Landschaftsökologie und Landschaftsplanung

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Prevalence of cardiovascular disease (CAD) due to industrial air pollutants in the proximity of Islamabad Industrial Estate (IEI), Pakistan
(2024-07-17) Rayan, Muhammad; Khayyam, Umer; Hussain Adil, Iftikhar
Contaminated air quality, in lieu of massive industrial pollution, is severely attributing to health anomalies in the proximity of industrial units. Cardiovascular Disease (CAD) is rising around industrial units in the planned capital city of Pakistan, Pakistan. To study self-reported CAD in the proximity of Industrial Estate Islamabad (IEI) by equating two distinct study groups as ‘Band-I’: the residence 0–650 meters and ‘Band-II’ 650–1300 meters radius around the perimeter of IEI. The perimeters were digitized using Google Earth and GIS. Field survey was conducted on deploying 388 (194 in each Band) close-ended (self-administered) questionnaires at the household level, after adjusting the potential confounding variables. The research calculated odds ratios (ORs) of the CAD at 95% CI. The study’s findings of the multiple logistic regression for ORs confirmed a significant increase in CAD problems due to industrial affluents in Band-I than in Band-II which were less severe and less life-threatening. Study confirmed high incidences of high blood pressure and breathing issues (up to 67%), due to accumulation of unhealthy affluents thus leading to heart stroke (Band I = 56.20% and Band II = 60.30%). It is aided by smoking that has increased CAD in Band-I. Societal attributes of knowledge, beliefs, attitudes, and preferences fail to safeguard the local residents amid high concentration of harmful pollutants. As a counter measure the affected respondents engaged in highlighting the issue to the concerned public offices, yet there is a high need on part of the capital government to take mitigative measures to immediately halt the disastrous industrial air emissions to save precious lives.
Evaluation von Hoch- und Höchstspannungsfreileitungstrassen in bewaldeten Gebieten am Beispiel der Freileitung Kruckel – Dauersberg sowie Entwicklung von Determinanten zur Steigerung der Akzeptanz von Hoch- und Höchstspannungsfreileitungstrassen seitens der Eigentümer*innen und Bewirtschafter*innen
(2024) Klar, Corinna; Gruehn, Dietwald; Faulstich, Martin
Bei der Planung sowie dem Bau und Betrieb von Hoch- und Höchstspannungsfreileitungen gewinnt ein ökologisches Trassenmanagement seit Jahren an Bedeutung und wird bereits teilweise seitens der Netzbetreiber umgesetzt. Ein entwickeltes Wuchshöhenmodell im Schutzstreifen einer bewaldeten Freileitung wird hinsichtlich einer akzeptanzsteigernden Wirkung evaluiert. Es wird ein Methodenmix zur Evaluation aus zwei teilnehmenden Beobachtungen, zehn Experteninterviews und einer Onlineumfrage durchgeführt. Als Untersuchungsgegenstand dient das Ersatzneubauprojekt Kruckel – Dauersberg im Abschnitt C, welches als Vorhaben Nr. 19 des Energieleitungsausbaugesetzes geführt wird. Die Arbeit zeigt auf, ob die Planung von Hoch- und Höchstspannungsfreileitungen pfadabhängige Strukturen aufweist, welchen Einfluss ein ökologisches Trassenmanagement auf die Freileitungsplanung hat, ob ein Wuchshöhenmodell eine akzeptanzsteigernde Wirkung entfalten kann und wie sich die Akzeptanz von Hoch- und Höchstspannungsfreileitungen für Eigentümer und Bewirtschafter steigern lässt. Ferner werden Handlungsempfehlungen für Akteure, die der Planung übergeordnet sind, identifiziert und formuliert.
Green infrastructure planning framework
(2024) Rayan, Muhammad; Gruehn, Dietwald; Khayyam, Umer
The concept of GI, multi-stakeholder participation and resilient cities has emerged as a new dimension of sustainable urban development for green growth - leading to the strengthening of the resilience of the urban eco-system. Since Pakistan is undoubtedly at high risk to climate change and its impacts, especially flooding, makes the region vulnerable to in-daunting climatic catastrophes, the northwestern areas of Khyber Pakhtunkhwa (KP) province were no exception, gives evidence of the high relevance of the topic. Furthermore, the outdated and unbalanced Urban Landscape and Urban Greening (UL-UG) planning policies show the need to create a framework of synergies between the theoretical and practical implementation of nature-based GI planning practices (under multi-stakeholder participation) at all administrative levels. This empirical study has provided a foundation for deeper investigation into the complex dynamics of linking GI planning–urban resilience–multi-stakeholder participatory planning (MSPP) concepts (nexus) to develop a sustainable UGI framework. This framework/model is developed under MSPP that recommends UGI indicators, grounded upon the Triple Bottom Line " (TBL)" of sustainability and their spatial functional linkages with the innovative multi-functional GS, tailored to the native built environment. Which are to be implemented in the UL-UG design guidelines of Pakistan as a whole, and, more specifically, the KP province. Such a UGI model bolsters MSPP, taking (into account) the input of all native multi-stakeholders (top-down planning experts and bottom-up household community members) and enables the building of safer, greener and climate-resilient regions (fortified to withstand CC) in the KP region and across the country. The work is deemed as the first pioneering step that embeds (the GI) study (under the MSPP approach) in its relevant local context of the 'Peshawar', 'Mardan', and 'Charsadda' districts of the KP region. Since no such empirical study has been conducted on such a subject and the integration of a bidirectional sustainable development pathway in the context of a non-collaborative planning environment as prevails in countries like Pakistan. This remains true even for the northwestern parts of the KP region. This reality makes this study novel.
