Browsing by Subject "Maantieteen maisteriohjelma"

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  • Myllys, Jasmiina (Helsingin yliopisto, 2020)
    Short-term rental platforms have become widely popular in recent years, but their growth has left cities to face a variety of problems. Studies have shown, for example, that short-term rentals have led to an increase in long-term rental prices. When more and more apartments are used as short-term rentals, the supply of long-term rentals decreases. This causes more pressure on the long-term rental market and leads to increased prices. In this study I examine the possible impacts of Airbnb, the biggest and most popular short-term rental platform, on the rental market of Helsinki. First, I analyse how many apartments have been removed from the long-term rental market to the Airbnb market, and second, how likely it is that the number of Airbnb rentals rises in the future. Presumably, renting through Airbnb becomes more popular when the potential income from Airbnb rentals is larger than from long-term rentals. In Neil Smith’s terms, this difference between actual and potential rental income constitutes a rent gap. Therefore, I also analyse whether renting short-term in Helsinki is more profitable than renting long-term. In addition, I discuss the current city and tourism policies of the city of Helsinki in the light of the results of the above research questions and give recommendations on issues to be taken into account in the future. This study uses AirDNA’s data of Airbnb rentals in Helsinki and long-term rental price data from KTI Property Information Ltd, and it focuses on data from year 2019. Data analysis is conducted using statistical and geospatial methods. The results of this study show that in 2019 there were a significant number of professional Airbnb rentals in Helsinki, 863 in total. However, their number varied substantially between the districts of Helsinki. There was a large amount of professional Airbnb rentals especially in the city centre and Kallio area. On the scale of the whole of Helsinki, professional Airbnb rentals comprise approximately 0,5 % of all rental apartments whereas in some districts in the city centre the percentage was considerably higher, in the Kamppi district as much as 3,9 %. Based on the results, the number of Airbnb rentals will likely grow in the future because Airbnb rental income was, on average, greater than long-term rental income in each of the study areas. In most areas, the rent gap was substantial. However, the size of the rent gap varied significantly, between 50 and 1350 euros, based on the location and amount of rooms of the apartment. Some policy recommendations can be made based on the results of this study. When designing future policies, it is important to acknowledge that a sizeable part of the Airbnb rentals in Helsinki is professional and that the number of professional rentals will probably continue to increase. Since the number of professional rentals is still quite small on the city level, the impacts of short-term rentals in Helsinki are presumably not yet significant. Nevertheless, in the future problems can arise especially in the city centre and Kallio area, as these areas have a lot of professional Airbnb rentals. Since only professional Airbnb rentals are disadvantageous for the long-term rental market, assigning certain restrictions would be justifiable in order to prevent future problems and to promote sustainable tourism. Restricting Airbnb activity could be done by enforcing current regulations more rigorously or setting a yearly renting limit like many other European cities have done. This would help to inhibit activity that is against the current legislation and to support the real sharing economy.
  • Vuorinne, Ilja (Helsingin yliopisto, 2020)
    Biomass is an important parameter for crop monitoring and management, as well as for assessing carbon cycle. In the field, allometric models can be used for non-destructive biomass assessment, whereas remote sensing is a convenient method for upscaling the biomass estimations over large areas. This study assessed the dry leaf biomass of Agave sisalana (sisal), a perennial crop whose leaves are grown for fibre and biofuel production in tropical and subtropical regions. First, an allometric model was developed for predicting the leaf biomass. Then, Sentinel-2 multispectral satellite imagery was used to model the leaf biomass at 8851 ha plantation in South-Eastern Kenya. For the allometric model 38 leaves were sampled and measured. Plant height and leaf maximum diameter were combined into a volume approximation and the relation to biomass was formalised with linear regression. A strong log-log linear relation was found and leave-one-out cross-validation for the model showed good prediction accuracy (R2 = 0.96, RMSE = 7.69g). The model was used to predict biomass for 58 field plots, which constituted a sample for modelling the biomass with Sentinel-2 data. Generalised additive models were then used to explore how well biomass was explained by various spectral vegetation indices (VIs). The highest performance (D2 = 74%, RMSE = 4.96 Mg/ha) was achieved with VIs based on the red-edge (R740 and R783), near-infrared (R865) and green (R560) spectral bands. Highly heterogeneous growing conditions, mainly variation in the understory vegetation seemed to be the main factor limiting the model performance. The best performing VI (R740/R783) was used to predict the biomass at plantation level. The leaf biomass ranged from 0 to 45.1 Mg/ha, with mean at 9.9 Mg/ha. This research resulted a newly established allometric equation that can be used as an accurate tool for predicting the leaf biomass of sisal. Further research is required to account for other parts of the plant, such as the stem and the roots. The biomass-VI modelling results showed that multispectral data is suitable for assessing sisal leaf biomass over large areas, but the heterogeneity of the understory vegetation limits the model performance. Future research should address this by investigating the background effects of understory and by looking into complementary data sources. The carbon stored in the leaf biomass at the plantation corresponds to that in the woody aboveground biomass of natural bushlands in the area. Future research is needed on soil carbon sequestration and soil and plant carbon fluxes, to fully understand the carbon cycle at sisal plantation.
