Detecting Invasive Amur Honeysuckle in Urban Green Spaces of Cincinnati, Ohio Using Landsat-8 NDVI Difference Images

2020 ◽  
Vol 38 (3) ◽  
pp. 139-144
Author(s):  
Bridget Taylor ◽  
Denis Conover ◽  
Richard Beck
2018 ◽  
Vol 15 ◽  
pp. 77-86
Author(s):  
Mahendra Singh Thapa ◽  
Gokul Poudel

Urban green spaces are integral part of urban infrastructure. Green spaces can offer a number of benefits ranging from inner spiritual to outer materialistic values. Available green spaces in particular area especially in urban places need to be identified and located properly with scientific way and means so that we can use those places in emergency caused by natural or human induced hazards. This study has tried to measure the green space available for people dwelling in Butwal Sub-Metropolitan City of Nepal. An attempt was made to quantify green spaces in urban environments from Landsat 8 OLI imageries using object-oriented approach and field verification. The study concluded that the total green space available in Butwal Sub-Metropolitan City is 86.37 km2 i.e., around 86% of total municipal area and per capita green space is around 623 m2.


Land ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 453
Author(s):  
Marcin Feltynowski ◽  
Jakub Kronenberg

Urban green spaces are frequently presented as being important for urban quality of life and urban development in general, but more detailed interpretations and discussions are typically confined to large urban centers, the so-called first- and second-tier cities. Not enough attention has been paid to smaller urban units, the third-tier towns. The main goal of this article is to investigate the share and types of urban green spaces in five selected towns in Poland. We compare different sources of data based on satellite imagery and land-use maps with those used in public statistics, to check whether town authorities are managing all potential green spaces or only a selected part of them. We find that the predominantly used data, based on what is classified as “urban green space” for the purposes of public statistics, obscure the complexity of urban green spaces and focus on the narrowly understood formally managed public green spaces (which occupy 3.5–5.7% of town areas). Meanwhile, based on other sources, such as the national land-use map (BDOT10k), Urban Atlas, and satellite imagery (Landsat 8), what is considered to be green space turns out to cover 50–80% of the town area. The latter large numbers are associated with the predominance of arable land, grasslands, and forests, overlooked in any green space management practices based on data and definitions adopted for the purposes of public statistics. The situation found in our five case study towns resembles that identified in larger cities in Poland, and it exhibits the inadequacy of public statistics definitions and the related management practices, hindering the management of urban green spaces as an interconnected system of urban green infrastructures.


2020 ◽  
Author(s):  
Maria Polinova ◽  
Haim Kutiel ◽  
Lea Wittenberg ◽  
Anna Brook

<p>Climate change, increased frequency of natural disasters and their anomaly in the modern world demand review existing knowledge about environment and approaches for its management. In recent decades, one of the phenomena that humanity met with is urban wildfires. Experience has shown that existing approaches from forest fire management are not effective in a built-up environment. In practice, studying this phenomenon is limited due to lack of empirical knowledge.</p><p>To bridge this knowledge gap, the fire dynamic patterns in an urban area was reconstructed based on fire service data on the example of wildfire in Haifa (Israel) in November 2016. The results of reconstruction show that unlike forest fires, where fuel is almost unlimited around the ignition point, urban areas are sensitive to wildfire because of 'fire connectivity' through vegetation: fire moves from one green patch to another, bypassing nonflammable structures.</p><p>Although the role of urban vegetation in the spread of fires is obvious, it is difficult to define a suitable term in case of fire management. Today, cities and vegetation are studied together in the urban planning and ecosystem services and have different definitions, depends on study propose: ‘Urban Green Spaces’, ‘Green Infrastructure’, ‘Urban Forestry’, etc. The closest term in fire management for vegetation interaction with structures is ‘Wildland Urban Interface’ (WUI). However, WUI considers vegetation surrounding the city and excludes urban green spaces. Since before this time the inner-city vegetation was not considered in the fire management and wasn’t estimated its essential parameters for this case, it does not have an exact term and definition. The reconstructed wildfire allows to analyze and define vegetation in context of fire connectivity.</p><p>The results show that wildfire spreads in the urban area through ember attacks. Meanwhile, the embers led to ignition only in some patches and only in a few cases the energy amount was enough for new embers emission. Thus, the fire vegetation connectivity in urban areas can be defined by its ability to ignite and reproduce new embers.</p><p>To support fire management and risk assessment in urban areas, it is important to map vegetation based on its ignitability and potential energy emission. The task is complicated due to the uncertainty of surface fuel (including both litter and human waste). Citywide, detecting and monitoring such patches through field surveys is time-consuming work. To solve this objective by remote sensing technique, we analyzed series of Landsat 8 images for 2015 to identify spectral and temporal features of vegetation related to its flammability. The proposed approach supports estimation and mapping of vegetation connectivity in case of urban wildfire based on its multi-temporal spectral signature.</p>


