The aim of the study was to investigate the influence of meteorological factors on the phenological phases of the vegetation in broadleaved forests under varying climatic conditions. To attain the aim, the following objectives were set: 1. Characterize the changes of values of meteorological parameters (temperature, precipitation) in the studied period; 2. Determine solar radiation intensity under the canopies of trees, phenological phases of trees and bushes and their changes; 3. Determine the changes of projection coverage, height and phenological phases of herbaceous plants during the growing period; 4. Ascertain the relationship between meteorological factors and phenological phases of woody and herbaceous plants. Scientific novelty, theoretical and practical significance. Up till now in Lithuania phenological studies mostly of agricultural plants have been conducted. Phenological studies on woody and herbaceous plants in the forests of Lithuania are almost absent. Most of the studies were conducted with indicator species, such as hazel, coltsfoot, etc. During the study, for the first time in Lithuania a complex investigation of forest community was carried out and the influence of meteorological factors on the phenological phases of herbaceous and woody plants in Kamša botanical-zoological reserve was determined. The results of the study allow to better assess the influence of meteorological factors on seasonal development (phenology) of herbaceous plants, trees and... [to full text] / Darbo tikslas – ištirti meteorologinių veiksnių įtaką plačialapių lapuočių miškų augalijos fenologiniams tarpsniams skirtingų klimatinių sąlygų metais. Tyrimo uždaviniai: 1. charakterizuoti meteorologinių rodiklių (temperatūros, kritulių) reikšmių kaitą tiriamuoju laikotarpiu; 2. nustatyti apšvietimą po medžių lajomis, medžių ir krūmų lapojimo fenologinius tarpsnius ir jų pokyčius; 3. nustatyti žolinių augalų projekcinio padengimo, aukščio, fenologinių tarpsnių kaitą vegetacijos metu; 4. nustatyti ryšį tarp meteorologinių veiksnių ir sumedėjusių, žolinių augalų fenologinių tarpsnių. Darbo mokslinis naujumas, teorinė ir praktinė reikšmė. Lietuvoje iki šiol daugiausia atlikta fenologinių tyrimų su žemės ūkio augalais. Sumedėjusių augalų ir miško žolinių augalų detalių fenologinių tyrimų Lietuvoje beveik nėra. Daugiausia atlikta indikatorinių rūšių, kaip paprastasis lazdynas, paprastasis šalpusnis ir kt., tyrimų. Pirmą kartą Lietuvoje kompleksiškai tirta miško bendrija, nustatyta meteorologinių veiksnių įtaka sumedėjusių augalų lapojimo ir žolinių augalų fenologiniams tarpsniams Kamšos botaniniame-zoologiniame draustinyje. Darbo rezultatai leidžia geriau įvertinti meteorologinių veiksnių įtaką miško žolinės augalijos, medžių ir krūmų sezoniniam vystymuisi (fenologijai). Gautos žinios svarbios ne tik teoriniam išsamesniam atskirų rūšių biologijos pažinimui, bet ir praktiniams tikslams: dendrologijoje, fitopatologijoje ir t. t.

No abstract available. / Thesis (Ph.D.)-University of Natal, Durban, 1985.

Mechanisms controlling the productivity, abundançe and taxonomic composition of phytoplankton in tropical Lake Malawi were examined by monitoring phytoplankton dynamics in 8 regions covering the length of the lake (560 km) over a 10-12 month period, and relating these dynamics to spatio-temporal changes in thermal structure, nutrient availability, and meteorological conditions. In addition, nearshore benthic photosynthetic rates were measured in 7 different months.Spatial and temporal changes in areal photosynthetic rates were due almost entirely to changes in the efficiency of light utilization by the phyroplankton community. An evaluation of potential factors which might influence tight utilization indicates that nutrient availabitity is the most important. Most of the photosynthetic N and P demand is met by internal recycling within the upper 200 m, and therefore spatio-temporal variation of phytoplankton photosynthetic rate is closely related to changes in mixing regime. It is shown that the dominant meteorological factors responsible for changes in the mixing regime were solar radiation and windspeed. A comparison with previous photosynthesis data for Lake Malawi indicates that windspeed is a dominant factor controlling interannual variability. Shallow areas of the lake were more productive than deep areas, due to more intense upwelling and more efficient internal nutrient recycling in shallow waters. Within the littoral zone, benthic photosynthetic rates were very high, accounting for 14% to 28% of total net photosynthesis within the shallow southeast arm. Phytoplankton biomass was not correlated with photosynthetic rate, indicating that biomass loss processes were important in controlling biomass variability. Changes in phytoplankton taxonomic composition were related to changes in mixing regime. Cyanobacteria and chlorophytes were dominant throughout much of the study period, but diatoms made up a significant proportion of total biomass during periods of increased turbulence and nutrient availability. An analysis of phytoplankton surface area : volume ratios revealed that organism shape and size are important determinants in species succession. Previous studies have emphasized the low variability of phytoplankton biomass and photosynthetic rates in tropical lakes, relative to temperate lakes. An inter-lake comparison reveals that this tenet does not apply to large lakes. Fluctuations in the mixing regime of large tropical lakes have an effect on phytoplankton variability similar in magnitude to the effect of fluctuating solar irradiance in large temperate lakes.