  • Aalto, Iris (Helsingin yliopisto, 2020)
    Global warming is expected to have detrimental consequences on fragile ecosystems in the tropics and to threaten both the global biodiversity as well as food security of millions of people. Forests have the potential to buffer the temperature changes, and the microclimatic conditions below tree canopies usually differ substantially from the ambient macroclimate. Trees cool down their surroundings through several biophysical mechanisms, and the cooling benefits occur also with trees outside forest. Remote sensing technologies offer new possibilities to study how tree cover affects temperatures both in local and regional scales. The aim of this study was to examine canopy cover’s effect on microclimate and land surface temperature (LST) in Taita Hills, Kenya. Temperatures recorded by 19 microclimate sensors under different canopy covers in the study area and LST estimated by Landsat 8 thermal infrared sensor (TIRS) were studied. The main interest was in daytime mean and maximum temperatures measured with the microclimate sensors in June-July 2019. The Landsat 8 imagery was obtained in July 4, 2019 and LST was retrieved using the single-channel method. The temperature records were combined with high-resolution airborne laser scanning (ALS) data of the area from years 2014 and 2015 to address how topographical factors and canopy cover affect temperatures in the area. Four multiple regression models were developed to study the joint impacts of topography and canopy cover on LST. The results showed a negative linear relationship between daytime mean and maximum temperatures and canopy cover percentage (R2 = 0.6–0.74). Any increase in canopy cover contributed to reducing temperatures at all microclimate measuring heights, the magnitude being the highest at soil surface level. The difference in mean temperatures between 0% and 100% canopy cover sites was 4.6–5.9 ˚C and in maximum temperatures 8.9–12.1 ˚C. LST was also affected negatively by canopy cover with a slope of 5.0 ˚C. It was found that canopy cover’s impact on LST depends on altitude and that a considerable dividing line existed at 1000 m a.s.l. as canopy cover’s effect in the highlands decreased to half compared to the lowlands. Based on the results it was concluded that trees have substantial effect on both microclimate and LST, but the effect is highly dependent on altitude. This indicates trees’ increasing significance in hot environments and highlights the importance of maintaining tree cover particularly in the lowland areas. Trees outside forests can increase climate change resilience in the area and the remaining forest fragments should be conserved to control the regional temperatures.
  • Farstad, Miia (Helsingin yliopisto, 2021)
    Due to the harsh conditions in high latitude alpine and arctic regions, climate or land use changes make them very vulnerable. Thus, it is vital to study the habitats of these regions and increase our understanding of what factors impact species distributions. Species distribution modelling can be used to predict possible habitats for species and further inspect the relationships between different environmental variables and species. Generally, these species distribution models have been created using variables describing the topographical and climatic conditions of the study area. Recently there has been more evidence supporting the inclusion of biotic variables to species distribution models at all scales. Including biotic variables can be difficult, as these relationships can be challenging to quantify. This study uses the Normalized Difference Vegetation Index (NDVI) as a surrogate for plant biomass, thus representing biotic interactions. This study aims to answer what are the relationships between environmental variables and the predicted distributions and will including a biotic variable improve the species distribution models. The study data includes observational data from 683 arctic and alpine plant species from Norway, Sweden, and Finland. The observation data were collected from the three national databanks of Norway, Sweden and Finland and completed with observations from the Global Biodiversity Information Facility and observation data collected by the BioGeoClimate Modelling Lab. The cohesive study area was outlined with the biogeographical regions defined by the European Environment Agency. Overall, six environmental variables are used in this study: annual mean temperature, the maximum temperature of the warmest month, annual precipitation, elevation difference in a cell, bedrock class, and NDVI. The NDVI data was gathered by NASA’s MODIS sensors. The observations and the environmental variables were projected into a grid consisting of 1 x 1 km cells covering the whole study area. This study uses the ensemble modelling technique with four individual modelling methods: generalized linear models (GLM), generalized additive models (GAM), generalized boosted models (GBM) and random forests (RF). The modelling process consisted of two modelling rounds so that the impact of NDVI could be evaluated. The first modelling round included all the environmental variables except NDVI (the topoclimate model) and the second modelling round included all the environmental variables (the full model). The two temperature variables, annual mean temperature and the maximum temperature of the warmest month, had the highest mean variable importance values. With the topoclimate model, annual precipitation ranked third with the rest of the climate variables, but when NDVI was added to the models, it rose above annual precipitation. Overall, among the studied arctic and alpine species, the variable importance values of both the edaphic and topographical variables were low. In general, both the topoclimate models and full models performed very well. The mean AUC- and TSS-values were all higher for the full models, indicating that including a biotic variable improved the models. When the binary predictions of both modelling rounds were compared, it was clear that NDVI refined the projected distributions for most species. The results from this study confirm the discovery that including a biotic variable, such as NDVI, has the potential to increase the predictive power of species distribution models. One of the main problems with including biotic variables in species distribution models has been the difficulty of quantifying biotic interactions. NDVI can thus be a promising tool to overcome these difficulties, as it is one of the most direct variables to describe ecosystem productivity, can be acquired at various scales, and as remotely sensed data, it can also cover areas that are difficult to access.
  • Ehnström, Emil Mattias (Helsingin yliopisto, 2021)
    The number of people belonging to a language minority in Finland is increasing and people are becoming more and more spatially mobile. This has also led to an increase in transnationals and higher rates of cross-border mobility. With new methods involving social media big data, we can map spatial mobility patterns in new ways and deepen the understanding of how people relate to space. Differences in spatial mobility can for example give us an indication of the rate of integration into society. Some claim that a more spatially mobile life is a sign of success, but can we see differences in spatial mobility between people in Finland? The three language minorities considered in this thesis are Swedish, Russian, and Estonian. The history and culture of these groups are different as well as their status in Finnish society. Swedish speakers, with a national language status, have a different role in society, but do this well integrated minority differ from the other ones spatially? By using Twitter data and looking at the spatial mobility within Finland, we see where differences occur between language groups. To understand how strong ties the language groups have with neighbouring countries, we look at cross-border mobility to Estonia, Russia, and Sweden. The results show that there are differences in the spatial mobility of language minorities in Finland. Estonian speakers most frequently visit Estonia, while at the same time they are less mobile within Finland. The variation was large for Russian speakers, with some visiting Russia often and others almost never. Swedish speakers seem to have relatively weak ties to Sweden, compared to the other language groups and have very similar spatial mobility to the majority Finnish speaking population.
