Impacts of Urbanization on the Muthurajawela Marsh and Negombo Lagoon, Sri Lanka: Implications for Landscape Planning towards a Sustainable Urban Wetland Ecosystem

Urban wetland ecosystems (UWEs) play important social and ecological roles but are often adversely affected by urban landscape transformations. Spatio-temporal analyses to gain insights into the trajectories of landscape changes in these ecosystems are needed for better landscape planning towards sustainable UWEs. In this study, we examined the impacts of urbanization on the Muthurajawela Marsh and Negombo Lagoon (MMNL), an important UWE in Sri Lanka that provides valuable ecosystem services. We used remote sensing data to detect changes in the land use/cover (LUC) of the MMNL over a two-decade period (1997–2017) and spatial metrics to characterize changes in landscape composition and configuration. The results revealed that the spatial and socio-economic elements of rapid urbanization of the MMNL had been the main driver of transformation of its natural environment over the past 20 years. This is indicated by a substantial expansion of settlements (+68%) and a considerable decrease of marshland and mangrove cover (−41% and −21%, respectively). A statistical analysis revealed a significant relationship between the change in population density and the loss of wetland due to settlement expansion at the Grama Niladhari division level (n = 99) (where wetland includes marshland, mangrove, and water) (1997–2007: R2 = 0.435, p = 0.000; 2007–2017: R2 = 0.343, p = 0.000). The findings also revealed that most of the observed LUC changes occurred in areas close to roads and growth nodes (viz. Negombo, Ja-Ela, Wattala, and Katana), which resulted in both landscape fragmentation and infill urban expansion. We conclude that, in order to ensure the sustainability of the MMNL, there is an urgent need for forward-looking landscape and urban planning to promote environmentally conscious urban development in the area which is a highly valuable UWE.

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Ecosystem Services Monitoring in the Muthurajawela Marsh and Negombo Lagoon, Sri Lanka, for Sustainable Landscape Planning

Sustainability ◽

10.3390/su132011463 ◽

2021 ◽

Vol 13 (20) ◽

pp. 11463

Author(s):

Darshana Athukorala ◽

Ronald C. Estoque ◽

Yuji Murayama ◽

Bunkei Matsushita

Keyword(s):

Ecosystem Services ◽

Sri Lanka ◽

Landscape Planning ◽

Urban Expansion ◽

Metropolitan Region ◽

Wetland Ecosystems ◽

Ecological Protection ◽

Urban Wetland ◽

Business As Usual ◽

Sustainable Landscape

In this study, we examined the impacts of urbanization on the natural landscape and ecosystem services of the Muthurajawela Marsh and Negombo Lagoon (MMNL) located in the Colombo Metropolitan Region, Sri Lanka, with the goal to help inform sustainable landscape and urban planning. The MMNL is an important urban wetland ecosystem in the country but has been under the immense pressure of urbanization where the natural cover (e.g., marshland and mangrove areas) is continuously being converted to urban use (e.g., residential and commercial). Here, we estimated and assessed the changes in the ecosystem service value (ESV) of the MMNL based on land use/cover (LUC) changes over the past two decades (1997–2017). Considering two plausible scenarios, namely a business-as-usual (BAU) scenario and ecological protection (EP) scenario, and using a spatially explicit land change model, we simulated the future (2030) LUC changes in the area and estimated the potential consequent future changes in the ESV of the MMNL. The results revealed that from 1997 to 2017, the ESV of the MMNL decreased by USD 8.96 million/year (LKR 1642 million/year), or about 33%, primarily due to the loss of mangrove and marshland from urban expansion. Under a BAU scenario, by 2030, it would continue to decrease by USD 6.01 million/year (LKR 1101 million/year), or about 34%. Under an EP scenario, the projected decrease would be lower at USD 4.79 million/year (LKR 878 million/year), or about 27%. Among the ecosystem services of the MMNL that have been, and would be, affected the most are flood attenuation, industrial wastewater treatment, agriculture production, and support to downstream fisheries (fish breeding and nursery). Overall, between the two scenarios, the EP scenario is the more desirable for the sustainability of the MMNL. It can help flatten its curve of continuous ecological degradation; hence, it should be considered by local government planners and decision-makers. In general, the approach employed is adaptable and applicable to other urban wetland ecosystems in the country and the rest of the world.

