Dear Sir Greetings!
For the first
question,
In my view water
budgeting & accounting should be done both for SW and GW.SW accounting has
been done daily by taking the yield of the particular water structure(using
rain gauge),inflow and outflow of the water structure(using rise and fall
method the water storage will be assessed) from the begining of water year to
end of the water year (e.g july'17 -june'18).
Budgeting will be done
based on the water balance statement and the demand.
GW accounting should
be done separately,(daily basis) based on rainfall intensity,soil properties
etc., as well regular gw level should be checked so that water drawn and
can be assessed.Hence water accounting has to be done separately for SW &
GW.
For the second
question.
Yes,we have to
consider the dams,weirs and watershed works to determine runoff.ofcourse weirs
and reservoirs are used to gauge the rainfall or snow melt(based on size). As
well watershed drainage patterns will play a role in determing runoff
as well as
deepening & widening of nalla has to be taken into
account . The runoff speed, both overland and in drainage channels, depends to
a large extent upon channel and land slope.
Sand Mining within or near riverbed has a direct impact on
the stream's physical characteristics, such as channel geometry, bed elevation,
substratum composition and stability, in-stream roughness of the bed, flow
velocity, discharge capacity, sediment transport capacity, turbidity, temperature
etc. Alteration or modification of the above attributes may cause hazardous
impact on ecological equilibrium of riverine regime.which will influence the
run off.
Uncontrolled GW
pumping:
Lowering of ground
water table in the flood plain because of lowering of riverbed level as well as
river water level takes place because of extraction and draining out of
excessive ground water from the adjacent areas. So, if a floodplain aquifer
drains to the stream the base flow can be affected as a result of
uncontrolled pumping.Excessive pumping of ground water in the process of
mining in abandoned channels depletes ground water causing scarcity of
irrigation and drinking water. In extreme cases it may create ground fissures
and subsidence in adjacent areas.
Sir,this is my view
out of little knowldge acquired.Hope you would have clearly explain.Eagerly
waiting Sir.
Thank you Sir
Leela.G (Participant
of IDL)