Browsing by department "Geotieteiden ja maantieteen osasto"
Now showing items 41-60 of 85
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(2019)Soil carbon stocks of arctic regions are globally a remarkable carbon storage and a fundamental component in the global carbon cycle, as they store more than twice the amount of carbon compared to the atmosphere. Environmental controllers and mechanisms behind soil carbon stocks should be comprehensively studied, as there is no clear agreement of the climate change impacts on the sensitive tundra ecosystems and the soil carbon storages. Therefore, there is an urgent need for reliable and extensive soil carbon data to evaluate both local and global impacts of ecosystem changes in tundra regions. Typically, the upscaling of soil organic carbon predictions made in arctic regions has been based totally or partly on vegetation and land cover classifications. This might be one reason why we are lacking a wide view of the potential of using topographical variables in the upscaling of carbon stocks. Even though, the theory has proven a strong indirect relationship between topography and soil properties. Consequently, only variables extracted from a terrain model were used in this study. The aim of the study was to produce as realistic regional soil organic carbon prediction as possible and to investigate the potential of modeling soil organic carbon with topographical variables. Additionally, the variation of soil carbon stocks in relation to the topographical position were examined closely. The landscape scaled subarctic research area located in northern Norway in a mountainous region with relative elevation reaching almost one thousand meters. Hence, the area has a wide range of environmental gradients, which makes it a great area for studying ecological impacts. The research material consisted of field measurements and soil samples of which carbon contents were analyzed in laboratory. Carbon storages were examined against topographical variables extracted from the terrain model using two different multivariate models: generalized additive model (GAM) and generalized boosted regression modeling (GBM). Models were assessed through correlations between observed and predicted values and through model residuals and their root mean square errors (RMSE). Based on the predictive models, soil carbon stocks varied on the research area between 0–34,5 kg C m-2 and the regional mean estimate was 4,2 kg C m-2. These estimates and the regional variation in stocks are in line with earlier inventories made in similar environments. The largest soil carbon stocks were found above the treeline in valleys, at gently sloping hillsides and in local water-logged peatlands. Soil carbon stocks were generally smaller in the mountain birch forest compared to the shrub and heath tundra areas. Local scale variability in carbon stocks were significant and a great portion of total storages was found on a limited area. Above a height of 700 meters, steep topography and harsh climate conditions limits soil formation leaving only barren ground, which explains the low observed carbon storages. Relationships between local topography and soil carbon stocks presented in theory were also recognized in the results of the multivariate models. Absolute height above sea level regulated soil carbon stock especially through the impact on vegetation and temperature conditions. Hence, these mechanisms made up the robust landscape scaled distribution in predicted carbon storages. Instead, soil moisture determined the fine scaled variation. As well, the results indicated soil moistures essential role in soil carbon accumulation. Earlier observations of topographical variables potential in soil carbon prediction modeling are supported by the fairly good models of this research. Nevertheless, large uncertainties are still associated with regional upscaling of soil carbon stocks, which should be paid attention to in future researches to improve the reliability of predictions. A holistic perspective will be necessary to understand the spatial distribution and environmental factors influence on soil carbon storages. Reliable estimations of soil carbon stocks are a key component when determining future climate change impacts and feedbacks as these mechanisms have globally reaching consequences.
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(2020)The arctic-alpine tundra environment, located above treeline at mountainous areas in high latitudes, is a varying fine-scale mosaic of landscapes and biotopes driven by harsh and extreme environmental conditions. Soil moisture and temperature play a key part in the environmental processes of the area, as they regulate especially vegetation and soil microbial activity. Both soil moisture and temperature vary greatly in spatial as well as temporal scales even in small scale environments. Despite their variability and importance, the mechanisms driving these variables have been scarcely studied. In this study the focus was how soil moisture and temperature vary in the different biotopes of arctic-alpine environment in the Kilpisjärvi region. The study area is located in the slopes and valley between the fjells Saana and Korkea-Jehkas, where 1 200 study plots, 1 square meter in size and 50 meters from each other, were placed systematically. Soil moisture and temperature were measured from the plots three times during the growing season: in June, July and August. A vast collection of field measurements was gathered from the plots and then supplemented with variables extracted from a digital elevation model. The next step was to use statistical models to determine how topographic, soil and vegetation variables affect the spatial variability of soil moisture and temperature during the growing season. The methods used were Generalized Additive Models (GAM), Generalized Boosted Methods (GBM) and Random Forest (RF). The effect of the variables was studied by how adding different variable groups affected the explanatory and predictive powers of the different models. In addition the effect of individual explaining variables was examined by their relative influence on GBM-models. Soil moisture and temperature varied significantly during entire growing season and not only in the entire study area but also within biotopes as well. Soil temperature values increased throughout the growing season, whereas soil moisture values were highest in July and lowest in August. Modelling results suggest that topography and soil variables have stronger effect in June and July and the effect of vegetation variables strengthens in August. GBM-models suggest that the best individual variable in explaining soil moisture´s spatial variation during all field measurement periods is biotope class and organic layer depth. The best individual variable explaining soil temperature´s spatial variation during all field measurement periods is potential solar radiation. In addition elevation has a strong effect in June and July and soil moisture in August. In principle, the moisture models´ explanatory and predictive powers decrease during growing season due to drying soil while temperature models´ explanatory and predictive powers increase due to warming soil. The results of this study support and expand the findings of former studies on spatial and temporal variation of soil moisture and temperature modelling in arctic-alpine environment. In future studies it is important to consider the impact of using different variables in soil moisture and temperature in a versatile way. It is also important to study the temporal variation of soil moisture and temperature more thoroughly to understand the effects of climate change on arctic-alpine biotopes better.