Sustainable consumption for effective ecosystem-based adaptation in urban and peri-urban settlements in the lowlands of Nepal
(2024) Bista, Samjhana; Gruehn, Dietwald; Schmidt-Kallert, Einhard
The concept of sustainability is not new to Nepal and was accepted as early as the Brundtland Commission published its report in 1987. However, very few studies have been conducted to see the linkage between sustainable consumption and nature conservation, such as ecosystem-based adaptation (EbA), and no research was reported from Nepal. A mixed research method was applied which included primary data collection from household surveys, focus group discussions, key informant interviews and experts’ consultation workshop, as well as secondary data from literature reviews and documents published by the Government of Nepal. The major factors influencing household/individual consumption were people’s lifestyle being more luxury-oriented, busy schedule of household members, availability of modern facilities, peer-pressure, increasing income, laziness, and modernisation. The people in the study area were found less aware on climate change and their impacts. Under conditions such as awareness on climate and health benefits, people were willing to pay the premium price for green food products and urban green parks. The individuals who are engaged in conservation initiatives were found to practise environment-friendly behaviours at the household level such as growing their own vegetables, using bicycles to work, using green parks instead of sophisticated gym centres, among others. The study, therefore, collected evidence to claim that sustainable consumption should be considered as one of the indicators of effective EbA. The findings will be very relevant to the policy makers, academia, private sector and development practitioners. Furthermore, it will pave the path for national as well as international discussions and commitments for climate financing efforts that are evidence-based, locally driven and local solutions-oriented.
Strengthening the evidence base for urban planning in the era of climate change
(2023) Klopfer, Florian; Gruehn, Dietwald; Siedentop, Stefan
We are living in a world, in which continuous change is one of few constants. Amidst the transformations taking place, climate change, with its manifold impacts on nature and society, is undoubtedly amongst the most omnipresent ones. In the age of ongoing global urbanization, urban climate change implications, such as the urban heat island (UHI) effect, affect a major part of humanity. Thus, cities as both drivers of and sufferers from adverse conditions are a main focus of climate related research, which can be seen in a constantly growing body of relevant scientific contributions. Associated with that is the necessity of a common understanding of key concepts and definitions. However, as conceptual frameworks are not standardized and furthermore undergo thorough changes, e.g., initiated by the publication of influential IPCC (International Panel on Climate Change) reports, scientific advance is slowed down by varying perceptions, leading to not always comparable results and insights. When analyzing urban heat, there are physical and social factors to be considered. While the former ones can influence the pronunciation of heat, the latter are important to look at in terms of potentially emerging environmental (climate/thermal) injustices. Regarding heat explaining physical variables, a focus of recent research is on land use and land cover characteristics as well as landscape metrics. Urban morphology or fabric as the result of historical developments is rather rarely considered. On the social side, mostly two-sided relationships between, e.g., heat and green supply or green/heat and social status are analyzed. Here, integrated considerations are missing. The research incorporated in the dissertation at hand intends to foster the evidence base for sustainable and resilient urban planning under climate change conditions tackling the before-mentioned shortcomings. The first article featured deals with conceptual and definitional ambiguities in urban climate change research. Amongst others, a strong dominance of certain concepts (e.g., vulnerability) and a huge influence of IPCC reports could be discerned. In the second study, urban morphology and its influence on urban heat is researched for the case of Berlin. Applying a GWR (geographically weighted regression) model, the thermal performance of various urban structure types (UST) could be determined while at the same time obtaining insights on the specific effect of urban morphology parameters on heat intensity. The third article presented is dedicated to explore multi-burden areas in the Ruhr region. Besides heat, green supply as well as social factors are put in relation here via correlations and a cluster analysis. The relationship between heat and social status is found to be ambiguous depending on the city regarded. The cluster analysis could reveal areas suffering from heat, low green provision, and lower social status with a significant amount of the area's population living there (around 27%). In summary, the research featured can be seen as describing three steps necessary in order to achieve resilient cities. A common knowledge base, with common definitions and conceptual framework understandings is needed (1) before the physical urban structure has to be analyzed unleashing adaptation potentials (2). Lastly, the social aspect needs to be included in order to be able to promote tailored solutions in adaptation action benefiting the respective population (3). The outlined procedure can serve as an adaptable blueprint for further research and practice in the area while also exhibiting various connecting points.
