Spatial and temporal variation of extremely low minimum temperatures in Hungary during the period between 1951 and 2010

For this study, data of 16 meteorological stations have been processed over a period of 60 years with the purpose to reveal thespatial and temporal structure of the frequencies of absolute extreme minima in Hungary with special reference to the surmised global rise oftemperatures on a worldwide scale. In the main areas of fruit growing, the monthly or seasonal absolute temperature maxima and minima arepresented during the 60 year-long period and projected on the geographical map.For the main fruit- and vegetable growing regions the probability of winter- and late frosts is of prime interest. The time series of extremetemperatures though did not prove signifi cant changes over the period observed, but the information upon changes and their tendencies is aprecious tool being utilised in planning, choice of adequate varieties for a longer period of time in the future.The deleterious winter frosts experienced in fruit production is not a consequence of a sole drop to a minimum temperature, but of an earlierperiod of mild temperatures during the winter, which sensibilised the trees. Frequent and extreme variations of temperatures may causetroubles at any time during the year and reduce the yields conspicuously.We ought to get familiar with the hazards of our climate and fi nd optimal solutions to mitigate the damages expected.The seasonal and monthly distribution projected on the geographical map we can follow up also the spatial relations and the signifi cance oftheir occurrence. Coeffi cients of variation between meteorological happenings at different localities facilitate the calculation of the probabilityof risks on the surrounding areas

Spatial and temporal variation of extremely low minimum temperatures in Hungary during the period between 1951 and 2010

For this study, data of 16 meteorological stations have been processed over a period of 60 years with the purpose to reveal the spatial and temporal structure of the frequencies of absolute extreme minima in Hungary with special reference to the surmised global rise of temperatures on a worldwide scale. In the main areas of fruit growing, the monthly or seasonal absolute temperature maxima and minima are presented during the 60 year-long period and projected on the geographical map. For the main fruit- and vegetable growing regions the probability of winter- and late frosts is of prime interest. The time series of extreme temperatures though did not prove signifi cant changes over the period observed, but the information upon changes and their tendencies is a precious tool being utilised in planning, choice of adequate varieties for a longer period of time in the future. The deleterious winter frosts experienced in fruit production is not a consequence of a sole drop to a minimum temperature, but of an earlier period of mild temperatures during the winter, which sensibilised the trees. Frequent and extreme variations of temperatures may cause troubles at any time during the year and reduce the yields conspicuously. We ought to get familiar with the hazards of our climate and fi nd optimal solutions to mitigate the damages expected. The seasonal and monthly distribution projected on the geographical map we can follow up also the spatial relations and the signifi cance of their occurrence. Coeffi cients of variation between meteorological happenings at different localities facilitate the calculation of the probability of risks on the surrounding areas

Spatial and temporal variation of extremely abundant maxima of precipitation in Hungary during the period between 1951 and 2010

The study deals with the accumulated database of 16 meteorological stations in Hungary during a period of 60 years. The purposewas to reveal the spatial and temporal structure of the appearance of extreme values in the daily distribution of data concerning precipitation.We strived to answer the question whether the frequency of incidences of daily maxima did they change or not during the 60 year-long periodin the main growing regions of the country. It is demonstrated on geographical maps how the size and frequency of precipitation episodesensued, and what are the typical traits of changes in intensity as well as in frequency of happenings projected according to their spatial andtemporal distribution.From the point of view of fruit and vegetable growing, it is of prime interest what kind of frequency and intensity of changes occurredin precipitation. The temporal distribution of extremities though did not seem to change signifi cantly in some areas, but the recognitionof changes may help conspicuously the planning and the choice between alternatives of species and varieties as well as technologies ofhorticultural managements for the long run.Extremely intense rains during a short time may cause erosion and stagnant water, thus we have to know what are the odds of risk.The temporary distribution of changes helps us to judge upon the reality of anxieties, which are expected according to the existence of trends.Seasonal or monthly distribution is visualised by maps, what is expected and what is accidental as for a decision in planning. The spatialdistribution of coeffi cients of variation help us to decide what is the local chance of extreme happenings at different parts of the country andwhat is its coeffi cient of uncertainty. The risk of any undertaking dependent on conditions of weather could be expressed numerically by acoeffi cient of risk

Spatial and temporal variation of extremely abundant maxima of precipitation in Hungary during the period between 1951 and 2010

