Gully Density

AUS-AIF-URB-GUL General High confidence

Benchmark Value

0 m/ha
Range: 0 to 0 m/ha
Thresholds: Lower: 0, Upper: 0
Optimal Range: 0 to 0
Direction: Lower is desirable ↓
Form: Point

Scoring Curve

This curve shows how a field measurement for this indicator would score across all available benchmark forms in this context. The scoring engine uses 4 benchmarks together — the Point form drives the primary score, while 3 guard(s) constrain the result.

Evidence & Context

Based on this logical conclusion, the reference value for Gully Density in a best-practice urban system within Australia's Arid Inland Floodplains & Ephemeral River Systems is 0 m/ha.

Metric Definition:

Gully Density is defined as the length of active gullies per unit area, typically expressed in metres per hectare (m/ha).

Benchmark Definition:

This benchmark represents the ideal condition of zero active gullies in urban areas of Australia's Arid Inland Floodplains & Ephemeral River Systems, reflecting best-practice urban design to prevent erosion.

Justification:

The benchmark of 0 m/ha represents the best available condition for a new or redeveloped urban area adhering to modern best practices such as Water-Sensitive Urban Design (WSUD) and comprehensive Erosion and Sediment Control (ESC). The rationale is that the core principle of these practices is the prevention of concentrated, erosive stormwater flows, which are the primary driver of gully formation. Therefore, the presence of any active gully is evidence of a failure in design, construction, or maintenance, not an acceptable feature of a high-health system.

Sources (2)

Preview of (PDF) Gully erosion prediction across a large region ... - ResearchGate, accessed July 21, 2025,
(PDF) Gully erosion prediction across a large region ... - ResearchGate, accessed July 21, 2025, GreyLiterature

(PDF) Gully erosion prediction across a large region ... - ResearchGate, accessed July 21, 2025,

View Source
Preview of Desertification in Australia: Definition, Causes and Environmental Impact - Access EP, accessed July 13, 2025,
Desertification in Australia: Definition, Causes and Environmental Impact - Access EP, accessed July 13, 2025, GreyLiterature

Gully mapping and drivers in the grazing lands of the Burdekin ..., accessed July 21, 2025,

View Source

Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Preview of nesplandscapes.edu.au, accessed May 15, 2025,
nesplandscapes.edu.au, accessed May 15, 2025,
Direct Evidence Journal

Alluvial Gully Erosion Rates and Processes Across the Mitchell ..., accessed July 21, 2025,

View Source

Context

  • Region Australia
  • Biome Arid Inland Floodplains & Ephemeral River Systems
  • Land Use Urban & Developed Use
  • Assessment Pristine Reference
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 25 Mar 2026

Notes

Lower/Optimal Boundary: The optimal state is 0 m/ha. The concept of a 'critically low' density is not applicable, as gullies are a degradation feature. Upper Detrimental Threshold: Any value > 0 m/ha is considered detrimental as it indicates active erosion and system failure. A density > 10 m/ha (0.1 km/km²), a level found in degraded agricultural landscapes, indicates a transition to a significantly degraded state with severe ecological and economic consequences.

Related Benchmarks

Other benchmarks in the AUS-AIF-URB-GUL family.