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Maatutkaprofiilien syvyyskalibrointi CMP-luotauksella esimerkkikohteissa Helsingissä ja Hollolassa (2019)Tässä tutkimuksessa perehdytään CMP-luotauksen teoriaan ja käytäntöön maatutkaluotausten profiililinjojen syvyyskalibroinnissa. CMP-luotaus on Suomessa harvoin käytetty nopeusanalyysimenetelmä ja tutkimuksessa haluttiin selvittää CMP-luotauksen tuomia mahdollisuuksia. Tutkimuskohteet sijaitsevat Etelä-Suomessa, Helsingissä ja Hollolassa. Tutkimuskohteet valikoitiin toisistaan poikkeavan geologian vuoksi. Patolassa metsässä maakerrokset olivat pääosin moreenia ja kalliomaata. Tattarisuon pohjavesialueella kerroksissa vaihtelivat hiekkaiset ja saviset kerrosrakenteet. Hollolan deltamuodostumalla maakerrokset vaihtelivat karkeasta sorasta hiekkaan. Sekä Tattarisuolla että Hollolassa saatiin myös aineistoa pohjavesikerroksesta. Kohteissa tehtiin sekä profiililuotaukset että CMP-luotaukset. Tutkimuksissa hyödynnettiin Malå:n ja GSSI:n maatutkalaitteistoja, joita käyttökokemuksen perusteella vertailtiin myös keskenään. CMP-luotauksella saatuja kerrosnopeuksia verrattiin kohteiden referenssiaineistoihin, keskiarvoiseen 0,1 m/ns:n nopeuteen, taulukkoarvoihin sekä Patolassa hyperbelianalyysin tuottamaan tulokseen. Tulokset olivat rohkaisevia, joskin myös poikkeavia arvoja löytyi. Patolassa haasteena oli moreenin ja rikkonaisen kallionpinnan tunnistaminen profiililuotauksista. Tämä aiheutti hajontaa CMP-luotauksella ja muilla referenssiaineistolla saatujen tulosten välillä. Osa tuloksista oli hyvinkin lähellä referenssiaineistoja, mutta moreeni-kallio-rajapinnan tulkinnan haasteellisuuden vuoksi myös huomattavia poikkeamia saatiin. Tattarisuolla tulkinnan haasteena oli monimutkainen kerrosrakenne ja paikoin profiililuotauslinjoja häiritsevät heijasteet. CMP-luotauksen kerrosnopeudet vastasivat hyvin hiekkaisten kerrosten nopeuksia. Lisäksi CMP-luotauksella voitiin varmistaa luotauslinjalla 2 oleva pohjavesikerros ja että luotauslinjalla 1 pohjavettä ei CMP-luotauksella saatujen nopeuksien perusteella ollut. Hollolassa CMP-luotausaineisto kärsi päällisin puolin huomattavasti häiriösignaaleista. Aineiston prosessoinnin jälkeen saadut kerrosnopeudet vastasivat kuitenkin erinomaisesti referenssiaineistojen kerrossyvyyksiä. Kahden maatutkalaitteiston ja useamman antennikonfiguraation hyödyntäminen profiililuotauslinjoissa mahdollistivat hyvän luotausresoluution niin matalammilla kuin paksummilla kerrospaksuuksilla. Malå:n ja GSSI:n luotauslaitteistot toimivat pääosin hyvin eikä kumpikaan laitteisto ollut selkeästi toista parempi. Tässä tutkimuksessa saadun kokemuksen perusteella CMP-luotauksella voidaan saada merkittävää hyötyä maatutkalinjojen tulkintaan. Kun CMP-luotauksen heikkoudet osataan tunnistaa ja aineiston tulkitsija omaa riittävän hyvän kokemuksen, voidaan CMP-luotauksen avulla tehdyillä syvyyskalibroinneilla saada luotettavia tuloksia tutkimusalueen kerrospaksuuksista.
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(2020)The ST1 Deep Heat company has been developing an enhanced geothermal system for district heating in Espoo, Southern Finland by St1 Deep Heat Company. Complete project will consist of geothermal doublet which involves two wells expanding up to 6,1 km depth. The stimulation of the first well was conducted in summer of 2018 as a 7-week period during which the fluid permeability of the crystalline rock at the base of the well was increased by pumping water with high pressures into the well. The stimulation process interacts with the ambient stress field of the subsurface and similar processes have been associated with induced seismicity when the stress changes lead into earthquakes as pre-existing faults and cracks are activated and new ones are created. For the monitoring of the seismic activity associated with the project a seismic network was installed in the Espoo/Helsinki area. The network consisted of 12 borehole installed 3-component seismometers provided by ST1 Deep Heat Company and from 5 semi-permanent surface 3-component broadband seismometers and in total 100 geophones installed by the Institute of Seismology, University of Helsinki (later ISUH). The geophones were installed in 3 large 25 instrument arrays, 3 smaller 4- instrument arrays and as single stations. Data from suitable seismic stations from the Finnish Seismological network was also used in the study. The aim of the study was to map possible differences and trends in the determined event magnitudes between different types of seismic stations used in the seismic network during the stimulation. The effect of different filter choices on amplitude measurement is also studied and discussed for some of the seismic events involved in the study. The results are also compared to the traffic light system warning thresholds of the EGS project and automatically calculated magnitudes of the monitoring system. The Finnish local magnitude formula is also discussed considering near-source events. Reliability and behaviour of the seismic arrays used during the stimulation is studied and discussed. Azimuthal effects noted during the data processing are illustrated. According to the results there appears to be clear differences in estimated magnitudes between the different station types used in the network and differences and trends between the seismic arrays and between individual instruments of single arrays. In total 21 induced events were chosen based on their automatically determined magnitudes, favouring events with large as possible magnitudes. Magnitude range for the events was from ML 1.8 to ML 1,0. The events were picked for P- and S-wave arrivals and for amplitudes estimated from vertical component S wave arrivals. The locations and magnitudes of the events were determined using the currently used practices of the ISUH. Main tools used in the study are the Geotool software for waveform analysis, an ISUH program used for earthquake locating and GNU Octave programs written by the author used in the data procession.
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(2019)Abstract Land-sea interactions are intensifying and getting more complex. Marine spatial planning (MSP) and integrated coastal zone management (ICZM) are concepts for organising the use of marine space in a sustainable manner. Due to the EU Marine spatial planning directive the European coastal states are required to compile coherent MSP by 2021. Cross-border interactions are needed in order to organize sea management coherently. At the same time interactions on regional level create new regionalized marine spaces. The aim of this thesis is to study construction of the trilateral Wadden Sea region as a common marine space between Denmark, Germany and the Netherlands, and to explore the dialogue between the trilateral regionalisation and the MSP processes in the area. Transboundary and national construction of the Wadden Sea space are investigated by conducting content analysis to relevant policy documents. 7 experts were interviewed in order to gain deeper understanding of MSP processes taking place in the region. The results show that the Wadden Sea region is constructed in a complex manner and it is characterized by multi-layered regulation. Wadden Sea region consists of the trilateral cooperation, which relies strongly on nature protection discourse. At the same time the Wadden Sea regionalization can be recognized at the national scales as well, as the Wadden Sea provinces and municipalities have created their own cooperation structures. In addition, the Wadden Sea region is recognized by the external parties especially due to the ecological values. EU directives and the UNESCO World Heritage nomination are based on the nature protection discourse, and they direct the construction of the Wadden Sea region. Furthermore, the results show that the Wadden Sea is visible in the MSP processes mainly via its’ physical, environmental understanding. Second, due to the mutual understanding of the ecological values, it the Wadden Sea is perceived as a harmonizing factor in cross-border MSP processes in the southern North Sea. In the light of results there would be more potential to utilize the trilateral Wadden Sea network more efficiently in MSP, but currently the countries prefer to e.g. use their national data.
