Slides in this set
What is soft engineering?
· Soft engineering are protection schemes that work with nature instead of
against it, so they are much more sustainable than other hard engineering
· Relatively cheap compared to hard engineering.
· It is used along with harder engineering schemes on some rivers.
· Some examples are afforestation, flood prediction and land use zoning.
· Soft engineering is often more attractive to look at than hard engineering.
This is when trees are deliberately planted in areas around the river,
where there has not previously been any vegetation.
· It helps to prevent a flood by preventing surface run-off and
increasing interception and evapotranspiration. This means that the
water takes longer to reach the river (increases lag time), which
lowers the peak discharge.
· All in all, there is a reduced risk of the river flooding and if it should
flood, a lot of the force and velocity from the water is absorbed by
the vegetation, so the flood becomes less damaging.
· Fairly Cheap. · Increases fire risk.
· Natural. · If trees are planted in certain
patterns (i.e- straight lines of trees),
· Environmentally friendly. it may not necessarily look natural.
· Creates habitats for wildlife. · Not as effective as some other
· Looks attractive. management strategies, such as
· Jobs are provided (people are dams or levees.
employed to plan, implement and
maintain the strategy).
· Regulates stream temperature by
Afforestation of Damodar River Basin,
· There was 40million hectares of land prone to flooding in India.
· The Damodar River rises in Jharkhard and flows South-East into West
Bengal. It joins the river Hoogly just after Kolkata. After Durgapur, West
Bengal, the river changes its course and splits into 2 different channels
(The Damodar Channel and the Kanka-Mundeshwari channel). Eventually,
the main channel reaches the Hoogly River once again and joins the Bay of
· Annual rainfall varies between 1000mm and 1800mm.
· Delhi, Kolkata and many sites of industrial importance had a risk of
flooding. They were protected with artificial levees but heavy floods often
· A management plan was put in place, which involved the afforestation of
121,500 hectares of land. *…read more