Magistrantūros studijų baigiamajame darbe pateikiami internetinės prognozavimo „iMETOS®sm“ sistema atlikti bakterinės degligės rizikos faktorių analizė bei prognozavimo galimybes Lietuvos versliniuose soduose Darbo objektas –. obelys (Malus); ligos sukėlėja - bakterinė degligė (Erwinia amylovora Burr.). Darbo metodai: tiriamas meteorologinės stotelės Pessl Instruments „iMETOS®sm“ Erwinia amylovora Burr. infekcijos rizikos prognozavimo modelio pritaikymas Lietuvos versliniuose soduose. Darbo rezultatai. 2011 m. Lietuvos agrarinių ir miškų mokslų centro filialo Sodininkystės ir daržininkystės institute atlikti tyrimai prognuozuojant bakterinės degligės (Erwinia amylovora Burr.) pasireiškimo galimybes Lietuvos versliniuose soduose taikant internetinę „iMETOS®sm‘‘prognozavimo sistemą. Bakterinės degligės prognozavimo modelis numato skirtingus ligos pasireiškimo fonus (PETΣ): 1) paskutinius du sezonus degligės nebuvo; 2) paskutinius du sezonus degligė pasireiškė atskirose vietose; 3) praeitą sezoną degligė pasireiškė atskirose vietose; 4) bakterinė degligė aptikta šalia sodo; 5) netoliese dabar aktyvios degligės žaizdos. Visuose stebėtuose ūkiuose per 2011 m. vegetacijos periodą bakterinės degligės prognozavimo modelis apskaičiavo iš viso 310 dienų, kai bakterinės degligės infekcijos rizikos indeksas DIV rodė didžiausią E. amylovora pasireiškimo galimybę pagal PETΣ. Stebėtuose obelų soduose, kai paskutinius du sezonus degligės sode nebuvo, nustatyta, kad didžiausia patogeno... [toliau žr. visą tekstą] / Master’s thesis submitted to the online prediction "sand'' iMETOS ® forecasting system to perform fire blight risk factor analysis and the predictive ability of Lithuanian business orchards. Object of the work- apple (Malus) to cause disease - a fire blight (Erwinia amylovora Burr.). Method of the work: working methods studied meteorological station Pessl Instruments iMETOS ® sm 'Erwinia amylovora Burr. infection risk prediction model for Lithuanian business orchards. The results of work. In 2011. Lithuanian Institute of Agrarian and Forest Sciences Centre branch of the Institute of Horticulture forecasting studies of fire blight (Erwinia amylovora Burr.) The possibility of a Lithuanian business orchards using an online "sand'' iMETOS ® forecasting system. Fire blight forecasting model for the different disease backgrounds (PETΣ): 1) the last two seasons were not fire blight, 2) the last two seasons fire blight occurred in different places, and 3) last season fire blight occurred in different places, 4) fire blight found near the orchards, 5) nearby is now active fire blight wounds. All the observed farms in 2011. fire blight vegetation period forecasting model documented a total of 310 days after infection, fire blight DIV risk index showed the highest E amylovora by PETΣ to occur. Apple orchards in all observed the last two seasons did not fire blight the garden, it was found that the greatest manifestation of the pathogen by orchards PETΣ option was: „Luksnėnų sodai” UAB... [to full text]