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(2020)Globalization, climate change and the principles of sustainable development have made responsibility an important part of the societal debate. Responsibility is, above all, responsibility for the effects of activities. As festivals also have complex effects on the surrounding society, corporate responsibility thinking has also become part of festival production. Responsibility can be implemented by considering the stakeholders and their needs, and by ensuring not only economic viability but also the vitality of environmental resources. Sustainable development can be achieved by responsible actions. The purpose of the study was to show how responsibility has been considered in festivals organized in Finland. The aim of the study was to find out what measures and choices the festival organizers have used to promote the festival's economic, socio-cultural and ecological responsibility. The study also explored how the festival organisers see the responsible choices affecting stakeholders and the image of the festival. One of the aims of the study was also to find out what are the reasons behind more responsible activities and what challenges festivals have experienced in implementing responsibility into festival production. In addition, it was studied how festivals have measured and communicated the realization of their responsibility. The research problem is approached by reviewing the literature on tourism impacts, the principles of sustainable tourism and theories of corporate social responsibility. The growth and importance of cultural tourism was used as a basis for defining events and their role in tourism. Through events and event tourism, the definition of festivals and the connection of festivals to tourism was deepened. The context of the responsible festival was approached through the framework of responsible tourism. The empirical part consisted of a survey and interviews for festival organisations. A total of 40 responses were received to the survey and there were three festival representatives interviewed. The study utilized both qualitative and quantitative methods in the processing of the results and material. This wider perspective supported the broad dimensions of both responsibility and festivals. The study found that festivals have already incorporated responsibility into their activities. About every other festival already had responsibility-related action plan and all festivals considered it likely that they would increase their acts of responsibility in the future. Financial responsibility had been promoted, among other things, by supporting the local economy and following good governance. Socio-cultural responsibility had been considered, for example, by positively influencing the image and attractiveness of the festival’s region. In terms of environmental responsibility, the festivals had focused above all on waste management and accessibility. The most significant reason for promoting responsibility was the organisation's own ideology and values behind its activities. In addition, the festival visitors' demands for responsibility were also one of the essential reasons. Surveys aimed for festivalgoers were considered as a primary measure of responsibility. Responsibility had been communicated mainly in the instructions of the employees, but also on the social media sites of the festival. The biggest challenge in responsibility was the lack of common guidance in the event industry. Indeed, festival representatives felt that responsibility could best be promoted in the industry by creating such a guide. Festival representatives felt that responsibility has the most impact on promoting positive image of the event. It was also seen that responsibility influences the satisfaction of festival visitors as well as encourages their own responsibility. Thus, it seems that in festivals, responsibility has already been implemented in many ways, even if the festivals do not have an actual conscious responsibility plan. This also signals that responsibility is becoming part of all festival production activities, which provides good foundation for striving for the sustainability of festivals
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(2020)Tutkielman tavoitteena on ollut selvittää Meri-Rastilan luontoalueiden merkitys eri osapuolille käyttäen erilaisia, toisiaan täydentäviä tutkimusmetodeja ja teorioita. Tutkimusalueeksi valitsin Meri-Rastilan, koska asukkaiden arvostama ulkoilumetsä on useiden vuosien ajan ollut rakentamisuhan alla ja tämä on herättänyt runsaasti keskustelua, joka liittyy osaksi yleistä pääkaupunkiseudun asuinalueiden viihtyvyyden säilyttämiseen ja infrastruktuurin kehittämiseen liittyvää diskussiota. Lähdin liikkeelle aikaisempien tutkimustulosten ja tutkimuskirjallisuuden pohjalta kumpuavasta hypoteesista, jonka mukaan metsäiset luontoalueet ovat Meri-Rastilan ja Vuosaaren asukkaiden päivittäisessä elämässä merkityksellisiä. Tavoitteena on ollut myös soveltaa eri tietotyyppejä ja erilaisia luonnon arvottamiseen liittyviä teorioita niin, että ne konkretisoituisivat tällaisen ajankohtaisen ja paikallisen esimerkin avulla ja tuovat tähän aihealueeseen uutta tietoa. Tämän tutkimuksen keskeisenä tutkimusmenetelmänä on haastattelututkimus, jossa otantajoukon edustajat valittiin Meri-Rastilan ulkoilumetsän alueella satunnaisotannalla. Haastateltavia kertyi yhteensä 92, joista vähän yli puolet oli Meri-Rastilan asukkaita, osa taas Vuosaaren ja muun Helsingin asukkaita. Haastattelujen ja teoreettisen viitekehyksen muodostavan tutkimuskirjallisuuden lisäksi täydensin tietoa valokuvaamalla ja tutkimusaluetta havainnoimalla, mikä mahdollisti syvällisemmän ja yksityiskohtaisemman tulkinnan ja eliminoi väärinkäsitysten mahdollisuudet. Haastateltavien antamien vastauksien perusteella voidaan päätellä, että Meri-Rastilan luontoalueet ovat asukkaiden elämänlaadulle tärkeitä ja erilaiset ulkoilijat arvostivat luontoalueiden eri piirteitä, vaikka suurin osa ulkoili samoilla alueilla. Selvisi myös, että eri tietotyyppien edustajien eroavaisuuksiin perustuva luokittelu oli tässä tutkimuksessa toimiva työkalu. Tämän tutkimuksen herättämät lisäkysymykset kannustavat jatkamaan aihetta koskevien lisätutkimusten parissa niin Meri-Rastilan alueella, että muuallakin Vuosaaressa.
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(2019)The Greater Region of Luxembourg is the largest cross-border labor market in the European Union with the greatest number of cross-border workers in the area. European integration, the Schengen Area, and socio-economical divergences have been the main factors facilitating human cross-border movements in the area and thus the birth and expansion of the borderland community. Despite the freedom of movement, country borders have not been erased and socio-economic divergences have not been levelled. In addition, the spatial extent of the daily movements is not well known. Thus, it is important to study cross-border dynamics and try to separate daily movements from infrequent mobility patterns. Thus far, cross-border mobility studies have mainly leaned on national registers and census data. These datasets have mostly been too scarce in trying to understand the complexities of cross-border mobility. Many studies have only focused on aggregate-level movement patterns, and the viewpoint of individuals has been missing. Hence, there has been a growing need for individual-level data to be applied in cross-border mobility research. In this study, a person-based approach is employed using geotagged Twitter Big Data to study spatio-temporal cross-border mobility patterns in the Greater Region of Luxembourg. The aim is to examine how to implement social media in cross-border research as well as how to separate daily cross-border movers from infrequent border crossers and consequently move beyond aggregate-level inspections. Being one of the first studies of its kind, a heuristic programmatic approach is utilized. To the writer’s knowledge, social media data sources have not been applied previously to distinguish different cross-border mobility types. All developed scripts in this study are openly available on Digital Geography Lab’s GitHub -pages (https://github.com/DigitalGeographyLab/cross-border-mobilitytwitter) to promote open science and to introduce new quantitative method tools for cross-border mobility research. The results show that social media can be implemented in cross-border mobility research, and social media Big Data can provide a relatively good proxy for daily cross-border mobility of people on a regional level. Aggregate-level cross-border mobility patterns and activity location densities correspond closely with previous studies, and outcomes from temporal variation inspections indicate a valid cross-border mover type identification; Twitter users classified as daily cross-border movers seem to be more mobile on weekdays whereas infrequent border crossers on weekends. Daily cross-border mobility patterns also provided new information about the spatial extent of the movements. In addition, heuristic approach resulted in high accuracy in home detection; the “unique weeks” algorithm introduced in this study produced an accuracy of 88.6 % with respect to the ground truth. Although the results are promising on a regional level, they should be considered in relation to population densities and Twitter use activity; attributes that both vary spatio-temporally and thus can cause bias. Further studies and method development are also needed to draw global conclusions about cross-border mobility; other geographical areas and study settings could result in varied outcomes. In addition, some solutions with data and methods should be considered with a critical stance due to scarcity of valid references. Yet, this study has identified that the coverage of geotagged Twitter data is dependent on data acquisition processes and that Twitter can provide valuable information for cross-border mobility research. In future studies, multi-level data acquisition processes are recommended jointly with person-based approach combining spatio-temporal and content analysis methodologies.
