the seawater intrudes into underground water resources, thereby forming the wedge. A wide transition zone occurs between this seawater wedge and fresh water aquifers. Consequently, island groundwater reserves turn brackish to a certain extent. In this study, 77 water samples were collected from a wide variety of water resources. Comprehensive statistical and mathematical multivariate analysis of these data was performed. Simple statistical approach showed several useful correlations among some parameters, and more complex multivariate techniques extracted three factors in connection with three natural processes: (1) mixing with the seawater, (2) carbonate dissolution and (3) human influence (pollution) and nitrogen transformation processes. The results of this study demonstrate that in situ measurement of electrical conductivity is adequate for the very rough field estimation of numerous parameters.  相似文献   

14.
Ten gravity springs from the slopes of the Biokovo Mt, Adriatic coast of Croatia were investigated. Three of them are included in the regional water supply system. The aim of this study was to investigate hydrogeological and geochemical characteristics of watershed, presenting one of the most typical karstic areas in the world.Hydrogeological investigations were performed during two seasons with dye tracing, using Na-fluoresceine which was poured into two pits, observing springs at distances of 1.82–8.8 km. Apparent velocities were 0.21–0.51 cm s?1. Dye tracing was first time partially effective and second time ineffective, what could be due to immanent ore mineralization, which presents a natural barrier and was discovered by geochemical and mineralogical methods.Concentrations of 17 dissolved and total trace elements were determined first time in groundwater samples. Their concentrations were extremely low, more than 3 orders of magnitude less than allowed by the Croatian directives for the first category of groundwater and drinking water. The mass fractions of 60 elements were determined in 3 representative spring sediments. Highest concentrations of some metals in sediments (mg kg?1) are: lead 5440, chromium 118, manganese 935, zinc 116 and barium 238. Origin of some elements and mineralogy is discussed.  相似文献   

15.
The emigration of juvenile Atlantic menhaden,Brevoortia tyrannus (Latrobe), from the York River Estuary, Virginia, was studied during the years 1981 and 1982. Concurrent observations of menhaden catch, water temperature, and phytoplankton abundance suggested that the migration began in response to environmental events in the estuary. Juvenile menhaden appeared to begin their migration five days after the sustained onset of water temperatures below 24 °C. The temperature change was hypothesized as the proximate factor that initiates the migration. Coincident with the migrations, phytoplankton communities in the estuary bloomed, suggesting that the ultimate factor that initiates the migration may be the occurrence of sufficient food for the emigrating menhaden as they moved down and out of the estuary. Migration timing may have evolved as a mechanism to enhance the survival of migrating juvenile menhaden during a period of physiologic stress.  相似文献   

16.
17.
Presently, 235 submerged caves and pits have been recorded along the Croatian coast and islands, partly or completely submerged by sea water. Contrary to the inland situation, recorded submerged features are predominantly horizontal (60%), though there are indications that the real situation is similar to that of the continental part where 69% are vertical pits. Completely marine conditions are established in 126 caves and the rest are anchihaline caves and submarine springs. Speleothems are found in more than 140 caves. By their origin, the investigated caves are all continental features formed in Mesozoic and Palaeogene carbonates, subsequently submerged owing to sea transgression. Due to the relatively low wave energy, rapid sea level rise and maturity of the host rock, they do not fit into concepts of a sea cave or a flank margin cave development, but they fulfil several conditions for being the blue holes. Since the term ‘blue hole’ is mainly associated with the Bahamian karst, our attempt is only to show the possible similarities with no intention of ascribing that term to the Croatian caves. Beside karstological issues, Croatian submerged caves are unique environmental, archaeological and tourism assets.  相似文献   

18.
Low-grade schists from the Slavonian Mountains (Tisia Mega-Unit, Mt Papuk, Croatia), previously assigned to Precambrian to Lower Palaeozoic metamorphism, have been subjected to geochemical investigations, P-T modelling, and in situ age dating of monazite. The studied fine-grained metasediments consist of chlorite (5–15 vol.%), K white-mica (40–55 vol.%), quartz (20–35 vol.%), feldspar (albite 15–20 vol.%), opaques (<2 vol.%), and accessory minerals. According to their whole-rock geochemistry, the detritus of the former sediments came from upper crustal felsic rocks as they occur, for instance, at Mt Papuk. The schists show a complex microtectonic fabric, including well-developed schistosity systems. P-T pseudosections in the system MnNCKFMASHTO, constructed for typical schists of the study area, resulted in peak P-T conditions of 445–465 °C and 4.6–6.0 kbar for a sample from Kutjevo (eastern part of the study area) and 450–460 °C and 5.2–6.0 for a Vranovo sample (western part). Electron microprobe (EMP) dating of monazite in the schists gave a weighted average age of 109.0 ± 13.1 Ma (2σ) eventually with three subgroups of ages at 225 ± 63 (two analyses), 114 ± 24 and 83 ± 22 Ma. We conclude that the metamorphism of the studied schists at depths of c. 20 km is due to an Alpine collisional event.  相似文献   

19.
Jean Rémy 《GeoJournal》1993,31(3):265-278
The French Urban Sociology is divided between people interested on appropriation of space and other interested in the production. In this orientation till year 1970 — Marxist theory had a strong influence. After that, the research was more orientated to collective negociation between social actor, with a preoccupation to define the real power of different level of political decision. The state is financing most of the research. This institutional situation explains also the research orientation.  相似文献   

20.
In northern Croatia, the Neogene sediments cover complicated basement rocks which consist of Alpine and Dinaridic elements in the Zagorje area, and Variscan - Alpine formations of the Tisia (Tisza) megatectonic unit in the Slavonian Mountains (Mts.). The Neogene sediments were deposited in two separate basins before the Karpatian, but sedimentation became uniform from the Karpatian onwards (~17.5 Ma). Of the 24 localities that we have studied so far paleomagnetically from northern Croatia, 16 localities are of Karpatian or younger age, while the rest are pre-Karpatian. As a result of laboratory analysis, 16 localities yielded tectonically interpretable results. Our data suggests that northern Croatia shifted northwards, while rotating moderately counterclockwise, probably before the Karpatian. A second counterclockwise rotation occurred at the present latitude in post-Pontian times. There is no significant difference between localities situated above different basements, though Tisia is pictured as rotating clockwise in the Neogene. The paleomagnetic pattern of northern Croatia resembles that of areas situated north of the Periadriatic-Balaton line. Therefore, we conclude that northern Croatia is part of a larger block, dissected by several important tectonic lines, driven by the counterclockwise rotated Adriatic microplate.  相似文献   

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