Browsing by discipline "Geography"
Now showing items 1-20 of 172
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(2013)Boreaaliset suot ovat globaalilla tasolla merkittäviä hiilen varastoja sekä monimuotoisia ekosysteemejä. Ombrotrofisia keidassoita esiintyy erityisesti eteläboreaalisella vyöhykkeellä, kun minerotrofiset aapasuot ovat yleisempiä keski- ja pohjoisboreaalisella vyöhykkeellä. On kuitenkin odotettavissa, että ilmastonmuutos siirtäisi keidas- ja aapasuovyöhykkeen rajaa pohjoisemmaksi, mikä tarkoittaisi nykyisten aapasoiden rahkoittumista keidassoiksi. Keidas- ja aapasoiden suhteellisten osuuksien muuttuminen vaikuttaisi soiden kaasuvirtoihin sekä monimuotoisuuteen. Tutkimuksen tavoitteena on selvittää nykyisten aapasuovyöhykkeen soiden sukkessiovaihetta rahkoittumista indikoivien avainlajien kautta. Kasvillisuus- ja ympäristöaineisto tutkimukseen kerättiin 21:ltä luonnontilaiselta suolta Pohjois-Pohjanmaalta sekä Pohjois-Karjalasta ja Kainuusta. Avainlajien optimielinympäristöä mallinnettiin yleisten lineaaristen mallien ja regressiopuumenetelmien avulla. Myös ekologisten monimuuttujamenetelmien (DCA ja CCA) avulla selvitettiin suokasvien esiintymistä suhteessa ympäristötekijöihin sekä tutkimusalueiden välisiä mahdollisia eroja. Tulosten perusteella avainlajien (Eriophorum vaginatum, Sphagnum angustifolium, S. balticum ja S. magellanicum) esiintymistä selittää parhaiten sekä pH, sijainti sekä turpeen paksuus. Ilmastomuuttujien osuus on vähäinen, mutta niiden mukanaolo kuitenkin paransi GLM-mallien selityskykyä. DCA:n perusteella myös vedenpinnantaso vaikuttaa avainlajien esiintymiseen. Vasteet ympäristötekijöiden suhteen kuitenkin vaihtelevat avainlajien välillä. Itäisen ja läntisen tutkimusalueen välillä on havaittavissa tilastollisesti merkitsevää lajistoeroa, ja erityisesti S. balticumin esiintyminen on painottunut itäiselle tutkimusalueelle. Yhdistettäessä avainlajien dominanssitulokset ja soiden trofiatasot havaittiin tutkimusalueella kolmea erilaista kehitysvaihetta: selkeät aapasuot, selkeät rahkasuot, sekä muutosvaiheen suot. Aapasoiden osuus aineistosta on 43 %, muutosvaiheen soiden 19 % ja keidassoiden 38 %. Tulokset kertovat, että rahkoittuminen on jo alkanut aapasuovyöhykkeen eteläisissä osissa. Rahkoittumisen taustalla voi olla useita tekijöitä. Koska soiden välillä on suuriakin eroja kehitysvaiheen suhteen, voidaan päätellä, ettei suurilmaston merkitys ole kovinkaan voimakas soiden kehityksen kannalta. Itäisen tutkimusalueen suot ovat tulosten perusteella hieman enemmän rahkoittuneet, mutta itäisellä tutkimusalueella vallitsee edelleen myös selkeitä aapasoita. Niinpä rahkoittumiskehitykseen näyttää vaikuttavan erityisesti paikalliset ympäristötekijät. Tulosten perusteella on oletettavaa, että avainlajien dominanssi tulee kasvamaan erityisesti muutosvaiheen soilla ja suot muuttuvat keidassoiksi. Aapasoiden rahkoittuminen vähentäisi ravinteikkaiden suotyyppien monimuotoisuutta, joten aapasoiden suojelu tulee jatkossa olemaan nykyistäkin tärkeämpää. Boreaaliset suoekosysteemit ovat muutoksen alla, ja ilmastonmuutoksen ja soiden sukkession välisten suhteiden selvittäminen vaatii lisätutkimusta.
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(2014)Koulujen puutarhatoiminta on yhtä aikaa koululaitoksemme kanssa kehittynyt ilmiö. Aikojen saatossa koulupuutarhatoimintaa kohtaan tunnettu kiinnostus on vaihdellut ja tällä hetkellä se on ilmeisesti taas kasvussa. Koulupuutarhatoimintaa voidaan tarkastella monenlaisista näkökulmista, esimerkiksi osana koulun ympäristökasvatusta, terveyskasvatusta tai oppiainerajat ylittävää opiskelua. Aihetta on tutkittu vain vähän ja tämän tutkimuksen tavoitteena on selvittää millaista koulupuutarhatoimintaa Suomessa on ja miten puutarhoja hyödynnetään opetuksessa. Lisäksi tarkastelun kohteena on havainto, jonka mukaan koulupuutarhatoimijat usein ajattelevat oppilaiden oppivan toiminnan kautta 'mistä ruoka tulee'. Nykyaikainen ruokajärjestelmä on kuitenkin monimutkainen kokonaisuus, jonka muodostavat kuluttaja, tuottaja, jatkojalostajat ja pakkausteollisuus, sekä kauppa ja muut ruoan kautta tekemisissä olevat verkostot. Ymmärtääkseen ruoan matkaa pellosta pöytään ei siis riitä että tietää miten kasvit kasvavat. Tutkimuksessa selvitetäänkin lisäksi mitä koulupuutarhojen avulla opetetaan ruokajärjestelmästä. Tutkimuksen empiirinen aineisto kerättiin teemahaastattelujen avulla. Tutkimusta varten haastateltiin 11 opettajaa eri puolilta maata sijaitsevista kouluista, joissa on aktiivista koulupuutarhatoimintaa. Tutkimuskoulujen joukossa on ala- ja yläkouluja, lukio ja kaksi steinerkoulua. Tavoitteena oli saada tutkimukseen mukaan mahdollisimman laaja otos erilaisia koulupuutarhoja, joten kustakin koulusta haastateltiin vain yhtä toiminnasta hyvin perillä olevaa opettajaa. Litteroitu haastatteluaineisto analysoitiin teemoittelun ja tyypittelyn avulla. Teemoittelun kautta aineistosta löytyneiden ilmiöiden yleisyyttä selvitettiin sisällön erittelyllä. Tutkimuksen tulosten perusteella ei voida määrittää suomalaisen koulupuutarhan tyyppiesimerkkiä, sillä toimintatavat, toiminnan laajuus, sille asetut päämäärät ja puutarhojen hyödyntäminen opetuksessa vaihtelevat kouluittain paljonkin. Puutarhojen toimintamallit on kehitetty koulukohtaisesti niiden resurssien varassa, joita kullakin koululla on ollut käytettävissään. Toiminnan ensisijaisena tavoitteena on oppimisen tukeminen, mutta eri kouluissa puutarhan merkitystä painotetaan eri tavoin: ympäristökasvatuksen, kokonaisvaltaisen