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(2020)The research of nationalism is spread through different branch of science. One way to research nationalism is to see it through its origins. The ethnic composition of a group of people can be one reason for the rise of nationalism. Also, modern developments in society can be the starting point for nationalism and nationalistic idealization. Furthermore, nationalism can be researched through new ways which combine more than one discipline. Ethnic nationalism includes emotional concepts, for example, people, language, and symbols which makes it so emotionally charged. Due to its emotionally charged nature ethnic nationalism can be a reason for conflicts. This research looks at the dissolution of Yugoslavia (1991–1995) as an example how ethnic nationalism can be one of the core problems in a society and the cause for an ethnic conflict. The research is based on literature. Federal Republic of Yugoslavia was born after the second World War. The constituent republics were Slovenia, Croatia, Macedonia, Serbia, Montenegro and Bosnia-Herzegovina. In addition to the republics there were two autonomous provinces of Vojvodina and Kosovo. The area has gone through many wars over the last hundred years and the latest of them was the Yugoslavia wars. The area has tried to create a union of Slavic people and strong sense of nationalism, but the effort has not really created a permanent long-lasting solution. The Federal Republic of Yugoslavia was the first successful effort to create an alliance between the nations in the Balkans area. The political changes, for example, the end of the Cold War and the collapse of the Soviet Union created political problems in Yugoslavia. Due to the political turmoil several nationalistic leaders were able to get in to power by using nationalistic rhetoric and symbols. Especially ethnic rhetoric was used by the leaders and other political figures. The dissolution of Yugoslavia was a series of wars, political maneuvering and slow response from the international community. The conflict was ended by Dayton Agreement in December 1995. Nationalism can be a way to define one’s country but at the same time nationalism can be so fascinating that people can go to war and conduct acts of violence. Despite the research nationalism can rise very easily and unnoticed. Ethnicity and ethnic nationalism use symbols and rhetoric that is charged with emotion. The emotional connection makes it dangerous and while strong emotions relate to nationalism the result is usually an ethnic conflict. The dissolution of Yugoslavia was not only an ethnic conflict. The conflict started as a political and economic problem and the areas ethnic tensions made the conflict very brutal. The political elite made the conflict last longer by using nationalistic rhetoric, propaganda and symbols to gain more political power and influence. Some of the leaders managed to keep themselves in power even after the war. The international intervention was slow and ineffective causing a lot of criticism. In this research sports are used to illustrate the connection between nationalism and sporting event. The main idea is to see how a nationalism can be seen in the society and it is not just an armed conflict. In the case of Yugoslavia, the underlining ethnic tension have been there for centuries and they have not been resolved. Sports and the fan groups are one example to see how the nationalistic energy is still present in the Balkans area.
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(2020)The aim of this study was to make a quantitative map inventory of the amount of temporal and spatial changes in meadow area in Finland during 1925-1992 and to make an estimation of the total amount of meadows in Finland in 1980’s and in the beginning of 1990’s. The environmental factors were also evaluated in the same areas. Initially this reseach was a part of FIBRE program. In the temporal study the area values of meadows and environmental factors were studied in three time steps: in 1930’s, 1960’s and 1980’s The oldest data from 1930’s were collected from black and white parish maps 1:20 000 and the two younger phases from base maps 1:20 000. The study area of the temporal change study was 7 500 km² and the mean areal coverage was 4,4% of the 11 studied provincial areas. North Karelia, Kainuu and Lappland were not included in this temporal change study as there were not available the oldest parish maps in these areas. The studied areas were Uusimaa, Lounais-Suomi, Häme, Pirkanmaa, Etelä-Savo, Pohjois-Savo, Keski-Suomi, Länsi-Suomi, Pohjois-Pohjanmaa and Åland. In the larger sample study of the meadow area in 1980’s in Finland the aim was to get an estimate of the total meadow area in Finland that time and also search for the differencies between different areas – which areas still contain most meadow hectares and which is the proportion between meadow hectares and studied surface area or proportion between the land area and meadow area or the relation between acricultural field hectares to meadow hectare amount. This larger study contained 14 provincial areas and the study area was 26 000 km² and the mean study coverage was 12 %. In the study 315 base maps 1.20 000 were inventoried – the meadows were counted hectare by hectare from the maps. The results showed that the largest changes in meadow area hectares took place already between 1930 and 1960. The biggest proportional declines were in the areas were the initial hectare amounts were highest at the start. A significant result was that the total area of meadows in Finland was not so low as estimations have given reason to expect. In this large study many areas had still left a third of the 1930 meadow hectares, in the best areas even 40% in the 1980’s and in the beginning of 1990’s. Although also in this study there were places were 99% of the original hectares of meadows were all vanished – from the hundreds of hectares were left only 2-10 hectares. Of the studied areas the most rich in meadows was Åland throughout all the three studied time steps. Other meadow high areas were Lounais-Suomi, Pirkanmaa and Keski-Suomi in the 1930’s, Pirkanmaa, Pohjois-Pohjanmaa and Häme in the 1960’s and Länsi-Suomi, Uusimaa and Lounais-Suomi. For the total amount of meadow hectares in Finland this study gives estimates: 680 000 – 980 000 hectares in the 1930’s, 330 000 – 475 000 hectares in the 1960’s and 275 000 hectares in the 1980’s.
