Which of the following statements represents a conflict between economic development and ecosystem quality?

1. Due to the high cost of land in cities, people often choose to build building higher (with more floors) instead of expanding into undeveloped land.

2. Swimming in a river is fun recreation acitivty, but it also disturbs aquatic animals.

3. Some people are able to make a living through showing off local plants and animals to tourists.

4. Adding large quantities of fertilizer to farmland increases the amount of food grown, but it also introduces pollutants into nearby water supplies.

Select all of following statements that are true:

1. Groundwater often provides support for the ground above it

2. Groundwater is avaliable year-round, unlike some surface water sources

3. Groundwater is a completely nonrenewable resource

4. Groundwater is often cheaper to extract than surface water

Answer: the conflict between economic development and ecosystem quality is number 4, about fertilizers in farmland. The true statements about groundwater are 1 and 2.

Explanation: In the first exercise, the only alternative which shows conflict between economic aspects and ecosystem quality is number 4, because fertilizers are able to pollute water supplies nearby the farmland soil after its absorption by the soil. So, having an increased production of food has this environmental cost that might harm the production later. The other alternatives only show economic development sides.

In the second exercise, groundwater is responsible for providing support for the ground above it since it's usually made of impermeable rock, which keeps the groundwater stored. The deepest layers of soil are known to support the ones closer to the surface also by the effect of gravity. Also, groundwater can be stored in such a large amount that they might be available for a longer time period compared to surface sources, that need more frequent recharge periods, such as rainy periods. Alternative number 3 is false because groundwater can be recharged by water absorption in the soil. Alternative number 4 is false as well, because very advanced perforation methods are needed in order to explore it, and those are often more expensive than the ones used to extract surface water, since it's easier to reach.