oppimisen tai jonkin tietyn kurssin oppimisympäristönä tai koulun pihaa viihtyistävänä tai koulun arkeen vaihtelua tuovana tekijänä. Toiminnalle asetetut tavoitteet määrittävät sitä kuinka paljon puutarhaa hyödynnetään opetuksessa ja lisäksi hyödyntämisen laajuuteen vaikuttaa puutarhan koko. Vaikka myös monet opettajat ajattelevat koulun puutarhatoiminnan avulla opittavan mistä ruoka tulee kauppojen hyllyille, opetetaan ruokajärjestelmästä puutarhatoiminnan kautta vain tiettyjä osia. Alkutuotannon roolia painotetaan vahvasti, mutta osassa kouluista näkökulmaa laajennetaan valmistamalla satoa myytäväksi myyjäisissä tai sitä tarjotaan kouluruokalassa. Kahdessa koulussa tehdään lisäksi maatilayhteistyötä lähitilojen kanssa. Uusien oppimisympäristöjen ja opetusmetodien hyödyntämistä opetuksessa pidetään yleisesti suositeltavana, mutta niiden käyttöönotto vaatii opettajalta edelleen erityistä rohkeutta. Koulupuutarhatoiminta kannustaa opettajia kokeilemaan koulussa monenlaisia uusia toimintatapoja ja opetusmetodeja, kuten ulkona opettamista ja kokemuksellista oppimista. Tutkimukseen osallistuneet opettajat eivät juuri kokeneet tarvitsevansa apua koulun puutarhatoiminnan kehittämiseen, mutta se voisi hyödyttää heitä etenkin puutarhakasvatuksen osalta, sillä monilla on melko suppea käsitys puutarhan hyödyntämismahdollisuuksista opetuksessa. Koulupuutarhojen aiheuttama innostus ja lisääntynyt oppilaiden motivaatio, sekä käytännön tekeminen, oikeat ongelmat ja konkreettisen lopputuloksen näkeminen puoltavat paikkaansa koulussa, sillä tällaiset tekijät edistävät tutkimusten mukaan esimerkiksi oppilaiden luonnontieteiden osaamista. Tutkimus on esiselvitys suomalaisen koulupuutarhatoiminnan käytännöistä ja se avaa runsaasti lisätutkimuksen aiheita. Jotta puutarhakasvatuksen parhaista käytännöistä päästään selville, on tehtävä esimerkiksi hyvin dokumentoituja kokeiluja erilaisista puutarhakasvatuksen muodoista, joiden vaikuttavuutta arvioidaan. Tarvetta on myös tutkimuksille, jotka selvittävät puutarhakasvatuksen vaikutuksia oppilaiden oppimiseen suomalaisen koulun kontekstissa. Ruokajärjestelmäopetuksen suhteen tutkimuksessa ilmeni ristiriita sen suhteen, mitä opettajat toivovat oppilaiden oppivan koulupuutarhatoiminnan kautta ja mitä he näyttävät käytännössä opettavan, joten lisätutkimusta tarvitaan myös tämän ristiriidan vahvistamiseksi ja selvittämiseksi.
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(2018)The aim of the study is to inspect with GIS methods socio-economic structures in relation to homicides of youth in the context of Mexican Drug War. The escalation of violence has impacted youth, who fell victims to homicide more often since 2006. The study’s concentration is how the local conditions of poverty, marginalization risk of youth and violence of criminal organizations are related to elevated homicide rates of youth in 2005 and in 2010. Mexico was a relatively peaceful country before the escalation of violence since 2006. The crisis of violence has been branded by media as the Mexican Drug War, where over 200 000 people have died. Conflicts between criminal organizations and the changes in political atmosphere have been considered as main reasons for the escalation. However, the escalation of intentional homicides was recorded to exceed the areas where criminal organizations operate. The impact of increased violence on youth and the cost to the society underlie the importance of studying conditions of where violence takes place. There is no theoretical framework for conflicts where drug cartel related homicides and unrelated homicides increase at the same time, only other examples been recorded only in favelas of Brazil and to an extent in Columbia. Theoretical framework was drawn from comparing gang and criminologist studies to theories on civil conflicts. Through the literature, poverty has been theorized as a primary cause of increase in level of violence. The high marginalization risk of youth has been connected to criminal behaviour. The increased activity by criminal organizations has had an indisputable impact of murder rates. These three statements set the hypotheses for the thesis. The variables were collected to represent the municipal conditions of population, households and interest points of criminal organizations. The spatial analysis was conducted by using Ordinary Least Square Regression to represent the global impacts of variables across Mexico and Geographically Weighted Regression for the local variance. The results of analysis demonstrate that the spatial dimensions of violence have changed between 2005 and 2010. The homicides of youth have increased across the country, were more clustered in 2010 than in 2005. The results suggest that the increased number of homicides in 2010 are more strongly related to marginalization than to absolute poverty. The effect of variables for poverty fell in significance between 2005 and 2010. The marginalization on the other hand, seemed to have a greater explanatory power to local increase in young homicide victims in 2010, especially when concurring with bloodshed by criminal organizations. The violence between criminal organizations had the strongest increasing impact on homicide rates, non-existent in 2005 and eminent in 2010. The regression models’ performance was weaker in 2005 than in 2010. However, the moderately weak performance of regression models and the residuals suggest that the results are not comprehensive and further research is called for.
