5 research outputs found
Monitoring urban greenness evolution using multitemporal Landsat imagery in the city of Erbil (Iraq)
Most cities in the world have experienced major developments in the past 20–25 years. However, research has showed that the development aspect of these cities has led to a decrease in green areas. This paper aims to assess the spatiotemporal variations of urban green areas during the period 1990–2015 with special regard to city of Erbil. The study uses a mix of fuzzy functions, linear spectral mixture analysis, and maximum likelihood classification for the classification of Landsat imagery from 1990 to 2015 to extract the four main classes of land use, namely agricultural land, vacant land, built-up land, and green vegetation. Both the classification approaches used in this research produced excellent and reliable results, as an overall accuracy of more than 80% was able to be obtained. The spatiotemporal analysis of land use within the city of Erbil shows a series of major changes between 1990 and 2015. Therefore, the results of the spatiotemporal evolution of urban greenness assessment in the Erbil region can be used both for spatial planning purposes and as an urban greenness assessment method in dry climate areas
Spatiotemporal Assessment of Vegetation Indices and Land Cover for Erbil City and Its Surrounding Using Modis Imageries
The rate of global urbanization is exponentially increasing and reducing areas of natural vegetation. Remote sensing can determine spatiotemporal changes in vegetation and urban land cover. The aim of this work is to assess spatiotemporal variations of two vegetation indices (VI), the Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI), in addition land cover in and around Erbil city area between the years 2000 and 2015. MODIS satellite imagery and GIS techniques were used to determine the impact of urbanization on the surrounding quasi-natural vegetation cover. Annual mean vegetation indices were used to determine the presence of a spatiotemporal trend, including a visual interpretation of time-series MODIS VI imagery. Dynamics of vegetation gain or loss were also evaluated through the study of land cover type changes, to determine the impact of increasing urbanization on the surrounding areas of the city. Monthly rainfall, humidity and temperature changes over the 15-year-period were also considered to enhance the understanding of vegetation change dynamics. There was no evidence of correlation between any climate variable compared to the vegetation indices. Based on NDVI and EVI MODIS imagery the spatial distribution of urban areas in Erbil and the bare around it has expanded. Consequently, the vegetation area has been cleared and replaced over the past 15 years by urban growth
Spatiotemporal assessment of vegetation indices and land cover for Erbil city and its surrounding using modis imageries
Spatiotemporal Assessment of Vegetation Indices and Land Cover for Erbil City and Its Surrounding Using Modis Imageries
The rate of global urbanization is exponentially increasing and reducing areas of natural vegetation. Remote sensing can determine spatiotemporal changes in vegetation and urban land cover. The aim of this work is to assess spatiotemporal variations of two vegetation indices (VI), the Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI), in addition land cover in and around Erbil city area between the years 2000 and 2015. MODIS satellite imagery and GIS techniques were used to determine the impact of urbanization on the surrounding quasi-natural vegetation cover. Annual mean vegetation indices were used to determine the presence of a spatiotemporal trend, including a visual interpretation of time-series MODIS VI imagery. Dynamics of vegetation gain or loss were also evaluated through the study of land cover type changes, to determine the impact of increasing urbanization on the surrounding areas of the city. Monthly rainfall, humidity and temperature changes over the 15-year-period were also considered to enhance the understanding of vegetation change dynamics. There was no evidence of correlation between any climate variable compared to the vegetation indices. Based on NDVI and EVI MODIS imagery the spatial distribution of urban areas in Erbil and the bare around it has expanded. Consequently, the vegetation area has been cleared and replaced over the past 15 years by urban growth
Spatial distribution of vegetation cover in Erbil city districts using high-resolution Pléiades satellite image
Green spaces are playing an essential role for ecological balance and for human health in the city as well.They play a fundamental role in providing opportunities for relaxation and enjoying the beauty of naturefor the urban population. Therefore, it is important to produce detailed vegetation maps to assist plannersin designing strategies for the optimisation of urban ecosystem services and to provide a suitable planfor climate change adaptation in one fast growing city. Hence, this research is an investigation using 0.5m high-resolution multispectral Pléiades data integrated with GIS data and techniques to detect andevaluate the spatial distribution of vegetation cover in Erbil City. A supervised classification was usedto classify different land cover types, and a normalised difference vegetation index (NDVI) was usedto retrieve it for the city districts. Moreover, to evaluate the accessibility of green space based on theirdistance and size, a buffer zone criterion was used. The results indicate that the built-up land coverageis 69% and vegetation land cover is 14%. Regarding NDVI results, the spatial distribution of vegetationcover was various and, in general, the lowest NDVI values were found in the districts located in the citycentre. On the other hand, the spatial distribution of vegetation land cover regarding the city districts wasnon-equal and non-concentric. The newly built districts and the districts far from the Central BusinessDistrict (CBD) recorded the lowest vegetation cover compared with the older constructed districts.Furthermore, most of the districts have a lack of access to green spaces based on their distance and size.Distance and accessibility of green areas throughout the city are not equally distributed. The majority ofthe city districts have access to green areas within radius buffer of two kilometres, whereas the lowestaccessibility observed for those districts located in the northeast of the city in particular (Xanzad,Brayate, Setaqan and Raperin). Our study is one of the first investigations of decision-making supportof the spatial planning in a fast-growing city in Iraq and will have a utilitarian impact on developmentprocesses and local and regional planning for Erbil City in the future