Le micotossine sono metaboliti tossici prodotti da funghi in grado di svilupparsi sulle derrate alimentari. Diverse strategie sono state considerate per risolvere questo problema studiando la crescita di funghi/produzione di micotossine. Questa tesi è focalizzata sullo sviluppo/validazione di modelli matematici per prevedere la contaminazione di micotossine (deossinivalenolo, fumonisine e aflatossine) in cereali (mais/grano) sulla base di dati meteorologici. Il primo capitolo fornisce un’introduzione sulla teoria dei modelli e sui pat-sistemi modelizzati. Il secondo si concentra sulla presenza di tricoteceni e zearalenone nel frumento coltivato in Italia. Nel cap.3 sono stati confrontate le differenze predittive di modelli empirici/meccanicistici per la contaminazione di deossinivalenolo nel grano. Nel cap.4 è stata descritta la contaminazione da fumonisine e aflatossine in mais coltivato in Italia. I capitoli 5 e 6 analizzano il pato-sistema mais-Aspergillus flavus, il primo si concentra sulla sporulazione di A. flavus , il secondo sullo sviluppo di un modello per prevedere la contaminazione da aflatossina. Un altro modello meccanicistico per prevedere la presenza di fumonisina nel mais è descritto nel cap.7. L'ultimo capitolo riassume l'attività svolta nel progetto europeo MYCORED in cui sono stati coinvolti diversi paesi in tutto il mondo che hanno fornito i dati necessari per la validazione dei modelli. / Mycotoxin are toxic secondary metabolite produced by fungi able to colonize crops and thus posing a potential menace to human/animal health. Several strategies have been considered to mitigate the problem studying the variables related to mould growth and mycotoxin production. This thesis focuses on the development and validation of mechanistic models to predict mycotoxins (deoxinivalenol, fumonisins and aflatoxins) contamination in cereals (maize/ wheat) based on meteorological data. The first chapter introduce modelling theory, and patho-systems analysed. Chapter 2 focuses on trichothecenes and zearalenone occurrence in wheat produced in Italy. Predictive performance of empirical and mechanistic models for deoxnivalenol contamination in wheat were discussed in chapter 3. Chapter 4 described fumonisins and aflatoxins occurrence in maize grown in Italy. Chapters 5 and 6 analised the patho-system maize-Aspergillus flavus; the former focuses on the dynamics of A. flavus sporulation the lalatter on the development of a mechanistic model to predict aflatoxin produced by A. falvus. Another mechanistic model for Fusarium ear rot and fumosin production in maize (chapter 7). The last chapter summarised the activity done in the European project MYCORED in which several countries worldwide were involved and wheat and/or maize samples collected with data necessary for model validation.

Wind power can be related to natural disasters in several ways. This licentiate thesis gives some background and introduces four papers devoted to two aspects of this relation. The first section looks into how small-scale wind energy converters (WECs) could be used to generate power after a natural disaster. For this application diesel generators are the most common solution today, but there would be several advantages of replacing these systems. A study of off-grid systems with battery storage at 32 sites showed that photovoltaics (PV) were more suitable than WECs. The results were confirmed by a study for the entire globe; PV outperformed WECs at most sites when it comes to small-scale application. This is especially true for areas with a high disaster risk. Hybrid systems comprising both PV and WECs are however interesting at higher latitudes. For the Swedish case, it is shown that gridded data from a freely available meteorological model, combined with a statistical model, give good estimates of the mean wind speed at 10 meters above ground. This methodology of estimating the mean wind speed can be used when there is no time for a proper wind measurement campaign. The second section is directed towards wind power variability and integration. The results presented in the thesis are intended as a basis for future studies on how a substantially increased wind power capacity affects the electric grid in terms of stability, grid reinforcement requirements, increased balancing needs etc. A review of variability and forecastability for non-dispatchable renewable energy sources was performed together with researchers from the solar, wave and tidal power fields. Although a lot of research is conducted in these areas, it was concluded that more studies on combinations of the sources would be desirable. The disciplines could also learn from each other and benefit from the use of more unified methods and metrics. A model of aggregated hourly wind power production has finally been developed. The model is based on reanalysis data from a meteorological model and detailed information on Swedish WECs. The model proved very successful, both in terms of low prediction errors and in the match of probability density function for power and step changes of power. / Vindkraft kan relateras till naturkatastrofer på flera olika sätt. Den här licentiat\-avhandlingen ger bakgrund till och introducerar fyra artiklar som beskriver två aspekter av detta samband. I den första avdelningen undersöks hur småskalig vindkraft skulle kunna användas för att generera el efter en naturkatastrof. I dagsläget är det dieselaggregat som används för detta ändamål, men det skulle finnas stora fördelar med att övergå till förnybara system. En studie av 32 platser (myndigheten MSB:s utlandsstationeringar augusti 2012) visade att solceller var mer lämpade än vindkraftverk. Resultaten bekräftades av en studie för hela världen; solceller ger billigare system än småskaliga vindkraftverk för de flesta platser, inte minst om man tittar på områden som är utsatta för naturkatastrofer. Hybridsystem med både solceller och vindkraftverk var dock intressanta på högre breddgrader. För Sverige så visas det att data från en fritt tillgängliga meteorologisk modell tillsammans med en statistisk korrigering beroende på terrängtyp ger bra uppskattningar av medelvinden på 10 meters höjd. Den föreslagna metodiken kan vara användbar som ett komplement till vindmätningar eller om det inte finns tid eller möjlighet till en riktig mätkampanj. Den andra avdelningen är inriktad mot vindens variabilitet och integrering av vindkraft i kraftsystemet. De resultat som presenteras i denna avhandling är tänkta som en bas för framtida studier av hur en kraftigt ökad andel vindkraft påverkar elsystemet med avseende på stabilitet, nödvändiga nätförstärkningar, ökade krav på balanskraft etc. En översiktsstudie av variabilitet och prognosbarhet för intermittenta förnybara energikällor gjordes tillsammans med forskare inom sol-, våg och tidvattenkraft. Även om mycket forskning pågår inom dessa områden så var en slutsats att mer studier för kombinationer av olika källor skulle vara önskvärt. Forskare inom de olika disciplinerna skulle också kunna lära från varandra och dra fördel av gemensamma metoder och mått. Slutligen har en modell av aggregerad timvis vindkraftproduktion tagits fram. Modellen baseras på data från en meteorologisk modell samt detaljerad information om vindkraftverk i Sverige. Modellen visade sig vara mycket träffsäker, både vad gäller låga prediktionsfel och i överensstämmelse av sannolikhetsfördelning av effekt och stegförändring av timvis effekt.