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(Helsingin yliopistoHelsingfors universitetUniversity of Helsinki, 2010)This master s thesis is concerned with the airline network geography of the Baltic Sea Area. The developments in economical liberties in the area and new liberties in air transport give special interest in researching this matter. Also the requirements of airlines to consolidate their activities give a reason to predict the possible outcomes of the geography of airlines in the area. Airlines networks organize themselves according to economic principles, most often attempting to reconciliate their form with the needs of passengers. The passengers are the centermost actors with their utilities as the main determinants of when and where air services are provided. States have interests in controlling parts of airline transportation as connectivities at cities act as instruments of local economic development. Cities as transport nodes can be characterized by their transport linkages as being central and/or intermediate. This characterization is created by the actions of the passengers, the airlines and the states. This interplay is central to the airline networks being formed in the Baltic Sea Area. Two empirical measurements of international airline connetivity were made from the study cities of Copenhagen, Helsinki, Oslo, Riga and Stockholm. The measurements were made from the database of flights during week 49 in December 2009, which has been acquired for this thesis. This database consists of the data of available passenger seats per flight per destination. From the database a measure of connectivity based on network analysis was made from all the study cities. This connectivity reveals geographic directionality of airline links between the study cities. To compare the situation with the natural transport demand, a gravity model was formulated from the same database to explain the divergent geographic airline connections. Airline connections have specialized in intercontinental airline connections mainly due to strategic business selections made by the region s airlines. In intracontinental connections, much less geographic divergence is found and this is also explained well by the gravity model. Potential is seen for some of the study area s cities to specialize geographically towards Eastern Europe in the future.
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(2015)The Akwé: Kon Guidelines, based on the Article 8(j) of the Convention on Biological Diversity, are voluntary guidelines for cultural, environmental and social impact assessment. The Guidelines are intended to be applied in the impact assessments of plans and projects conducted in areas that are inhabited or used by indigenous populations or that contain sacred places of indigenous peoples. The Guidelines have been applied for the first time ever in Finland in Hammastunturi wilderness area. The research question of the thesis is 'To what extent the Akwé: Kon Guidelines have affected on the consideration of Sami perspective in the management plan of Hammastunturi wilderness area'. The data of the thesis consists of two management plans of Hammastunturi wilderness area published in different years. In the new plan the Akwé: Kon Guidelines have been applied whereas in the old plan the Guidelines have not been used. The management plans produced by the Finnish forest administrator Metsähallitus are secondary data. The qualitative research methods used in the thesis are comparative content analysis and thematic analysis. As a result of the content analysis four themes about the consideration of Sami perspective came up from the data. The themes are Sami perspective in the structure of the plans, attitude towards the indigenous people, values and the actions presented in the plans. The key differences of the new plan compared to the old plan are that the Sami people are concerned more extensively in the context of cultural heritage and traditional livelihoods, the Sami people are referred to as an indigenous people, the Sami culture is defined as a cultural value of the area and the new plan contains actions that directly aim at the protection of Sami culture. The conclusions are that in the new plan the Sami perspective is integrated into the other sections better than in the old plan. In addition, the Sami people are considered as an indigenous people and not as a minority. Contrary to the old plan, in the new plan the cultural values regarding the indigenous people are essential part of the plan. In the actions of the old plan the protection of the Sami culture is in passive level whereas the actions of the new plan aim more actively at the protection of Sami culture. In conclusion, the Akwé: Kon Guidelines have affected positively on the consideration of Sami perspective in the management plan of Hammastunturi wilderness area. The Guidelines have affected above all on the attitude towards the Sami people but less on the concrete actions of the plan.
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(2016)The Pro Gradu thesis is handling social impact evaluations of Sports for Development and Peace projects, particularly football projects. The thesis is answering to questions on how a regional perspective should be included to an impact evaluation tool, that is used in heterogenous locations. The thesis is also taking part in the conversation about how impact evaluation tools of global Sports for Development and Peace can be developed to respond to local change. The research material is collected from participants of Cross Cultures Project Associations Open Fun Football Schools. A two-stepped baseline and follow-up questionnaire and group interviews are used as a method. The question material is based on local needs and goals defined by local volunteers in a volunteer training seminar. The regional perspective is included in the research method in dividing the aspired goals to indicators which can be chosen as the goals of the local Open Fun Football Schools by the volunteers of the project. The impact evaluation was conducted based on these goals. The conclusions of the research are based on a critical evaluation of the impact evaluation conducted in Crimea, Ukraine. The results show that a social impact evaluation will be successful when local needs, the pedagogical contents of the project and the questions asked in the questionnaires and interviews are aligned. The local needs analysis and finding out the baseline of the area turned out to hold primary importance. When the indicators presented in the research are portraying the realistic possibilities of the project, they are creating a base for successful use of an impact measurement tool that has the ability to take regional and project based differences in consideration.
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(2016)The main subjects of this research are corporate social responsibility (CSR) and sustainability reporting. The aim of this study is to describe the contents and appearance of some of the most sustainable companies' sustainability reports. The leaders in CSR were selected from five well known global sustainability indices. A total of 29 companies' CSR reports from different industries and countries were selected for the study. Additional nine companies were included in the analysis of the best practices in CSR reporting but excluded from the content analysis. The purpose of this study is also to understand how the contents of the CSR reports have been defined. Content analysis is conducted in the four research areas: sustainability strategy or vision, materiality assessment, material topics, and sustainability targets. The study finds out how the four research areas are influenced by the company's operating environment and company-specific factors which form the contents of a CSR report. These factors are studied through stakeholder, legitimacy and other theories and concepts of CSR in its widest definition, such as creating shared value and corporate citizenship. The study also focuses on CSR reporting according to the Global Reporting Initiative. The results show that the leaders in CSR have many features that follow the most recent guidelines in CSR reporting and contain some of the most current topics concerning CSR, CSR reporting and global challenges. Most of the reporters recognize their role in the society and they are committed to tackle global challenges. The reporters emphasize the importance of sustainability and innovation which enables companies to create wellbeing and find solutions to global problems. The reports have certain similarities regarding their contents and appearance. Companies engage both external and internal stakeholders in the materiality assessment process. Companies' identified material topics represent the global challenges as well as the company-specific approach for creating shared value. Most of the best reports present a clear strategy and/or an ambitious vision that takes sustainability into account. Many companies have a credible sustainability program or plan which is visible throughout the report. Best reports focus only on topics that are most important for the company and stakeholders. In addition, an excellent report is reader-friendly with a clear structure, interesting graphics that simplify the complex matters of sustainability, is well-written and has case examples to enliven the story. The report is convincing and tells a distinctive story of the company's sustainability journey where sustainability seems to be well integrated into the business strategy. According to the subjective evaluation of the reports' appearance, the best reports belong to Adidas, Biogen, BMW, Henkel, IKEA, Johnson & Johnson, Natura Cosmeticos, Nestlé and Unilever. Other companies that were not included in the analysis but have excellent reports are: Air France-KLM, BG Group, LEGO, Outotec and Sodexo. Future research could be done in the field of sustainability targets and performance in CSR: how the leading companies in sustainable business measure the progress of their commitments for creating shared value and whether the progress is visible.
