Breakout Session – Environmental Applications

Coffee, Donuts and GIS

April 2, 2011

User To User GIS Network

How is GIS Presented to Novices?

• Layers

Alternate Metaphor – Components of an Information System

• Applications

• Data

• Software

• Hardware

• People

The Data-Applications Relationship

• Applications are processes that work on data to produce information

• Applications need data and produce information

• So what to do first?

• Applications don’t run without data – so data is first

Common Data Layers for Environmental GIS Applications

• Topography

• Land cover

• Existing preserved open space

• Land parcels

• Hydrography (streams, lakes, marshes, etc..)

• Wetlands

• Floodplains

• Soils

• Surficial and bedrock geology

• Natural Diversity Database

• Critical habitats

• Orthophotography backdrop

Topography

• Formats– Pixels (raster)

– Triangulated Irregular Network

– Traditional contours

Land Cover

• Not the same as land use– Consider a polo field and a turf

farm

• Usually derived from satellite imagery and in raster format

• Usually developed by government so is available for free

• Classes of land cover may not exactly match your desires; more is better (combine)– USGS national land cover layer has

590 different classes at highest level, 43 at level 2 and 7 at level 3.

• We will see an example in the gap analysis application

Existing Preserved Open Space

• One of the most difficult to keep current; always out of date

• Based on parcel layer – wide range of quality in the state

• State DEP has several different layers – which is best for you depends on where you are:– Near shore – use ProtectedOpenSpace Phase1 -Town

of Essex Example (Bookmarks - DifferentSources; ThatchbedIsland)

– Away from shore if PROTECTED_OPEN_SPACE is available use it; if not use MUNICIPAL_PRIVATE_OPEN_SPACE

– Activate StateLayers

– Only some towns in PROTECTED_OPEN_SPACE

– All in MUNICIPAL_PRIVATE_OPEN_SPACE (oldest of the layers)

• Example: TownOfEssex.pmf (ArcReaderApplication)

Land Parcels

• Usually maintained by town or city, sometimes by regional entity, e.g. Windham RPO

• Key layer for much of town GIS management

• Widely varying accuracy

• Not all towns in the state have them

• DEP layer is quite out of date but..

• Most new parcels will be developed so not of much value for preservation

• Attribute information is geared to assessors

Hydrography

• Contain all “blue” information from 7.5’ topographic map series, including marshes.

• Principle source is 1:24,000 Digital Line Graphs (USGS –from 7.5 minute topographic maps)

• Because of scale of production appears “blocky” when zoomed in to a large scale

• Narrow streams modeled as lines, wider ones as polygons: in separate layers

• Many streams that show on this layer actually no longer exist – buried, channelized, etc..

Wetlands

• CT Definition: Poorly Drained and Very Poorly Drained Soils and Alluvial and Floodplain Soils

• Existing digital sources cannot be official wetland layer– Attribute information is good but

spatial information is poor

– Generally over-estimate wetlands

– Example – Soils in Ashford.pmf

• National Wetlands Inventory– Harder to deal with

– Complex hierarchical classification system

– Going to skip it for today (see source)

Other Soils of Interest

• Farmland (hierarchy)– Prime

– Statewide importance

– Local importance

• Soil potential for sub-surface sewers (development pressure)

Bedrock and Surficial Geology• Multiple different layers at DEP site• Some geology background is needed even

for figuring out which to download.• Surficial geology gives you the glacial and

immediately post-glacial situation• Surficial geology of CCSU – ice dammed

pond– Dam was where the football stadium was– Summers, the dam would melt down and

water would flow out of the pond into Glacial Lake Middletown

– Winters, dam would build up and water was imponded.

– Annual flow visible in cross-section of the delta exposed when they built the football stadium

• Glacial features are worthy of preservation

– Eastern side of the drumlin in A.W. Stanley Park was not preserved allowing housing to be developed by cutting away the edge of the drumlin.

