A.3.3 Human Pressures on Lakes and Aquifers Notes

Economic and Demographic Influences on Water Scarcity

1. Imagine moving to a rapidly growing city.
2. The streets are alive with activity, new businesses are opening, factories are expanding, and people are arriving daily in search of opportunities.
3. Yet, amidst this growth, you notice a troubling pattern: water shortages are becoming more frequent, and rivers are increasingly polluted. What’s causing this?
4. This scenario illustrates the critical relationship between economic and demographic changes and water scarcity. By understanding these influences, you can uncover solutions to one of the world’s most pressing challenges.
5. Let’s explore two major drivers of water scarcity: economic growth and population migration.

Economic Growth: Industrial Expansion and Urbanization

1. Economic growth often brings prosperity, but it also intensifies water demand.
2. As industries expand and cities grow, the need for water increases, whether for industrial processes, urban infrastructure, or residential use.
3. However, this growth can lead to over-extraction of water resources and pollution, creating a cycle of scarcity.

How Does Economic Growth Increase Water Demand?

1. Industrial Water Use: Industries like manufacturing, mining, and energy production require substantial amounts of water. For example, producing steel or textiles consumes vast quantities of water. As economies grow, these industries expand, driving up water demand.
2. Urbanization: Growing cities require water for residential needs, sanitation, and municipal services. Even the construction of urban infrastructure, such as roads and buildings, demands water.
3. Agricultural Intensification: Economic growth often leads to increased food production to meet the demands of wealthier populations. This requires more irrigation, a sector that accounts for the largest share of global freshwater use.

Consequences of Over-Extraction and Pollution

1. Depletion of Aquifers: In many regions, groundwater is extracted faster than it can naturally replenish. For instance, the Ogallala Aquifer in the U.S. has seen water table declines of up to 50 meters in some areas, largely due to agricultural and industrial use.
2. Water Pollution: Industrial processes release pollutants like heavy metals, chemicals, and untreated wastewater into rivers and lakes, reducing the availability of clean water.

Population Migration: Urban Growth and Water Stress

1. Population migration, particularly rural-to-urban migration, is another significant factor driving water scarcity.
2. As people move to cities in search of better opportunities, urban centers face mounting pressure on their water resources.

Why Does Urban Migration Increase Water Stress?

1. Higher Per Capita Water Use: Urban residents typically use more water than rural populations due to access to amenities like showers, washing machines, and flush toilets.
2. Strain on Infrastructure: Rapid urbanization often outpaces the development of water supply and sanitation systems, leading to inefficiencies like leaks in distribution networks.
3. Concentration of Demand: Urban migration concentrates water demand in specific areas, often leading to overuse of local water sources such as rivers, lakes, and aquifers.