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Quantifying the Spatial Integration Patterns of Urban Agglomerations along an Inter-City Gradient

Sustainability ◽

10.3390/su11185000 ◽

2019 ◽

Vol 11 (18) ◽

pp. 5000 ◽

Cited By ~ 2

Author(s):

Yiliang Wan ◽

Chuxiong Deng ◽

Tao Wu ◽

Rui Jin ◽

Pengfei Chen ◽

...

Keyword(s):

Urban Landscape ◽

Landscape Planning ◽

Urban Expansion ◽

Landscape Composition ◽

Urban Agglomeration ◽

Metropolitan Region ◽

Sustainable Urban Development ◽

Spatial Integration ◽

Urban Agglomerations ◽

Urban Rural

Understanding the integration process of urban agglomeration is essential for sustainable regional development and urban planning. However, few studies have analyzed the spatial integration patterns of metropolitan regions according to the impacts of landscape ecology along rail transit corridors. This study performed a comprehensive inter-city gradient analysis using landscape metrics and radar charts in order to determine the integration characteristics of an urban agglomeration. Specifically, we analyzed the evolution of spatial heterogeneity and functional landscapes along gradient transects in the Changsha–Zhuzhou–Xiangtan (CZT) metropolitan region during the period of 1995–2015. Four landscape functional zones (urban center, urban area, urban–rural fringe, and green core) were identified based on a cluster analysis of landscape composition, connectivity, and fragmentation. The landscape metric NP/LPI (number of patches/largest patch index) was proposed to identify the urban–rural fringe, which revealed that the CZT region exhibited a more aggregated form, characterized by a single-core, continuous development, and the compression of green space. The integration of cities has resulted in continued compression and fragmentation of ecological space. Therefore, strategies for controlling urban expansion should be adopted for sustainable urban development. The proposed method can be used to quantify the integration characteristics of urban agglomerations, providing scientific support for urban landscape planning.

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Assessing the Impact of Urban Expansion on Surrounding Forested Landscape Connectivity across Space and Time

Land ◽

10.3390/land10040359 ◽

2021 ◽

Vol 10 (4) ◽

pp. 359

Author(s):

Zhouqiao Ren ◽

Jianhua He ◽

Qiaobing Yue

Keyword(s):

Landscape Connectivity ◽

Urban Expansion ◽

Landscape Fragmentation ◽

Sustainable Urban Development ◽

Delayed Response ◽

Conservation Practices ◽

Rapid Urbanization ◽

Dynamic Landscapes ◽

The Impact ◽

Over Time

Landscape connectivity is important for all organisms as it directly affects population dynamics. Yet, rapid urbanization has caused serious landscape fragmentation, which is the primary contributor of species extinctions worldwide. Previous studies have mostly used spatial snap-shots to evaluate the impact of urban expansion on landscape connectivity. However, the interactions among habitats over time in dynamic landscapes have been largely ignored. Here, we demonstrated that overlooking temporal connectivity can lead to the overestimation of the impact of urban expansion. How much greater the overestimation is depends on the amount of net habitat loss. Moreover, we showed that landscape connectivity may have a delayed response to urban expansion. Our analysis shifts the way to understand the ecological consequences of urban expansion. Our framework can guide sustainable urban development and can be inspiring to conservation practices under other contexts (e.g., climate change).

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Urban Expansion and Its Impact on Green Spaces of Dehradun City, Uttarakhand, India

International Journal of Environment ◽

10.3126/ije.v3i4.11731 ◽

2014 ◽

Vol 3 (4) ◽

pp. 57-73 ◽

Cited By ~ 1

Author(s):

Peeyush Gupta ◽

Swati Goyal

Keyword(s):