– My mechanic, Pete, is cutting away on his small parcel to get a flat place for his kids to play

Natural Diversity Database (NDDB)/Critical Habitats

NDDB

• Approximate location - .5 mi circles from randomized location

• Species not identified

• Overlay of NDDB and Critical Habitats can provide some insight

Critical Habitats

• key habitats for species of Greatest Conservation Need in the Comprehensive Wildlife Conservation Strategy

Critical HabitatsCommunity Type NumberInLayer

Floodplain Forest 1019

Acidic Rocky Summit Outcrop 531

Beachshore 224

Intertidal Marsh 202

Subacidic Rocky Summit Outcrop 185

Poor Fen 163

Dry Subacidic Forest 157

Acidic Atlantic White Cedar Swamp 123

Sand Barren 73

Rich Fen 72

Alluvial Grassland/Outcrop 49

Circumneutral Spring Fen 34

Acidic Red/Black Spruce Basin Swamp 30

Medium Fen 29

Coastal Bluffs and Headlands 17

Coastal Woodland/Shrubland 15

Coastal Grassland 13

Dry Circumneutral Forest 7

Dry Acidic Forest 6

Freshwater Aquatic 6

Old Growth Forest 5

Subacidic Cold Talus Forest/Woodland 5

Circumneutral Rocky Summit Outcrop 4

Circumneutral Northern White Cedar Swamp 2

Sea Level Fen 1

Orthophotography

• Digital aerial photography processed be “map-like”– Same scale at all locations

– As close to straight down at all points as possible

• LARGE files – easiest way to obtain is through image services (images served through the Internet)

In Capital Region Council of Governments Region – 2009, leaf-off color, 3 in cell resolution

In Urban Connecticut – USGS/Homeland Security 2008, leaf-off color, 1 ft cell resolution

In rural Connecticut – USDA National Agricultural Inventory Program 2010 leaf-on color, 1 meter cell resolution

An oldy but goody – CT DOT/DEP, leaf-off, black and white, 10 inch resolution

Additional Coastal – CT DEP-2004, leaf-on, color (and infra-red for vegetation), 1 meter cell resolution

Oblique Aerial Photography

• Product of PictometryCorporation

• Public access is limited (FOI court case currently underway)

• Much is available on-line, however.

• All you need is the latitude/longitude of where you want to look.

• http://bing.com/maps/default.aspx?cp=41.3575065~-72.638278&lvl=18&style=b

• Examples on web page

Sample – ArcReader: Ortho.pmf

• Scale dependent drawing– BaseMap: Set by Uconn and DEP (map service)– Photography

• Will not show above 1:10,000

– Muncipal/Private OS• Will not show above 1:25,000• Labels will not show above 1:10,000• Set 40% transparent for air photo to show

– Inland Wetlands• Will not show above 1:50,100 (DEP/Uconn set – map service)• Set 40% transparent

• Click orthophotography on one at a time

Common Application - Clipping

• Taking part of a larger layer

• Commonly called a “cookie cutter” operation

• Three layers required

– Input features (layer to be clipped)

– Clip features (cookie cutter)

– Output layer (new layer is always produced)

Watershed outline

State layer of critical habitats

Clip Critical Habitat with Outline - WatershedCriticalHabitat

You Do One

• Close any GIS Application

• Double click on ClipExample.mxd on web page

• In ArcToolbox, expand Analysis toolbox, then Extract toolset and double click on Clip

• Using the pull down menus:

– Input features: CriticalHabitat

– Clip features: Outline

• Enter: C:\temp\Habitat.gdb\CRITICAL_HABITAT_POLY_CLIP as the output feature class.

• Click OK

• You would use this function for clipping out you area of interest from larger layers– Freeware does not usually do this function

Common Application – Select by Attribute

• Open SelectByAttribute

• Select by attribute is the most common database analytical tasks– Selection/Select by Attributes

– Fill in the SQL query to read: Select from Parcels * where “MBL” = ‘36 9’ (use the Get Unique values button after entering = and click on ‘36 9’

– Right click on Parcels in the table of contents select Selelction/Zoom to selected features

– Wetlands touches the parcel

• From Selection menu choose Clear Selected Objects

Occasional – Select by Location• Currently procedures of your inland wetlands

commission require that if any suspected wetland soil type (from DEP soils layers) is within 100 ft of land parcel before the P&Z or ZBA it must come to your commission for review and decision.

• What would the impact be on land owners if you extended a 150 ft buffer and required all land parcels within 150 ft of suspected inland wetland to come before the commission?

• Select by Location: I want to select features from the following layer(s): Parcels that: are within a distance of the features in this layer: WetlandSoils. Apply a buffer to the features in WetlandSoils of 100 ft.

• Click OK• Right click on Parcels and Open Attribute Table• (Bottom of table): 933 of 3114 selected.• Close the table and rerun the spatial query with 150

buffer applied (bottom of select by location box)• 1073 of 3114 selected; or only an additional 140

parcels would be affected by this change.