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(2015)The attempts of the Canadian government to abolish Indigenous ways of being through forced assimilation has resulted into a collective trauma and marginalization of Indigenous peoples. The legacy of this colonial genocide has been particularly devastating to Indigenous women who experience oppression by Euro-Western patriarchy through both their race and their gender. Colonial mind-sets and structures of the society in the past have denigrated and dehumanized Indigenous womanhood, and persist to victimize the women in particular and hurtful ways today. Despite being one of the most disadvantaged groups in Canada, Indigenous women are not victims – they are survivors, resisting the forces that oppress them by reconstructing the identity of Indigenous womanhood and taking action for social change. Regarding this topic and urban Indigenous realities in general, the city of Winnipeg in Manitoba is a place of special interest. It has lately become the toponym of violence and racism against Indigenous people in Canada, and especially Indigenous women. However, the city also has, for quite a while now, fostered a determinant and organized Indigenous community whose women are strongly expressing themselves and working for social change. This thesis describes the relationships I have built with the urban Indigenous community in Winnipeg to deepen the understanding of some the ways Indigenous women engage in colonial resistance through collective identity constructions and direct action in the city. By participating in the everyday life of the community, having one-on-one conversations and exploring personal narratives in social media I have learned how colonial resistance takes place in the women's lives and in the city. I have transcribed my learning into three individual stories of three women who were my main participants. These stories speak of resistance through self-expression and action to reclaim spaces of autonomy. They reveal the significance of healing from colonial and personal trauma through the reconnection with spirituality and tradition, education and sense of belonging to a community. This thesis, centering the inspirational stories of resistance, is situated in anti-colonial framework, incorporating philosophical and methodological premises of Indigenous research paradigm. As such, the purpose of this study has been not only to uncover the power of Indigenous resistance but to support the ongoing global effort of Indigenous peoples to decolonize and restore their cultural-political sovereignty, identity and ways of knowing.
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(2015)This thesis looks at an example of how cities can be affected by large scale destruction and subsequent reconstruction, through the case study of post WW2 London bombing and rocket damage and rebuild. This is viewed with the idea that there was a promised effort by planners of the period to move to a more Utopian city layout for London as set forth in the ideals of Ebenezer Howard's Garden Cities of To-Morrow. This thesis seeks to answer three questions: (1) What impact did the Blitz Bombings/V Strikes of WW2 have on London? (2) Which green space or public areas around today were created as a result of the bombings? (3) Did the urban planners apply E. Howard's Garden City Theory to the restructuring of land use as promised? This has been done by the use of a comparative GIS exercise utilising pre and post War maps of six London boroughs forming the study area, and an aggregate of bomb and rocket incidents recorded from various sources, to determine which areas which has been previously urban in nature and then damaged were rebuilt as a Green or Open Space. Emphasis was placed on transformation of the old and new maps as well as categorisation of the various Green and Open Space types. The findings of this thesis were that although the damage to urban areas was extensive during this period, the overall layout of London did not change significantly in terms of Green and Open spaces, and any changes that were made were opportunistic rather than a noted trend towards Howard's ideals. It also offers commentary on the process of utilising pre-GIS maps in a modern context and its shortcomings in terms of data accuracy.
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(2015)Soil moisture regulates a wide range of ecosystem processes at high latitude ecosystems. Soil moisture and temperature control carbon cycle in arctic soils and therefore had impacts on many climate change feedback loops. Arctic-alpine vegetation is adapted for cold and often dry or water saturated soil conditions though the adaptations are species specific. Therefore the aim of this study is to examine how soil conditions, especially moisture, affect on species fine scale distributions in low energy ecosystems. The data contains 21 study grids and holds 378 study plots (1 m2 each) in total. The data is collected during three summers in 2011-2013 at Saana massif in northwestern Finland. Vascular plant, moss and lichen species are sampled from all plots. Soil moisture and temperature are measured in situ, pH is determined from soil samples at a laboratory and radiation is calculated based on the fine scale topography. NMDS-ordination and nominal GBM-models are carried out to study how the explanatory variables affect on species composition. Species richness and diversity are examined by comparing GLM, GAM, and GBM models with the base variables to models which soil moisture is added as a fourth explanatory variable. The same two variable combinations are used to model distributions of individual species in biomod2 platform. Soil moisture and pH were the most effective variables that control vascular plant species composition. Soil moisture was alone the most important variable for mosses but none of the variables showed importance over others in case of lichens. Vascular plant and moss species richness increased with increasing soil moisture. Lichens showed an opposed trend. The community evenness is highest in moist habitats excluding lichens that showed the highest evenness in the driest end of the moisture gradient. Including soil moisture as an explanatory variable into the models improved the predictions of species distribution models in every species group. Vascular plants, mosses, forbs and decidious dwarf shrubs responded positively to soil moisture. Lichens had mostly negative and evergreen dwarf shrubs mostly unimodal response curves towards soil moisture. Soil moisture was the single most important variable in species distribution models but there was a lot of variation between the individual species. Soil moisture is the most important environmental variable that controls species distributions and vegetation characteristics at fine scale in the arctic-alpine environment. The moist habitats maintain the highest vascular plant and moss species pools and are therefore the most important ones for diversity on landscape level. Lichens are distributed more randomly and variables used in this study failed to model lichens as accurately as the other species groups. Most of the lichen species favored dry and acidic soil conditions but results could be due to low competition through low productivity, not direct effects on lichens survival. The individual species vary strongly in their responses to the environmental variables but the different growth forms appears to react quite similarly towards the explanatory variables. This research supports the idea of environmental heterogenity as an important factor for species distributions and confirms the need for local and fine scale studies. According to results of this study soil moisture should be included in species distribution models when predicting climate change effects on the arctic-alpine vegetation.
