Browsing by discipline "Geography"

Maankäyttö vaikuttaa vedenlaatuun. Kaupungistuminen aiheuttaa pintavalunnan lisääntymistä ja veden laadun heikentymistä. Merkittäviä kaupunkivesissä esiintyviä aineita ja epäpuhtauksia, joiden pitoisuudet kasvavat kaupungistumisen myötä, ovat muun muassa ravinteet ja metallit. Viime aikoina veden laadullisten ja määrällisten muutosten hillinnässä on alettu käyttää uudenlaisia ekologisia huleveden hallintatapoja. Nämä ekologiset hallintatavat pyrkivät veden laadullisten ja määrällisten ominaisuuksien säilyttämiseen maankäytön muutoksista huolimatta. Tutkielmassa kuvataan Helsingin Kuninkaantammen ojavesien fysikaalis-kemiallista vedenlaatua. Tutkimus toteutettiin kolmella pienellä osavaluma-alueella kesä-joulukuussa 2011. Tutkimuksen tarkoituksena on selvittää alueen yleinen vedenlaatu sekä tarkastella vedenlaadussa valuma-alueittain ilmeneviä eroja. Tutkimusalueella tapahtuu lähivuosina merkittäviä maankäytön muutoksia, joiden vaikutuksia vedenlaatuun ja määrään pyritään minimoimaan hyödyntämällä ekologisia hulevedenhallintamenetelmiä. Kuninkaantammi on Helsingin kaupungin hulevesistrategian pilottialue, jossa uudenlaisten menetelmien vaikuttavuutta vedenlaatuun halutaan selvittää. Tutkielma vastaa kysymykseen, mikä on vedenlaatu ennen alueen rakentamista. Vesinäytteistä tutkittiin muun muassa kiintoaine-, ravinne-, metalli- ja hivenainepitoisuuksia. Ojavesien laatu Kuninkaantammessa on pääosin hyvä. Pitoisuudet ovat luonnonpurojen pitoisuuksia korkeampia, mutta hulevesien pitoisuuksiin verrattuna matalia sekä Helsingin kaupunkipuroihin verrattuna keskimääräisiä tai matalia. Maankäyttö valuma-alueilla heijastuu vedenlaatuun. Alueella, jolla on enemmän rakennettua pintaa, fosfori-, nitraatti-, kupari-, nikkeli- ja hivenainepitoisuudet ovat korkeampia kuin vähemmän rakennetulla alueella. Kuitenkin toisella metsäisellä valuma-alueella typpi- ja fosfaattipitoisuudet sekä kromi-, rauta-, lyijy- ja sinkkipitoisuudet ovat näytepisteistä korkeimmat. Metsäisimmällä valuma-alueella epäpuhtauspitoisuudet ovat alhaisimmat. Jotta vedenlaatu myös pysyisi hyvänä ja uudenlaisista hulevedenkäsittelyjärjestelmistä olisi hyötyä, tulee toteutukset mitoittaa riittävän suuriksi. Ympäristöongelmien perimmäinen syy johtuu ihmisten käyttäytymisestä. Veden laatuun vaikuttaa voimakkaasti vesistön sosiaalinen ympäristö, joten pelkät rakenteelliset ratkaisut eivät riitä vedenlaadun kohentumiseen. Yhteiskunnalliset instituutiot, kuten muodollisten instituutioiden ympäristöasenne, vaikuttavat ihmisten käyttäytymiseen. Viestinnällä ja tietoisuuden lisäämisellä voidaan vaikuttaa asenteisiin ja käyttäytymiseen. Vaikuttava viestintä on luonteeltaan positiivista ja joko faktoihin perustuvaa tai tunteisiin vetoavaa. Positiiviset ympäristökokemukset lisäävät ympäristömyönteisyyttä, jolla voidaan saavuttaa mahdollisesti myös kaupunkivesien vedenlaadun kohentumista. Ihmisten tietoisuuden kasvattamiseen kaupunkivesien merkityksestä tulisi kiinnittää huomiota.