Social Services ◽

Urban Expansion ◽

Remote Sensing Data ◽

Urban Ecosystems ◽

Fold Increase ◽

Green Spaces ◽

Population Pressure ◽

Tree Cover ◽

Rapid Urbanization

Urbanization is on increase because of heavy population pressure, industrialization, and better job opportunities in plane areas compared to Himalayan terrain. The urbanization has also added hypertension because of very fast life and lack of recreational opportunities within easily accessible distances. Deforestation is the permanent destruction of indigenous forests and woodlands. The term does not include the removal of industrial forests such as plantations of gums or pines. Deforestation is clearing of forests on a massive scale, often resulting in damage to the quality of the land. Urbanization is one of the major causes of the deforestation. Urban green space planning is an important component of urban ecosystems; provide many environmental and social services that contribute quality of life in the cities.The green spaces are said to be the lungs of the urban ecosystem. The process of urbanization led to natural landscape change. In the process tree cover, green spaces and wetlands were recklessly converted into built-up areas in the past and the process is still going on. Due to availability of required infrastructure, Dehradun was named interim capital of the nascent Himalayan state of Uttarakhand in 2000. Other regions of Uttarakhand is also experiencing rapid urbanization. The hill districts adjoining Dehradun district have witnessed a four-fold increase in the number of towns between 1901 and 2001. The population of Dehradun registered increase of 41.08 % between1961-1971, 32.84 % between 1971-81, 25.39 % between 1981-91 and during 1991-2001 it increased by 52.45 %. The temporal imaging of remote sensing data and socio-economic data of 1982 will be used for overall spatial monitoring.DOI: http://dx.doi.org/10.3126/ije.v3i4.11731 International Journal of EnvironmentVolume-3, Issue-4, Sep-Nov 2014Page: 57-73

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Interaction Analysis of Urban Blue-Green Space and Built-Up Area Based on Coupling Model—A Case Study of Wuhan Central City

Water ◽

10.3390/w12082185 ◽

2020 ◽

Vol 12 (8) ◽

pp. 2185 ◽

Cited By ~ 1

Author(s):

Jing Wu ◽

Shen Yang ◽

Xu Zhang

Keyword(s):

Landscape Pattern ◽

Green Space ◽

Interaction Analysis ◽

Central City ◽

Urban Expansion ◽

Landscape Fragmentation ◽

Coupling Model ◽

Coordinated Development ◽

Rapid Urbanization ◽

Development Level

Urban “blue-green” space is the basic element of urban natural ecological space. The rapid urbanization process has a significant impact on the pattern of urban blue-green space and seriously threatens the urban ecological environment. It is of great significance for urban ecological protection and sustainable development to study the change in characteristics of blue and green space during urban expansion. In this paper, a comprehensive method of remote sensing image, landscape pattern analysis, sector analysis, and coupling analysis is applied to analyze the spatio-temporal evolution characteristics and coordinated development level of the blue-green space and built-up area in central Wuhan from 1987 to 2018. The results showed that the land use and landscape pattern in the central city of Wuhan underwent a drastic change process, and the dominant change was the occupation of blue-green space by urban built-up areas, which led to the increase of landscape fragmentation and the decrease of heterogeneity. Urban green space is gradually marginalized and concentrated in local areas. The blue space has an obvious blocking effect on the expansion of the built-up area, and its spatial pattern tends to be stable gradually. In addition, the coupling degree between urban blue-green space and urban built area presents an inverted U-shape, and the coordinated development level among the three has entered a stage of moderate imbalance. It is urgent to strengthen the protection of blue-green space, curb the disorderly expansion of cities, and improve the quality of urban development.

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Study on Ecological Approach of Urban Green Space Based on Low Carbon Idea

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.955-959.4025 ◽

2014 ◽

Vol 955-959 ◽

pp. 4025-4028

Author(s):

Chen Gu Hua Fu

Keyword(s):

Green Space ◽

Urban Landscape ◽

Landscape Planning ◽

Global Climate ◽

Low Carbon ◽

Rapid Urbanization ◽

Regional Sustainable Development ◽

City Construction ◽

Low Carbon City ◽

Planning And Construction

The sharp degradation of urban ecological environment resulted from global climate change and rapid urbanization has become an important affecting factor of regional sustainable development. Low carbon city is a considerable countermeasure to solve this problem. Being an important part of low carbon city construction, low carbon urban landscape has attracted increasing interests from city managers and planners. The strategy of the low carbon urban landscape development was discussed from an ecological perspective, and the strategies of low-carbon urban landscape planning and construction were proposed, in order to provide practical reference for planning and construction of low-carbon city and low-carbon urban landscape. These strategies included selecting plant varieties, improving plant community structure, optimizing spatial structure of green space, constructing low maintenance green space, and synthesis utilization of water resources etc.