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(2017)Hiilidioksidivuon alueellista jakautumista maisemamittakaavassa on tutkittu melko vähän. Suurin osa aiemmasta hiilidioksidivuotutkimuksesta on keskittynyt temporaalisten vaihteluiden selvittämiseen tai suuremman mittakaavan alueelliseen vaihteluun. Arktis-alpiiniselle alueelle on tyypillistä, että kasvillisuuden määrä vaihtelee voimakkaastikin hyvin pienellä alueella. Sen takia ilmiötä lähdettiin tutkimaan myös maisemamittakaavassa. Etenkin pensaikon odotetaan lisääntyvän tundralla lämpötilojen noustessa, joten hiilidioksidivuonkin voi tundralla odottaa muuttuvan tulevaisuudessa. On mahdollista, että tundra muuttuu vähitellen hiilidioksidin nielusta hiilidioksidin lähteeksi. Kasvillisuuden määrän ja lämpötilojen voi odottaa vaikuttavan hiilidioksidivuohon, mutta muutkin ympäristömuuttujat voivat olla merkittäviä tekijöitä. Kammiomittauksessa hiilidioksidivuon voimakkuutta tutkitaan asettamalla maahan valoa läpäisevä kammio, jonka sisältä mitataan hiilidioksidipitoisuutta säännöllisin väliajoin. Mittauksia tehdään kirkkaassa valossa, himmennetyssä valossa ja pimeässä. Näitä tuloksia käsittelemällä saadaan määriteltyä kohteen tuotanto ja respiraatio. Tutkimusalueen koko on n. 50 km2 ja se sijaitsee pohjoisessa Norjassa n. 40 kilometrin päässä Jäämeren rannalta Rastigaissa-tunturin ympäristössä. Koealojen korkeus vaihtelee välillä 121m m.p.y ja 1004m m.p.y. Alueen vuotuinen keskilämpötila on -2,5°C. Alueella on ollut melko vähän ihmistoimintaa. Suuri korkeusgradientti tarjoaa monipuoliset ympäristömuuttujat kohtuullisen kokoisella tutkimusalueella. Hiilidioksidivuoaineistoa on 27 koealalta, yhteensä 57 mittauskaulukselta. Tuotannon ja respiraation jakautumista alueella tutkittiin GAM (generalized additive model) -mallien avulla. Koealakohtaista tietoa selitettiin kaukokartoitusmuuttujilla ja kauluskohtaista tietoa paikan päältä mitatuilla ympäristömuuttujilla. Kaukokartoitusaineiston perusteella tärkein hiilidioksidivuota selittävä tekijä on NDVI (normalized different vegetation index). Kauluskohtaisella aineistolla tärkein ympäristötekijä on keskilämpötila. Keskilämpötila on myös oleellinen NDVI:n selittäjä, joten lämpötilan vaikutusta voi pitää varsin merkittävänä. Tärkeimmän selittävän muuttujan osalta vaikutus oli samanlainen sekä fotosynteesille että respiraatiolle. Kammiomittausta kokeiltiin tässä tutkimuksessa uutena menetelmänä Helsingin yliopiston Geotieteiden ja maantieteen laitoksella. Merkittävässä osassa tutkimusta oli menetelmän käyttökelpoisuuden ja luotettavuuden arviointi. Kammiomenetelmä on kohtuullisin ponnistuksin käytettävissä erämaisissa olosuhteissa, vaikkakin mittaamiseen kuluu melko paljon aikaa. Mikäli verkkosähköä ei ole tutkimusalueella käytettävissä, on laitteistoa mahdollista ladata aurinkopaneeliin perustuvalla järjestelmällä. Useista epäluotettavuuslähteistä johtuen mittauskampanjaa ei kuitenkaan voi pitää pelkästään mekaanisena suorittamisena, vaan on jatkuvasti kiinnitettävä huomiosta useisiin yksityiskohtiin. Virheitä voivat aiheuttaa esimerkiksi vääränlainen kauluksen asennus maahan, varomaton kammion asetus kaulukselle, liikkuminen koealalla mittauksen aikana, liian lyhyt kammion tuuletusaika mittauksen jälkeen ja olosuhteiden muutokset. Ottamalla kaikki virhelähteet huomioon on kuitenkin mahdollista kerätä aineistoa melko hankalassakin maastossa.
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(2013)The ongoing global change challenges us to examine the key factors of rapidly changing northern ecosystems. One of the most important factors in these environments is living vegetation biomass, also known as phytomass. This thesis examines above ground phytomass in an artic-alpine environment, located in northwesternmost Finland and Ráisduottarháldi –area, Norway. The most important aim of the study was to produce a best possible estimate of the phytomass in the study area. Typically, phytomass modelling in artic-alpine areas has been done by using linear regression models having spectral vegetation index (SVI), usually NDVI, as an explanatory variable. Goodness of the model is typically assessed by coefficient of determination (R2). This thesis expands this approach and tests different SVI's alongside NDVI. Bias, root mean square error (RMSE), and correlation of observed and predicted phytomasses are used in addition. The effect of sample size is also briefly tested. Factors affecting phytomass, such as topography, were also examined. Topographic variables, such as the topographic wetness index (TWI), slope, potential yearly radiation and curvature were derived from digital elevation model and used as a predictors. Rock and soil variables were also used, but the quality of the data was found poor. In addition to linear regression models (LM), generalized linear models (GLM) and variation partition were used to find out wether the simple SVI-models can be improved by adding topographic factors into the models. Boosted regression trees (BRT) were utilized to find out the importance of individual effects of topographic factors to phytomass. NDVI was found to be the best SVI to predict phytomass (R2 61,6 %, RMSE 593,5 g/m2). However, the model was slightly biased (–4,3 %), although not statistically significantly. Forest areas cause significant deviaton to the data, which might explain why the explanatory power of the NDVI model is lower compared to other similar studies carried in pure arctic environments. Based on variation partition, the NDVI-model cannot be improved by topograhic nor soil or rock variables. In BRT-models, elevation was found to be the single most important variable explaining phytomass. The relative importance of elevation in the phytomass model was 72,8 %. Potential radiation (11,3 %) and calcium contet of parent material (11,4 %) were also important. TWI also had a slight effect, as its relative importance was 4,9 %. Curvature was not a significant factor in the models. Based on the linear regression model (NDVI), phytomass varied between 0– 6790 g/m2: Mean phytomass of the study area was 687 g/m2. Most of the phytomass is located in trees and other vascular plants located in low elevations (< 600 m a.s.l.). Phytomass decreases rapidly above treeline, which is typically located around 600–700 m a.s.l. at the study area. Only 0,1 % of the total phytomass is located above 1000 m a.s.l. South- and southwestern slopes have higher phytomasses compared to average (c. +17–21 %), which is caused by higher thermal radiation. Phytomass estimates of the study are well in line with other similar studies. Model uncertainties were assessed carefully in comparison to many other studies. The results imply that this kind of approach is needed as the model results varied a lot. Sample and sample size had a significant effect to results and therefore need to be addressed in future studies more carefully. The number of observations was high in this study compared to almost any other similar studies, but it has to be noted that the study designs differ. Clearly, there is a need of more extensive research on the uncertainties of phytomass estimates.