Longinoja brook is one of the biggest brooks in Helsinki by catchment area and it is one of the most important spawning areas of brown trout (Salmo trutta) of River Vantaanjoki. The brook and its catchment have undergone significant changes in the process of industrialization and urbanization ever since the 19th century. In the 21st century Longinoja has been restored in order to improve habitats and spawning areas of bown trout, to prevent erosion and to increase the recreational and aesthetic value of the brook. The aim of the thesis was to study the changes in Longinoja's water quality in time and space, the loadings of its side ditches and the effect of land use on areal differences in water quality. The thesis was a part of a survey made by the City of Helsinki Environment Center. The water quality of Longinoja was monitored with an automatic probe 19.4.–6.10.2010 and 4.4.2011–10.1.2012, during which time water samples were collected in every 1–2 weeks. In addition water samples were collected four times a year from different parts of the catchment, in winter, spring, summer and fall in 2010 and 2011. Water quality and loadings of the side ditches and the effect of land use on areal differences in water quality were examined on the basis of water samples collected from the side ditches. Samples were collected four times during growth season in 2011 on rainy days. Intense changes in water quality during snowmelt and especially heavy rains are characteristic of Longinoja. Also hygienic water quality alters greatly. On the basis of median concentrations, the water quality was similar in 2010–2011 than in 2004. Only the concentrations of suspended solids and total phosphorus were clearly higher in 2010–2011 than in 2004. Concentration of phosphate was quite low in comparison with mean concentration of brooks in Helsinki. Compared with Finnish headwaters the conductivity and concentrations of nitrate, iron, copper, zinc and nickel are quite high in Longinoja as they are in other brooks in Helsinki. The loading of suspended solids in spring months is about 8 times greater in comparison with fall months and about 11 times greater in comparison with summer months. The loading of phosphorus in spring months is about 7 times greater compared with fall months and about 9 times greater compared with summer months. Estimated load of suspended solids in Longinoja in year 2011 was 17 100–17 900 kg/km²/y and load of phosphorus 32–34 kg/km²/y. Few relationships between water quality and land use were found because of small dataset. Only low density residential areas could be seen to increase concentration of suspended solids. The Helsinki-Malmi Airport seems to increase loading of nitrogen (TN, NO₃-N, NH₄-N) and nickel and the industrial area in Tattarisuo seems to cause loading of some oxygen consuming contaminants. Based on the results future restoration measures should be focused in the catchments of Longinoja's side ditches Suurmetsänoja, Teerikukonoja and Lentokentänoja. With increasing runoff loading of suspended solids and phosphorus from Suurmetsänoja, phosphate, zinc and copper from Teerikukonoja and suspended solids, nickel and nitrogen from Lentokentänoja is significant.

The changes in our society have had their ramifications in the sense of community in neighborhoods, the latest big social change being the fast alteration of the media environment. Digital forms of communications allow people to communicate almost instantly all over the world. Yet people still tend to form social ties locally, and a growing interest to local themes has been on the rise. The aim of this case study was to find out which underlying housing and socio-economic factors affect the sense of community in neighborhoods, sense of community in areal Facebook groups and the activity of use of these groups, and if there is overlapping in the factors affecting these. The other aim was to examine if communality in areal Facebook groups or the activity of their use increases sense of community in neighborhoods in Helsinki. The research was descriptive, and the objective was not necessarily to make generalizations to the whole study population. Two differing views have shaped the grand theories of sense of community in neighborhoods. In the first wave, there was a division between idealizing the feudal communities, where a strong dependency of neighborly relationships was a given and the relationships of the urban neighborhoods, where residents were seen as isolated and unsatisfied. The changing society shifted the view to examining relationships as a personal network and the form of communities in the overlapping of these networks. These two views differ most importantly in their views of the meaning of distance to social relationships, and the importance of neighborly relationships in general. In the Internet era relationships can be seen to be formed in networks, but neighborhoods and physical proximity still carry a meaning to local relationships. Two different research areas, in terms of common housing types and the amount of children in families, were chosen from neighborhoods in Helsinki; the northern study area around Paloheinä, Pakila and Torpparinmäki, and the southern area around Kallio and Vallila districts. A questionnaire was sent to three different areal Facebook groups and the total amount of responses received was 335. Sum variables were formed to indicate the sense of community among the respondents, sense of community in their areal Facebook group and the use activity of that Facebook group. These variables were then further analyzed statistically and compared to each other and the respondents’ background factors. The responses split up quite evenly between the two study areas, and the background information reported by the respondents reflected the same factors that these areas were chosen by. All the sum variables correlated positively with each other, thus indicating that those who had a greater sense of community in their neighborhood also possessed a greater sense of online community in their areal Facebook group. The respondents from the northern study area had altogether a higher sense of community, sense of community in the areal Facebook group, and a more active use of the group. The results reflected the ones from previous studies, as a higher sense of community was attached to older age, longer residence in the area, apartment ownership, having children in the family and living in a one-family house. Living in a one-family house was also attached to higher sense of community in the areal Facebook groups, as well as having children, long residence in the area and apartment ownership. According to the results in this case study, some of the same background factors produced a higher value in the sense of community in neighborhoods and the sense of community in the areal Facebook groups studied. These shared factors and the correlations between the sum variables indicate that higher sense of community in areal Facebook groups could lead to a higher sense of community in neighborhoods as well. Distance in relationship still possesses a meaning as neighbors form areal groups in social media that can develop into lively communities.

