Empirical Method ( 12- 05- 2011 L: 5 )

The maximum flood discharge Q_p(m³/s) from a catchment area  A(km²)is given by the following empirical formula as

a) Dickens Formula (1865): Q_p = C_dA^3/4, where C_d Dicken’s constant (6~30).

b) Ryres Formula:  Q_p = C_RA^2/3, where C_R Ryres constant.

c) Inglis Formula (1930):  Q_p =  

 

d) Fuller’s Formula (1914): Q_TP = C_fA^0.8(1+0.8logT)

Where, Q_TP = Maximum 24hr flood with a frequency of T year in m³/s,

And C_f = constant (0.8~1.88).

e) Envelop curves Formula:
 

 

Administrative/ non structural measures ( 08-05-2011 L: 4)

The main idea is to keep the general civil & industrial activities undiminished during flood which can be ensured by

Administrative/ non structural measures ( 08-05-

The confluence of three major rivers- the Ganges, the Brahmaputra, the Meghna (03-05-2011 L: 3)

The runoff from their vast catchment (about 1.72 million km²)

types of floods ( 28-04-2011 L: 2)

The common flood types in Bangladesh are:

Flash flood:  Flash flood in the eastern and northern is characterized by a sharp rise followed

GBM ( Ganga, Brahmaputra, Meghna) Basin

Flash flood ( North part, East part )   (26-04-2011       L: 1)

Picture of Some Wonders