The researchers used a method called SCS curve number to estimate surface runoff in Vadodara City. They combined this method with remote sensing and GIS tools to analyze the data. By linking curve numbers with NDVI values, they found that both methods produced similar results in predicting runoff. The study focused on a specific soil type in the area and found that lower curve numbers indicate more infiltration and less runoff, while higher numbers mean more runoff and less infiltration. The researchers validated their results by comparing them with observed data, showing a strong correlation between NDVI and runoff values. This method can be used to estimate surface runoff in any area effectively.