The three$-$day non$-$stop torrential raining starting on Friday $(17$ December $2021)$ until Sunday $(19$ December $2021)$ resulted in a series of floods and flash flood in several parts of Malaysia. As of $21$ December $2021,$ The Malaysia$$s National Disaster Management Agency $($NADMA$)$ has reported $33$ districts in $8$ states affected by floods with a total of $62,999$ persons displaced in $430$ evacuation centres with the majority from Pahang: $8,881$ families$/34,924$ persons displaced in $266$ evacuation centre $(10$ districts$)$ followed by Selangor: $3,667$ families$/22,947$ persons displaced in $109$ evacuation centres $(9$ districts$).$ In Selangor, the most affected district was Hulu Langat, followed by Shah Alam and Sepang.

a$)$ Compare and contrast why certain flooding areas in Selangor takes $2$ days to clear whereas some part takes longer times

b$)$ Discuss the impact of this disaster on the socio$-$economy, human health, education, and environment.