Determining spatial disparities and similarities regarding heat exposure, green provision, and social structure of urban areas - a study on the city district level in the Ruhr area, Germany
(2023-05-19) Klopfer, Florian; Pfeiffer, Antonia
Heat islands and ongoing urbanization make cities places where the negative impacts of global climate change on society are becoming increasingly evident. Especially the interplay and potential multiplication of heat, low green provision, and the presence of socially deprived urban dwellers constitutes complex challenges. Emerging climate injustices and potential health issues require a powerful counter-reaction in form of adaptation action. For our study, we consider eight cities located in the densely populated and historically highly segregated Ruhr area in Western Germany, which is one of the largest metropolitan areas in Europe with a heterogeneous distribution of socio-spatial problems, economic potential, heat stress, and green infrastructures. We use land surface temperature (LST), data on green provision (normalized difference vegetation index (NDVI)), and social indicators to reveal the relationships between these indicators on the city district level (n = 275). Therefore, we first analyze the data regarding spatial autocorrelation (Moran's I) and clustering (Gi*) before calculating study area wide and city specific correlations between the three factors regarded. Finally, we conduct a cluster analysis (k-means) to disclose similar areas with or without multiple burdens. Our results show distinct disparities in heat exposure, green availability, and social status between city districts of the study area. We find strong negative correlations between LST and NDVI as well as between NDVI and social status. The relationship between LST and our social indicator remains ambiguous, affirming the necessity of further detailed studies. The cluster analysis furthermore allows for the visualization and classification of districts featuring similar characteristics regarding the researched components. We can discern in parts pronounced climate injustice in the studied cities, with a majority of people living in unfavorable environmental and socio-economic conditions. Our analysis supports governments and those responsible for urban planning in addressing climate injustice in the future.
Association between land surface temperature and green volume in Bochum, Germany
(2022-11-07) Schmidt, Pauline; Lawrence, Bryce T.
Average temperatures continue to rise throughout the world due to climate change and, thus, also in Europe, often occurring as heat waves. The negative effects of climate change-related heat waves can be observed, especially in urban areas where land sealing is the greatest and so is population density. Past studies have indicated that green volume can provide climate improvement by balancing humidity and regulating temperature. This study aims to estimate the distribution of surface heat islands and green volume and test the relationship between these variables in a case study of Bochum, Germany. A method to develop a temporally longitudinal 30-m Landsat 8-based land surface temperature (LST) analysis and 30-m LiDAR-based green volume dataset are presented, and their relationship is tested using Pearson’s correlation (n = 148,204). The results show that heat islands are moderately negatively correlated with green volume (r = −0.482; p < 0.05), LST can vary as much as 28 degrees °C between heat islands and densely vegetated areas, and the distribution is heterogeneous across Bochum.
Planning for sustainable green urbanism
(2022-09-20) Rayan, Muhammad; Gruehn, Dietwald; Khayyam, Umer
Rising vulnerability of the urban green infrastructure (UGI) is grabbing global attention, for which inclusive urban landscape and greening policies (ULGP) and frameworks are crucial to support green growth. As such, this research intends to explore the local community’s perspective to assemble sustainable UGI indicators for vital taxonomy of the urban green space (UGS) elements, aiming to develop a multi-functional and sustainable UGI-indicator-based framework that is eco-friendly and supports green-resilient cities in Khyber Pakhtunkhwa (KP) province, Pakistan. An in-depth household survey was executed in three KP districts: Charsadda, Peshawar, and Mardan, placing self-administered 192 questionnaires while covering themes around climate change adaptation, urban resilience, and UGI. Relative importance index (RII) and the interquartile range (IQR) methods were set up for data analysis that revealed excellent reliability (α > 0.88) and internal consistency. The results confirmed community-based UGI indicators with a focus on promoting green-energy-saving strategies as e-imp (level 9, RII = 0.915), while other (ten) UGI indicators as important (RII = 0.811–0.894) and (eleven) as moderately important (RII = 0.738–0.792). These UGI indicators were found to be enhanced by UGS elements (RII ≥ 0.70). These findings provide a foundation for urban policy change and the development of a sustainable UGI framework to build an eco-regional paradigm for greener growth.