Inland Wetlands and Watercourses Maps

• Click on InlandWetlandMap.mxd

• Right click on HydroLineClasses and open table

• 5 kinds of HydroLines in Essex– Boundary of Channel in Open Water

– Dam or Weir

– Manmade Shoreline

– Shoreline for Stream, Lake and Open Water polys

– Single line Rivers, Streams and Brooks

• Last one is watercourses.

• Right click on HydroLines, go to Properties and in the Properties window click on the Definition Query tab.

• Click Query Builder and fill in Select query as "HYDRO_ARC" = 'Single line Rivers, Streams and Brooks‘ Click OK and OK again.

• Only the watercourses will show; the rest are still there but just not active.

Creating Buffers

• Process described– Buffer wetland soils 100 ft

– Buffer watercourses 100 ft

– Symbolize for map

• Buffer HydroLines– Open ArcToolbox from the menu bar

– Expand Analysis Tools/Proximity

– Click on Buffer

• Input Features – pull down to Hydrolines

• Output Feature or class – take default

• Distance [value or field[ 100 ft

• Side type – default

• End type – default

• Dissolve Type – all

• Click OK

• Do the same with WetlandSoils

Symbolizing Map

• Double click on WetlandSoils_Buffer

– Click Symbology, click on the Symbol and take Green, click OK

– Click on Display tab and set Transparent: to 40%; click OK

• Do the same for Hydrolines_Buffer but take Blue for the symbol color

• Marvel at your work – zoom around

Gap Analysis – How Closely Does the Vegetation of Preserved Land in a Region Match the Vegetation of a Larger Reference

Region?

• Hall River Watershed in NW Connecticut• Data Layers (top to bottom)

– Outline – the watershed boundary– DEPProperty – DEP owned land in the watershed– MunPrivOS – municipal and privately owned open space in the watershed– MunPriveOS_Merge – a merge of the top two layers– Sne_land_cov1: a raster (pixel) layer of satellite derived vegetation type. 215

different vegetation categories. Pixels are 100 ft x 100 ft

• Step 1 - Choose the reference region.

– SNE is too large; who would expect the holdings in a single watershed to match the entire region

– So… the watershed is the reference region

• Step 2 – Extract the watershed from Southern New England– Create an attribute field in Outline and give it a value of 1– Convert it from a polygon to a raster using that value of 1 as the value for the

raster– Multiply that raster of 1’s x Sothern New England = WatVeg– Only pixels inside the watershed calculate; the rest of the region disappears.– There are 43 different vegetation types in the watershed (number of rows in

Watveg)

• Step 3 – determine the land cover types you feel worthy of preserving

– Join the regional land cover table to the SNE land cover table using Value and VegCode as the common fields.

– This puts the descriptions of the vegetation codes back with the codes

Step 2 – Extract the Watershed from Southern New England

1. Add a field with value = 1 to Outline

2. Convert Outline to a raster (pixels) using Value = 1 as the raster value (all pixels have a value of 1) – outline2

3. Multiply (map algebra) outline2 x

4. Result is land cover in the Hall River watershed – has 43 of 70 land cover classes (WatVeg)

x

=

Step 3 – Determine the Land Cover Types of Interest1. Join table of WatVeg to sne_land_cov1 using Value in WatVeg and VegCode

in sne_land_cov1 as common fields

2. Export the 43 records of that table that have some value (27 land cover types are not found in the watershed)

3. Calculate the percentage of watershed covered with each of the 43 land cover classes

4. Remove all land cover classes that:

1. Are less than 2% of the watershed

2. Or are non-forested land cover types

3. 14 of 43 meet the criteria

4. VegCode 14

Gap Analysis Cont

• Step 4 - Do Steps 1 through 3 using only the area of preserved open space.

– Note: About 30% of the entire watershed is currently preserved; the larger this gets the more likely you are to come close to matching the desired land cover types.

– Result OSVegCode14

• Compare the two tables (OS_WatShed_Compare)

– Under-Represented Land Cover - Percentage in Watershed Table is Greater Than in Open Space Table

– Over-Represented Land Cover -Percentage in Watershed Table is Less Than in Open Space Table

VEGCODE DEFINITION MAJORTYPE PerCentWatShed PerCentPres PerCentDif

2N. Hardwoods with up to 20% White Pine (cis Hemlock)N.Hardwoods (Sugar Maple dominant) 4.9 5.7 0.8

4Red Maple dominant deciduous Red Maple dominant 12.2 11.9 -0.3

6N. Hardwoods with up to 20% Red OakN.Hardwoods (Sugar Maple dominant) 4.1 4.4 0.2

