employed over the years in the assessment of the environment. Now these urban, um, impervious surfaces are a land cover type which have higher absorption of solar radiation and they also have high thermal conductivity. Impervious surface release heat during, start during the day and night and so the impervious surface have a warming effect on

the urban land surface temperature. Over the years, impervious surface area have found relevance as it is being used as a key environmental indicator. Three major algorithms have been created and utilized to extract impervious surface area from remotely sensed imagery. These include spectral unmixing techniques, machine learning methods and the spectral index methods

with their soft categories as seen here. The normalized difference impervious surface index belongs to the category of special index and these spectral index indices have been found to measure the biophysical properties of the surface more accurately than the two other methods.

Normalized difference, uh, difference, uh, impervious surface index was utilized in the study to estimate the impervious surface areas. The index can efficiently enhance and extract impervious surfaces from satellite imagery and the proportion of the impervious

surface can be represented as well. The city of Abuja is currently experiencing rapid urbanization and so there is a rise in anthropogenic activities such as construction of roads, pavements and residential areas. All of this give rise to the formation of impervious surfaces. The impervious surface increases the urban mean surface temperature over time and this concern is noticed in the formation of urban heat island facilitated by

impervious surfaces. Analyzing the relationship between impervious surface and land surface temperature is very important in recognizing, controlling and mitigating the environmental impacts of urban heat islands in planning and developing the city of Abuja. This study

examines the impacts of the spatial distributions of impervious surface on land surface temperature in the study area for a 14-year period from 2004 to 2018 using both graphical and quantitative approach. This is with a view to investigate the impact of impervious surface on the urban heat environment. The study area is a federal capital territory of Nigeria. It's

popularly known as Abuja City. It is located between this latitude and longitude. It has an area of about 8,000 kilometers square situated at 840 meters above mean sea level. As of 2020 it has a population of about 2.99 million and the climate it enjoys a

tropical wet and dry climate with mean annual mean temperatures ranging between 25 degrees Celsius to 30 degrees Celsius and with a mean annual rainfall of about 1,631 millimeters. Now we can see a map of study area. Next slide. The method of data acquisition.

The data sets used in the study basically were Landsat images that's Landsat 7 and Landsat 8 and here we see the characteristics of this of the satellite images they all have 30 meter

resolution and these are the dates of collection with zero percent cloud. After data acquisition geometric and radiometric correction were carried out and the reason for carrying out this correction is correct for sensor and platform specific distortions due to variations in scene

illumination and viewing geometry. Atmospheric condition and sensor noise and response are also corrected in geometric and radiometric correction and then on that the radiometric correction as well there is combustion of email pictures to add sensor reflectance. Scanline error correction was carried out for Landsat 7 imagery and the image was finally subset to the

administrative boundary of the study area. Next the land surface temperature was retrieved using this formula and after that the top of atmosphere brightness temperature was also retrieved using the the spectral radiance which was created earlier on. After this creation the normalized

vegetation index was used to estimate the proportion of vegetation and the surface emissivity further used to calculate the land surface temperature using this using this formula. In this study the the threshold method was used to obtain that land surface emissivity. This

formula was used to derive the NDVI used in the study. Two reasons why the NDVI was calculated for was for understanding the city's vegetation pattern and secondly is to extract the emissivity value. Then the impervious surface were extracted. The index-based technique was used

in this study to map out the impervious surface of aperture. A normalized difference impervious surface index was estimated to depict each epoch using this equation and the

this index can isolate impervious surfaces from non-impervious surfaces such as soil, water, and vegetation. Lastly the statistical analysis was carried out using correlation regression analysis which were used to examine and analyze the impact of urban surface and impervious surface on urban surface temperature and biodiversity.

This was achieved by examining its quantitative relationship with land surface temperature and vegetation represented by the vegetation index. The sample points selected were distributed across conspicuous impervious surface features such as built-up area, pavements, bare surfaces, vegetation, and water. These are the results of the study. This shows the spatial distribution

of land surface temperature in Abuja City for the year 2004-2008. On next slide we see the distribution for 2014 and 2018. And also this figure shows the summary of the

trend of land surface temperature between 2004 and 2018 and we can see a gradual increase in surface temperature both the minimum, the maximum, and mean temperature in Abuja City between 2004 and 2018. Results show a gradual increase in mean surface temperature by at least

