(b)Study Figure 2 which is an extract from a news website about the cause of floods in Pakistan in August With the help of Figure 2 explain why floods occurred in Pakistan in August (4 marks)

Mark scheme. One mark per valid point Rainfall has become more intense with more than half the normal monsoon rain falling in one week. This means that a large amount of precipitation reaches the river channel in a short amount of time so peak discharge above the river’s bankfull capacity. Also levees have been built along the river banks of the Indus. This initially increases bankfull level but in low flow conditions sediment is dropped on the river bed and the channel silts up. This raises the river bed above the level of the flood plain so when the river tops it s banks water cannot naturally drain back into the river and flooding is more severe. Also deforestation has decreased interception, interception storage and evapotranspiration so more water reaches the river channel increasing peak discharge above bankfull capacity so the river floods. (4)