  • Lämsä, Suvi (Helsingin yliopisto, 2021)
    Urban environments are constantly changing and expanding. They grow, evolve, and adapt to society and residents’ needs. Environmental changes have an impact also on urban green such as trees. This is because the increase of building stock and expanding cityscape will target these green spaces. However, the significance of those green spaces is understood as they have a positive impact on the residents’ well-being and health. For example, urban trees are known to improve the air quality and to provide mentally relaxing environments for residents. As this importance is emphasized, changes in the areas must be monitored, which increases the importance of the change detection studies. Change detection is a comparison of two or more datasets from the same area but at different times. Principally, changes have been detected with various remote sensing methods, such as aerial- and satellite images, but as airborne laser scanning technology and multi-temporal laser scanning datasets have become more common, the use of laser scanning data has also increased. The advantage of the laser scanning method is especially in its ability to produce three-dimensional information of the area. Therefore, also vertical properties can be studied. The method’s advantage is its ability to detect changes in urban tree cover as well as in tree height. The aim of this study was to investigate how tree cover and especially canopy height have changed in the Kuninkaantammi area in Helsinki during 2008‒2015, 2015‒2017, 2017‒2020, and 2008‒2020 from multi-temporal laser scanning data. One of the starting points of this study was to find out how airborne laser scanning datasets with different sensors and survey parameters are suitable for change detection. Also, what kind of problems the differences between datasets will raise and how to reduce those problems. The study used laser scanning data from the National Land Survey of Finland and from the city of Helsinki for four different years. The canopy height models were produced of each dataset and changes were calculated as the difference of each canopy height model. The results show that multi-temporal laser scanning data require a lot of manual processing to create datasets comparable. The greatest problems were differences in point density and in classification of the data. The sparse data from the National Land Survey of Finland affected how changes were managed to be studied. Therefore, changes were detected only in general level. In addition, each dataset was classified differently which affected the usability of the classes in the datasets. The problems encountered were reduced by manual work like digitizing or by masking non-vegetation objects. The results showed that the change in the Kuninkaantammi area has been relatively large at the time of the study. Between 2008 and 2015, 12.1% of the tree cover was lost, 9.9% between 2015 and 2017, and 13.2% between 2017 and 2020. In addition, an increase in canopy height was detected. Between 2008 and 2015, 44.2% of the area had greater than 2 m increase in canopy height. Similarly, increase occurred in 11.1% and 3.5% of the area in 2015‒2017 and in 2017‒2020, respectively. Although the changes were observed at a general level, it can be concluded that the used datasets can provide valuable information about the changes in urban green that have taken place in the area.
  • Aroalho, Sari (Helsingin yliopisto, 2021)
    Africa has recently increased its share of the global market, and the continent’s potential has been recognized globally. The continent has experienced a lot of oppression and forced changes in history, and it is currently developing its new identity with relatively young states and its fast-growing population. African Union (AU) is calling pan-African ideology to bring together the African people in their blueprint and master plan Agenda 2063, where the cultural heritage is at the core. Culture is also at the core of the creative economy, and the creative economy's share of the global economy is growing. Due to globalization and digitalization, the knowledge from other cultures is spreading rapidly, which is the basis of a cultural shift both at local and global levels. This research investigated the culture and the creative economy as builders of society in Kenya. Kenya has been very successful in the field of Information and Communications Technology (ICT), the state takes its cultural heritage seriously in its development programs and their focus is especially on the potential of the youth in the creative economy. Kenya has a vast cultural diversity in the state with its officially recognized 44 tribes. This cultural diversity plays a significant role in the creative economy. According to the United Nations Conference on Trade and Development (UNCTAD, 2020), the creative economy has no single meaning, as the concept is constantly evolving. The basic elements of the concept are from human creativity, ideas, and intellectual property, knowledge and technology. The creative industries include such as music, film, video, arts and crafts and performing arts. These elements are the basis of the creative economy, in addition, they have a significant commercial and cultural value. The research was conducted in Kenya during January and February 2021, and the data was collected from two main geographical research areas, the city of Nairobi and Taita-Taveta County. The geographical research areas were chosen by their cultural diversity, the creative economy and their urban and rural statuses. Nairobi has a classification of a creative city where the digital creative economy is booming, and the city is attracting people around East Africa. Taita-Taveta respectively is a rural county near the Kenyan coast, where the creative economy is mainly in the traditional form, for example, crafting and basket making. The research combined the elements from the ethnographical, hermeneutical and critical approaches by using unstructured, structured interviews and observation, as the methods combined qualitative methods with numerical data. The results show that the culture and the creative economy do build the society in Kenya. It is seen in each level of society, for example, among the families, tribes, counties and even the government. Each level influences and controls the way culture and the creative economy build the society in Kenya. The meaning of the community arose in culture and the creative economy shifts, as they provide help in the mitigation and adaptation into new situations. With the exponential population growth, the share of the youth is rising, culture and the creative economy have the potential to provide jobs for the youth in the future. There are challenges with culture and the creative economy in Kenya. First, to preserve the cultural diversity in Kenya among the youth. Second, to target the governmental policies to the right actions and towards the right groups, which would then support the sector itself. Due to attitude shifts, the role of the youth is a significant point to consider. Furthermore, there is a vast gap between the government and the community, which causes a lot of harm to the creative economy, as the policies do not support the creative sector. If these significant points are solved, there is a vast potential for the culture and the creative economy to continue building the society in Kenya.