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(2020)Maailma muuttuu kiihtyvää vauhtia ja suomalainen koulutusjärjestelmä pyrkii vastamaan muutokseen huomioimalla tulevaisuuden haasteet osana opetuksen suunnittelua. Linkittyminen, verkostoituminen, vuorovaikutus, laaja-alaisuus ja ovat sanoja, jotka toistuvat nykypäivän työelämässä. Vaikka maailman moninaisuus ei ole uusi asia, on sen merkitys nykyään ymmärretty paremmin opetuksessa sekä opetuksen suunnitellussa. Yksittäisten palasten sijaan pyritään rakentamaan kokonaisvaltaista kuvaa asiakokonaisuuksista. Perusopetuksen opetussuunnitelman perusteet 2014 pyrkii vastaamaan yhteiskunnan vaatimuksiin laaja-alaisen osaamisen kautta. Laaja-alaista osaamista toteutetaan uudessa opetussuunnitelmassa opetuksen eheyttämisen sekä monialaisten oppimiskokonaisuuksien kautta. Näiden tarkoituksena on asettaa oppilaiden kokemukset opetuksen keskiöön. Opetussuunnitelma ohjaa koulukohtaisia opetussuunnitelmia, mutta laaja-alaisen osaamisen toteutuminen on pitkälti koulujen vastuulla. Koulut siis päättävät itse, miten opetuksen eheyttäminen sekä monialaiset oppimiskokonaisuudet järjestetään. Käytännössä tämä tarkoittaa sitä, että suunnittelu jää usein opettajien itsensä vastuulle. Tarkastelen tutkielmassani sitä, miten peruskoulun yläkoulun maantiedon opettajat suhtautuvat opetuksen eheyttämiseen sekä monialaisin oppimiskokonaisuuksiin. Peruskoulun opetussuunnitelma 2014 on ollut käytössä porrastetusti vuodesta 2016 luokkaasteilla 7–9. Nyt kun opettajien kokemuksia on kertynyt kaikilta luokka-asteilta, on mielestäni todella hyvä aika tarkastella opettajien havaintoja aihepiiriin liittyen. Tutkielmani aineisto koostuu 281 peruskoulun yläkoulun maantiedon opettajille lähettämästäni lomakekyselystä, kolmen opettaja teemahaastatteluista sekä nykyisestä perusopetuksen opetussuunnitelmasta. Aineiston analyysissä olen hyödyntänyt sisällönanalyysin menetelmää, jonka perusteella olen luokitellut aineiston seuraaviin luokkiin: 1. Toteutuminen maantiedon opetuksessa 2. Opettajien suhtautuminen 3. Kehitysehdotukset Tutkielmani aineiston perusteella maantieto soveltuu erinomaisesti eheytettäväksi sekä osaksi monialaisia oppimiskokonaisuuksia. Eniten maantietoa eheytetään biologian kanssa rinnakkaisopetuksena saman opettajan toimesta. Maantieto soveltuu laajuutensa ansiosta usein myös osaksi monialaisia oppimiskokonaisuuksia. Aina tämä ei ole kuitenkaan mahdollista, mikä johtuu yleensä aikatauluongelmista tai epäsopivasta aihepiiristä. Opettajat suhtautuvat opetuksen eheyttämiseen sekä monialaisiin oppimiskokonasuuksiin pääosin positiivisesti. Tulos on samansuuntainen aikaisemman aihepiirin tutkimuksen kanssa. Opetuksen eheyttämisen nähdään edistävän laaja-alaista oppimista sekä yhteistyötä eri oppiaineiden välillä. Monialaisten oppimiskokonaisuudet nähdään niin ikään hyvänä asiana, mutta ne herättävät eheyttämistä enemmän kritiikkiä opettajien keskuudessa. Suurimpana ongelmana opetuksen eheyttämiseen sekä monialaisiin oppimiskokonaisuusiin liittyen nähdään resursointi. Yleisempänä kehitysehdotuksena mainitaan parempi suunnittelu. Muita mahdollisia parannuksia ovat opettajien koulutuksen lisääminen sekä valmiit oppimiskokonaisuudet, joita koulut voisivat halutessaan hyödyntää.
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(2020)Accessibility – what can be reached from a given point in space and how – is an essential field of study to measure the physical structure of cities, travel mode choices of residents, and the competitiveness of areas. Researchers increasingly acknowledge that accessibility is a fundamental concept on understanding how urban regions work and its position in future development of cities is paramount. Travel time is considered an intuitive measure to indicate accessibility and a strong predictor of mode choice, and usually, private car is the fastest mode of transport in urban environments. A central issue which stems from private cars and accessibility is the process of searching for parking. An understudied issue, the rather stressful activity is engaged in when arriving by car at the general area of desired parking, but no space is available. Motorists are then forced to continue search for parking, significantly contributing to urban congestion. In catering to mobility rather than accessibility, the modern urban planning has made it challenging to move away from private cars toward alternative, often more sustainable, modes of transport. Travel time studies, and more specifically, parking studies, can produce accurate data to aid in this transformation. In this thesis, a parking related research survey was developed and conducted in the Helsinki Capital Region, Finland. Adhering to the door-to-door approach, the survey respondents were enquired how long it took for them to find a parking place and park their car, and walk from the car to the destination in different postal code areas of Helsinki Capital Region. To explain a hypothetical variation in parking process durations (searching for parking, and walking to one's destination) in different areas, additional questions, such as the time of the day of parking, were presented. The invitation to respond to the survey was mostly spread on the social media platform Facebook. The survey, filled out with a web application specifically programmed for this thesis, received 5200 data rows from over 1000 unique visitors. The survey results indicate that there are spatial differences in parking process durations in different postal code areas of the Helsinki Capital Region. The inner city of Helsinki was experienced as the most difficult location to park in with regional subcenters such as Matinkylä, Espoo and Tikkurila, Vantaa, receiving relatively long parking process durations. Short parking process durations were reported from scarcely built areas but more often than not these areas had extreme values reported. Interestingly, area familiarity did not necessarily translate to faster parking process, while the type of the usual parking place was a better indicator. Out of the spatial explanatory variables added in the survey data processing, zones of urban structure (yhdyskuntarakenteen vyöhykkeet) could be used to find statistically significant differences in the parking process between variable groups and study area municipalities. Making use of the Helsinki Region Travel Time Matrix, a dataset developed by the research group Digital Geography Lab of the University of Helsinki, the thesis survey data was compared to total travel chain durations. The thesis survey data indicates that the proportion of time it takes to park one's car and walk to one's destination is a much larger part of the entire travel chain than previously estimated in the dataset. The parking process times are proportionally largest in the inner city of Helsinki, where the reported parking process duration exceeds that of the actual driving segment. This thesis, its entire version history, and all of the scripts developed for it have been made available at GitHub: https://github.com/sampoves/thesis-data-analysis.
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(2020)Large-scale transport infrastructure projects change our daily mobility patterns, as they change the geographical accessibility of the places where we spend most of our time, such as our homes and workplaces. Thus, there is a clear need for advance evaluation of the effects of those projects. Traditionally, however, the available methods have imposed severe limitations for both measuring accessibility and surveying mobility, and despite modern data collection methods enabled by the ever-present mobile phones, surveying mobility remains challenging due to data accessibility restrictions. Furthermore it would not enable any advance evaluation of mobility changes. However, using a modern accessibility dataset instead of a mobility one does offer a possible answer. In my study, I set out to investigate this possibility. I combined a modern, multimodal and longitudinal accessibility dataset, the Helsinki Region Travel Time Matrix (TTM), with a spatially compatible, census-based longitudinal commuting dataset to evaluate the aggregated journey times in the Helsinki Capital Region (HCR), the area covered by the TTM, and estimated the shares of different transport modes based on a previously published travel survey. Armed with this combined dataset, I assessed the changes in aggregated journey times between the three years that were included in the TTM dataset – 2013, 2015 and 2018 – by statistical district to estimate its usability for these kind of advance mobility evaluations. As a small subset of the commuting dataset was classified by industry, I also assessed regional differences between industries. My results demonstrate that for travel by public transport, the effects of new transport projects are plausibly identifiable in these aggregated patterns, with a number of areas served by several new, large-scale public transport infrastructure projects – the Ring Rail, the trunk bus lane 560 and the Western extension of the metro line – being outliers in the results. For travel by private car and for the industry-level changes, the results are more inconclusive, possibly due to absence of massive projects affecting the road network throughout the dataset timeframe, potential inaccuracies in the source data and limitations of the industry-classified part of the dataset. In conclusion, a modern accessibility dataset such as the TTM can be plausibly used to estimate the mobility effects of large-scale public transport infrastructure projects, although the final accuracy of the results is likely to be heavily dependent of the precision of the original datasets, which should be taken into account when such assessments are made. Further research is clearly needed to assess the effects of diurnal variations in travel times and the effects of more precise transport mode preference data.
