If one plots the tank irrigation in India and superimposes it with map of well irrigation, one may find that the two are negatively related. Which of the following statements explain the phenomenon?
- 1Tank irrigation predates well irrigation.
- 2Tank irrigation is in the areas with impervious surface layers.
- 3Well irrigation requires sufficient groundwater reserves. reserves.
- 4Other forms of irrigation are not available.
Select the correct answer using the code given below :
- A1, 2 and 3
- B2 and 3 only
- C3 and 4
- D1 and 4
Explanation
Tank irrigation in India is concentrated in the hard-rock, impervious terrain of peninsular India, where surface layers prevent deep percolation and groundwater reserves are poor. Well irrigation, by contrast, requires sufficient groundwater, which is scarce in precisely those areas. This complementary geography produces the negative spatial correlation between the two. The antiquity of tanks and the availability of other irrigation forms do not explain it. Hence option B is correct.