Question

Where were the highest increases of salt in river systems, and what was the hypothesis as to the reason behind the increase?

a. Amazon River - Deforestation
b. Nile River - Industrial Pollution
c. Mississippi River - Climate Change
d. Danube River - Agricultural Runoff

Answer 1

What causes high salinity in water?

Excess salinity can occur in areas where evaporation is high and made worse by repeated use of water for irrigation or water withdrawals, where road de-icers are applied and in mining, oil and gas drilling and wastewater discharges

Step-by-step explanation:

Answer 2

The Nile River has experienced an increase in salt content due to changes in irrigation practices and the lack of annual flooding, which was historically responsible for washing away accumulated salts in the soil.

Step-by-step explanation:

The increases in salt content in river systems can be attributed to different causes depending on the river in question. For the Nile River, the hypothesis for the increase in salt is largely due to changes in the irrigation system and lack of annual flooding. Without the yearly floods, which previously washed away accumulated salts, there has been a buildup of salt in the soil, leading to declining soil quality and agricultural yields. This change was exacerbated by the construction of the Aswan High Dam in 1968, after which the annual floods no longer occurred.