Frameworks for urban green infrastructure (UGI) indicators
(2022-06-29) Rayan, Muhammad; Gruehn, Dietwald; Khayyam, Umer
Climate-induced pressures spur on the need for urban green infrastructure (UGI) planning. This approach offers a possible way to improve ecosystem functionality and human well-being in adversely affected urban regions, wherein UGI is perceived as a green and nature-based climate change mitigation/adaptation strategy. In Pakistan, the Khyber Pakhtunkhwa (KP) province lacks such urban landscape and greening policies (ULGP) or legislative frameworks for transitioning to green action plans (GAP), to alleviate the risk of multi-climatic hazards. Thus, this study aims to investigate a sustainable UGI-indicator-based framework model, based on the due inclusion of the concerned stakeholders. The relative importance index (RII) and inter-quartile range (IQR) techniques are employed for field data analysis. The findings proclaim excellent reliability (α > 0.7) and internal consistency, wherein sustainable UGI indicators are grouped based on their importance. The results portray the ecological and economic sustainability dimensions as being important (RII = 0.835 and RII = 0.807, respectively), socio-cultural dimensions as being moderately important (RII = 0.795), and a set of UGS elements (RII ≥ 0.77) as vital for bolstering individual UGI indicators. The main UGS elements emerging in each category can be grouped as follows: ecological category—“reducing rainwater runoff” (RII = 0.94); socio-cultural category—“enhancement of mental and physical health” (RII = 0.90); and eco category—“minimizing the risk of flood disasters” (RII = 0.96). The simulation results demonstrate the need for an inclusive perspective when building the urban green space (UGS) infrastructure (and standards) that will be most suitable for ensuring climate-resilient urban regions. This study contributes to putting the scientific research knowledge of the natural green-landscape-based (NBLB) approach into practice. The study calls for the establishment of an effective, pragmatic relationship between the urban landscape and greening policies, alongside a constructive relationship with the native inhabitants to ensure eco-friendly and resilient settlements
The impact of the Persian garden principles as traditional ecological landscaping on thermal comfort
(2021) Bashirizadeh, Mohammad; Gruehn, Dietwald; Taghvaei, Seyed Hassan
Outdoor thermal comfort is a key factor generally affecting both physical and mental human health. The increased temperature on days caused by the urban heat island effect is a common phenomenon in cities, which has affected various indicators of quality of urban life such as air quality, use of fossil fuels, human health, etc. Accordingly, to mitigate the heat island effects, the thermal quality of urban open spaces and cooling strategies have been considered by climatologists, urban planners, and landscape designers. In the case of Iran, despite the efforts, studies, and research conducted in this field in recent years, there is no climatic vision at the planning and site design level in most projects. Therefore, it is necessary to emphasize the significance of climatic landscape planning and design and outdoor well-being, not only among urban planners and landscape designers but also among the general public. The Persian garden, known as a traditional ecological landscape in Iran, is the result of valuable experiences of human coexistence with nature and adaptation to climatic conditions during centuries. In fact, the Persian garden not only meets the needs of man and nature but also creates a beautiful environment and provides thermal comfort under the harsh conditions of Iran's hot and dry climate. In this term, the study of the Persian garden, which is based on Iranian culture and believes, is desired and beneficial. Therefore, in this study, after identifying the concept, the structures, and the fundamental elements of the Persian garden and after conceptualizing its ecological design principles, Persian gardens in different climatic zones are selected in order to determine their responses to the changing climatic conditions and their influential factors. Then based on these extracted principles, several scenarios of applying a variety of Persian garden structural elements in the Fin Garden of Kashan, as an outstanding registered world heritage garden, are defined. In order to find the principles of climatic design in the Persian gardens, the ENVI-Met simulations of these scenarios are analyzed on a typical summer day. In the end, the results' efficiency was proved through hypothetical redesign and simulation applied in a similar green space in Kashan with almost equal dimensions. This study concludes that in hot and dry climates, a variety of parameters such as landscape planning, selection and combination of vegetation, water system, geometry, site orientation, surface materials, wind and sunlight control, and spatial arrangement and design influence the outdoor thermal comfort. In conclusion, these results are presented as green strategies and design guidelines for future climate designs in Iran's hot and dry climate.
Conceptual frameworks for assessing climate change effects on urban areas: a scoping review
(2021-09-28) Klopfer, Florian; Westerholt, René; Gruehn, Dietwald
Urban areas are amongst the most adversely affected regions by current and future climate change effects. One issue when it comes to measuring, for example, impacts, vulnerabilities, and resilience in preparation of adaptation action is the abundance of conceptual frameworks and associated definitions. Frequently, those definitions contradict each other and shift over time. Prominently, in the transition from the IPCC AR (International Panel on Climate Change Assessment Report) 4 to the IPCC AR 5, a number of conceptual understandings have changed. By integrating common concepts, the literature review presented intends to thoroughly investigate frameworks applied to assess climate change effects on urban areas, creating an evidence base for research and politically relevant adaptation. Thereby, questions concerning the temporal development of publication activity, the geographical scopes of studies and authors, and the dominant concepts as applied in the studies are addressed. A total of 50 publications is identified following screening titles, abstracts, and full texts successively based on inclusion and exclusion criteria. Major findings derived from our literature corpus include a recently rising trend in the number of publications, a focus on Chinese cities, an imbalance in favor of authors from Europe and North America, a dominance of the concept of vulnerability, and a strong influence of the IPCC publications. However, confusion regarding various understandings remains. Future research should focus on mainstreaming and unifying conceptual frameworks and definitions as well as on conducting comparative studies.