Congestion of traffic is one of the biggest challenges for urban cities in global perspective. Car traffic and traffic jams are causing major problems and the congestion is predicted to worsen in the future. The greenhouse effect has caused a severe threat to the environment globally. On the other hand from the point of view of companies and other economic parties time and money has been lost because of the congestion of traffic. This work studies some possible traffic payment systems for the Helsinki Metropolitan area introducing three optional models and concentrating on the point of view of the economic parties. Central part of this work is formed by a research questionnaire, which was conducted among companies located in the Helsinki area and where more than 1000 responses were gained. The study researches the approaches of the respondents to the area s current traffic system, its development and urban congestion pricing and the answers are analyzed according to the size, industry and location of the companies. The economic aspect is studied by economic theory of industrial location and by emphasizing the meaning of smoothly running traffic for the economic world. Chapter three presents detailed information about traffic congestion, how today s car-centered society has been formed, what concrete things congestion means for economic life and how traffic congestion can be limited. Theoretically it is examined how urban traffic payment systems are working using examples from London and Stockholm where successful traffic payment experiences exist. The literature review analyzes urban development, increasing car traffic and Helsinki Metropolitan area on a structural point of view. The fourth chapter introduces a case study, which concentrates on Helsinki Metropolitan area s different structures, the congestion situation in Helsinki and the introduction of the traffic payment system clarification. Currently the region is experiencing a phase where big changes are happening in the planning of traffic. The traffic systems are being unified to consider the whole region in the future. Also different advices for the increasing traffic congestion problems are needed. Chapter five concentrates on the questionnaire and theme interviews and introduces the research findings. The respondents overall opinion of the traffic payments is quite skeptical. There were some regional differences found and especially taxi, bus and cargo and transit enterprises shared the most negative opinion. Economic parties were worried especially because of the traffic congestion is causing harm for the business travel and the employees traveling to and from work. According to the respondents the best option from the traffic payment models was the ring model where the payment places would be situated inside the Ring Road III. Both the company representatives and other key decision makers see public transportation as a good and powerful tool to decrease traffic congestion. The only question, which remains, is where to find investors willing to invest in public transportation if economic representatives do not believe in pricing the traffic by for example traffic payment systems.

