Q37-13TYU - Campbell Biology

Question

In many countries, irrigation is depleting aquifers to such an extent that land is subsiding, harvests are decreasing, and it is becoming necessary to drill wells deeper. In many cases, the withdrawal of groundwater has now greatly surpassed the aquifers’ rates of natural recharge. Discuss the possible consequences of this trend. What can society and science do to help alleviate this growing problem?

Step-by-Step Solution

Answer

The possible consequences of aquifer depletion are further groundwater depletion, increased water, and soil salinity, decreased crop production, expensive water, and increased electricity cost.

The growing problem of groundwater depletion can be alleviated by practicing the drip irrigation method. Drought-resistant crop varieties could be planted, and water could be saved by providing it to plants only during the growing season.

Step 1: Aquifer depletion

Groundwater, when removed, gets naturally replenished, and the aquifer is maintained. An aquifer is present deeper down the geological layers of the earth’s crust. But as irrigation has continually increased since the past decades, it leads to groundwater or aquifer depletion. 

Step 2: Possible consequences of aquifer depletion

Many negative consequences arise with a simultaneous high irrigation rate and a lower rate of aquifer recharge. The possible consequence of this trend is further aquifer or groundwater depletion. As the aquifer continues to deplete, more land subsidence would occur.

As the depth of groundwater through the aquifer increases, the salinity also increases. So, as the upper parts of the aquifer are depleted, the world will be left with saline water.

If the saline waters are withdrawn, it would affect the soil salinity. An increase in soil salinity will, in turn, affect the crops and vegetation. As a result, there would be a decrease in crop production.

With a decrease in groundwater, water would become more expensive. Electricity is produced from water power or hydropower. As water becomes costly, the cost of electricity would hike.

Step 3: Strategies to alleviate the growing problem due to aquifer depletion

Society and science can help alleviate this growing problem of depleting aquifers by embracing the following approaches.

A drip irrigation method could be chosen that allows saving water. People can switch to drought-resistant varieties of crops due to less water availability. Water could be supplied to plants only during the growing season when susceptible to water stress.