Analyse von Bewertungsveränderungen des Landschaftsbildes durch Windenergieanlagen in unterschiedlichen Landschaftskategorien Nordrhein-Westfalens auf der Grundlage von Online-Befragungen
(2021) Haubaum, Christina; Gruehn, Dietwald; Greiving, Stefan
Bei der Planung von neuen Windenergieanlagen ist das Landschaftsbild ein häufiger Diskussionspunkt in der Abwägung. Für dessen Bewertung gibt es kein einheitliches Verfahren, das war der Anlass bereits existierende Landschaftskategorisierungssysteme daraufhin zu untersuchen, ob man sie für eine Abschätzung der Bewertungsänderungen durch Windenergieanlagen nutzen kann. Die Datengrundlage stammt aus einer Online-Befragung mit über 800 teilnehmenden Personen, die ihre Wahrnehmungen zu über 200 Fotos aus ganz NRW mitteilen konnten. Diese Daten wurden auf drei Arten ausgewertet und zeigen: • Es gibt keine personenabhängigen Bewertungsunterschiede, z.B. durch das Alter • Für die verschiedenen Kategorisierungssysteme sind signifikant unterschiedliche Durchschnittsbewertungen von Landschaften ohne Windenergieanlagen festzustellen • Es konnte keine Anzahl von Windenergieanlagen bestimmt werden, ab der sich die Bewertung der Vielfalt, Eigenart, Schönheit oder des Erholungswertes nicht mehr ändert • Mit der Methode der ordinalen Regression können Effekte von Windenergieanlagen als Einflussfaktoren auf die Wahrnehmung von Landschaften beschrieben werden, aber keines der Kategorisierungssysteme liefert gut interpretierbare Ergebnisse
Development of spatial strategies for small island landscapes in the Philippines
(2020) Medrano Reyes, Edgar; Gruehn, Dietwald; Hellmanzik, Christiane
Small islands are among the most fragile and vulnerable yet diverse and unique ecosystems on Earth. This complexity is enhanced by human communities relying on its resources. Understanding small islands therefore, includes analyses of its innate character and the spatial interaction. These ideas form the two-pronged theme of this research including (1) comprehensive profile gap analysis of the small island and (2) its spatial interaction analysis through the natural resources, which provided bases for recommending island spatial strategies. Represented by the small island provinces of Batanes, Siquijor and Camiguin in the Philippines, the following results were highlighted: a) unique characters of the small island provinces from the socio-demographic and cultural (High Population density and low growth rate, Isola Effect, Sea-faring culture, migration patterns); environmental (coastline to physical size ratio, vulnerability to hydro-meteorological hazards and disasters, complex geographies and ecosystems, ecosystem continuum); economic (narrow and concentrated economic base, vulnerability to environmental shocks, import orientation, prominence of varied informal economy, subsistence and extractive economy); Infrastructure (Physical isolation and accessibility concerns, centralization for provision of support services); and institutions (satellite town effect, unclear hierarchical spatial roles) and b) the spatial interaction analyses confirming these characteristics and provide deeper context on the actual conditions of small island provinces not seen on the usual island analysis conducted for planning small islands (weak spatial interaction scores, direct association of natural island ecosystems to the livelihoods and the inequitable distribution of these resources through material flows skewed towards the regional environment). Insightful island policy strategies transcending from the protection, production settlements and infrastructure policy areas were done including: (a) creation of Small Island Province Ecosystem Continuum (SIPEC) addressing island vulnerability; (b) spatio-temporal measures for the production perspectives; (c) mainstreaming of the island communities concern including the indigenous rights and island living context to alleviate impoverish conditions; d) and green or nature-based solutions as supporting mechanisms for island development, to mention a few. All these options translate to spatial strategies for small island provinces in the Philippines.