  • Heikkinen, Janne (Helsingin yliopisto, 2020)
    Subarctic ponds are important habitats for many freshwater species. The recent increase in global temperatures have stressed on the study of these habitats as rising water temperatures may have severe consequences to these cold and harsh ecosystems. Despite its importance, this topic has been largely overlooked in scientific research. Diatoms are microscopic, single-celled benthic algae, which are important indicators for environmental quality. Elevation is one of the main environmental variables controlling the composition and richness of diatom species as it shapes communities through several environmental variables such as temperature and water chemistry. The aim of this thesis was to illustrate the variability in diatom species richness and community composition along an elevational gradient in Kilpisjärvi and reveal the most important environmental drivers. As an additional focus, the applicability of the BenthoTorch sampling device was tested in measuring benthic algae biomass. Field and laboratory measurements were done using universal standards. Statistical analyses included multiple univariate and multivariate data analysis techniques. It was found that water pH, aluminium concentration and air temperature explained the variation in species richness and community composition the most. Elevation had only a secondary, non-significant role in shaping the diatom communities in subarctic ponds. Nearby sites showed similar compositions in terms of water chemistry and diatom communities. Biotope characterisation did not provide any further insight into the differences or similarities of diatom community composition or species richness. There were some differences in how genera responded to environmental variables. The centre of distributional range of many taxa was below the mid-point of the elevational gradient but species often occupied the whole elevational gradient. Rare taxa appeared at the ends of the elevational spectrum. The amount of singleton taxa was high (25.8%) and can be expected to increase with climate change. The BenthoTorch did provide reasonable results for benthic algae in the subarctic when compared to previous literature, but further research is required to grasp its full potential. More examination into the relationship between explanatory variables can be suggested (e.g. total phosphorus and ion balance) to gain better understanding on the changes in diatom species richness and community composition along elevational gradients.
  • Edvinsson, Pontus (Helsingin yliopisto, 2020)
    Socio-economic segregation has been increasing in Helsinki for decades and the relation between socioeconomic factors and educational outcomes have been discussed frequently recently and have been an important topic for politicians and researchers. An increasing segregation and dwindling school results in the more disadvantaged areas of Finland have been connected in various reports. The main objective in this master’s thesis is firstly to investigate the spatial socio-economic differences between school catchment areas of the 26 municipalities in the Uusimaa region. And secondly, the relationship between educational outcomes and socio-spatial segregation in Uusimaa, as the former research evidence has only documented the socio-spatial differentiation within the municipalitan core of the region. The aim is to analyze the relationship of the four different socio-economic variables of basic level education, higher education, unemployment and low income households in each school catchment area and present them with help of four different maps created in GIS. Lastly data consisting of educational outcomes from first year pupils (N=1 920) from 41 different schools in the Uusimaa region provided by Kansallinen koulutuksen arviointikeskus were analysed. The data consisted of two standardized tests, one regarding mathematics and one about the finnish language. These two tests were part of a longitudinal evaluation which started in the fall of 2018. The core finding of this study is that Helsinki is by far the area with the largest socio-economic differences between the school catchment areas in the Uusimaa region, where eastern Helsinki often displayed low socio-economic levels and where western Helsinki and southern Espoo often presented a high socio-economic level compared to the rest of the Uusimaa region. And that the educational results regarding the Finnish language had a stronger correlation with the socio-economic data compared to the mathematical educational outcomes. These findings offer new insights for Finnish educational policies and demonstrate the need for supporting schools in disadvantaged neighbourhoods in different types of urban and rural areas.
  • Rönnberg, Oskar (Helsingin yliopisto, 2020)
    Segregation is usually treated as a place-based phenomenon based on residential locations, but during the last ten years more emphasis has been put on understanding segregation as a multi-contextual phenomenon, where mobility in urban space affects the individual’s exposure to segregation. Such research has not yet been done in Helsinki, where socio-economic and ethnic segregation has been on the rise since the 1990’s, but there is anecdotal evidence of for example young people from disadvantaged neighbourhoods not being as mobile in the urban space as others. The aim of this study is to find out how socioeconomic differences and experiences from the past are linked to how people move around and use urban space in Helsinki. A survey study was carried out (N=1 266) in spring 2020 for the purposes of this research. The study is based on a self-selected sample, so the results cannot be generalized for the whole population. Spatial mobility is analyzed with four measures: which parts of the city the respondent usually moves around in, how often they visit the city center, how many of their everyday activities are located near their home, in the city center and in other neighbourhoods and municipalities, and how many of the listed places in the survey they had visited during the last year. The main research methods are linear regression, correlation analyses and statistical tests. Spatial mobility varies based on education, age, family background and mobility practices in the youth. These factors explain at most a quarter of the variance in mobility. Cultural and economic capital also correlates with mobility, but their explanatory power diminishes when education and age are controlled for. The spatial mobility is low for them who had small activity spaces in their youth, and especially for them who still live in the same neighbourhood. Those who live in the outer suburbs are among the least mobile and many of the respondents in Northeastern and Eastern Helsinki do not regularly visit Southern Helsinki. Even though there are many different factors that influence the level of mobility that are not ad-dressed in this study, the results confirm that family background and past experiences affect the individuals’ mobility practices. The results indicate that people who live in disadvantaged neighbourhoods risk exposure to segregation in different contexts of everyday life as a result of low mobility. As people with low education are underrepresented in the study, it is possible that there are some kind of immobilities in the city that have not been covered in this study. The results underline the need for more research in multi-contextual segregation and the experiences and conceptions of the city, especially regarding children and young people.