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(2018)The Arctic ecosystems are facing pressure to adapt to a changing climate. In these low-energy systems, the abundance of shrubs has increased in response to the climatic changes. Shrubification is predicted to increase the amount of shrubs c. 50 % by 2050. This will affect both the abiotic and biotic environment through changes in soil moisture and temperature as well ashorizontal interactions in vegetation. Soil moisture and temperature are important drivers in various ecosystem processes, as they affect e.g. plant species distribution, cardon cycling and permafrost thaw. Due to the complex and vast environmental impacts, shrubification should be taken into consideration in climate change predictions of the Arctic nature. The link between shrubs and soil temperature has been studied on areas with tall shrubs. The impact of low and prostrate shrubs on soil temperature is not fully understood yet, as most studies have been carried out on tall shrubs. In this study, I investigated how shrubification of an Arctic-alpine ecosystem affect vegetation, soil temperature and moisture. This research was based on a paired study design, in which I compared plots with shrubs to shrubless ones, using in situ measurements of soil and vegetation variables. The study area covers large environmental gradients (e.g. soil moisture and topography) as well as prostate to tall shrubs. Landscape level variation was studied using topographic variables derived from high-resolution LiDAR-data. Mean soil temperature was lower (0.8 ºC) under shrub canopies and the effect might be considerable during vegetational stress periods. In addition, there was a positive linear relationship between soil temperature and shrub canopy cover. Mean soil moisture was 6 % lower underneath the shrub canopies, but as vegetation, it is mediated by topography as well. Further research on the shrubification of the Arctic is needed, and remote sensing provides a cost-effective way to collect data on large areas. Arctic shrubification may have cascading effects on a global scale through changes in the tundra carbon cycle, which makes it a timely and important research topic
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(2017)The photosynthetic light use efficiency (LUE) is used to estimate the rate of photosynthesis in green vegetation. LUE is generally defined as the carbon uptake divided by absorbed photosynthetically active radiation (PAR). Several proxies for LUE estimation from remotely sensed data have been introduced, while the most promising results have been achieved by the Photochemical Reflectance Index (PRI) and chlorophyll fluorescence (ChlF). Both PRI and ChlF can serve as a proxy for photosynthetic downregulation and photoprotection, and can theoretically be measured and calculated from hyperspectral remote sensing data. Fluorescence and PRI were measured at leaf-level for sample trees of Pinus sylvestris and Betula pendula during two field measurement campaigns at Hyytiälä Forestry Field Station in 2014 and 2015. The spectrometer measurements were performed at crown height, separately for sunlit and shaded foliage. The measurements were taken at different hours of day to observe the diurnal variation of fluorescence and PRI. Along with the spectral measurements, CO2 exchange was constantly measured in shoot chambers attached to the sample trees. The diurnal trend of CO2 assimilation and LUE was then projected against the spectral indicators. An airborne campaign was conducted concurrently with the field measurement campaign in 2015. Hyperspectral data (< 5 nm spectral, 60 cm spatial resolution) was collected over the study area using AISA Eagle II line scanner. ChlF was estimated from the data using Fraunhofer line discrimination (FLD) approach. A change in ChlF between morning and noon acquisitions was estimated using different flight lines covering the same area. The reliability of the estimation was tested in several ways including noise reduction and a change analysis of non-fluorescent targets. Moreover, the non-physiological impact of shadow fraction on apparent fluorescence was estimated. The leaf-level results show a distinctive diurnal trend in fluorescence values measured with the spectrometer. The diurnal variation of PRI appears more unpredictable within the sample trees. Statistically, fluorescence values and PRI were only able to predict CO2 assimilation and LUE during the midday measurements with higher values of PAR, fluorescence performing slightly better. The results obtained at canopy level show an increase in radiance emitted as fluorescence and a decrease in PRI between morning and midday acquisitions. The change was observed in all the canopy types, including low vegetation, broad-leaved forests and coniferous forests. The average change of FLD-derived fluorescence (F763) between different canopy types varied between +24.0 units (14.9 %) and +6.3 units (4.9 %). Furthermore, it was observed that illumination conditions and shadow fraction had a major impact on F763 values, which must be considered when estimating ChlF using the FLD approach.
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(2013)Urbanization effects on hydrology and water quality on catchment area because of the land use change. Construction sites in catchment causes water quality problems. Waters from construction sites are usually led straight to watercourses without any purification actions. This has also been the practice at residential construction site in Suurpelto, Espoo. The aim of this study is to evaluate how discharge, water quality and loadings have changed during construction at Suurpelto. This research is the second part of the 'Kaupunkirakentamisen vaikutukset Lukupuron hydrologiaan ja veden laatuun' (LUPU) -project which is conducted by the University of Helsinki and city of Espoo. The observation period begins from the year 2006 and has divided into three sections. The first section represents time before construction. At the second section (Construction phase 1) construction work has started, and streets and municipal infrastructure are being built. During the third section (Construction phase 2) residential construction is very intensive and municipal infrastructure is expanding to new areas. The purpose of this study is to compare these sections with each other and report differences between water quality, discharge and loadings. Spearman's rank correlation coefficient is used to evaluate the dependences between water quality variables. Wilcoxon signed rank test is used to discover statistical significance in load variations. This study was carried out by analyzing 22 different variables: Discharge, electrical conductivity and pH was measured by automatic water quality probe. Suspended solids, nutrient concentrations (total phosphorus and total nitrogen) and dissolved substances including metals (total dissolved solids, sodium, potassium, magnesium, calcium, fluoride, chloride, sulphate, chromium, iron, nickel, chopper, arsenic) were measured in laboratory. The hypothesis of this study is that water quality has changed statistically significantly as a result of land use change in the catchment. Another hypothesis is that loadings have increased. Results of this study indicate that loadings of suspended solids, total phosphorus and iron as well as discharge are statistically significantly increased because of construction works. However, electrical conductivity has decreased because of increased discharge. For instance suspended solid load has sixfold in a year, total phosphorus has fourfold and iron load has increased even 11 -fold, when comparing construction phase 2 and time before construction. The growth of discharge has been particularly large in construction phase 1. Between construction phases 1 and 2 the change has been minor and statistically insignificant. Hence, the most significant changes have occurred during construction phase 1 and for instance total phosphorus loading has decreased during construction phase 2. Effects of construction is depended on other human activity and natural causes such as dredging of the channel, fertilization of the fields, weather conditions and the soil type. If one want to decrease the negative effects that construction work causes to water quality, one have to consider new ways to process waters flowing from construction area. Possible new means have been already considered during the restore planning of Lukupuro in spring 2013. Dredging took place in the new part of the Lukupuro main channel and effects were very significant to water quality. Based on the knowledge we have now it is important to consider pros and cons of relocating the channel in the future.
