ANALYSIS OF THE IMPERVIOUS SURFACE EXPANSION ON URBAN RUNOFF

Analysis of impervious surface expansion in urban areas has been a great deal all over the world. The impact of this expansion has been challenging the environment, people in particular. This study has considered the expansion in urban imperviousness as one of the root causes of urban water accumulation and the subsequent disturbances that people incur in urban areas especially during rainstorms. Goal and Objectives: Analyzing the relationship between urban imperviousness and the resulting urban runoff Methodology: The determination of the impervious surface was through the Normalized Built-up Index (NDBI) from Landsat 5 (1995 and 2009) and Landsat 8 (2017) imagery whereas the determination of runoff of the area of interest was through the SCS-CN method Results: The two datasets were found to be positively correlating, i.e. an increase in the impervious surface resulted into an increase in urban runoff and vice versa. It was found that, although 2017 had the lowest runoff interval of 3.907-72.08 due to a least amount of rainfall, it had a maximum coverage (imperviousness) of 93.16 Sq.km for runoff compared to 1995 and 2009