(b) Which has an advantage over the other and why?

Solution –

( a )Figure 16.1 (a ) is a pond ecosystem .

      Figure 16.1 (b ) is an underground water body .

( b ) ground water body has more advantages when compared with the pond ecosystem . The reasons are –

• Evaporation of water does not take place .
• Less vulnerable to the pollution
• Can be easily used for irrigation
• Can be used public water supply
• Keeps the area moisturised