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Spatial Forecasting of the Landscape in Rapidly Urbanizing Hill Stations of South Asia: A Case Study of Nuwara Eliya, Sri Lanka (1996–2037)

Remote Sensing ◽

10.3390/rs11151743 ◽

2019 ◽

Vol 11 (15) ◽

pp. 1743 ◽

Cited By ~ 16

Author(s):

Manjula Ranagalage ◽

Ruci Wang ◽

M. H. J. P. Gunarathna ◽

D. M. S. L. B. Dissanayake ◽

Yuji Murayama ◽

...

Keyword(s):

Sri Lanka ◽

Urban Development ◽

Agricultural Land ◽

Urban Landscape ◽

Negative Relationship ◽

Support Vector ◽

Landscape Changes ◽

Rapid Urbanization ◽

Lulc Changes ◽

Urban Rural

Forecasting landscape changes is vital for developing and implementing sustainable urban planning. Presently, apart from lowland coastal cities, mountain cities (i.e., hill stations) are also facing the negative impacts of rapid urbanization due to their economic and social importance. However, few studies are addressing urban landscape changes in hill stations in Asia. This study aims to examine and forecast landscape changes in the rapidly urbanizing hill station of Nuwara Eliya, Sri Lanka. Landsat data and geospatial techniques including support vector machines, urban–rural gradient, and statistical analysis were used to map and examine the land use/land cover (LULC) change in Nuwara Eliya during the 1996–2006 and 2006–2017 periods. The multilayer perceptron neural network-Markov model was applied to simulate future LULC changes for 2027 and 2037. The results show that Nuwara Eliya has been directly affected by rapid urban development. During the past 21 years (1996–2017), built-up areas increased by 1791 ha while agricultural land declined by 1919 ha due to augmented urban development pressure. The pressure of urban development on forest land has been relatively low, mainly due to strict conservation government policies. The results further show that the observed landscape changes will continue in a similar pattern in the future, confirming a significant increase and decrease of built-up and agricultural land, respectively, from 2017 to 2037. The changes in agricultural land exhibit a strong negative relationship with the changes in built-up land along the urban–rural gradient (R2 were 0.86 in 1996–2006, and 0.93 in 2006–2017, respectively). The observed LULC changes could negatively affect the production of unique upcountry agricultural products such as exotic vegetables, fruits, cut flowers, and world-famous Ceylon tea. Further, unplanned development could cause several environmental issues. The study is important for understanding future LULC changes and suggesting necessary remedial measures to minimize possible undesirable environmental and socioeconomic impacts.

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Measuring compactness of the urban landscape within a city territory for environmental capabilities: the case of 50 cities in eastern China

Proceedings 24th ISUF 2017 - City and Territory in the Globalization Age ◽

10.4995/isuf2017.2017.5094 ◽

2017 ◽

Author(s):

Shuang Sophia Chen ◽

Tong Zhang ◽

Guangyu Li ◽

Yue Yan

Keyword(s):

Urban Form ◽

Urban Landscape ◽

Central City ◽

Urban Expansion ◽

Natural Habitat ◽

Eastern China ◽

Remote Sensing Data ◽

Developed Countries ◽

Environmental Capability ◽

The Developed Countries

When a compact city is pursued as the strategy for urban sustainability the understanding of compactness is varied from the developed countries to the developing countries. In China the historical cities are characterized with high density and mixed land use. After a short time of motorization they still show compact forms in the central city. A large amount of newly developed areas are distributed in clusters near or far from the center. The crop land and natural habitat are encroached to different degrees. This paper developed an approach to measure the structural compactness of urban landscape patches within a city territory. It included six spatial metrics to measure the shape and density of the central agglomeration, the area configuration and distant relationship between the central agglomeration and the other clusters, and the distribution of all urban patches. By this approach the 50 cities in eastern China were categorized into five classes of forms: one center, multi-centers, centralized groups, cluster groups and scatter. Then the vegetation biomass loss with urban expansion was calculated based on remote sensing data, and used to assess the environmental capability of the five types of urban form. The suggestions of urban form optimization could be put forward for the five categories of cities.