2021 ◽  
Vol 13 (14) ◽  
pp. 7863
Author(s):  
Antonios Kolimenakis ◽  
Alexandra D. Solomou ◽  
Nikolaos Proutsos ◽  
Evangelia V. Avramidou ◽  
Evangelia Korakaki ◽  
...  

Urban green areas present a lucid example for the harmonious co-existence of the artificial and natural environments best illustrated by their interdependence and interconnection in urban spaces. Urban green areas are essential for the health and wellbeing of citizens. The present study aimed to investigate those multiple benefits for citizens that arise through the existence of urban green areas, as well as important policy dimensions that should be considered when designing the expansion of urban green spaces in urban development. The study was based on a literature review to examine for available evidence on the benefit levels derived by the existence of urban green areas. An extended literature review was followed by a structured review, based on specific inclusion and exclusion criteria, which partly followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The search was conducted in two databases, and a total of 1674 articles and abstracts were identified through the database searches. After removing 114 duplicates, 1560 records were initially screened based on title and abstract. Following inclusion and exclusion criteria, 14 articles were incorporated in the structured review and a total of 47 in the extended review. The extended literature review identified 33 additional articles examining aspects of benefits that did not fall under the pre-established inclusion and exclusion criteria used in the structured review, such as health benefits and other social parameters associated with urban green spaces. The selected studies were allocated in five principal groups according to study types: three of the them consisted of studies employing “willingness to pay” (WTP) methods, five were based on property values, two studies assigned monetary values, while another two assigned CO2 values, and, finally, two studies were based on qualitative criteria. The results indicated benefits to citizens and increased welfare levels gained by the existence of urban green areas. The conducted review revealed a number of findings and recommendations that could direct future research and urban policy. Those hints could assist local authorities as well as stakeholders in order to measure and assess the benefits of green spaces and urban parks and promote measures and programs to assist their further deployment.


2021 ◽  
Vol 70 ◽  
pp. 102603
Author(s):  
Lucía Rodriguez-Loureiro ◽  
Lidia Casas ◽  
Mariska Bauwelinck ◽  
Wouter Lefebvre ◽  
Charlotte Vanpoucke ◽  
...  

2021 ◽  
Vol 10 (4) ◽  
pp. 251
Author(s):  
Christina Ludwig ◽  
Robert Hecht ◽  
Sven Lautenbach ◽  
Martin Schorcht ◽  
Alexander Zipf

Public urban green spaces are important for the urban quality of life. Still, comprehensive open data sets on urban green spaces are not available for most cities. As open and globally available data sets, the potential of Sentinel-2 satellite imagery and OpenStreetMap (OSM) data for urban green space mapping is high but limited due to their respective uncertainties. Sentinel-2 imagery cannot distinguish public from private green spaces and its spatial resolution of 10 m fails to capture fine-grained urban structures, while in OSM green spaces are not mapped consistently and with the same level of completeness everywhere. To address these limitations, we propose to fuse these data sets under explicit consideration of their uncertainties. The Sentinel-2 derived Normalized Difference Vegetation Index was fused with OSM data using the Dempster–Shafer theory to enhance the detection of small vegetated areas. The distinction between public and private green spaces was achieved using a Bayesian hierarchical model and OSM data. The analysis was performed based on land use parcels derived from OSM data and tested for the city of Dresden, Germany. The overall accuracy of the final map of public urban green spaces was 95% and was mainly influenced by the uncertainty of the public accessibility model.


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