The aim of this study is to examine what kind of mental images are attached to twelve city districts in Helsinki. More accurately put the research questions are 1) to find out how images are portrayed when writing about them in newspapers or spoken about by real-estate agents. 2) What kind of effect mental images has on people and 3) what kind of discursions affects those images. The districts are chosen so that they represent well different areas in Helsinki from their socio-economic and cultural background, as well as architecturally. These districts are Kruununhaka, Töölö, Kallio, Haaga, Oulunkylä, Paloheinä, Viikki, Malmi, Jakomäki, Herttoniemi, Mellunmäki and Östersundom. The research data contains real-estate agents' interviews and articles from Helsingin Sanomat. Real-estate agents provide an interesting viewpoint to different districts with their expertise of neighborhoods and clients. Helsingin Sanomat, for one, portrays the word of media in this research. The influence of media is very powerful, even so that the image it gives of unknown districts becomes 'the truth' of them. The newspaper data contains over 300 articles of different city districts and matters that are associated with mental images of those districts. The real-estate agents' data consist of 43 answers to internet based survey questionnaire. Based on the results it turns out that the real-estate agents are very familiar with almost every district, especially those located in downtown. Most poorly they know about the image of Östersundom, which has been merged to Helsinki most recently. Downtown districts' mental images are perceived positively, as also is the case with residential district Paloheinä and green functionalistic suburb Haaga. The mental images of areas located in eastern or north-western Helsinki, such as Malmi, Jakomäki and Mellunmäki, are perceived most negatively. The impression that newspaper articles give is the same. Articles about those districts very often contain negative expressions even though during the year 2014 aspect of writing has been more positive and has given more peaceful and better image of districts that have bad reputation. The data of real-estate agents' questionnaires also imply that mental images have very great significance for people, especially for the citizens of Helsinki when they are making decisions where to move. Many mental images are also stereotypical and dated. Based on the results can be discovered that mental images are composed by many factors. Firstly, architecture and building time have great influence especially to techno-rationally built areas. They usually have week images for example because of the hard times Finland was going through during the building time. Areas that were built during Empire, Jugend or Functionalistic eras are very popular and perceived positively. They are commonly portrayed by good historical matters. New districts are perceived mostly positively and are sometimes linked to images that are created during city planning. Secondly, geographical location has prejudiced influence on image. Location in eastern or north-western Helsinki dramatically pushes the mental image towards negative conceptions even though it was unsuitable. Thirdly, poverty discursion stigmatizes disadvantaged areas with slummy things such as alcoholism and disquietude. Mental images are altered very slowly but the change is important for example for the city of Helsinki, which is actively trying to create plans for making all city districts' images better.

Some of the most important causes of coastal sand dunes being threatened today are overgrowth of habitats, mechanical wear and construction. The study area, the boreal sand dunes of Vattajanniemi (belongs to Natura 2000 -network), is under heavy trampling (mechanical wear) because the area is in military and recreational use. Plant communities form clear zones parallel to the shore for topographically varied gradient driven by abiotic and biotic factors of stress and disturbance. There has been grazing, harvesting trees and scrub and limitations in trampling as management practices in Vattajanniemi to reduce the mechanical wear and to prevent the overgrowth. This study examined the changes in cover of vegetation, species richness and species composition six years after the management practices were started. The data was collected from 142 vegetation plots in July 2006 and 2012. The plots were located in six habitat types. Descriptive statistics, histograms and Wilcoxon tests were used to discover changes in vegetation cover and species richness between the years. Sørensen Index was used to study the change in species composition in the whole area as well as in different habitat types. The changes in vegetation cover, species richness and species composition (Sørensen Index) were viewed by management practices (grazing, harvesting) and habitat types in boxplots. In addition, the variation Sørensen Index (beta-diversity) with respect to the 2006 total vegetation cover, species richness and the distance to the beach was examined. Generalized linear models were used to explore how much habitat type and management practices (grazing, harvesting) explain the change in total vegetation cover and species richness and the vegetation cover and species richness of the year 2012. Results of this study indicate that total vegetation cover and species richness are statistically significantly increased. As well there has been positive changes in the vegetation cover and species richness of the different functional groups. Vegetation type has been a very significant factor to explain the vegetation cover and species richness in 2012. Grazing has affected differently in different habitat types. The rate of beta-diversity varies between habitats. Species turnover rate was significantly higher in those plots that have been grazed or harvested compared to those plots, which were not. Trampling limitations are considered to increase vegetation cover and species diversity in all habitat types. Management can increase species richness and diversity in coastal dune systems. Each habitat type tolerates disturbance differently and needs its own kind of management plan. Several consecutive years of study, or longer-term (over ten years) research would give a better understanding of which changes are caused by management practices and which are a part of a natural variation.

