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This paper contains only hydrological analyses related to the new conceptual solution for the project "Zagreb na Savi". The emphasis was placed on determination of the number of days per year with discharges of the Sava River at Podsused higher than: (1) 500 m3 s-1; (2) 600 m3 s-1; i (3) 700 m3 s-1. The calculations were carried out with the use of daily discharges of the Sava observed at the water gauging station Podsused in the period from 1949-2012. It is pointed out that there is an existing disturbing trend of decrease in the minimum and mean annual discharges of the Sava at Podsused, and thus also a decrease in the number of days when water from the Sava spills over into the Odra canal. It is further pointed out to a downward trend of groundwater levels in the vicinity of the City of Zagreb, and to complex relations between the groundwater and water in the Sava river bed. The aim of the paper is to assist in final decision making with regards to the relation between the City of Zagreb and the Sava River. Source

Derezic D.,Trepce 61 | Vucetic V.,Drzavni hidrometeoroloski zavod
Hrvatski Meteoroloski Casopis | Year: 2012

Classic meteorological instruments for measuring soil temperature are mercury geothermometers. They are placed in the ground at prearranged depths (2, 5, 10, 20, 30, 50 and 100 cm), so that each station has standardized measurements. In this paper the annual and seasonal mean soil temperatures have been analyzed, at different depths for selected meteorological stations: Osijek, Vinkovci, Križevci, Zagreb-Maksimir, Ogulin, Gospić, Poreč, Rijeka, Rab, Knin and Dubrovnik, for which a long-term data series in the period 1961-2009 is available. The main aim of the paper is to study the impact of climate change on soil temperature by depth. A comparison of mean annual soil temperature between a more recent period 1981-2009 and the standard climate period 1961-1990 shows that at most stations soil temperature has increased by approximately 1°C at all depths in the last three decades. The analysis of the linear trend and the Mann-Kendall test confirm the existence of a significant positive trend of mean annual soil temperature. A significant increase in soil temperature is observed, at the depth of 2 cm in particular, at all meteorological stations in the period 1961-2009. In shallower soil layers, up to a depth of 10 cm, the positive trend is between 0.2 and 0.7°C/decade. In deeper layers, up to 100 cm, the trend is slightly less pronounced (0.3-0.6 °C/decade). Seasonal trends show the greatest contributor to the increase in mean annual soil temperature is their increase in the spring and summer. A more significant trend of temperature increase is in the upper layers. The shallower soil layers are heated more quickly during the priliday and cooled more quickly during the night, due to low heat conductivity. The surface layers are heated more quickly in the summer, and cooled more quickly in the winter over the period of a year. Due to low heat conductivity, the deeper layers are cooler during the summer and warmer during the winter than the surface layers. Source

Trninic D.,Znanstveni Savjetnik | Bosnjak T.,Drzavni hidrometeoroloski zavod
Hrvatske Vode | Year: 2012

The primary aim of this paper was the definition of some characteristics of mean and average annual discharges in the past based on analyses of long-time series of discharge, e.g. the Danube time series at Oršova (1840-2010), and the estimate, based on analyses of outputs of the regional climate model, RegCM3, which, among other things, assess potential runoff changes in the near and far future for the area of Croatia and its close vicinty. Analyses of temporal distribution of runoff by summary deviation curve (RAPS) method indicate that summary modular deviations of mean annual discharges behave in a similar manner at the analyzed hydrological stations on the Danube and Sava Rivers, and also the existence of dry and rainy periods, while noting that dry/wet intensity is not identical nor occurring simultaneously. Following the analyses of long-term changes of mean and average discharges at some hydrological stations on the Danube and Sava Rivers from 1840 until the present, the most probable developments in the near future in the area of Croatia and its close vicinity were considered. A marked seasonal and spatial variability in view of runoff amount and trend is present. The most important change, as a result of deviation from the regional climate model RegCM3, relates to a strong indication of potential decrease in precipitation quantities and surface runoff during autumn. The results of the paper show that monitoring should continue - of meteorological, hydrological, hydrogeological, morphological and other aspects, while taking into account anthropological impacts and climate variabilities and change. The development of regional climate models should also continue, since it enables assessment of events which will happen in the near and far future. Only this approach will enable us to respond to ever growing needs for water as a key raw material whose spatial and temporal distribution is very uneven and which is increasingly becoming a limiting factor to economic and social development, i.e. a factor affecting politics as well. Source

Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: ENV.2010.1.1.4-1 | Award Amount: 4.68M | Year: 2011

CLIM-RUN aims at developing a protocol for applying new methodologies and improved modeling and downscaling tools for the provision of adequate climate information at regional to local scale that is relevant to and usable by different sectors of society (policymakers, industry, cities, etc.). Differently from current approaches, CLIM-RUN will develop a bottom-up protocol directly involving stakeholders early in the process with the aim of identifying well defined needs at the regional to local scale. The improved modeling and downscaling tools will then be used to optimally respond to these specific needs. The protocol is assessed by application to relevant case studies involving interdependent sectors, primarily tourism and energy, and natural hazards (wild fires) for representative target areas (mountainous regions, coastal areas, islands). The region of interest for the project is the Greater Mediterranean area, which is particularly important for two reasons. First, the Mediterranean is a recognized climate change hot-spot, i.e. a region particularly sensitive and vulnerable to global warming. Second, while a number of countries in Central and Northern Europe have already in place well developed climate service networks (e.g. the United Kingdom and Germany), no such network is available in the Mediterranean. CLIM-RUN is thus also intended to provide the seed for the formation of a Mediterranean basin-side climate service network which would eventually converge into a pan-European network. The general time horizon of interest for the project is the future period 2010-2050, a time horizon that encompasses the contributions of both inter-decadal variability and greenhouse-forced climate change. In particular, this time horizon places CLIM-RUN within the context of a new emerging area of research, that of decadal prediction, which will provide a strong potential for novel research.

Bajic A.,Drzavni hidrometeoroloski zavod
Hrvatski Meteoroloski Casopis | Year: 2013

Wind action, together with the earthquake action, represents dominant horizontal action on structures in his lifetime. Special significance of this action is that it is changing over time and its intensity varies depending on the meteorological characteristics of each area, and cannot be unified. In existing Eurocodes wind load calculation is based on the reference wind speed defined as a maximum 10-minutes average wind speed to be expected in a 50 years period. Wind with the reference wind speed results with so called static wind load. However, in 10 minutes wind speed varies significantly. That is particularly case during the severe and turbulent bora wind. Due to its gusty character and extreme turbulence, estimates of wind load in the bora region have to include the dynamical wind load caused by bora turbulence. This is confirmed during the example situation of strong bora wind conditions by the values of the exposure coefficient of 4 times greater than the exposure coefficient obtained using only static wind load. Source

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