Environmental Engineering Reference
In-Depth Information
Table 4.1
Landscape Function Analysis Indicators for assessing biophysical processes affecting landscape functions such as
retaining vital resources (water, soil) and providing goods and services (food, materials, clean water). Numbers in brackets
relate to processes numbered in Figure 4.2.
Indicator type
Indicator name/
description
Process assessed
Landscape
organization
Location and size of
patches that accumulate
resources (litter, soil)
along a gradsect*
Capacity of a landscape to capture resources such as by infi ltrating
water (1) and reducing runoff (2a) triggered by rainfall events
Location and size of bare
interpatches that lose
resources along a
gradsect
Potential for landscapes to lose resources such as water (2a) and
soil (2b) during rainfall and wind storm events
Soil surface
condition**
Rainsplash protection
Soil particle displacement and physical crusts formation by rain
drop action, restricting water infi ltration (1 and 4b)
Perennial vegetation cover
Estimates the below-ground biomass available for decomposition
(3 and 4a)
Plant litter:
amount and degree
of decomposition
Soil development and nutrient cycling mediated by litter
decomposition (3 and 4a)
Cryptogam cover
Role of cryptogams in stabilizing the soil surface, preventing erosion
(2a and 4a)
Soil crust brokenness
Nature of soil physical crust affecting surface infi ltration (1) and
stability (2)
Soil erosion:
type and severity
Identifi es the form and estimates the rate of soil loss (2b)
Sediment deposition
Estimates the type (soil, litter) and amount of run-on material being
deposited on site (1)
Surface roughness
Degree of surface roughness to slow fl ows and retain mobile
resources (1 and 4b)
Soil surface dry coherence
Evaluates the resistant of the soil surface to physical disturbances
(2 and 4a)
Soil surface wet
coherence (Slake test)
Estimates the cohesion (stability) of soil fragments during rain
events (2 and 4a)
Surface soil particle size
distribution (Texture)
Role of surface soil texture on initial water infi ltration rate (1)
Ephemeral
drainage line
stability***
Slope steepness
Potential for high energy overland fl ows to erode slopes and
ephemeral drainage lines (1 and 2b)
Slope surface protection
Amount of rock and vegetation cover regulating runoff into a
drainage line (1)
Drainage line wall
vegetation
Amount of vegetation protecting drainage line walls from erosion
(1 and 2b)
Drainage line fl oor
vegetation
Amount of vegetation protecting fl oors (channel beds) from erosion
(2b)
Drainage line cross-
section shape (profi le)
Evaluates the degree of active erosion (caving, fl uting, mass
wasting) on walls (2b)
Drainage line longitudinal-
section (profi le)
The effect of strength of downstream fl ows to create linear drainage
lines (1 and 2b)
Drainage line wall
erodability
The intrinsic susceptibility of exposed drainage line wall materials to
erosion (2b)
Drainage line fl oor
erodability
The potential for drainage line fl oors (channel beds) to incise further
(2b)
Continued
