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Monitoring River Health in the Murray-Darling Basin using Full Wave Form LiDAR
FUNGISFUNGIS30 May 201130 May 2011AlysAlys WallWall
Outline1. Sustainable Rivers Audit Case
Study2. Full waveform LiDAR3. Physical Form Variables4. Examples5. Vegetation Variables6. Examples
Sustainable Rivers Audit
Sustainable Rivers Audit (SRA)• Establish 1750 Reference Condition
• Assess five themes against reference condition
1. Fish
2. Macro Invertebrates
3. Hydrology
4. Physical Form (of River Channels)
5. Vegetation• Ongoing monitoring of themes against land-use, water–use
vegetation cover, Climate
Background
Methods• Metrics = Observed/Expected• Expected = Reference Condition value
Integration:• to indicators, Theme Indices, Ecosystem health• using Expert Rules
Current DataCurrent Data Reference DataReference Data
MetricsMetrics
Aggregation: from Site to Basin
• Zones for stratifying sampling effort
• Samples at random sites or census of reaches within Zones
• Aggregation from– Site to Zone; and– Zone to Valley.
Full Wave Form LiDAR
(Chauve, 2007)
• Entire backscattered signal recorded• Acquisition of a continuous section • Additional information on the illuminated surface structure
Data collection for new ThemesDerived layers and data include:• 1 m surfaces• 25 cm contour lines• Vegetation height surfaces• Bank and channel delineation• Channel wetted area polygons• Bank geometry and vegetation height
measurements• Summarised to valley/zone reporting of
River Health (observed vs expected)
Project ScopeSITES
23 Valleys across 1M sq. kmX 70 sites per Valley = 1610 river sites
+ 31 control sites near airfields+ 71 check sites= Total 1710 surveyed sites
Primary DATA SETS27 x base data sets for each site
Measurements50 x Physical Form Channel Measurements for each of 19 transectsper site.
17 x Vegetation Measurements per bank area per vegetation polygon.
TOTALOver 2,000,000 measurementsOver: 200,000 files
Full Wave Form LiDAR
(TopoSys, 2007)
Full Wave Form LiDAR
Full Wave Form LiDAR
Vexcel Imagery
RGBVNIR
Vexcel Survey ParametersAltitude: 1,500m, 1 flight strip per siteResolution: 30cm - no Pan SharpeningAccuracy: 50cm
Physical Form Variables
Mean Channel WidthChannel Mean DepthChannel Width VariabilityChannel SinuosityChannel Meander WavelengthLongitudinal Bank Variability
(Gippel, 2008)
1. Map Channel Features2. Generate 19 x transect profiles3. Measure 50 x Channel attributes for each site / transect
Left Bank Length
Convexity Left B.
Bed width
Channel Width
x-sectional area
Channel Depth
Left Bank Inflexions
Right B
ank
Angle
LiDAR Vegetation VariableCanopy Height
Vegetation
Pink = < 10 cmBrown = 10 cm to 50 cm
Green = 50 cm to 1m
Orange = 1 to 3 mPurple = > 3m
Wetted Riversurface
Wetted Riversurface
Summary: SRA Report II due to be released mid 2011Full extent of LiDAR metrics for geomorphology
and vegetation still to be investigated
Conclusion
Full waveform LiDARis extremely information rich data for environmental assessment
Thank you
Vegetation