Climate Change and Population Growth Will Increase Urban Water Demand by Up to 19% by 2070

Why It Matters

Understanding these demand shifts is crucial for urban planners and water utility managers to ensure sustainable water resource allocation and infrastructure development. Proactive planning can mitigate potential shortages and optimize resource management strategies.

Key Finding

Future urban water demand is expected to rise significantly by 2070, with population growth being the main contributor, while climate change impacts are less pronounced but still present, especially under higher emission scenarios.

Key Findings

• RCP2.6 scenario predicts an average 14% increase in water demand for 2051–2070, with climate change contributing a negligible 0.7% increase.
• RCP4.5 scenario predicts a 16% increase in water demand.
• RCP8.5 scenario predicts the highest increase of 19% in water demand.
• Population growth is identified as the dominant factor contributing to the projected increase in water demand.

Research Evidence

Aim: To forecast urban peak water demand by integrating climate indices and demographic trends, and to assess the impact of different climate change scenarios on future demand.

Method: Quantitative modelling using multiple linear regression.

Procedure: An existing water demand model was enhanced with new climate indices. The model was trained on historical data and validated using a separate test dataset. Its performance was evaluated using metrics like mean absolute percentage error. The model was then applied to climate projections (RCPs) and combined with population growth projections to estimate future water demand changes.

Context: Urban water management and climate change adaptation.

Design Principle

Integrate long-term environmental and demographic forecasts into resource management system design.

How to Apply

When designing or upgrading water supply systems, use climate projection data and population growth forecasts to size components and plan for future capacity needs.

Limitations

The model's accuracy is dependent on the quality and availability of climate and demographic data. The study focuses on peak water demand, and other demand patterns might require different modelling approaches. The specific geographical context of the study sites might limit generalizability without further adaptation.

Student Guide (IB Design Technology)

Simple Explanation: Cities will need more water in the future because more people will live there and the climate will change, but more people is the bigger reason.

Why This Matters: This research shows that designs for water systems need to be future-proof, considering how environmental and social changes will impact resource needs.

Critical Thinking: How might the interplay between climate change and population growth create feedback loops that further exacerbate water scarcity or demand in specific regions?

IA-Ready Paragraph: This research highlights the critical need to design for future resource demands, projecting significant increases in urban water consumption by 2070 driven primarily by population growth and secondarily by climate change. This underscores the importance of developing adaptive and resilient water management systems that can accommodate these evolving needs.

Project Tips

• When researching a design problem, consider how external factors like climate and population trends might affect the long-term viability of your design.
• Use data from reputable sources for climate projections and demographic trends to inform your design decisions.

How to Use in IA

• Use the findings to justify the need for a robust and scalable design solution for water management or conservation.
• Reference the projected increases in water demand to demonstrate the importance of your design's efficiency or capacity.

Examiner Tips

• Demonstrate an understanding of how external environmental and demographic factors can influence the performance and relevance of a design over its lifecycle.
• Ensure that any proposed solutions for resource management are supported by evidence of future demand or scarcity.

Independent Variable: ["Climate indices (e.g., temperature, precipitation patterns)","Demographic trends (population growth)","Representative Concentration Pathways (RCPs)"]

Dependent Variable: ["Urban peak water demand"]

Controlled Variables: ["Study sites (specific urban areas)","Time periods (e.g., 2051–2070)"]

Strengths

• Integration of multiple drivers (climate and population) for a more comprehensive demand forecast.
• Validation of the model using a test dataset to assess predictive accuracy.

Critical Questions

• To what extent can localized climate variations and specific urban development policies alter these general projections?
• What are the ethical implications of resource allocation when demand is projected to outstrip supply, particularly in vulnerable populations?

Extended Essay Application

• Investigate the potential impact of climate change and population growth on the demand for other essential resources (e.g., energy, food) in a specific region.
• Develop a conceptual design for a water-efficient building or community that accounts for projected future water demand increases.

Source

Forecasting Urban Peak Water Demand Based on Climate Indices and Demographic Trends · Water · 2023 · 10.3390/w16010127