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(2021)The mafic-ultramafic Kevitsa intrusion, located within the Central Lapland Greenstone Belt in Northern Finland, hosts a disseminated Ni-Cu-PGE deposit. Drillhole KVX018 penetrates through the intrusion, intersecting its bottom contact at 1772 meters and is associated with relatively low resistivity at the bottom of the intrusion. The KVX018 drillhole is the deepest drilled into the intrusion so far and the observed low resistivity zone is unique for the study area. Previous studies have shown the bottom contact of the Kevitsa intrusion to be associated with seismic reflections and possible mineralization. This paper studies the characteristics of the bottom contact of the Kevitsa intrusion from the drill core KVX018 and interprets the origin of the low resistivity and its relationship with mineralogy. From geochemical and petrophysical characteristics, four layers with different characteristics were observed within the studied section: footwall, contact zone, lower cumulates and upper cumulates. The lower cumulates were found to be strongly contaminated by elements associated to hydrothermal fluids from country rocks. The contamination was observed for 125 meters upwards from the basal contact as elevated concentrations of e.g. lithium, lanthanum, rubidium and potassium, and footwall rocks close to the contact were found to be depleted in these elements. The contact zone was found to be strongly altered by silicification and albitization. Hydrothermal fluid activity at the bottom contact was also observed by epidote alteration of plagioclase feldspar. Contact zone mineralization was observed and it was found to be false ore type with Ni tenor of 2.28 %. Upwards from contact mineralization, the mineralization was found first to change into local low-grade Ni-PGE ore and then into normal ore on top part of the studied drill core section. Ultramafic intrusive rocks were observed to be pervasively altered by amphibole alteration locally into a degree where in many rocks, alteration had overprinted the primary mineralogy and textures to be undistinguishable. Alteration intensity was found to increase downwards within the lowermost part of the intrusion. Salt minerals were observed by eye on the surface of some samples and by X-Ray Diffraction in one sample. XRD studies indicated nitratine and sylvite minerals present in the studied sample. These salt minerals are presented commonly in evaporites and their presence indicates an evaporitic source. Resistivity of rocks is generally affected by e.g. sulfide content, salinity, porosity and alteration. Resistivity and chargeability were found to be correlative, indicating resistivity to correlate also with presence of sulfide minerals. However, after depth of 680 meters, resistivity decreases without a correlating trend in other petrophysical properties. This paper concludes that the observed low resistivity is resulted from a presence of salt and sulfide minerals as well as alteration intensity.
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(2020)Geological Survey of Finland conducted bedrock mapping in the eastern parts of Central Finland Granitoid Complex (CFGC) and the area next to the Archean craton in the 1990s. The area consists mainly of Paleo-proterozoic paragneisses, with minor volcanic rocks present. The granitoids belonging to the Central Finland Granitoid Complex make up part of the bedrock in the area. The granitoids of CFGC are divided into a 1.89-1.88 Ga syn-kinematic group, and a crosscutting, 1.88-1.87 Ga post-kinematic group. In this Master’s thesis, three post-kinematic granitoid intrusions of Löytölamminvuori, Sorsakoski and Karvalevä are studied, covering their lithological, petrographical and geochemical features. The intrusions are non-foliated, porphyritic granites and quartz-monzonites, with a minor mafic phase of mostly dioritic composition in the Karvalevä intrusion. The main mafic silicates in the granite phase are biotite and hornblende, in the quartz-monzonite and mafic phases also clino- and orthopyroxene are present. Resembling the other post-kinematic plutons of the CFGC, the studied intrusions are geochemically high in Al2O3, FeO and K2O, and low in MgO, CaO and Sr. One U-Pb age of 1876+6 Ma has been measured for the Löytölamminvuori intrusion, which places the intrusion at the same time frame as the other post-kinematic plutons. Geochemically the intrusions show A-type affinity and close similarities to the post-kinematic pluton Types 2 and 3, fitting best with the Type 3a, which is transitional between the two. The magmas forming Löytölamminvuori, Sorsakoski and Karvalevä were derived from partial melting of mantle derived basalts, which underwent crustal contamination by partial melts from the lower crust. Slight deviation in composition from the strictly A-type magma and the volcanic arc affinity can be explained by the crustal component. The mafic phases show more primitive geochemistry, and thus present the mantle-derived source component with less crustal assimilation in the source. The intrusions show signs of bimodal mafic-felsic magmatism, the dioritic phases in Karvalevä intrusion and one syn-plutonic dyke in Sorsakoski intrusion representing the mafic component. The mafic magmatism was cogenetic with the felsic phases, but not comagmatic, the diorites intruding simultaneously but slightly after the felsic phases. The mafic phases show a continuum in chemical composition to the granites and quartz-monzonites, but with a slight compositional gap.
