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