Question

1. Circle the correct answer of the following (True/False)
2. 1. Groundwater flows faster that surface water (T/F)
   2. Water table is the locus of points where water pressure is zero relative pressure (T/F)
   3. Aquiclude is a synonym to confining layer (T/F)
   4. Perched water table is a water table that forms below a restrictive layer near the soil surface (T/F)
   5. In confined aquifer, hydraulic gradient equals to the slope of the piezometric surface (T/F)
   6. In unconfined aquifer, hydraulic gradient is the water deriving force and equals to slope of water table surface (T/F)
   7. oceans lose more water by evaporation than they gain by precipitation (T/F)
   8. Land surfaces receive more water as precipitation than they lose by evapotranspiration (T/F)
   9. Residence time of lakes is lower than that in rivers (T/F)
   10. Residence time is the time required to replace a given ocean constituent by river supply (T/F)
   11. Residence time tells how quickly or slowly a river constituent can respond to a change in the constituent supply or removal rates (T/F)

Answer 1

a)- false, as surface water flows faster than ground water, but ground water flow also depends on hydraulic gradient. If hydraulic gradient is quite high than surface gradient then ground water flow faster than surface water.

b)- True. As water table is locus of atmospheric pressure, so relative pressure to atmosphere becomes zero.

c)- False , as acquiclude may retain water but they don't allow permeability through it. Whereas confining layer contains lower and lower water.

d)- True, perched water table is water retained in restricted layer of soil where water permeability not allowed.

e)- false, as unconfined aquifer has hydraulic gradient equal to slope of piezometric level.

f)- true, as in unconfined aquifer hyraulic gradient is slope of piezometric level.

g)- true, oceans lose more water by evaporation than precipitation which balance the hydrologic cycle.

h)- true, while surface receives more water by precipitation and less loss in evaporation.

i)- false , as resident time of lake is greater than river water since water stay here for longer than river .

j)- true, as resident time is the time inwhich a reservoir water gets removed or added. So in oceans rivers fills this in that time. Oceans have high resident time as 3000 years or more.

k)- true. As if a reservoir quickly emptied then its reaction is too high and resident time is low.