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Sources of and Control Measures for PTE Pollution in Soil at the Urban Fringe in Weinan, China

Land ◽

10.3390/land10070762 ◽

2021 ◽

Vol 10 (7) ◽

pp. 762

Author(s):

Lei Han ◽

Rui Chen ◽

Zhao Liu ◽

Shanshan Chang ◽

Yonghua Zhao ◽

...

Keyword(s):

Land Use ◽

Urban Expansion ◽

Pollution Sources ◽

Urban Fringe ◽

Control Measures ◽

Atomic Fluorescence Spectrometry ◽

Human Beings ◽

Rapid Urbanization ◽

Kriging Interpolation Method ◽

The Impact

The environment of the urban fringe is complex and frangible. With the acceleration of industrialization and urbanization, the urban fringe has become the primary space for urban expansion, and the intense human activities create a high risk of potentially toxic element (PTE) pollution in the soil. In this study, 138 surface soil samples were collected from a region undergoing rapid urbanization and construction—Weinan, China. Concentrations of As, Pb, Cr, Cu, and Ni (Inductively Coupled Plasma Mass Spectrometry, ICP-MS) and Hg (Atomic Fluorescence Spectrometry, AFS) were measured. The Kriging interpolation method was used to create a visualization of the spatial distribution characteristics and to analyze the pollution sources of PTEs in the soil. The pollution status of PTEs in the soil was evaluated using the national environmental quality standards for soils in different types of land use. The results show that the content range of As fluctuated a small amount and the coefficient of variation is small and mainly comes from natural soil formation. The content of Cr, Cu, and Ni around the automobile repair factory, the prefabrication factory, and the building material factory increased due to the deposition of wear particles in the soil. A total of 13.99% of the land in the study area had Hg pollution, which was mainly distributed on category 1 development land and farmland. Chemical plants were the main pollution sources. The study area should strictly control the industrial pollution emissions, regulate the agricultural production, adjust the land use planning, and reduce the impact of pollution on human beings. Furthermore, we make targeted remediation suggestions for each specific land use type. These results are of theoretical significance, will be of practical value for the control of PTEs in soil, and will provide ecological environmental protection in the urban fringe throughout the urbanization process.

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Planning for a neighborhood and city-scale green network system in Qatar: the case of MIA Park

Environment Development and Sustainability ◽

10.1007/s10668-021-01280-9 ◽

2021 ◽

Author(s):

Raffaello Furlan ◽

Brian R. Sinclair

Keyword(s):

Urban Landscape ◽

Single Case ◽

Landscape Fragmentation ◽

The State ◽

Network System ◽

Design Strategies ◽

Structured Interviews ◽

Main Mode ◽

The Past ◽

Neighborhood Scale

AbstractIn the past decade, Doha has witnessed fast-urban growth, an increased population rate, and an over-reliance on the automobile as the main mode of urban transportation. These factors caused social and environmental problems related to (1) the loss of a compact urban pattern, (2) an increased level of air pollution (3) high traffic congestions and (4) increasing landscape fragmentation. In consideration of such concerns, The State of Qatar invested large funds into the urban landscape development of Doha, as envisioned by Qatar National Vision 2030. As a result, in the past five years various parks and/or green areas, such MIA Park, a major public green space located around the Museum of Islamic Art (MIA), were planned and developed within metropolitan Doha. The authors argue that this park is currently facing issues and challenges related to (1) accessibility to/from the neighboring districts, and (2) connectivity to/from the neighboring parks. Therefore, this research study aims at assessing the existing conditions of MIA Park, at considering the broader city context and, at recommending strategies for implementing MIA Park’s green network system. It approached the investigative challenge using a multi-pronged comprehensive methodology, that deployed focus groups, semi-structured interviews and a comprehensive network analysis based on graph theory. The findings, revealed through these hybrid research tactics, allowed the researchers to generate a framework to enhance accessibility and connectivity of MIA Park through a green network system, planned at inter-related neighborhood-scale and city-scale levels. While the research examines most notably a single case, it is advocated that the proposed framework represents not just an optional feature pertaining to the case in Doha, but a valuable reference for the sustainable master planning of future cities in the State of Qatar and across the GCC. The paper proffers numerous key contributions, including the critical exploration of manufactured landscapes in Doha Qatar and the delineation of broadly applicable environmental design strategies to improve the fabric and livability of cities.

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