Geomorphology — Controls on Developing Hillslope Form In systems thinking for landscapes, what chiefly controls the evolving shape (form) of a developing hillslope?

Introduction / Context:
Hillslopes are open systems where mass and energy enter and leave continuously (rainfall, runoff, sediment influx, weathering, transport). Geomorphology frames slope evolution through budgets and feedbacks, emphasizing that the net balance between inputs and outputs determines whether a slope aggrades, degrades, or attains steady form.

Given Data / Assumptions:

• Inputs: precipitation, runoff energy, sediment supply, vegetation growth.
• Outputs: sediment export, evapotranspiration, dissipation of energy.
• Form responds to the net budget over time.

Concept / Approach:
When inputs exceed outputs, material accumulates; when outputs exceed inputs, erosion dominates; when balanced, the slope may approach a graded or quasi-steady profile. This systems view explains why neither inputs nor outputs alone fully determine slope form—the interaction and balance do.

Step-by-Step Solution:

Verification / Alternative check:
Conceptual models (e.g., Schumm’s systems approach) treat landforms via mass balance; steady form aligns with input≈output conditions.

Why Other Options Are Wrong:

• Inputs only or outputs only: Partial view; cannot capture steady states or thresholds.
• None of the above: Incorrect because the systems balance is the recognized control.

Common Pitfalls:
Attributing slope shape solely to rainfall amount or solely to erosion rate. It is the interplay that matters, mediated by substrate, climate, and vegetation.

Final Answer:
balance between inputs and outputs from the hill slope system