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(2019)This work presents a new set of petrophysical laboratory measurements from Kylylahti, a Cu-Au-Zn mine in the Outokumpu mining district, in the eastern Finland. Results are discussed and compared to earlier petrophysical data from the area. The study was aimed to provide a solid base for accurate interpretation of already existing geophysical exploration data and to new seismic data collected during the COGITO-MIN (COst-effective Geophysical Imaging Techniques for supporting Ongoing MINeral exploration in Europe) project. The sample set covered the most common rock types found in Kylylahti. A small set of samples represented sulphide mineralizations from several mining sites in the Outokumpu district. In the area, ophiolitic ultra-mafic massifs consisting of Outokumpu assemblage rocks, are embedded in Kalevian sediments, black schists and mica schists. Several massifs, Kylylahti being one of them, contain polymetallic (Cu-Co-Zn-Ni-Ag-Au-Cd-Sn-As-Se-Mo) massive, semi-massive or disseminated sulphide mineralizations. The petrophysical parameters measured were density, seismic P-wave velocity, porosity, magnetic susceptibility, intensity of remanent magnetization, inductive resistivity, galvanic resistivity and chargeability. Additional parameters calculated from the measurements were seismic impedance, Königsberger (Q) ratio and induced polarization (IP) estimates. Density data divides the Kylylahti rocks in three categories: 1) Massive and semi-massive sulphide mineralizations with an average density of 3750 kg/m 3 , 2) Outokumpu assemblage rocks with densities close to 3000 kg/m 3 and 3) Kalevian rocks with densities a bit under 2800 kg/m 3 . Sulphide disseminations are common in Outokumpu assemblage carbonate-skarn-quartz rocks and black schists elevating the densities when abundant. The average P-wave velocities for almost all Outokumpu assemblage rock types are a bit over 6 km/s. Soap stones, mica schists and black schists have lower P-wave velocities, around 5.5 km/s. Porosity of the samples was very low overall. Most of the Kylylahti rocks belong to paramagnetic group (susceptibilities under 2000 μSI). Serpentinites and tremolitic calc-silicate rocks (TRECS) belong to strongly magnetic group as well as samples rich in disseminated sulphides. Low Q ratios reveal that magnetic mineral in serpentinites and TRECS is coarse-grained magnetite. Samples with disseminated sulphides have high Q ratios, thus the disseminations are mainly monoclinic pyrrhotites. Both Kylylahti sulphide mineralizations and black schists are conductive as well as rocks rich in dissiminated sulphides. The rocks containing disseminated sulphides have high IP estimates. Conductivity of black schists is due to graphite and to some extent due to disseminated sulphides. Physical properties of the ore samples from different mining sites reveal the differences in their mineralogy, mainly their changing proportions of pyrite, pyrrhotite and magnetite. The differences are due to metamorphic zoning in the Outokumpu district; the degree of metamorphism becomes higher when going from east to west or from surface to depth. Recommended parameters, densities and P-wave velocities for seismic modelling in Kylylahti are given. Based on the results, the sulphide mineralizations should produce a detectable reflection against any background due to their high density. Also the other Outokumpu assemblage rocks have a clear contrast against the mica schists and black schists. Soap stones are an exception. The contact between Kalevian rocks and soap stones is hardly reflective at all, whereas soap stones in contact with other Outokumpu assemblage rocks form a reflecting contact.
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(2019)Tutkimuskohteena on Lammin Löyttynoja ja Koiransuolenoja, jotka ovat olleet Lammin biologisen aseman tutkimuksen alla jo pitkään. Tutkielman tarkoituksena on kartoittaa purojen kemiallisia ja fysikaalisia ominaisuuksia ja verrata niitä aiempiin tutkimustuloksiin sekä selvittää kuinka pohjavesivaikutteisia purot ovat. Puroista otettiin näytteitä vuoden 2016 maalis- ja heinäkuussa, samalla näytteitä otettiin myös alueen lähteistä, Pääjärvestä sekä Lammin biologisen aseman pohjavesiputkista. Näytteistä analysoitiin pääionit (F-, Cl-, NO3-, SO42-, Na+, K+, Ca2+, Mg2+), alkaliteetti, liuennut silikaatti (DSi) ja hapen ja vedyn stabiilit isotoopit (18Oja D). Näytteenoton yhteydessä näytepisteiltä mitattiin sähkönjohtavuus, pH ja veden lämpötila sekä heinäkuussa myös sedimentin lämpötila. Lisäksi tutkimuksessa hyödynnettiin Lammin biologisen aseman keräämää seurantatietoa Löyttynojan ja Koiransuolenojan kemiallisista ominaisuuksista sekä lämpötilan ja virtaaman vaihtelusta Löyttynojan pääionipitoisuudet vastaavat Hämeen alueen puroveden taustapitoisuuksia, mutta Koiransuolenojan Na-, K-, Ca-, Cl-, NO3- ja SO4-pitoisuudet ylittävät tausta-arvojen pitoisuudet. Löyttynojaan verrattuna Koiransuolenojan pääionipitoisuudet ja sähkönjohtavuus ovat lähes kaksinkertaisia ja pitoisuuksien eroja voidaan selittää valuma-alueiden erilaisuudella. Löyttynojan valuma-alueen maalajeista lähes 40 % on soraa ja hiekkaa, kun taas yli puolet Koiransuolenojan maalajeista on hiesua ja hietaa. Lammin alueen hienojakoinen sedimentti, Lammin lössi, sisältää paikoittain melko runsaasti kalsiumia, joka selittää Koiransuolenojan Löyttynojaa korkeampia pitoisuuksia. Hienojakoiset maalajit voivat myös sisältää reliktisiä suoloja, jotka nostavat kloridi- ja natriumpitoisuuksia. Koiransuolenojan valuma-alueella on enemmän peltoja, jolloin sähkönjohtavuuden, kalium- ja nitraattipitoisuuksien koholla olevia arvoja voidaan selittää maatalouden päästöillä. Purojen lämpötiloissa on selkeät erot, kesäisin Löyttynojan lämpötilat ovat Koiransuolenojan lämpötiloja viileämpiä, talvella tilanne on päinvastainen. Tämä viittaa suurempaan pohjavesivaikutukseen Löyttynojassa verrattuna Koiransuolenojaan. Myös Koiransuolenojan korkeammat TOC-pitoisuudet voivat viitata suurempaan pintavalunnan määrään. Liuenneen silikaatin, pH:n ja hapen ja vedyn stabiilien isotooppien arvot ovat samankaltaiset molemmissa puroissa, ja liuenneen silikaatin pitoisuuksien perusteella molemmat purot ovat pohjavesivaikutteisia. Virtaama on Löyttynojassa kautta linjan korkeampi kuin Koiransuolenojassa. Talven alivalumakaudella Löyttynojan virtaama pysyy voimakkaana, kun taas Koiransuolenojan virtaamat ovat alhaisia. Tämä viittaa siihen, että Löyttynojalla on melko suuri pohjavesivarasto toisin kuin Koiransuolenojassa, jossa pohjavesivarasto on selkeästi niukempi ja vesi liikkuu hienojakoisen maa-aineksen läpi hitaammin. Molempien purojen voidaan havaita olevan pohjavesivaikutteisia, mutta Löyttynojassa pohjavesivaikutus on voimakkaampaa kuin Koiransuolenojassa.
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(2020)Covid-19 epidemy spread to Finland in early 2020. Epidemy caused a worldwide crisis to which officials reacted with restrictions and orders. In Finland, the government gave its first notice in March 2020. This study examines changes of human mobility during a period on which Finnish Government had given guidance to work remotely and to avoid gatherings and later closing the border of Uusimaa Region. This research uses mobile phone data to observe changes in mobility and for determining the possible connection between mobility and new covid-19 cases. A literature review was assembled targeting articles published and in peer review process during 2019–2020 detailing mobile phone data. The review also examined mobile phone data in studies of coronavirus. All together 38 articles were chosen and categorized based on the mobile phone datasets used in them and the level of aggregation of data. This research used Telia’s origin-destination data aggregated to municipality level with temporal resolution of one day (24 hours). From the data sum of trips between different municipalities for one day can be observed as well as trips within a single region. Another dataset was used with information of the number of the mobile phone activities within a municipality during each day. Enriched datasets were calculated from the original data showing mobility and activity ratio for the period from March 2nd to March 29th, 2020 for every municipality and region. The baseline for the ratio was week 6 (February 3rd to February 9th, 2020). Third dataset containing the trips was constructed and data in it organized on the origin and destination of the trips and trip length. The datasets were compared to background material with information on housing, summer house ratio, centrality of municipality, amount of work-related inter-municipality commuting and to datasets provided by Google and Apple with information on changes of mobility. Results show that mobile phone data is suited to observe mobility. In March 2020 mobility decreased in most of the municipalities. The intensity of decrease as well as the beginning of decrease varied between municipalities. The amount of connections and routes between municipalities decreased more steeply in central municipalities. Longer trips of more than 120 km decreased the most. Explanatory results were provided, but none of them correlated strongly and significantly enough to explain the variations of the mobility ratio. Municipalities with more city-like housing gave intriguing results in Pearson’s correlation test when compared to mobility and trip volume decrease. A clear connection could not be found between mobility ratio and growth ratio of new covid-19 cases, but in Helsinki and Uusimaa Health Care District results were more promising.
