Hydrostatics and capillarity facts: identify the incorrect statement Consider the following about subsurface water: (i) smaller pores lead to higher capillary rise, (ii) below the water table, pore water may be static, (iii) hydrostatic pressure increases with depth below the free water surface, (iv) negative pore pressure above the water table causes soil suction. Which statement is incorrect?

Introduction / Context:This conceptual question reviews capillary action, hydrostatics, and matric suction in soils. Correct understanding is crucial for seepage analyses, slope stability in unsaturated zones, and foundation design near fluctuating water tables.

Given Data / Assumptions:

• Steady conditions considered (no transient flow unless stated).
• Standard definitions of capillarity, hydrostatic pressure, and soil suction (matric suction).
• No special cases like artesian conditions are implied.

Concept / Approach:

Each listed statement accords with basic soil mechanics: (a) Capillary rise is inversely proportional to pore size; (b) In the absence of a gradient, pore water can be static below the water table; (c) Hydrostatic pressure increases linearly with depth; (d) Above the water table, negative pore water pressures produce apparent cohesion often termed soil suction.

Step-by-Step Solution:

Verification / Alternative check:

Standard textbooks on unsaturated soil mechanics corroborate the definitions and relationships cited.

Why Other Options Are Wrong:

Choosing any of (a)–(d) as incorrect would contradict well-established hydrostatics or capillarity principles.

Common Pitfalls:

Confusing capillary rise with permeability; assuming water must be moving below the water table; overlooking that suction is a negative pore pressure phenomenon.

Final Answer:

None of these