This study focuses on households energy consumption in the Taita Hills of South-East Kenya, especially on the use of fuelwood. The wood use habits are approached through the local women and families who represent the grass root level actors. The Taita Hills are known for their rich biodiversity. Areas of indigenous mountain rainforests play a crucial role as the water towers as well as being home for many indigenous plants and animals. However, the high population pressure, lack of cultivated land, poverty and different socio-political factors has led to a degradation and loss of biodiversity. The main energy source of households in the Taita Hills is still firewood, the use of which has effects on the environment as well as on people s health and time management. This vulnerability caused by biofuels is examined in two case study areas. Both of these areas are located near an indigenous forest boarder but are situated on different agro-ecological zones. The present methods and circumstances of collecting firewood are also compared to the situation 30 years ago, when the legislation allowed more extensive use of forest resources. This research is a qualitative study. The primary data was gathered during two field trips in the Taita Hills, in 2009 and 2010, by using interviews and various participatory methods. All together 50 households as well as different district authorities, non- governmental organizations workers and private persons, were interviewed. The study concludes that the availability of firewood in The Taita Hills has diminished. People have to collect firewood from further away and from smaller areas. This has also increased the time used for collecting wood for fuel. Use of firewood increases households vulnerability by raising the work-load of women in particular, and also by its affect on the environment and health. In addition, this energy supply requires larger economical contributions, while people have to more often resort to purchasing. This weakens the economic situation of families and lessens their opportunities to plan their future or make other investments. Many people are not aware of the effects of the use of wood for fuel. For them it is difficult to understand that traditions passed down through many generations can have harmful consequences. Also poverty, lack of political interest and the lack of co-operation between local actors prevents implementation of new energy practices. Alternative methods should be introduced in order to change current unsustainable energy modes. However this should be done with respect and by taking into account the special features of the Taita Hills area.

Työssä tutkittiin Vantaanjoesta kesällä 2010 AISA (Airborne Imaging Spectrometer for Applications) -hyperspektrisellä sensorilla helikopterista kerätyn kaukokartoitusaineiston soveltuvuutta Vantaanjoen veden laadun selvittämiseen. Virtaavia vesiä ei ole helppo tutkia veden nopean vaihtuvuuden vuoksi. Työn tarkoituksena oli selvittää, voiko virtaavaa vettä, tässä Vantaajokea, tutkia kaukokartoituksen avulla. Hyperspektrisen kaukokartoitusaineiston lisäksi käytettiin vertailunäytteinä Vantaanjoen ja Helsingin seudun vesiensuojeluyhdistys ry:n keräämiä joen yhteistarkkailuun sisältyviä vesinäytteitä. Veden laadun kaukokartoitus perustuu vedessä olevien aineiden heijastusominaisuuksiin koska vedessä olevat hiukkaset heijastavat ja imevät itseensä valoa kukin itselleen ominaisella tavalla. Niitä ominaisuuksia, joita voidaan mitata kaukokartoitusmenetelmin, kutsutaan veden optisiksi parametreiksi. Tässä tutkimuksessa optisina muuttujina käytettiin veden klorofyllipitoisuutta ja kiintoainetta, jonka avulla tutkittiin veden sameutta. Ilmakehäkorjattu ja georeferoitu aineisto visualisoitiin paikkatieto-ohjelmaan, josta valittiin mahdollisimman hyvin jokivettä kuvaavia pikseleitä analyysiä varten. Pikseleitä poimittiin yhteensä 11 näytepisteeltä 53 kanavalta aallonpituusalueella 404–890 nanometriä. Aineiston laatua testattiin empiirisellä regressioanalyysillä aineistosta pääteltyjen kanavasuhteiden avulla. Kanavasuhteita verrattiin joesta kerättyihin vertailunäytteisiin. Kanavasuhde, jonka selitysaste R^2 oli korkein, valittiin tulosmallin pohjaksi. Näin saatu määritystarkkuus on melko hyvä. Paras tulos klorofyllille saatiin kanavasuhteella 22/28 (596/652 nanometriä) ja sameudelle kanavilla 10/9 (485/476 nanometriä). Tulosten mukaan kaukokartoitusaineiston avulla mallinnettujen ja joesta mitattujen arvojen selitysaste on korkeimmillaan sameudelle lähes 85 % ja klorofyllille liki 80 %. Tosin tulokset perustuvat melko pieneen havaintojoukkoon (vain noin 200 havaintoa) joten tulosten luotettavuus voisi olla korkeampikin. Kaukokartoitusaineiston avulla hankitut vedenlaatutiedot ovat onnistuessaan nopeita ja kattavia antaen laajemman kuvan veden laadusta kuin perinteiset laboratoriotutkimukset. Työssä esitetty empiiriseen mallinnukseen perustuva algoritmi soveltuu jokiveden havaitsemiseen vain samankaltaisissa ja -aikaisissa olosuhteissa, kuin kuvausajankohtana, tässä heinäkuun lopulla. Lisätutkimuksia tarvitaan siis jos tässä työssä kehitettyä veden laadun mallia halutaan soveltaa veden laadun tutkimukseen joesta myös jatkossa. Niin kutsutut bio-optiset mallit, joissa veden laatua mallinnetaan vedestä mitattujen luontaisten opisten ominaisuuksien avulla, antavat tutkitusti tarkempaa tietoa jokivesien tilasta. Jotta biooptista mallinnusta voitaisiin soveltaa Vantaanjoessa, tarvitaan tarkempien kaukokartoituskuvien lisäksi tarkempia vertailuaineistoja jokiveden ominaisuuksista.