Mechanisms controlling the productivity, abundançe and taxonomic composition of phytoplankton in tropical Lake Malawi were examined by monitoring phytoplankton dynamics in 8 regions covering the length of the lake (560 km) over a 10-12 month period, and relating these dynamics to spatio-temporal changes in thermal structure, nutrient availability, and meteorological conditions. In addition, nearshore benthic photosynthetic rates were measured in 7 different months.Spatial and temporal changes in areal photosynthetic rates were due almost entirely to changes in the efficiency of light utilization by the phyroplankton community. An evaluation of potential factors which might influence tight utilization indicates that nutrient availabitity is the most important. Most of the photosynthetic N and P demand is met by internal recycling within the upper 200 m, and therefore spatio-temporal variation of phytoplankton photosynthetic rate is closely related to changes in mixing regime. It is shown that the dominant meteorological factors responsible for changes in the mixing regime were solar radiation and windspeed. A comparison with previous photosynthesis data for Lake Malawi indicates that windspeed is a dominant factor controlling interannual variability. Shallow areas of the lake were more productive than deep areas, due to more intense upwelling and more efficient internal nutrient recycling in shallow waters. Within the littoral zone, benthic photosynthetic rates were very high, accounting for 14% to 28% of total net photosynthesis within the shallow southeast arm. Phytoplankton biomass was not correlated with photosynthetic rate, indicating that biomass loss processes were important in controlling biomass variability. Changes in phytoplankton taxonomic composition were related to changes in mixing regime. Cyanobacteria and chlorophytes were dominant throughout much of the study period, but diatoms made up a significant proportion of total biomass during periods of increased turbulence and nutrient availability. An analysis of phytoplankton surface area : volume ratios revealed that organism shape and size are important determinants in species succession. Previous studies have emphasized the low variability of phytoplankton biomass and photosynthetic rates in tropical lakes, relative to temperate lakes. An inter-lake comparison reveals that this tenet does not apply to large lakes. Fluctuations in the mixing regime of large tropical lakes have an effect on phytoplankton variability similar in magnitude to the effect of fluctuating solar irradiance in large temperate lakes.

In this thesis, it is aimed to investigate and analyze the effect of meteorological conditions on airborne dust measured at Ovacik Open Pit Gold Mine. Meteorological data must be sound and reliable which are used mainly to design an air model to predict the effect of industrial sites on air quality during production. Wind speed, wind direction, airtemperature, air pressure, relative humidity, rainfall, evaporation and sunshine. are the parameters investigated in this study. In the thesis, the meteorological data observed are analyzed and discussed together with the airborne dust measured by MP101M Suspended Particulate Beta Gauge Monitor at Ovacik Gold Mine. In this study, the most significant meteorological parameter affecting airborne dust concentration is determined as air temperature. In this study, it is also determined through airborne dust measurements that neither the short-term limit nor the long-term limit has been exceeded. Therefore, the airborne dust concentrations at Ovacik Gold Mine comply with the Turkish Air Quality Control Regulation.

Mémoire (M.Ress.Renouv.)--Université du Québec à Chicoutimi, 2001. / Document électronique également accessible en format PDF. CaQCU

Σκοπός της παρούσας εργασίας είναι η διερεύνηση των Μετεωρολογικών Παραμέτρων και η προσέγγιση του Υδρολογικού Ισοζυγίου στην ευρύτερη περιοχή της λεκάνης του ποταμού Κόσυνθου, στον Νομό της Ξάνθης. Για να συμβεί αυτό πρέπει να γίνει γνωστή η γεωμετρία του υδρολογικού συστήματος που μελετάται και οι παράμετροι, οι οποίες λαμβάνουν μέρος στο υδρολογικό ισοζύγιο. Προσεγγίζοντας και διερευνώντας αυτές τις παραμέτρους προσπαθούμε να καταρτίσουμε αντιπροσωπευτικά ισοζύγια κατά λεκάνη. / -