TOPICS: Flood control
Flood is the result of excessive rain or snowmelt. It is one of the natural disasters in Nepal.
Steep mountain slopes, poor land use practices and acute shortage of firewood are contributing more to floods in Nepal every year.
The damage is increasing mainly due to human action toward disturbing the ecological balance and human inaction and flood preparedness and prevention.
The past experience in many parts of the world has shown that the structural flood control measures as a means of reducing flood damage have been effective for medium and small-sized floods; but they are of little value for the control of every large and rare events.
The damage can be much more disastrous if the structure fails.
Till now, the general conception of accomplishing the prevention and safeguard of flood loss has been the structural control measures, which are mainly the construction of dams or dykes to regulate or control the flood flow.
However, the basic question here is whether the structural flood control methods, which are favored for many years, are fully satisfactory or not.
The major constraint associated with structural flood control methods are the increasing cost of construction and the rising environmental concern. The channelization of flood flow at upstream can cause detrimental effect by increasing flood peaks in downstream flood plains.
The construction of dams can have some value only if the benefit is shared in a regional basis with neighboring countries since the flood protection with this approach is useful for areas much more downstream.
The magnitude of floods directly depends on the rainfall capacity of watersheds. Hence, the best approach to reduce the flood peaks would be to conserve the water where it falls.
The massive deforestation and the unscientific land use are believed to be the main reason behind increasing flood peaks in recent years. The solution lies in increasing the rainwater retention capacity of the watershed by formulating and implementing proper management policies.
Actually, effective watershed management is possible only if the land users are willing to cooperate well.
If they realize that the top soil is vital for better production and if they protect it by consuming the rainwater falling on their farms, the result would be better than what the governments of many countries could achieve by spending huge funds in flood control.