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

Geomatics and Headwaters: Inventorying, Monitoring and Assessing

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

SummarySummary

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

Questions?Questions?