ENVIRONMENTAL SCIENCE : NATURAL RESOURCES 51
(7) The Nagarjunasagar
The Nagarjunsagar Project is built on river Krishna in Andhra Pradesh. It irrigates
8,67,00 ha land.
(8) The Chambal Project
The Chambal irrigation parts of M.P. and Rajasthan. There are many other such projects
on different rivers in the country.
ENVIRONMENT PROBLEMS CREATED BY DAMS
We can study the environmental side effects of river valley and hydle-power projects in
three categories as under:
(i) Effect within and around the area covered by the dam and reservoir.
(ii) Downstream effects consequent to the alternation in hydraulic regime,
(iii) Regional effects in terms of overall aspects including resources use and socio-
economic aspects.The Evil Impacts
The impacts caused by construction of dams and reservoirs include the following:
(i) Changes in the microclimate,
(ii) Loss of vegetal cover,
(iii) Soil erosion,
(iv) Variation in water level,
(v) Enhanced seismic activities due to pressure of water.(1) Effects of Blasting
In hilly tracts, blasting operations for road construction can cause considerable damage
to the environment through the following reactions:
(a) Loosening of hill sides and resultant landslides,
(b) Sedimentation of reservoirs,
(c) Drying up of spring and flash floods.
(2) The creation of new settlement for the workmen and rehabilitation of project oustees
in the watershed areas may aggravate the seriousness of advance impact.
The Guidelines
The guidelines refer to the environmental components to be taken in view during site
selection. These include the following points:
(i) Short and long-term impact on population in the unidentified and watershed areas;
(ii) Impact on wildlife,
(iii) Impact on land use,
(iv) Potential seismic impact of reservoir loading,