Geomatics Tools for Inventorying and Geomatics Tools for Inventorying and Assessing HeadwatersAssessing Headwaters
Adam HoggAdam HoggInventory Monitoring & Assessment, Ministry of Natural ResourcesInventory Monitoring & Assessment, Ministry of Natural Resources
Eastern Region Headwaters Streams WorkshopEastern Region Headwaters Streams WorkshopFebruary 25, 2011February 25, 2011
Outline
Presentation Objectives
My Background
How do we define headwaters?
Geomatics and Headwaters: inventorying and assessing
Summary
Presentation Objectives
To describe the spatial tools available for inventorying and assessing headwater areas (systems) and streams at local and regional (provincial) scales
To show an example application of a regional scale inventorying and assessing tool
My Background
A provincial role obtaining 10 years experience focused on regional land cover mapping using ELC, focus on wetlands
Instruction of geomatics related components of numerous courses:• Ontario Wetland Evaluation System
• ELC
• Fleming College Advanced Remote Sensing
Attended Temperate Headwater Wetland Restoration course
Last 3 years have been focused primarily on Ontario’s Far North
How Do We Define Headwaters?
Interest in a spatial perspective
Excellent direction from The Natural Functions of Headwater Features: A Literature Review (TRCA, 2007)
Distinction between headwater streams and systems (areas)
• Streams: “primarily ill-defined non-permanently flowing features in the upper reaches of catchments”
• Systems: these streams and the catchment areas that flow into them
Inventorying Headwater Streams Large scale digital air photography and elevation
• Orthophotography requires large scale DEM• Digital stereo imagery requires “estimation” under tree canopy
Recent stereo imagery will be available for Eastern Ontario and South Western Ontario (DRAPE / SWOOP)
Time consuming and heavy reliance on experienced interpreters
Water Resource Information Project and Conservation Ontario leading development of large scale mapping specifications (draft complete March 31, 2011)
• Capture of all “features where water is observed on imagery” are mandatory to meet the spec
• Ephemeral, intermittent and perennial codes “if desired”
Inventorying Headwater Streams: Interpretive Approach
Spring photo’s ideal
Existing stream data
Hydrologic indicators
Understand the topography
Inventorying Headwater Streams: Surface Flow Modelling
Source: Gomi et al. 2002
“Flow accumulation” Topographic Index (Beven & Kirkby,
1978)• flow accumulation• local slope• soil conductivity?
Case Example: North Carolina
Mapping Headwater Streams: Intermittent and Perennial Headwater Stream Model Development and Spatial Application (Russell, 2008)
Use high precision DEM for first and second order stream prediction
Survey grade GPS mapping for calibration and accuracy assessment
Successes:• Spatially accurate, presence absence, length of permanent streams
Challenges:• Commission error, stream length of non-perennial streams, labeling of
permanence
Inventorying Headwater Streams: Validation of Either Method
Very challenging to validate
Requires spatially precise field sampling
Field Operations Manual for Assessing the Hydrologic Permanence of Headwater Streams (Fritz K.M., Johnson, B.R. and D.M. Walters. 2006)• Sample design• Physical and biological sampling
Data Available For Southern Ontario: A Provincial Perspective
Streams & DEM’s
Orthophotos
Acquired (Drape)
Inventorying Headwater Systems Headwater system: the catchment area
defined by stream order and/or contributing area
More conducive to regional data, methods and planning
Correspondence between headwater streams and provincial inventory is unknown
An area based approach is more attractive
Assessing Headwater Systems
Engaged in a pilot project to develop a “headwater wetland database” decision support tool
A regional decision support tool that consists of headwater areas summarized by SOLRIS land cover and topographic modelling:
• Existing wetland• Potential wetland• Land use
MitigationMitigation
ProtectionProtection
RestorationRestoration
Note: source SOLRIS wetlands
Headwater Decision Support Tool
Note: Source topographic index
MitigationMitigation
ProtectionProtection
RestorationRestoration
Headwater Decision Support Tool
Note: source SOLRIS frequently tilled agriculture
MitigationMitigation
ProtectionProtection
RestorationRestoration
Headwater Decision Support Tool
Note: Source untilled SOLRIS agriculture
MitigationMitigation
ProtectionProtection
RestorationRestoration
Headwater Decision Support Tool
Cyan Ellipse: Development MitigationCyan Ellipse: Development Mitigation
Prevent developmentPrevent development
Magenta Ellipse: ProtectionMagenta Ellipse: Protection Blue Ellipse: RestorationBlue Ellipse: Restoration
Headwater Decision Support Tool
Inventorying And Assessing Headwater Systems
Engaged in a collaborative co-op project involving Fleming College and the Ontario Headwaters Institute:• To better understand the unknowns about provincial scale data• Develop a “first cut” at a Southern Ontario approach• Extend pilot decision support tool to Oak Ridges Moraine• Provide mapping examples for OHI website
A long term (recurring) intent
Summary
It is possible to map headwater streams:• Two potential ways of doing it
• Will be challenging and potentially time consuming depending on project objectives and scale
• Rigorous field calibration and validation is crucial
Regional mapping focusing on headwater systems
Simple assessment summaries and data organization can inform decision making