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(2019)Rakennustoiminta on yksi kaupunkialueiden veden laatua heikentävistä tekijöistä. Rakentamisen aikaiset vesistövaikutukset voivat olla suuria ja niitä on tärkeää tunnistaa, jotta kaupunkipurojen veden laatua ja ekosysteemejä voitaisiin suojella. Tutkimuksen tavoitteena oli selvittää, millaisia vaikutuksia valuma-alueella tapahtuvalla rakennustoiminnalla on kaupunkipuron veden laatuun verrattuna rakentamista edeltävään aikaan. Lisäksi tavoitteena oli arvioida puron nykyistä veden laatua ja sitä, onko Kuninkaantammen hulevesipilottialueen vesiensuojelutoimenpiteillä ollut vaikutusta veden laatuun. Hypoteesinä oli, että rakentaminen on heikentänyt veden laatua lisäämällä merkittävästi kiintoaine- ja ravinnekuormitusta sekä metallipitoisuuksia ja että rakentamisen aikaisen hulevesisuojelun toimenpiteet eivät ole olleet riittäviä. Tutkimuskohteena oli Luoteis-Helsingissä sijaitseva kaupunkipuro Hakuninmaanoja, joka sijaitsee valuma-alueella, jolla on käynnissä Kuninkaantammen kaupunginosan rakennustyöt. Rakentaminen alkoi vuonna 2013 ja hankkeen arvioidaan valmistuvan vuonna 2025. Veden laatua tutkittiin kesän 2018 aikana aikavälillä 1.6.–11.9.2018, minkä lisäksi tutkimuksessa hyödynnettiin laajaa, 4.7.2011 lähtien kerättyä Hakuninmaanojan veden laadun aineistoa. Tutkittuja muuttujia (21 kpl) olivat kiintoaine ja orgaaninen aines, ravinteista kokonaistyppi ja kokonaisfosfori, liuenneen aineen kokonaispitoisuus, liuenneista kationeista natrium, kalium, kalsium ja magnesium, liuenneista anioneista fluoridi, kloridi, nitraatti ja sulfaatti, ja metalleista alumiini, mangaani, rauta, nikkeli, kupari, sinkki, kadmium ja lyijy. Tutkimuksessa tarkasteltiin muuttujien pitoisuuksien muutoksia havaintojakson aikana sekä verrattiin vuoden 2011 havaintoja vuoden 2018 havaintoihin. Muutoksen tilastollista merkitsevyyttä arvioitiin wilcoxonin merkittyjen sijalukujen testillä ja muuttujien välisiä korrelaatioita spearmanin järjestyskorrelaatiokertoimella. Kokonaistyppi- ja nitraattipitoisuudet kohosivat voimakkaasti esirakennustöiden aikana tehtyjen kallioräjäytystöiden myötä. Kokonaistyppipitoisuus oli kolmin- ja nitraattipitoisuus lähes viisinkertainen verrattuna rakentamista edeltävään aikaan. Kiintoaine- ja kokonaisfosforipitoisuudet laskivat rakentamista edeltäviin pitoisuuksiin nähden kolmas- ja neljäsosaan ja pysyivät korttelirakentamisen aikana verrattain matalina. Metallipitoisuudet laskivat tai pysyivät ennallaan tutkimusjakson aikana lukuun ottamatta sinkkipitoisuutta, joka kohosi korttelirakentamisen aikana. Metallipitoisuudet olivat kaiken kaikkiaan verrattain matalat ja useimpien metallien pitoisuusvaihtelun ei voitu arvioida olleen yhteydessä rakentamiseen. Kalium- ja fluoridipitoisuudet kohosivat typen lailla runsaimman maanmuokkauksen aikana eroosiosta ja räjäytystöistä johtuen. Rakennustöillä ei ole juuri ollut vaikutusta tutkittujen liuenneiden anionien ja kationien pitoisuuksiin. Hakuninmaanojan veden laatu on rakennustoiminnasta huolimatta useimpien muuttujien osalta tyydyttävä tai hyvä. Kuninkaantammen hulevesipilottialueen hulevettä puhdistavien ratkaisujen myötä ainakin kiintoaine- ja fosforipitoisuuden huippuarvot ovat pysyneet matalalla tasolla verrattuna aiempiin rakennustoiminnan vaikutuksia selvittäneisiin tutkimuksiin.
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(2020)Rietveld refinement and synchrotron powder diffraction are both rather unknown for the common geologist, although very powerful methods in academic and industry applications. The aim of the study is to resolve phase composition of a complex geological sample and investigate the capabilities of the methods. Complex granitic rock, tirilite was selected for quantitative phase analysis to be carried out by Rietveld refinement utilizing Synchrotron Radiation X-Ray powder diffraction at the Swiss Light Source (SLS) synchrotron radiation facility maintained by Paul Scherrer Institute (PSI). Samples were measured using Vibrating Sample Holder (VSH), a novel sample handling approach developed originally for Martian exploration by NASA. This invention was further modified and developed with PSI and Stenman Minerals Ab for synchrotron beamline setup to answer increased demand of industrial diffraction analyses. The new approach might serve industrial as well as academic interest. A large bulk sample of tirilite were processed for the study. The sample was divided to different weight fractions using heavy liquid separation to reduce the number of mineral phases present in a powder diffraction sample. The motif for this was to decrease the number of diffraction peaks within a diffractogram for achieving better refinement for individual mineral phases. Mineral phases were recognized from the separate weight fractions. Each mineral in a rock was first refined from the weight fraction in which it was most represented. Refinements were carried out against database structure references. After refining the structure- and profile parameters of the present phases from the weight fractions, they were used as structural references for whole rock refinement. Quality of the refinements were compared to chemical analyses carried out by WD-XRF and ICP-MS. Correlation between analysed and refined chemical composition and lattice parameter references and refinement quality parameters suggests that the method is not limited for determination of accurate modal compositions. Also, a set of crystallographic parameters can be both accurately and precisely derived from the refinements: lattice parameters, compositions, and site occupancies. Determination of inter-site cation distribution can be used for geothermobarometry and samples can be measured faster than before. The method seems a promising new application of synchrotron powder diffraction for academic and industry applications.
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