Promoting urban spatial planning guidance for achieving physical sustainable urban development in Duhok City - Kurdistan Region, Iraq
(2019) Hajani, Ismail Ibrahim Suliman; Gruehn, Dietwald; Baumgart, Sabine
The main force that affects the city’s urban form is the process of urban growth. Kurdistan Region encounters great challenges characterized by high population growth and rapid expansion towards the surrounding rural region. The last five decades witnessed a series of wars and other political conflicts which has made the whole Iraq unstable and affected the performance of planning institutions, patterns of physical development, and destruction of social and physical infrastructure. As a result, the cities in Kurdistan Region- also in whole Iraq- did not keep track of perceptive planning schedules which generated many conflicts in the form and the structure of the cities and hardly influenced land use pattern, provision of essential infrastructure and the quality of the built environment, therefore, this has created a type of urban form and structure that is a malfunction and is not user-friendly. This research explores the way for the future urban development in Kurdistan to adopt the concept of sustainable urban growth. The notion of pursuing sustainable urban development is promoted through seeking better physical development that can uplift the quality of the urban built environment. Furthermore, the research explores the challenges facing the context and potentials needed for embracing sustainable development. The outcome of this research is depicted in the form of conceptual proposal suggesting compactness, density, mixed use, accessibility, diversity, enhancing greening and residents’ satisfaction as criteria for sustainable physical development in the cities of Kurdistan. Moreover, this dissertation recommends general strategies as the fundamental basement for changing towards sustainability. The recommendations are related to; regulatory and institutional structure, spatial practices and current opportunities for early change.
Understanding location and neighbourhood effects: An analysis of the housing submarkets in Accra – Ghana
(2020) Gavu, Emmanuel Kofi; Gruehn, Dietwald; Schulte, Karl-Werner
Housing is a global phenomenon and is the heartbeat of almost everyone. It is seen as one of the fundamental needs of mankind and the long term focus of many developments across the world. In housing markets research it has been long established that location does matter. That suggests that real estate goods and services place a premium on location. Although this is the case, such location and neighbourhood characteristics are not traded explicitly and their contribution cannot be directly observed. However the contribution of location characteristics on housing markets research to professionals both in Valuation practice and planning authorities cannot be over-emphasised. This research focuses on analysing rental values at the neighbourhood level which has been neglected by researchers. The main goal of this thesis was to develop a model that could be used to disaggregate residential rental housing values and use it to explain location and neighbourhood effects of housing sub-markets in Accra. The thesis empirically highlights the perception of stakeholders in Accra’s housing market in order to identify and conceptualise commonalities and differences in variables that determine Residential Rental Values (RRVs); the empirical conceptualisation of rental values in Accra; determinants of RRVs; empirical examination of submarket existence; and the determination of the price premium of location and neighbourhood attributes on rental values. The thesis adopts a mixed research approach. Two approaches are broadly operationalised in achieving objectives in this thesis. The first is a perception survey to understand stakeholder views on the rental housing market, and the second was an empirical survey to understand price movements within the market. The dataset for the perception survey adopted a relative importance index to rank 38 different variables that have been utilised in the extant literature to determine RRVs. Using the stratified sampling technique, the population of experts and stakeholders with knowledge in the rental market space were identified and categorised into six distinct strata. The sample frame was drawn from landlords; tenants; real estate agents; academic staff from real estate teaching departments in universities; valuation and estate surveyors; and a group labelled as ‘others’. Purposive sampling was then used to identify respondents within each stratum. The findings of the perception survey suggest that electricity and piped water connection, type of house, property condition and number of bedrooms are the most significant determinants of RRVs in Accra. Contrariwise, the least significant variables include storeroom availability, proximity to recreational facilities, proximity to place of worship, landscape quality and number of storeys. The first part of the thesis contextualises RRVs by identifying variables that reflect characteristics of the rental housing market in Accra. This serves as a guide in understanding rental market dynamics in a typical African city where access to data remains a challenge. The dataset for the empirical study is based on 536 rental transaction data collected during field study in Accra. Such data is not readily available, as Ghana’s housing market lacks the existence of an established data bank where such information could be obtained even at a fee. Some institutions may have some of the information (i.e. the Lands Commission), but such databases do not have all the required variables to model the market comprehensively as was attempted in this research. Moreover, there is no list of residential rental houses sample frame to draw sub-samples from. So the snowball technique served as the most practical means to select rental houses within each a priori submarket group during the field work. The thesis finds that submarket definition is a critical aspect in housing market analysis, and this is very useful in understanding market dynamics and making market predictions at a lower level of disaggregation. Using spatial, structural and nested definitions, submarket existence was tested using the Kruskal-Wallis H test (non-parametric), the Jonckheere-Terpstra test (non-parametric) and the hedonic pricing model (parametric). The results suggests that when pairwise comparisons are analysed, distinct submarkets existed within the aggregate market. The thesis further finds that variables such as electricity availability, real estate type, water availability, physical condition of property and number of bedrooms, are the top five determinants of rental value as perceived by market stakeholders; while on the other side, properties in high income neighbourhood, landscape quality, construction quality, bus stop availability and total floor area, are the highest contributors (51.85%) to rental value per empirical results. There seem to be a disconnect between these two groups of variables. The results suggests that the five highly ranked variables as perceived by market stakeholders was not confirmed by empirical analysis. The thesis also tested the hypothesis that, location and neighbourhood attributes determine to a larger extent residential rental values in Ghana than structural attributes does. Separate hedonic models were computed for both the aggregate market and submarket constructs. Using statistically significant model coefficients and the adjusted R2, the effects of location and neighbourhood are specifically analysed. The empirical results suggest that statistically significant structural variables contribute 43% to rental values, whereas location and neighbourhood variables contribute 20% and 25% respectively within the aggregate market. Similar trends are observed within submarket constructs. The findings have practical and policy implications; and methods utilised in this thesis can be replicated in similar cities in a developing country context where access to reliable data is a challenge. Findings also provide stakeholder investors in the rental space an understanding of market dynamics for profit maximisation, and end-users to maximise utility in deciding where to live – and as such households could benefit from making informed investment decisions on housing. The thesis finds that there exists several potential applications of quantifying the specific contributions of variables within the aggregate market as well as submarket constructs. The results of the quantification is influenced by the quality of data. It is further recommended that a national housing data bank is established by real estate teaching and research institutions of higher learning in Ghana to facilitate the acquisition of housing related data for research purposes. This thesis is one of the first attempts to empirically identify and test for submarkets existence; and to quantify the price premiums of structural, location and neighbourhood attributes in Ghana’s residential rental housing market.