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(Helsingin yliopistoHelsingfors universitetUniversity of Helsinki, 2012)While spaceborne satellite data has been extensively used to extract biophysical forest characteristics through reflectance features and indices, there are still many questions regarding seasonal changes in reflectance. Boreal forests have already seen changes in growth patterns from climate change, and the large scale monitoring of these forests is becoming more important. Understanding seasonal changes in reflectance in the boreal region will allow for the monitoring of seasonal biophysical changes using satellite imagery. For this monitoring to be possible the satellite imagery needs to be preprocessed and atmospherically corrected to create a time series of hemispherical-directional reflectance factors. The red edge is the abrupt change in reflectance between 680 and 740 nm seen in vegetation spectra. The red edge inflection point is the wavelength, at which the slope is steepest in the red edge. The red edge inflection point is sensitive to plant chlorophyll content and has been extensively used for estimating vegetation biophysical parameters including: leaf-area index, biomass and plant health levels. Hyperion is a narrowband imaging spectrometer aboard the Earth Observer-1 satellite. Hyperion captures data across 242 spectral bands covering a spectral range of 356 to 2577 nm resulting in a nominal spectral range of 10 nm. While the high spectral resolution of Hyperion makes it possible to calculate the REIP, there is no consensus on how this should be done, with different methods producing conflicting results. This study explains the preprocessing and atmospheric correction of a seasonal time series of five Hyperion EO-1 images (Provided courtesy of the USGS) from Hyytiälä, Southern Finland (61° 51 N, 24° 17 E). The time series ranges from 31.5.2010 to 12.8.2010, covering much of the growing season and the seasonal changes in reflectance. The first derivative, four-point linear interpolation, Lagrangian interpolation, and fifth-order polynomial fitting methods for calculating the REIP are looked at to determine their applicability for Hyperion imagery using this time series. Hyperion data requires considerable preprocessing before atmospheric correction can be done. In this study the preprocessing covered: destriping, desmiling, atmospheric correction and finally geocorrection. Atmospheric correction was done using both FLAASH and ATCOR, both of which are MODTRAN based absolute atmospheric correction algorithms. The final atmospherically corrected HDRF images were evaluated using in situ handheld spectrometer reference measurements of a grass field in the area. An average RMSE value of around 3% was achieved with both algorithms. The corrected Hyperion images were also compared against two MODIS products, which also showed good agreement. The aerosol retrieval however did not work with either algorithm, on any scene. The use of a sun photometer for aerosol level estimation was also not effective. Due to the dynamics of the red edge and expected seasonal red edge inflection point trends, the fifth-order polynomial fitting method was seen as the best method for calculating the red edge inflection point. The red edge inflection point did not correlate strongly with leaf area index overall, however there was a strong correlation with individual plots. A strong correlation was observed between Hyperion red edge inflection point and understory red edge inflection point, both overall and for individual plots.
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(2018)This paper studies discourses about suburbs that occur in newspaper writings about 1960s and 1970s infill development. The study aims to find out how writings about infill development are structured in the local newspaper Helsingin Sanomat between 2000 and 2016. The objective is to discover how a high-rise suburb appears as a site for infill development, and what kinds of discourses appear in newspaper writings about infill development. The paper uses discourse analysis to examine how high-rise suburbs built in 1960-1970 are discussed in Helsingin Sanomat between 2000 and 2016, using writings about infill development in Helsingin Sanomat in that period as research material. Due to the choice of newspaper, the addressed suburbs are found in the Helsinki metropolitan area. In recent years, Finnish urbanization has led to regional economic marginalization, which in the Helsinki metropolitan area is concentrated in the high-rise suburbs of the 1960s and 1970s. In addition to economic marginalization, these suburbs are seen to suffer from decreasing and aging population, and a need for renovations. The stated aims of infill development include urban unification and social diversification of the suburbs in order to prevent the cycle of economic marginalization. Combined with deterioration of apartments built in the 1960s and 1970s, structural and social problems in high-rise suburbs have led to a societally challenging situation. The writings contained four discourses about suburbs: potential of the suburbs, defense of the suburbs, the suburb as problematic, and the suburb as a conflict-prone site for infill development. The most powerful discourse was about potential. The defense discourse emphasized the uniqueness and meaningfulness of the suburb as the environment and home of its inhabitants. The conflict discourse refers to writings where the suburb is seen as an infill development site that causes conflict. While most of the newspaper writings mention the age and deterioration of the period’s suburbs, the problem discourse did not dominate the research material. Based on the research, the ways of talking about the suburb depend on the speaker, the speaker’s motives, and the subject. The discourses allowed a crucial observation that the suburb is an arena for wielding power where a contradictory and naïve attitude towards developing suburban social life is a major problem slowing down the prevention of economic marginalization. Because the suburbs of the Helsinki metropolitan area are very different, the research doesn’t reveal what suburbs are really like. Instead, the research shows how the suburbs of the metropolitan area appear in the context of writings about infill development, and reveals the persons featured in writings about infill development as well as the suburbs that are interesting to the media. The study also examines how different parties react to infill development, and seeks to shed light on the motives behind the remarks of different parties.