  • Kokkonen, Maija (Helsingin yliopisto, 2019)
    European Union is a notable political actor that strives for governing and producing EU territory through spatial policies and planning. So far, spatial planning has been a technology to govern the terrestrial environment, but now marine space is seen as the new frontier of spatial planning. In 2014, EU has given a directive of maritime spatial planning (MSP), which aims to that every coastal member state had established spatial planning practices to their national marine areas by 2021 according to EU’s spatial agendas. The MSP has been looked at as a managerial tool helping to enhance the ecological condition of the seas, but not as a policy that produces spatiality. In this research, EU’s MSP policy is used as to research Europeanization of space in ‘EU’rope. The aim of this research is to interpret how understanding of ’EU’rope as a territorial entity is shaped through the structure of the maritime spatial planning policy and the meanings attached to it, in order to create a perception of the future development of EU and marine areas in general. The research is conducted from a social constructionist approach as an interpretive policy analysis. The concept of policy integration is in-built to MSP and is used as an indicator to Europeanization in this study. The policy integration effort is seen to steer social networks of actors that create the MSP in practice. Therefore, semi-structured theme interviews were conducted to the actors carrying out the MSP process in Finland. These actors’ understanding of the Finnish MSP is seen to construct ‘EU’ropean space in and through the domestic MSP process. Accordance with the hermeneutic traditions, comprehensive contextualization is conducted in this research in order to understand the maritime spatial planning policy. The research suggests that the spatiality and territoriality of marine areas produces different kind of planning practices than is seen in the terrestrial environment. The EU’s MSP policy is a policy tool for the EU territory, but at the same time, it is used as a tool to carry out domestic regional objectives as well. In Finland, the coastal Regions have benefitted from MSP and gained more power over the Finnish marine territories and the MSP may be used as to reinforce Regional planning. By adopting MSP policy, EU has changed the spatial governance structure of marine Europe. It has transformed heterogenic marine areas in Europe into single entity in order to be spatially governable by EU. These spaces have therefore been submitted under larger decision-making processes than before and EU is able to harness the national marine territories for the benefit of the whole Europe, and mainly due increasing economic growth in the territory. By means of policy integration efforts, the MSP creates new kinds of socio-spatial dimensions to Europe in where political bargaining over domestic marine spaces becomes a norm for the domestic maritime spatial planners. The research suggests that the territorial policy integration efforts reinforce the objectives of the EU directive in transnational collaboration, and this new platform of negotiation can be predicted to unify neighbouring domestic planning practices and goals in some extent.
  • Dok, Matilda Carol (Helsingin yliopisto, 2020)
    Abstract This thesis explores the everyday spatial practices in the gentrified and micro-segregated Eastleigh, Nairobi. Gentrification is one of the most important aspects of urban studies, as well as social geography contributing to significant socioeconomic changes in many metropolitan cities in the world. Although the emerging empirical studies indicate socioeconomic impacts of gentrification, less research has been conducted to examine social and economic interaction in gentrified spaces in the Global South. Additionally, there are limited studies on how cultural diversity influences gentrification. In the case of a diversified neighbourhood, such as Eastleigh, assessing the effects of culture on gentrification is significant. Therefore, this study aimed to see by observing and interviewing residents, whether the developments in Eastleigh can be analysed and interpreted through the theoretical framework of gentrification and micro-segregation. The study used descriptive research to build on literature and graphics to collect data on gentrification indicators and socioeconomic interactions. The qualitative part of the study entailed observation, questionnaire survey, and key Informant interviews, while quantitative analysis was based on the graphical presentation of data. The outcomes of the study strongly suggest that an increase in the housing variables, the influx of wealthy population, increased employment, and shift in consumption trends are the significant indicators of ongoing gentrification in Eastleigh. The empirical studies indicate that social interactions in gentrified spaces appear to be marginalized due to cultural differences that have a strong impact on social and economic agents. The review made similar observations regarding social interactions between the new-comers and the long-time residents. The results of the study also found out that the reason for social and economic inequalities among the residents and the gentrifies was cultural differences which hindered access to social and economic services. However, since this study is one of the initial studies on gentrification in Eastleigh, Nairobi, more and in-depth studies are recommended
  • Jokinen, Ari-Pekka (Helsingin yliopisto, 2021)
    Glaciers and ice caps (GICs) excluding Greenland and Antarctic ice sheets account for large proportion of potential future sea level rise and are losing great amount of their mass in high confidence by 2100. Glacier elevation change observations covering whole Greenland’s GICs are limited to the 21st century and regional geodetic mass balance estimates are scarce. Recent development of photogrammetric software and rediscovery of old aerial photographs has been increasingly used to extend temporal resolution of glacier change studies. Besides for extended mass balance observations, historical photographs may be used in observing glacier surge events to improve their coverage in glacier inventories. In this study, 320 historical aerial photographs from 1953/1954 were photogrammetrically processed to create new digital elevation model (DEM) of the 1953 surface. Comparing the 1953 DEM with 1985 and 2016 DEMs extended the geodetic mass balance records on Nuussuaq peninsula to 63 years. Moreover, differenced DEMs were used with orthophotomosaics to identify glacier surface changes and advances and their possible relation to glacier surges. The study also explored the usage of Open Global Glacier Model (OGGM) with user defined input data for simulating future glacier changes in small scale regional setting. The geodetic mass balance results showed clear change from near equilibrium mass balance in 1953-1985 to overall mass loss in 1985-2016. Glacier surface lowering was found to shift to higher elevations along with the change to negative mass balance and occurred throughout the elevation range in 1985-2016. In contrast to generally retreating glaciers, advancing and/or surface elevation increases at the glacier fronts with glaciomorphological evidence of surging were observed on 5 glaciers. OGGM model is easily applicable for smaller regions but correcting the OGGM calibration with a fit to the geodetic mass balance data didn’t provide explicit result of the re-calibration efficiency. Historical photographs provide source to extend geodetic mass balance estimates and means to observe past glacier changes in more detail. Therefore, their incorporation in glacier change studies should be continued and create consistent datasets over larger regions. More research is needed with additional reference data to assess the reliability of the OGGM performance on a region without the reference data from default reference glacier network and the effect of re-calibrating with geodetic fit.