2°C over the years within the study period. Total average increase of 6°C between 2004 and 2018. The highest temperatures were observed in regions experiencing rapid urbanization mostly in the south of Abuja. Meanwhile a large portion of Abuja City experiences

maximum land surface temperature of over 14°C in the study period. The high temperatures are detected in large commercial and residential areas due to the influx of people and the possible air heating impacts of gases emitted from vehicles, building, cooling systems, and reflection

absorbance of routine sheets. These results show the spatial pattern of the distribution of vegetation in the study area. The high NDVI values indicate abundance of vegetative cover as compared to areas with low NDVI values. Areas of high vegetation are mostly cultivated lands,

grasslands, and other undeveloped natural surfaces while areas with least vegetation are the built up urban areas, the wet soil, the water, and the rocks as well. The next result is the spatial pattern of impervious surfaces in Abuja. This result shows the spatial pattern of

impervious surface as distributed over Abuja, Nigeria. It incorporates urban surface such as rooftops, roads, parking lots, and natural impervious surface such as wetlands and water bodies. The maps for the impervious surfaces are shown in the next slide. These maps are the maps of the impervious surfaces recorded in Abuja in 2004, 2008, 2014, and 2018.

From the result, it was found Abuja City indeed underwent widespread organization which in turn led to the creation of impervious surfaces such as rooftops, roads, parking lots, sidewalks, and driveways. The values of land surface temperature and impervious surface

were extracted to 150 sample points identical to all epochs in this study. These sample points were used for the regression and correlation analysis. You can see the result of this analysis in the next figure which is figure 6. This is a result of the correlation between land surface

temperature and the impervious surface index. This result shows a positive correlation between these two variables which implies that as the impervious surfaces increase around the study

area, the land surface temperature increases as well in all the years under study. The results indicate the positive correlation between impervious surface and land surface temperature for each epoch which correlation coefficient values are seen here for 2004, 2008, 2014, and 2018 respectively

all at 95 percent confidence interval. This demonstrates that the development of impervious surface contributes to temperature rise in Abuja City. For that suggests that the surface temperature rise is high in dense impervious surface areas and it's faster there

than in newly dense impervious surface areas. The impact of impervious surface on land surface temperature in 2018 was more prominent in other preceding years under study. The next result is the relationship between land surface temperature and the normalized different vegetation index as vegetation of the area. The relationship between land surface

temperature and normalized vegetation index was analyzed to test the correlation between these variables to see the effect that the vegetation in the area has on land surface temperature. The results are presented in the next figure which is figure seven. This figure shows a

negative correlation between land surface temperature and the NDVI for all the years under study. We can see the trend line slanting downwards which was a negative correlation which implies that the land surface temperature increases as the amount of vegetation in the study area

decreases. The results show that there exists a very strong negative correlation between land surface temperature and the normalized difference vegetation index in the study area. The year 2018 showed the strongest correlation with correlation

the coefficient of determination at of 0.738 which is quite strong while the weakest correlation was found in 2008 between the two variables with a percent of the determination of 0.6425.

The results imply that vegetation covers an influence on the mean surface temperature obtainable at a particular location and therefore where vegetation exists the temperature of the area is less compared to the built environment as affected by anthropogenic activities. Furthermore from the results obtained the negative correlation between land surface temperature and NDVI ascertained the cooling impacts of forest woodland parks and other green

city spaces. This study in conclusion sorry this study gives great insight on the concept of impervious surface and its partial pattern in Abuja City Nigeria over a period of 40 years. It reveals that surfaces such as roads rooftops pavements situated in urban areas are highly

impervious while surface covered with vegetation possesses low imperviousness. In this paper the relationship between impervious surface distribution and mean surface temperature of Abuja City Nigeria have been studied. The broad characteristics of impervious surface and their effects in enhancing high surface temperature are also being

unveiled. In previous surfaces an impervious surface as a variable show a significant bivariate relationship to land surface temperature in each period under study. The impervious surface proved to be a true indicator of variations in land surface temperature dynamics with a positive linear relationship with land surface temperature

whereas the land surface temperature and the NDVI had a negative linear relationship. It was observed that impervious surface contribute to the surface temperature rise in Abuja and this can be attributed to anthropogenic activities arising from rapid urbanization which consequently form amphibious surfaces. The study recommends the widespread use of

highly reflective or natural surfaces for rooftops pavements and roasts and that afforestation should be encouraged to increase green areas. Thank you for listening.