Nanosensor-based satellite images and GIS filter for urban expansion analysis and its impact on climate change

Karbala is one of the main cities in Iraq and gained its importance through religious tourism and more than three religious occasions, especially the Arbaeen visit, which brings the number of visitors to more than five million annually. Therefore, urban expansion has increased at the expense of vegetation cover and has even become a challenge for urban planning, which is the research goal. Obtaining reliable data for urban planning, evaluating, monitoring, and mapping vegetation cover and urban expansion using the Landsat-8 satellite image. Three indicators of the urban area, vegetation, and open land for five years (2003, 2010, 2015, 2020, and 2023) are used to evaluate and analyze urban expansion visually and quantitatively. In addition, some meteorological variables to evaluate the impact of urbanization on global warming in Karbala. The results show that the growth in population density has increased to reach 1,356,856 people in the year 2023, with an estimated growth rate of 1,794. This percentage is considered large when compared with other cities, and this indicates the city’s recovery from the economic, commercial, and urban aspects. Remote sensing is one of the tools that can analyze satellite images. Satellite images provided from Landsat-8 and Landsat-9 were then used (NDVI) filter, and the results indicated that there is a shrinkage in agricultural areas. This contraction began to appear in 2005 in central and northern Karbala, while the largest drought the city faced was in 2015. Analysis of satellite images can estimate climate change through some meteorological variables. The results showed that the ground temperature (LST, T2M) and the air temperature at an altitude of 2 meters increased by 2 o C, and their average was (24.602, and 24.216), respectively. The noticeable increase in vertical and horizontal urban expansion compared to the shrinkage of green spaces led to verifying this fact by analyzing the images obtained and by comparing the categories of vegetation cover, which are barren, well vegetation, medium vegetation cover, and low vegetation cover. It was found that there were two categories in which their percentages were exchanged, which is the contraction of the area of vegetation cover of the wells at the expense of an increase in the low vegetation cover of 6%, especially in the last five years with the visit of visitors during the visit of Ashura and Arbaeen. This expansion is unplanned from an urban and infrastructure standpoint, so the study pointed out the difficulties accompanying it. Increasing urbanization in this particular region is associated with several notable negative consequences.