7N. Hardwoods Red Oak mixture with up to 20% White Pine (cis Hemlock)N.Hardwoods (Sugar Maple dominant) 4.3 3.9 -0.4

12Oak dominant with up to 20% N. Hardwood (cis Red Maple mixture with Birch) Oak dominant 11.7 15.1 3.4

20Oak dominant with up to 20% N. Hardwood (cis Red Maple, Birch) and White Pine Oak dominant 5.9 6.1 0.2

33Black Birch dominant birch mixture Birch dominant 3.3 3.1 -0.2

40N. Hardwoods 60%, Red Oak mixture 40% (cis Red Maple) (assume Birch is present) Oak/Maple/Birch co-dominant 3.0 4.5 1.5

48Red Maple 60%, Red Oak mixture 40% Oak/Maple/Birch co-dominant 2.6 3.1 0.5

68Red Oak 60%, White Pine mixture 40% (cis Hemlock) with Maples (either RM or NH) Maple/Oak/Conifer co-dominant 2.9 3.0 0.1

84Conifers 60%, N. Hardwoods mixture 40% (cis Red Maple and/or Red Oak) Maple/Oak/Conifer co-dominant 33.2 22.8 -10.4

100White Pine stands Conifer 3.3 2.5 -0.8

128Scrub or shrub marsh Palustrine Wetlands 5.4 7.7 2.3

148Forested Wetland - Deciduous Palustrine Wetlands 3.4 6.4 3.0

How Would You Use This to Assist in Decision Making?

• Set Goals•How much acreage of White Pine do we need to acquire to reach our desired percentage?

Watershed White Pine Percent

Pixels in 14 cover type

93918 3065 3.26348517

Preserved Pixels in 14 Cover Types

28412 702 2.47078699

How many additional white pine pixels?

0 2.470786991

New Acres

0

Look for Parcels to Meet Goals

• Turn off everything except outline2 and WatVeg

•Right click WatVeg, open the table and find watveg.vat:VALUE = 100•Click in the left box and highlight it (light blue)•Right click WatVeg > Zoom to Layer•Blue areas are clusters of pixels of white pine stands•Turn on MunPrivOS_merge•Zoom in to the area marked with the circle•Click on the measure tool •Use the pull down menu; set Area to Acres•Click on the polygon tool and roughly outline the contiguous large blue polygon.•You should get around 100 acres•Add the parcels layer from c:\temp\Property geodatabase•What is the acreage of new white pine in the furthest east parcel that covers this area? (38)•What percentage of your goal does that make?(38/53)*100 = 71.%

Evaluate a Single Parcel with Respect to Your Goals

•An alternative process to rasterizing an area with a value of 1 and multiplying it by the land cover raster

•Convert land cover raster to polygons to produce a feature land cover layer•Intersect area of interest with feature land cover layer

•Summarize over land cover code taking the sum of the area of the polygon•Calculate percentages•Compare to goals

Feature land cover layer (14 categories) and parcel to evaluate

Intersection of two layers

Compare to Your Goals

VALUE DEFINITION MAJORTYPE AreaSF Acres Percent14

2N. Hardwoods with up to 20% White Pine (cis Hemlock)N.Hardwoods (Sugar Maple dominant) 100,905 2.3 0.62%

4Red Maple dominant deciduous Red Maple dominant 203,372 4.7 1.25%

7N. Hardwoods Red Oak mixture with up to 20% White Pine (cis Hemlock)

N.Hardwoods (Sugar Maple dominant) 338,661 7.8 2.09%

12Oak dominant with up to 20% N. Hardwood (cis Red Maple mixture with Birch) Oak dominant 80,000 1.8 0.49%

20Oak dominant with up to 20% N. Hardwood (cis Red Maple, Birch) and White Pine Oak dominant 793,562 18.2 4.89%

33Black Birch dominant birch mixture Birch dominant 3,945 0.1 0.02%

48Red Maple 60%, Red Oak mixture 40% Oak/Maple/Birch co-dominant 37,230 0.9 0.23%

68Red Oak 60%, White Pine mixture 40% (cis Hemlock) with Maples (either RM or NH) Maple/Oak/Conifer co-dominant 23,785 0.5 0.15%

84Conifers 60%, N. Hardwoods mixture 40% (cis Red Maple and/or Red Oak) Maple/Oak/Conifer co-dominant 14,499,097 332.9 89.28%

148Forested Wetland - Deciduous Palustrine Wetlands 160,000 3.7 0.99%

372.8 100.01%