Which of the following factors significantly influence per capita water demand in an urban water-supply system?
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ASize of the city
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BClimatic conditions
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CPressure in water mains
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DCost (tariff) of water
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EAll of the above
Answer
Correct Answer: All of the above
Explanation
Introduction / Context:Per capita demand varies widely due to demographic, climatic, economic, and system-operations factors. Planners must account for these when forecasting demand and sizing facilities for present and future populations.
Given Data / Assumptions:
- Urban service area with metered or unmetered consumption.
- Normal (non-drought) operating conditions unless tariffs or restrictions apply.
Concept / Approach:Large cities often show higher non-domestic and leakage components; hot climates increase outdoor and bathing uses; higher main pressure generally increases consumption and leakage; higher water charges can suppress discretionary use. Therefore, all listed factors affect per capita demand to varying degrees.
Step-by-Step Solution:
Acknowledge multi-factor dependence of per capita demand.Relate each factor to a plausible mechanism (size, climate, pressure, tariff).Select the comprehensive option 'All of the above'.Verification / Alternative check:Demand-forecasting manuals and CPHEEO guidelines list these influences explicitly.
Why Other Options Are Wrong:
- Any single-factor choice is incomplete; demand is multi-causal.
Common Pitfalls:
- Ignoring leakage sensitivity to pressure in unmetered systems.
- Neglecting price elasticity in demand forecasting.
Final Answer:All of the above