Floodplain Irrigation

There are two types of floodplain irrigation: flood rise and flood recession. In both types, a rising perennial river overtops its banks and inundates the plains alongside the river. Crops are grown on the rising or on the receding flow and the residual moisture. Floodplain agriculture usually takes place in Delta areas close to where the flood water reaches the sea.

One common practice on flood rise is the cultivation of deep water rice. About 1 million people in South and Southeast Asia rely on deep water rice for sustaining their livelihoods. Another flood rise practice in these areas is the use of floating farming systems. These systems has been used since prehistory (especially in Bangladesh) en consist of a floating platform made of decomposing heaps of water and hyacinth with an upper surface layer of ash, coconut fibre and (occasionally) soil. The size usually varies between 50-60m long, 1.2-1.5m wide and 25-50cm thick. Floating farming systems is a climate change adaptation method with high potential. Every year floodplains inundate of which 30% deeper than 1m. During heavy monsoon these floodplains can even rise to 60% which makes normal agricultural activities very difficult.

Example of  flood recession rice cultivation on a Cambodian floodplain (Mekong delta):

Examples of floating farming systems in Bangladesh:

 

 

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