  • Sallasmaa, Christa (Helsingin yliopisto, 2021)
    The topic of this thesis is participatory budgeting and its connection to the discussion between neoliberalism and participatory governance in the context of city development. Helsinki started its own model of participatory budgeting in 2018 and has pledged to continue the concept in the future. I examine whether Helsinki’s participatory budgeting has the potential to support the ideologies of neoliberalism or participatory governance. In practice, I am exploring the views from the city government and active members of Helsinki’s neighborhood associations. Neighborhood associations had a significant role in the original participatory budgeting of Porto Alegre. I used interview and qualitative survey to collect my data. Neoliberalism has influenced the inequality between regions and the so-called crisis of democracy. Direct involvement of citizens is seen as a solution to these problems. Neoliberalism and participation have a paradoxical relationship: they have received similar criticism. In participatory governance participation means deliberative decision-making based on exchange of knowledge, but in neoliberalism participation can be a rhetoric tool to cover up actual decision-making or a city branding technique. Porto Alegre’s original model of participatory budgeting is seen as a part of participatory governance, but many of the international models seem to be more compatible with neoliberal ideology. The city government has not reserved enough resources to the participatory budgeting. The execution was rushed and showed signs of rationalization. According to the interview and the qualitative survey, inequality between regions might be the downfall of Helsinki’s participatory model. The active members of neighborhood associations see the benefits of participation budgeting but only from the perspective of certain regions. Currently, Helsinki’s participatory budgeting works better as a branding technique than as a method of decision-making. It seems to be more compatible with neoliberalism than participatory governance.
  • Toikka, Akseli (Helsingin yliopisto, 2019)
    Urban vegetation has traditionally been mapped through traditional ways of remote sensing like laser scanning and aerial photography. However, it has been stated that the bird view examination of vegetation cannot fully represent the amount of green vegetation that the citizens observe on street level. Recent studies have raised human perspective methods like street view images and measuring of green view next to more traditional ways of mapping vegetation. Green view index states the percentage of green vegetation in street view on certain location. The purpose for this study was to create a green view dataset of Helsinki city through street view imagery and to reveal the differences between human perspective and aerial perspective in vegetation mapping. Street view imagery of Helsinki was downloaded from Google street view application interface. The spatial extent of the data was limited by the availability of street view images of summer months. Several green view maps of Helsinki were created based on the green view values calculated on the street view images. In order to understand the differences between human perspective and the aerial view, the green view values were compared with the regional land cover dataset of Helsinki trough linear regression. Areas with big differences between the datasets were examined visually through the street view imagery. Helsinki green view was also compared internationally with other cities with same kind of data available. It appealed that the green view of Helsinki was divided unequally across the city area. The lowest green view values were found in downtown, industrial areas and the business centers of the suburbs. Highest values were located at the housing suburbs. When compared with the land cover, it was found that the green view has a weak correlation with low vegetation and relatively high correlation with taller vegetation such as trees. Differences between the datasets were mainly concentrated on areas where the vegetation was not visible from the street by several reasons. Main sources of errors were the oldest street view images and the flaws in image classification caused by other green objects and shadows. Even though Helsinki has many parks and other green spaces, the greenery visible to the streets isn’t always that high. The green view dataset created in this study helps to understand the spatial distribution of street greenery and brings human perspective next to more traditional ways of mapping city vegetation. When combined with previous city greenery datasets, the green view dataset can help to build up more holistic understanding of the city greenery in Helsinki
  • Kärppä, Mai (Helsingin yliopisto, 2020)
    Arctic peatlands are globally extensive and long-lasting storages of carbon and are therefore important ecosystems controlling global carbon cycling. Changes in climate affect peatlands’ ability to accumulate carbon through changes in hydrology and water table level, vegetation, soil temperature and permafrost thaw. As climate warming is projected mostly to northern and arctic regions, it may change the peatlands’ capacity to sequester and release carbon as carbon dioxide and methane. In this Master’s Thesis I studied how the past climate changes are reflected in carbon accumulation rates over the past millennia. Known climate anomalies, such as the Medieval Climate Anomaly, Little Ice Age and the last rapid warming starting from 1980, and their impact on average long-term apparent rate of carbon accumulation were studied from the peat proxies. 15 peat cores were collected from northern subarctic Swedish Lapland and from North-East European Russia. Cores were collected from the active peat layer above permafrost that is known to be sensitive to climate warming. Cores were dated with radiocarbon (14C) and lead (210Pb) methods and peat properties and accumulation patterns were calculated for one centimeter thick subsamples based on chronologies. The Little Ice Age and the last rapid warming affected the carbon accumulation rate considerably whereas for Medieval Climate Anomaly period the peat records did not show very distinctive response. During the Little Ice Age the carbon accumulation rates were low (median 10,5 g m-2v-1) but during the post-Little Ice Age and especially during the last warm decades after 1980 carbon accumulation rates have been high (median 48,5 g m-2v-1). Medieval Climate Anomaly had only a minor positive effect on accumulation rates. On average, the long-term apparent rate of carbon accumulation during the past millennia was 43,3 g m-2v-1 which is distinctly higher than the previously studied rate of 22,9 g m-2v-1 for northern peatlands (p-value 0,0003). Based on results it can be concluded that warm climate periods accelerated the carbon accumulation rate whereas during cold periods accumulation decelerated. Warm climate prolongs the growth period and accelerates the decomposition of peat; cold climate shortens the period of plant growth and thickens the permafrost layer in peatlands, respectively. However, peat layers that are formed after the Little Ice Age are incompletely decomposed which amplifies the carbon accumulation rate partly. Nevertheless, permafrost thawing has been shown to increase accumulation rates, as well. Studying past carbon accumulation rates helps to understand the peatland and carbon cycling dynamics better. Even though accumulation rates reveal a lot about carbon sequestration capabilities of peat, it does not indicate whether a peatland has been a carbon sink or a source.
