Week 6: Water Resources

Lecture Overview

Course: ENVS 1010 Introduction to Environmental StudiesDate: February 16, 2025Instructor: Dr. Anita Simic MilasOffice: Overman Hall, Room 282Contact: 2-4035, asimic@bgsu.eduReading Assignment: Unit 7 in textCurrent Topic: Water ResourcesNote: Crucial updates regarding Quagga mussels in Lake Michigan and Lake Huron, concerning their impact on local ecosystems and water quality.

Importance of Water

Crucial Resource

• Water is essential for life, sustaining ecosystems, agriculture, and human societies. It is a key component in biochemical processes and is necessary for maintaining the health of flora and fauna.

• Usage: Beyond drinking, water is essential for municipal needs (sanitation, waste disposal) and various economic activities including agriculture, manufacturing, and energy production.

• Valuation Challenge: Assessing the value of water is complex; it is often viewed as a public good rather than a commodity, complicating valuation in economic terms. While bottled water is traded in markets, most freshwater resources are managed publicly, leading to discussions on pricing and access.

Global Water Distribution

Earth's Water Composition

• Approximately 70% of Earth's surface is covered by water.

• Oceans contain about 96.5% of this water as saline, with only 3% classified as freshwater.

• Freshwater Distribution: Significantly uneven across the globe, with some regions experiencing abundance while others face severe shortages. The distribution is affected by factors such as geography, climate, and human activity.

Future Water Scarcity

• Climate Migrants: Over 140 million people may become climate migrants by 2050 due to extreme weather conditions impacting water availability.

• Population Projections: By 2025, it is anticipated that 1.8 billion people will face water scarcity globally, exacerbated by rising temperatures and shifting weather patterns.

• Demand vs Supply: Increasing population and urbanization are predicted to lead to exceeding available water supplies, especially in densely populated areas such as India and China.

• Scarcity Statistics: Water scarcity currently affects one in three people worldwide, highlighting the urgent need for sustainable management and conservation strategies. Less than 1% of Earth's freshwater is suitable for drinking, raising concerns about access and health.

Types of Water Scarcity

Physical Water Scarcity

• Defined as limited physical access to water resources, seen in regions like the southwestern United States with Colorado River issues stemming from prolonged droughts and over-extraction.

Economic Water Scarcity

• This type reflects a lack of financial means to access available water resources. This highlights the inequalities caused by governance and socio-political factors, significantly impacting regions like sub-Saharan Africa where infrastructure may be inadequate.

Water Withdrawal and Consumption

Definitions

• Water Withdrawal: Refers to the total amount extracted from surface or groundwater sources for various uses, including agriculture and industrial purposes.

• Water Consumption: The portion of withdrawn water that is permanently lost through evaporation, transpiration, or consumption in use (e.g., irrigation).

• Irrigation: Not only is it the largest consumer of water worldwide, but agriculture as a whole consumes 70% of global water use. Enhanced understanding and management of both concepts are critical for evaluating regional water stress and developing sustainable solutions.

Global Water Challenges

Issues

• Quantity: Increasing water scarcity in various regions leads to competition among agricultural, industrial, and municipal needs.

• Quality: Deteriorating water quality poses threats to health and ecosystems, with polluted water sources leading to diseases and reduced biodiversity.

• Distribution: Many regions face a combination of both quantity and quality issues, complicating hydration and agricultural practices.

• Degradation: Renewable resources like freshwater can become degraded due to unsustainable practices, calling for action in resource management. The Ogallala Aquifer, a vital source in the U.S., is being depleted significantly faster than it can be replenished, raising alarms about future agricultural productivity.

Factors Contributing to Water Scarcity

• Geography: The spatial distribution of water resources often leaves certain areas in persistent shortage, while others face flooding.

• Population Growth: Increasing demand for water resources with rising populations exacerbates existing shortages, particularly in arid regions.

• Climate Change: Shifts in weather patterns lead to more frequent droughts and altered precipitation rates, severely impacting the availability and reliability of freshwater.

Water Quality Concerns

Potable Water

• Access to safe, drinkable water is a critical issue, with 1/5th of the global population lacking reliable access.

• Waterborne Diseases: Problems such as cholera arise from contaminated water supplies, resulting in significant health crises.

• Environmental Impact: Nutrient pollution can trigger algal blooms, resulting in hypoxic conditions that devastate aquatic ecosystems and harm fisheries.

Water Pollution Sources

Types of Pollution

• Point Sources: Discharge pollutants from identifiable sources, such as wastewater treatment plants and industrial facilities.

• Nonpoint Sources: More diffuse sources of pollution, such as runoff from agricultural fields, urban areas, and roads, complicating pollution management efforts.

Water Cycle and Groundwater

Groundwater Importance

• Often overlooked, groundwater is a critical resource for ecosystems and serves as a major water supply for agriculture and human consumption. A sustainable approach is needed for its management to ensure quality and availability for future generations.

Agricultural Water Use

Irrigation Statistics

• Currently, 20% of cultivated land globally is irrigated, resulting in 40% of food production.

• Improved water management in agriculture is necessary not just for enhancing productivity but also for satisfying global water scarcity challenges, ensuring food security and environmental sustainability.

Sustainable Solutions

Policy Improvements

• Initiatives such as the Clean Water Act (1972) and the Water Quality Act (1987) have been critical in regulating water quality and restoring ecosystems like the Everglades to support biodiversity and water safety.

Conservation Measures

• Encouraging behavioral changes in water use, implementing advanced technologies for desalination, and promoting equitable distribution of water resources are essential to manage the impending global water crisis.

Practical Consumer Actions

• Simple actions such as turning off taps when brushing teeth, fixing leaks, and choosing water-efficient appliances can contribute to conservation efforts and reduce personal water footprints.