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(2012)Plant-plant interactions, i.e. biotic interactions, shape plant communities and the vegetation's succession along abiotic environmental factors. Positive interactions (e.g. facilitation) may expand species niches and enhance growth and reproduction. Negative interactions (e.g. competition, allelopathy) can interfere with growth and reproduction, even out competing some species from their niches. Negative and positive interactions co-occur, but research has shown that positive interactions are generally more common and important than negative ones in harsh environments. The theory of change of net-interaction from negative to positive along an environmental gradient is called the stress gradient hypothesis (=SGH). This work examines nordic crowberry's (Empetrum nigrum ssp. hermaphroditum) effect on arctic-alpine species' sexual reproduction under different environmental stress levels. Crowberry is a dominant species in low-nutrient, acidic arctic-alpine ecosystems. Its competitive ability is based on allelopathic characteristics and a forming of dense mats. It is also unpalatable for herbivores. The species facilitative characteristics include providing shelter from the wind and maintaining an ericoidmycorrhiza community. In this research environmental stress is represented by geomorphological disturbance and soil moisture, with the interactions between crowberry and other species are examined as the relationship between crowberry cover and the fitness measures (e.g. abundance of flowers or fruits) of study species. Explanation for the variation in the effects of crowberry is tried to find from the traits of the study species. Data was collected in May 2011 from Kilpisjärvi, northernmost Finland. The study area comprised 960 1m2 cells. In each cell the cover of each species (including crowberry), the abundance of each species flowers or fruits, the cover of geomorfological disturbance and soil moisture were recorded. Generalized linear models (=GLM) were run for all species to identify the best model for predicting fitness (as selected by the AIC-criterion). Spatial autocorrelation was accounted for by repeating analyses using generalized estimation equation models (GEE), which explicitly account for the spatial structure of data. 17 species were included to the research based on the abundance of their flowers and berries in the research area. Crowberry is included in the best fit model for 14 out of 17 species. The effect of crowberry was positive for four species and negative for ten species based on the modeling results. Interactions of the crowberry and one of the environmental variables are included to the models 19 times. In ten of these cases the interactions agreed with the predictions of the SGH (i.e. effect of crowberry became less negative with increasing abiotic stress). No species traits were consistently related to the outcome of interaction between crowberry and environmental variable, although crowberry effects on dwarf shrub species appeared to be more commonly positive than on other growthforms. According to these results, crowberry has dominant role in arctic-alpine plant communities. The species effect on sexual reproduction of other plant species is commonly negative, but the effect can change to positive along environmental stress gradients, supporting the SGH. Dwarf shrubs may interact positively with crowberry because of sharing the same mycorrhiza type, while more generally species may benefit from crowberry due to its provisioning of shelter from the wind and increased soil moisture. The negative effect of crowberry might be related to its production of allelopathic compounds or its dense growth. The reason for crowberry having a facilitative affect under disturbed conditions might be an indirect effect of disturbance decreasing crowberry's allelopathic effects. These results show that the roles of crowberry and biotic interactions in arctic-alpine vegetation are important. Therefore understanding their effects and mechanisms is important in predicting how this vegetation will respond to changing climate.
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(2018)Parisian cycling increased importantly in the past twenty years. Reviewing fifty years of Parisian transport planning and details of the bike-sharing programme Vélib’, I argue in the background research that municipal biking planning and the public bicycles Vélib’ can explain this development of urban biking (1997-2015). The city also has high ambitions for the biking modal share, aiming for fifteen per cent of all Parisian transport by 2020. I want to discover what the determinants of Parisian biking are, and if the latter can be modelled and predicted; thereby, I can verify if predictions match municipal objectives for 2020. I calculate correlations between the Parisian cycling index and its possible determinants with annual values on biking and other variables from 1997 to 2015 in the first part of the analysis (chapter V). This analysis shows that cycling infrastructure, Vélib’ memberships and gasoline price are the strongest positive biking determinants, while car traffic is the strongest negative determinant. In the second part of the analysis, knowing these determinants, I can find multiple linear regression models with high R-squared values (around 0,97 and 0,98) and low standard errors. The best regression model combines linear infrastructure, car traffic volume and Vélib’ memberships. The predictions in the last part of the analysis chapter reveal that in the current tendencies, the Parisian biking modal share will reach about 7 per cent by 2020, instead of the 15 per cent aimed. But I illustrate how the objective can be accomplished, by either improving drastically one of the determinants or the three of them simultaneously to reach a modal share of 15 per cent. The results and the models found appear to be more satisfactory and accurate than the ones of previous researches, presented in the literature review. The findings may be useful for public authorities and decision-makers during processes of biking planning, and it might contribute to future research in this topic.
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(2014)Land use practices are changing at a fast pace in the tropics. In sub-Saharan Africa forests, woodlands and bushlands are being transformed for agricultural use to produce food for the rapidly growing population. Although food production is crucial for the survivability of the people the uncontrolled expansion of agricultural land at the expanse of natural habitats may in the longer term decrease food production due to disturbances in water balance, increased land erosion and eradication of natural habitats for pollinators. Before the impacts of land use/land cover changes on the ecosystem can be studied the study area needs to be mapped. The study area of this thesis is located in the Taita Hills, Kenya. In previous studies the land use/land cover was mapped on higher hierarchical level in classes such as agricultural land, forest and bushland. In this thesis high spatial and spectral resolution AisaEAGLE imaging spectroscopy data was used to map the common agricultural crops found in the study area. Ground reference data was collected from 5 study plots located in the study area. Over 50 plant species were mapped but only 7 of these were used in the classification. The AisaEAGLE data was acquired in January–February of 2012 and was radiometrically, geometrically and atmospherically corrected. Minimum noise fraction (MNF) transformation was applied to the data to reduce the noise and the dimensionality. Optimal number of MNF bands was defined based on analysis of the information content of the bands. The classification was done with support vector machine (SVM) algorithm using radial basis function (RBF) kernel. Gamma, penalty and probability threshold parameters for the classifier were defined based on analysis of different combinations of these values. The analysis showed that gamma and penalty values had only minor impacts on the classification result. Based on the analysis an optimal threshold level was defined where pixels that were not likely to belong to any of the classes were left unclassified while maximum number of the known targets were correctly classified. Study area was classified with the optimal threshold value 0.90. Classification with threshold value 0.00 was done for reference. The overall accuracies for the classified pixels were 91.52% and 99.70% for the classifications done with probability threshold values 0.00 and 0.90. As the threshold was increased to 0.90 61% of the pixels were left unclassified. At the optimal threshold level between classes misclassifications were almost completely removed whereas the total number of correctly classified testing samples decreased. Applying MNF transformation to the data before the classification increased the overall accuracy from 80.58% to 91.52% while other parameters stayed the same. Results of this thesis showed that SVM classifier used with MNF transformation yielded high overall accuracies for the crop classifications. Adjusting the probability threshold to an optimal level was important since the study area was heterogeneous and only fraction the species were classified. For further applications the possibilities of object-based classification should be considered. The results of this thesis will be shared with the Climate Change Impacts on Ecosystem Services and Food Security in Eastern Africa (CHIESA) –project.
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