In this MSc thesis the impacts of climatic factors and forestry operations on concentrations of total nitrogen (TN), total phosphorus (TP), suspended solids (SS) and total organic carbon (TOC) were examined in seven small forested catchments in Southern and Eastern Finland between 1985 and 2010. The study was conducted using statistical methods on discharge, water quality, temperature and precipitation data provided by the Finnish Environment Institute and Finnish Meteorological Institute. The results from forestry operations were mostly based on spatial data regarding age stand provided by the Finnish Forest Research Institute as well as the current peatland drainage status from Corine 2006 Land Cover. Overall the study results highlighted the impact of catchment characteristics on concentrations, which was clearly demonstrated by the significance of peatland percentage. The effects of global warming and changes in discharge were particularly evident in the northernmost catchments. Concentrations of TN and TOC mostly increased while concentrations of TP decreased in nearly all of the catchments during the study period. The single most important factor explaining changes in TN was temperature while increased winter and minimum discharge accounted for a major part of TP concentrations. Changes in SS and TOC were most notably explained by peatland percentage. Long term impacts of forestry operations correlated with TN, SS, and TOC but not with TP. In the future more long term studies and more specific information on catchment characteristics are needed to be able to reliably compare results between different catchments.

This research was situated in Tiong Bahru, a neighbourhood located in Singapore. The neighbourhood was selected because it has one of the highest proportions of residents who are ages 65 and above. Besides that, it was selected because of its status as a historically ‘conserved’ estate, with guidelines imposed on residents living there to preserve the historical look of the built environment. Furthermore, the fact that it is promoted as a tourist destination and its proximity to the downtown contributes to urban regeneration and a new wave of expatriate residents that moved in in recent years. Thus, by basing its conceptual frameworks on place, sense of place and intergenerationality, it explores the contributions of the elderly residents to their neighbourhood and why elderly residents continue to age in place in Tiong Bahru. By subscribing to the ontogenetic thought of space- where space is constantly in the process of change- it also points out the public neighbourhood spaces of interaction. Space syntax is also used to investigate how the built environment affects the establishment of intergenerational relationships between the elderly and younger residents. The data was collected using a triangulation of methods- static snapshot observation, observation, participant observation and semi-structured interviews. The qualitative data collected is then coded using Atlas.ti, while the static snapshot observations were then compiled and compared to the analyses, VGA, axial analysis, and agent simulations produced by DepthMapX. The research firstly challenged the idea of the public/ private dichotomy as it was observed that some residents had their own private territories in public spaces, and there were alternative spaces where residents interacted with each other in. The analysed qualitative data showed the contestations between new foreign residents and the elderly. It also explained the reasons the elderly continued to stay in Tiong Bahru- mainly because the established friendships and community enables the elderly to feel a sense of place in the neighbourhood. From the comparison of discrepancies between the static snapshot observations with the space syntax analyses, it is evident that a built environment with high visibility and orientability can only affect intergenerational interactions to a limited extent- by increasing the accessibility and thus enabling higher awareness of a public space. Combining space syntax analysis with the qualitative data, it was thus concluded that to facilitate intergenerational relationships, public neighbourhood spaces should also have activities or events in order to encourage more intergenerational interactions between residents who are initially strangers. Overall from the discussion chapters, this thesis thus supports the idea that establishing intergenerational ties within the neighbourhood community is one of the solutions to promote inclusivity and hence prevents contestations in public neighbourhood spaces.