Papantzin CidUniversity of Redlands

Delineating Geomorphic Landscape Units to assess sediment supply in

the San Diego River Watershed

Objectives

• Review of Original Geomorphic Landscape Units (GLUs) Approach

• Revised GLUs Approach• San Diego River Watershed

• Limitations

Original Approach to GLUs

• Classification of Slope, Geology and Land Cover

• Planning tool to predict effects of hydromodification based on sediment changes due to landscape alteration

• Rapid assessment technique that could inform management decisions

Escondido Creek Watershed

Escondido Creek Watershed

Escondido Creek WatershedRelative Sediment Production Rates

LowMediumHigh

Revised GLUs Approach

• Datasets:1. USGS 30 Meter elevation to derive slope2. CGS 1977 Jennings Geology3. SanGIS Current Land Use and Planned Land Use

San Diego River Watershed

• Second Largest

• 433 Sq. Mile

• Highest Population

Slope Classification

• 30 Meter Resolution

• Slope stability

Geology Reclassification

• CGS

• 68 Original

• Grouped by geologic characteristic

Coarse-Competent Classification

Crystalline Classification

Geology Reclassification

66%13%

10%

7%

3%1%

Geology ReclassificationFine-WeakCoarse-WeakFine-CompetentCoarse-CompetentCrystalline

Land Use Classification

• General & Community Plans

• 90 Original

• 3 Reclassified

Land Use Classification

1%

53%45%

1%2%

30%

67%

1%

Current 2012 Land Use Planned 2050 Land UseAgricultureDevelopedScrub/ShrubWater

Slope Geology Land Use

Unique Landscape Units – Current Land UseCoarse-Competent; Developed; LowCoarse-Competent; Developed; MediumCoarse-Competent; Developed; HighCoarse-Competent; Scrub/Shrub; LowCoarse-Competent; Scrub/Shrub; MediumCoarse-Competent; Scrub/Shrub; HighCoarse-Weak; Agriculture; LowCoarse-Weak; Agriculture; MediumCoarse-Weak; Agriculture; HighCoarse-Weak; Developed; LowCoarse-Weak; Developed; MediumCoarse-Weak; Developed; HighCoarse-Weak; Scrub/Shrub; LowCoarse-Weak; Scrub/Shrub; MediumCoarse-Weak; Scrub/Shrub; HighCrystalline; Agriculture; LowCrystalline; Agriculture; MediumCrystalline; Agriculture; HighCrystalline; Developed; LowCrystalline; Developed; MediumCrystalline; Developed; HighCrystalline; Scrub/Shrub; LowCrystalline; Scrub/Shrub; MediumCrystalline; Scrub/Shrub; HighFine-Competent; Agriculture; LowFine-Competent; Developed; LowFine-Competent; Developed; MediumFine-Competent; Developed; HighFine-Competent; Scrub/Shrub; LowFine-Competent; Scrub/Shrub; MediumFine-Competent; Scrub/Shrub; HighFine-Weak; Developed; LowFine-Weak; Developed; MediumFine-Weak; Developed; HighFine-Weak; Scrub/Shrub; High

Coarse-Competent; Scrub/Shrub; Medium

Coarse-Competent; Developed; LowCoarse-Competent; Developed; MediumCoarse-Competent; Developed; HighCoarse-Competent; Scrub/Shrub; Low

Coarse-Competent; Scrub/Shrub; HighCoarse-Weak; Developed; LowCoarse-Weak; Developed; MediumCoarse-Weak; Developed; HighCoarse-Weak; Scrub/Shrub; LowCoarse-Weak; Scrub/Shrub; MediumCoarse-Weak; Scrub/Shrub; HighCrystalline; Agriculture; LowCrystalline; Developed; LowCrystalline; Developed; MediumCrystalline; Developed; HighCrystalline; Scrub/Shrub; LowCrystalline; Scrub/Shrub; MediumCrystalline; Scrub/Shrub; HighFine-Competent; Developed; LowFine-Competent; Developed; MediumFine-Competent; Developed; HighFine-Competent; Scrub/Shrub; LowFine-Competent; Scrub/Shrub; MediumFine-Competent; Scrub/Shrub; HighFine-Weak; Developed; LowFine-Weak; Developed; MediumFine-Weak; Developed; HighFine-Weak; Scrub/Shrub;High

Unique Landscape Units – Planned Land Use

Unique Landscape Units – Current Land Use

Crystalline; Scrub/Shrub; High

Crystalline; Scrub/Shrub; High

Crystalline; Scrub/Shrub; Low

Coarse-Competent; Scrub/Shrub; High

Potential2050 Land

Use

Developed

Scrub/Shrub

Scrub/Shrub

Scrub/Shrub

Developed

Scrub/Shrub

Difference in Percent

-6.6

-8.1

-3.1

-0.7

-1.2

-0.2

Geology

Crystalline

Crystalline

CrystallineCoarse-

CompetentCoarse-

Competent

Coarse-Competent

Slope

Medium

Medium

High

Low

High

Medium

Current2012 Land

Use

Agriculture

Scrub/Shrub

Scrub/Shrub

Scrub/Shrub

Scrub/Shrub

Scrub/Shrub

Relative Sediment

Production

Low

Low

Low

Low

Medium

Medium

Legend

20122050

A predicted reduction in sediment could be used to identify areas of hydromodification

Relative Sediment Production

Limitations

• Defined by the coarsest dataset – Jennings Geology

• Reclassification of Categories

• Assessment of relative sediment production rates

Summary

• Goal was to identify unique landscape units that could be used in a rapid assessment of the watershed

• 3 indicators of potential sediment production

• Dataset and Classification limitations

• Predicted reduction in sediment could be used to identify areas of hydromodification and assist decision makers

Questions?

papantzin.cid@gmail.com