Towards resilience
(2019) Li, Zhao; Gruehn, Dietwald; Thinh, Nguyen Xuan
The frequency of extreme weather events increases as climate change. Rural settlements are affected by various natural hazards induced by climate abnormality. As a system, rural settlements have the capability to resist, response, and recover from the external changes. This capability is regarded as system resilience. Enhancing rural system resilience is one orientation of rural planning work. One thorny problem in conducting rural planning is the lack of scientifically recorded data. From the other side, rural residents boast local knowledge which has been inherited through generations. This research collects local knowledge related to land management and disaster prevention, elucidates the preservation status of local knowledge, testifies the correctness of local knowledge, and analyses how local knowledge influences settlement system resilience. Through literature research, fieldwork and on site survey, this research collected local knowledge and traced its evolution. The local residents in Chongqing rural region practice terraced rice field cultivation facilitated with a gravity irrigation system of Yantang. There are also Fengshui forests preserved from exploitation. The local knowledge about land management changes with time. Local knowledge about natural hazard prevention is compared with SWAT model simulation results and official records to testify the correctness. Since the accuracy of simulation is hindered by the insufficient data, local knowledge is superior to simulation results in the research region. The accuracy of local knowledge about the date when natural hazards happened is higher than that of the simulation result, so as the accuracy of the maximum water level during the previous floods. Local knowledge still contains the keen observation of the natural setting changes, and is applicable for predicting natural hazards and making contingency plans. Instructed by local knowledge, settlements apply different land use strategies and result in the divergence of system resilience. Since local knowledge has evolved in different directions, settlement resilience change accordingly in good way or bad way. The dissemination of local knowledge mainly depends on the social network of neighbors, relatives and local governors. But because of the disintegration of such social relationships caused by village hollowing and urbanization, the dissemination of local knowledge is hampered. The possessors of local knowledge are easily affected by foreign and new information. As a result, in some extreme cases, local knowledge is gradually forgotten and replaced by modern science and knowledge. This research suggests that the rural planning towards resilience to learn from local knowledge through its trails and fails, and urge the development of local knowledge alongside with modern science and technology.
The effects of urban expansion on spatial and socioeconomic patterns of the peri-urban areas: a case study of Isfahan city, Iran
(2017) Heidarinejad, Nasim; Gruehn, Dietwald; Thinh, Nguyen Xuan
Although urban areas cover a very small fraction of the world’s land surface, rapid urban expansion has significantly changed the landscape and formed immense environmental and social impacts. These effects are principally important in rapidly changing areas such as urban settlements in developing countries. Over the last decades, several studies have focused on the field of urban expansion. However, the implications of this rapid urban expansion have not been sufficiently analyzed. They presented some major challenges. Although most developed countries have comprehensive land cover information, the relative lack of geospatial data sets is a serious and real problem in the developing countries. Moreover, the analysis of urban expansion suffers from a general lack of knowledge and understanding of physical and socioeconomic factors. With this in mind, the main objective of the dissertation is to develop an effective methodology for identifying and addressing significant spatial and socioeconomic patterns to support effective management and program planning towards a sustainable urban development. Isfahan city in Iran is introduced as the case study. In order to achieve this aim, it is necessary to quantify the spatial and temporal dynamics of urban expansion which often requires spatial analysis. A combination of remotely sensed (RS) data and geographic information systems (GIS) technologies could provide an eminently suitable means of assessing urban planning. Methodologically, the study proposed adopting a research paradigm that integrates spectral indexes (i.e., modified normalized difference water index (MNDWI), soil adjusted vegetation index (SAVI), and urban index (UI)) and the classification approach. This method was proposed to reduce seven bands of an original Landsat image into three thematic-oriented bands. The next step was to analyze the growth of the expansion ratio in Isfahan between 1990 and 2010. Two main indexes were applied to quantify the urban expansion, including urban expansion differentiation index (UEDI) and urban expansion intensity index (UEII). Furthermore, a set of spatial metrics was developed to quantify the urban spatial patterns. The study also developed a core set of quantitative variables to characterize socioeconomic form. Three quantitative variables were developed to measure three dimensions of socioeconomic patterns: the intensity of physical activity, the degree that activities are evenly distributed, and the extent that high-density sub-areas are