The study deals with the accumulated database of 16 meteorological stations in Hungary during a period of 60 years. The purpose was to reveal the spatial and temporal structure of the appearance of extreme values in the daily distribution of data concerning precipitation. We strived to answer the question whether the frequency of incidences of daily maxima did they change or not during the 60 year-long period in the main growing regions of the country. It is demonstrated on geographical maps how the size and frequency of precipitation episodes ensued, and what are the typical traits of changes in intensity as well as in frequency of happenings projected according to their spatial and temporal distribution. From the point of view of fruit and vegetable growing, it is of prime interest what kind of frequency and intensity of changes occurred in precipitation. The temporal distribution of extremities though did not seem to change signifi cantly in some areas, but the recognition of changes may help conspicuously the planning and the choice between alternatives of species and varieties as well as technologies of horticultural managements for the long run. Extremely intense rains during a short time may cause erosion and stagnant water, thus we have to know what are the odds of risk. The temporary distribution of changes helps us to judge upon the reality of anxieties, which are expected according to the existence of trends. Seasonal or monthly distribution is visualised by maps, what is expected and what is accidental as for a decision in planning. The spatial distribution of coeffi cients of variation help us to decide what is the local chance of extreme happenings at different parts of the country and what is its coeffi cient of uncertainty. The risk of any undertaking dependent on conditions of weather could be expressed numerically by a coeffi cient of risk

Urban vegetation extraction from VHR (tri-)stereo imagery : a comparative study in two central European cities

The present study proposes a workflow to extract vegetation height for urban areas from Pléiades stereo and tri-stereo satellite imagery. The workflow was applied on a stereo image pair for Szeged, Hungary and on tri-stereo imagery for Salzburg, Austria. Digital surface models (DSMs) of the study areas were computed using the semi-global matching algorithm. Normalised digital surface models (nDSMs) were then generated. Objects of vegetation and non-vegetation were delineated based on the spectral information of the multispectral images by applying multi-resolution segmentation and support vector machine classifier. Mean object height values were then computed from the overlaid pixels of the nDSMs and assigned to the objects. Finally, the delineated vegetation was classified into six vegetation height classes based on their assigned height values by using hierarchical classification. The vegetation discrimination resulted in very high accuracy, while the vegetation height extraction was moderately accurate. The results of the vegetation height extraction provided a vertical stratification of the vegetation in the two study areas which is readily applicable for decision support purposes. The elaborated workflow will contribute to a green monitoring and valuation strategy and provide input data for an urban green accessibility study.DK W 1237N23(VLID)251709

Modelling the maximum development of urban heat island with the application of GIS based surface parameters in Szeged (Part 1): Temperature surveying and geoinformatical measurements methods

Vizsgálatunk célja az éves átlagos hősziget kialakulását, méretét és területi szerkezetét befolyásoló speciális városi struktúra, ezen belül a geometriai szerkezet és beépítettség hatásának számszerűsítése. A kétrészes tanulmányban a korábban már alkalmazott égboltláthatósági index és beépítettségi tényezők mellett az épületkompaktság klímaalakító szerepét is vizsgáljuk. A szakirodalom szerint is teljesen új paraméter három dimenzióban egyszerre jellemzi az épületek térfogatát, valamint tagoltságukat és elsősorban termodinamikai szempontból játszik fontos szerepet. Az első részben a városklíma egyes sajátosságainak áttekintése után bemutatjuk a vizsgált területet (Szeged), valamint a hőmérsékleti, terepi és térinformatikai felmérési módszereket, amelyek - a modell megalkotásának érdekében - elengedhetetlenül szükségesek a hőmérséklet és a különböző felszínparaméterek városon belüli eloszlásának meghatározásához. The aim of our research is to reveal quantitatively the effect of the peculiar urban structure on the development, magnitude and spatial distribution of the mean annual urban heat island. In this two-part study, besides the earlier applied sky view factor and different built-up parameters, we examine the climate modification role of the building compactness. This new parameter characterises the volume, plan area and thermodinamical role of the buildings at the same time. In the first part, after a general overview of some features of the urban climate, we will present the investigated area in Szeged, then the applied temperature, surveying and geoinformatical measurement methods. In order to establish the model, these methods are necessary to determine the intra-urban spatial distribution of the temperature and the different surface parameters

Land-use and meteorological aspects of the urban heat island

IgenIge