  • Mäntymaa, Eeva (Helsingin yliopisto, 2020)
    This thesis aims to examine the current regional identity of Jätkäsaari, a district of Helsinki, halfway of its construction phase. In the thesis I aim to find out, what are the most important factors in creating a regional identity for Jätkäsaari from the perspective of both the urban planners of the region and its residents. Moreover, I also sought to find out, how the regional identity of Jätkäsaari has been shaped in the planning phase of the district, and how the regional identity of Jätkäsaari has been modified by means of branding. In addition, the aim of the thesis is to find out how the residents of Jätkäsaari experience the identity of the area, and what factors make up regional identity. I interviewed three key experts for the thesis, who were substantially involved in the planning work of Jätkäsaari. In addition, I surveyed the opinions of Jätkäsaari residents on the topic by using a questionnaire published on Facebook. 80 people responded to the survey. The data was collected in the spring of 2019. The answers to the expert interviews and resident surveys are compared and used to find out, how the views of the residents and the planners relate to each other, and to determine the most important features of Jätkäsaari's regional identity. The results of the questionnaire show, that Jätkäsaari has clearly started to develop a distinctive identity. Maritimeity and the port's presence are important factors of the identity. However, Jätkäsaari is also designed as a clear extension to the city center of Helsinki. On the other hand, some residents of the area also perceive Jätkäsaari as its own territory and as an island that clearly stands out from the city center. Community spirit of Jätkäsaari has started to develop already from the early stage. Resident evenings have been popular from the beginning and there has been active discussion between the residents and the planners about the development of Jätkäsaari area.
  • Hanhirova, Elisa (Helsingin yliopisto, 2021)
    Large amounts of carbon is stored in the soil and vegetation of the tundra ecosystem. Carbon dioxide is stored in the vegetation in photosynthesis and is released into atmosphere from the soil and vegetation in ecosystem respiration. Rising temperatures can cause considerable changes to the delicate tundra ecosystem and create new potential feedbacks to global warming as the environment changes. There are several factors regulating carbon dioxide fluxes and their interactions and temporal changes are not yet fully known. Understanding carbon dioxide fluxes and the factors contributing to them is important in order to study and predict temporal and local changes. This research focuses on describing changes in net ecosystem exchange, primary production, and ecosystem respiration in the tundra as well as the factors contributing to them. The measurements were made with the chamber method in Saana fell, Kilpisjärvi in Finnish Lapland. This study includes 14 nivations with a total of 84 study points that were measured three times during the growing season in the summer of 2019. In addition to flux the measurements, information about controlling environmental variables were collected. These included vegetation, air temperature, soil moisture and soil temperature. The impact of the explanatory variables on fluxes at different times in the growing season was studied using mixed effects model and an estimated carbon budget was calculated for the region. The largest fluxes were measured mid-July during the peak growing season. Ecosystem respiration and primary production declined from the peak of the growing season in August towards the end of the growing season, but net ecosystem exchange increased slightly due to imbalances in the other two fluxes. Vegetation was an important explanatory variable (p ≤ 0,001) in every flux and during different times of the growing season. Air temperature had the greatest impact on net ecosystem exchange and ecosystem respiration, but the intensity of its response varied during different periods of the growing season. In both of these fluxes, higher temperatures increased the flux into the atmosphere. In primary production, the response changed in the middle of the growing season from positive to negative due to high temperatures. Soil moisture had a positive effect especially on ecosystem respiration, but its significance varied during the growing season (p = 0,0012; 0,02; < 0,001) and the response increased towards the end of the growing season. Also in primary production, response intensity and significance (p = 0,02) increased at the end of the growing season and in net ecosystem exchange the response changed from negative to positive at the end of the growing season. The response of soil temperature increased with all fluxes from the beginning of the growing season and decreased with ecosystem respiration and net ecosystem exchange towards the end of the growing season. Soil temperature was only significant in the second measurement campaign for net ecosystem exchange (p = 0,01) and ecosystem respiration (p = 0,005). During the growing season, carbon dioxide fluxes changed considerably and their explanatory factors also varied in time. The responses to soil moisture and air temperatures also turned negative or positive during the growing season. These changes and studying them is very important to understanding the processes behind different fluxes. The change in carbon dioxide fluxes and the variables that affect them in the tundra environment affects the region's carbon budget.