clustered. iv The results indicate that Isfahan city was characterized by significant rapid urban expansion, particularly over the first decade. The analysis of spatial patterns demonstrates that the city experienced phenomenal aggregated pattern in the central zones, leapfrogging pattern in the peripheral areas, as well as nodal and linear pattern in the middle regions of Isfahan city over the period considered. Through the adoption of socioeconomic measures, it is confirmed that local sprawl (discontinuity and strip development) was the dominant socioeconomic patterns of Isfahan city over 20 years. In other words, a sprawling pattern (job-based and population-based) was assured by the low value of the density and Moran coefficient, as well as the high score of Gini coefficient. Geographically weighted regression (GWR) was suggested to explore the effects of urban expansion on the spatial patterns. The results generated from GWR indicate that patterns of urban expansion were affected by the intensification of the urban expansion in Isfahan city. In contrast, urban expansion had a significant positive relationship with the aggregation pattern in the central zones of the city. Moreover, to investigate the effects of urban expansion on the socioeconomic patterns, the Pearson correlation was applied. The results show that the expansion of the urban areas in Isfahan led to the decrease in density of population an employment, the increase of concentration in some districts, and the decrease of clustering. Overall, two obtained outcomes show that the city experienced a sprawling pattern over 20 years. Making our cities more pleasant to live in is one of the main strategies being implemented as part of the national environment policy, which prioritizes maintaining a balance between urban expansion and protection of the environment and natural sites. In the case of Isfahan city, If the current expansion continues in the future, the new urban areas could develop in the fringe and rural areas and, therefore, the conflict between rapid urban expansion and limited land resource becomes more apparent.
Das Potenzial von ökonomischer Bewertung und Partizipation für die Planung grüner Infrastruktur
(2017) Wilker, Jost; Gruehn, Dietwald; Siedentop, Stefan
Green and open spaces are important components of green infrastructure. They offer a range of different ecosystem services society benefits from. Due to ongoing urbanisation and densification processes many urban and peri-urban green and open spaces disappear or degrade in quantity and quality, with negative impact on their ecosystems. The decline of the ecological functions of nature and landscape also weakens their social and economic merits, which are especially important for society. Hence, society strongly depends on eco-system services provided by healthy ecosystems. As a consequence of sprawl and land consumption people are increasingly losing contact with and knowledge about nature. Although there is generally support for the development of green and open areas in society, this is an alarming trend as society`s relation to nature is essential. How-ever, especially in cities space is limited and the pressure for development is high resulting in a competition between green and grey infrastructure, which green infrastructure is rarely able to win. Thus, investment in green and open areas is low in most cities and public needs are often neglected as investments are mainly driven by economic interests. However, public needs and local stakeholders‘ knowledge are relevant factors in planning as a majority of green infrastructure components are public spaces. Society as a whole benefits from their ecosystem services. The need to demonstrate the advantages of investments in green and open spaces is therefore high. It is also important to extend the knowledge about the services of nature in society and to pay more attention to the existing local knowledge about green infrastructure. By this means, aforementioned problems could be addressed sustainably through direct engagement of local communities. This doctoral thesis focusses on the concepts of green infrastructure and ecosystem services. For the author both concepts are closely interrelated. Based on this understanding the potential of economic valuation and participation to generate ecosystem knowledge for the support of green infrastructure planning is examined with the aid of empirical studies. Their key parts were published in four journal articles by the author and the particular co-authors. The thesis outlines and discusses the main findings from case studies in Belgium, England, Germany and the Netherlands, which were conceptualised and conducted by the author between 2009 and 2015. The published results show the potential of quantitative and qualitative information about ecosystem benefits deliverable by participation and economic valuation. The work indicates that both approaches are suited to generate different types of ecosystem knowledge by directly involving users and beneficiaries of green infrastructure and its ecosystem services. These means allow increasing the awareness of both issues in planning, politics and civil society and allow green infrastructure in general to gain in importance. This thesis is a contribution to the ongoing discussion about the green infrastructure approach and the ecosystem service concept and their application in planning practice.
The County Diagnostic: A regional environmental footprint framework for the USA
(2016) Lawrence, Bryce T.; Gruehn, Dietwald; Hahn, Ekhart

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