  • Lilja, Jiri (Helsingin yliopisto, 2021)
    Korkeuden vaikutusta eliöiden esiintymiseen on tutkittu eri alueilla jo 1800-luvulta lähtien, mutta vasta viimeisten vuosikymmenien aikana korkeuden vaikutuksen on tunnistettu olevan monimutkainen. Eri eliöryhmien lajirunsaushuiput saavutetaan korkeusgradientin eri vyöhykkeissä eri alueilla. Lintuihin korkeuden ja lajirunsauden välille on tunnistettu neljä toisistaan poikkeavaa trendiä. Korkeuden vaikutusta on tutkittu pääosin lauhkeilla ja trooppisilla alueilla, kun taas korkeiden leveyspiirien alueilta on tutkimusta vähän. Korkeuden lisäksi elinympäristöjen on todettu vaikuttavan merkittävällä tavalla lintujen esiintymiseen, mutta elinympäristöjen vaikutusta on tutkittu lähinnä metsissä, maatalousympäristöissä ja kaupungeissa. Ilmastonmuutos vaikuttaa pohjoisten alueiden elinympäristöihin erityisen voimakkaasti, mikä tekee näistä alueista tärkeitä tutkimuskohteita. Tämän tutkielman tarkoituksena on selvittää, miten korkeus ja elinympäristöt vaikuttavat lintujen esiintymiseen ja runsauteen tunturiympäristössä. Korkeuden ja elinympäristöjen vaikutusta tutkittiin tuottamalla alueellisia malleja kahdella eri mallinnusmenetelmällä (GLM ja GAM) lintuaineiston, korkeuden ja elinympäristöjen välille. Lintuaineisto kerättiin kesän 2019 aikana pistelaskennalla 420 tutkimuspisteeltä Pohjois-Norjassa Rásttigáisá-tunturin ympäristössä noin 180 km² kokoiselta alueelta. Lintuaineiston lajit luokiteltiin taksonomian mukaan lintulahkoihin varpuslintuihin, rantalintuihin, kanalintuihin ja päiväpetolintuihin. Tutkimuspisteet luokiteltiin viiteen eri elinympäristöluokkaan (metsä, metsänraja, kuiva avotunturi, kostea avotunturi, karukko) NDVI-aineiston ja ilmakuvien perusteella. Lintulajeille laskettiin Shannonin habitaatti diversiteetti-indeksi (SHDI), jonka avulla tutkittiin lajien esiintymistä eri elinympäristöissä. Sekä korkeus että elinympäristöt selittävät lintujen esiintymistä tunturiympäristössä. Korkeuden ja elinympäristöjen välillä havaittiin merkittävä suhde ja elinympäristöt sijoittuvat verrattain selvästi korkeusgradientille. Korkeuden ja lajirunsauden suhteen todettiin olevan huipukas, korkeimmat lajirunsaudet havaittiin 300–500 metrissä metsänrajalla ja sen yläpuolella. Korkeus selitti 30,3 % kokonaislajirunsauden, 30,8 % varpuslintujen ja 28,0 % rantalintujen lajirunsauden vaihtelusta (GAM). Elinympäristöluokat selittivät korkeutta paremmin etenkin esiintymisen muutoksia 50 metrin skaalalla. SHDI-arvon mukaan elinympäristöön erikoistuneimmat linnut ovat kosteiden avotuntureiden rantalintuja, kun taas varpuslinnuissa esiintyy enemmän generalistilajeja. Elinympäristöluokat selittivät tarkan skaalan lisäksi erityisen hyvin elinympäristöön erikoistuneiden rantalintujen lajirunsautta (35,5 %). Tulevat muutokset ilmastossa uhkaavat etenkin avotunturissa esiintyviä lajeja, joista monet esiintyvät vain tietyssä elinympäristössä. Korkeuden ja elinympäristöjen vaikutusten syvempään ja tarkempaan ymmärtämiseen tarvitaan lisää tutkimusta. Jatkotutkimusta tarvitaan useammalta korkeusgradientilta ja tarkemmalla elinympäristöluokituksella.
  • Bergström, Karoliina (Helsingin yliopisto, 2021)
    School environments have become increasingly challenging due to segregation in cities, escalating social problems and multiculturisation. The challenges do not emerge only in classrooms but are also reflected more widely to the school communities and surrounding areas. The growing challenges raise a question whether a school’s role could be extended from an educational institution to a more versatile node of services that supports not only children’s learning but also all residents’ wellbeing and lifelong learning in the neighbourhood. In this study I examine a school’s local role in increasing social capital, sense of community, inclusion and trust in its neighbourhood and I analyse how a community building, where the school is placed, could take a supportive role in it. The thesis is a case study of a Finnish multicultural urban neighbourhood where a new community building was opened a few years ago. The community building houses a school, daycare, library, youth centre and social- and health services. I take an institutional approach in the study and I interview five institutional actors representing the school and the city. The study material consists of these interviews and of a recording given to me by one of my interviewee who had interviewed other school representatives before my study. In the analysis part, I use a case analysis method, which sheds light not only on the policies and functional practices of the school and the community building but also on the challenges they face. Even as one case study, the knowledge gained from it can be viewed in a wider context in order to understand the functioning of school communities and to take part in discussing the operational school environments. The main results of the study indicate that the interviewed school and city representatives perceive the school as a larger local actor rather than only as an educational institution. The representatives see that the school is an important actor in building sense of community, inclusion and trust in the wider neighbourhood and also believe that it reflects its conventions and values to the whole community. Central finding in the thesis is also the interviewees’ common view that the community building and its versatile services strongly support the school in delivering education, wellbeing and assistance for children, families and all residents of the community. The school and community building are also regarded as important domains of integration for the people with an immigrant background to the Finnish society. A school represents one the most central institutions of the society and it reaches whole families due to compulsory education. Therefore, it works as a natural platform for integrating services and assistance not only for children but also for adults. The main challenges that the school and community building face in its functioning and in creating a wider local role were mentioned to be segregation with its negative side effects and policies made in the city level that do not fit as such to the neighbourhood’s local context. This study takes part in the discussion of segregation in cities and growing spatial inequality with their negative impacts on people’s wellbeing and on equal opportunities. This negative trajectory will also lead to malfunctioning of cities and the wider society. The results of this study provide insights to the question, whether a community building as a concept could be a solution in school and spatial development and in urban neighborhood improvement. A community building that supports a school in taking a stronger local role and working as a node of services for education, hobbies, leisure and assistance can possibly improve people’s everyday lives and wellbeing in the whole society.