HomeMy WebLinkAboutScenario Planning - Conservation and Urban Scores Report - City Explained (2020)
Analysis Documentation: Conservation & Urban Scores Report 1
PROJECT DOCUMENT
County of Hawaiʻi General Plan Comprehensive Review
Analysis Documentation: Conservation & Urban Suitability
Report
Date: February 20, 2020
Author: Ian Varley
Introduction
This technical report documents and describes a CommunityViz analysis built to assess areas of
conservation value in the County of Hawaii (CoH). This assessment used best-available GIS information
to represent diverse themes including native habitats, coastal resources, hazards, culture, history and
agriculture. This resulted in a weighted score of conservation value. The conservation score was then
compared with another scoring system that measured suitability for urban development. Areas that
both had high conservation scores and high urban scores were then highlighted to identify areas of
potential conflict.
About the Suitability Tool
One of the most powerful applications of CommunityViz is the land suitability analysis: the process of
determining which locations are best suited for certain uses. The CommunityViz Suitability Tool allows
the user to set up a weighted suitability analysis (sometimes referred to as multivariate suitability).
Suitability combines multiple factors having to do with location – such as proximity, overlap, slope, or
value – and comes up with a combined rating or score for each place (feature) on the map. “Weighted”
suitability analysis places more importance on some factors and less on others, so that the combined
rating more fairly represents the relative importance of each location criterion. This technique was used
for the CoH Conservation and Urban Suitability analyses.
To use the tool, the user specifies the factors they want to consider (for example, proximity to
protected areas or overlap with floodplains) and the Suitability Tool sets up a complete analysis. Once
the analysis has been created, the maps symbology can be set up according to which sites are most
suitable, and the user can change the weighting of each factor and see the results. Once appropriately
symbolized, the map looks like a “heat map” with warmer areas showing areas of great suitability and
cooler areas showing areas of lower suitability.
There are two main parts to a suitability analysis. The first is the factor rating, in which features in your
layer are rated according to their own attributes or to their relationship to other features or layers on
the map. For example, in the conservation suitability analysis, the critical habitat factor is rated based
on its overlap with the critical habitat layer. The more overlap with the critical habitat layer, the higher
the factor value. This overlap value is then rescaled using a numerical formula and the result is that the
grid cell with the most overlap receives the score of 100 and the least overlap receives a score of 0.
Analysis Documentation: Conservation & Urban Scores Report 2
Other factors are similarly scaled 0-100 but may use other spatial operations, for example amount of
distance to particular feature. The scaled scores for each factor in the analysis are then added together
and again rescaled between 0-100.
The second part of a suitability analysis is weighting. Here the user can place more importance on
some factors (e.g., proximity to wetlands) and less importance on others (e.g., proximity to streams).
The Suitability Tool sets up variable assumptions that control the weight of each factor, typically
between 0-10. Once the tool has been run, the user can change the variable assumptions to weigh
some factors more than others.
A key component to a Suitability Analysis is the choice of analysis unit. Experience has shown that
regular sized units (i.e., an analysis that uses units that are consistently the same size and shape), are
superior to units that vary size and shape. Different options were considered including parcels and
hexagons, before choosing square grid cells. The grid cell used for both the Conservation and Urban
suitability analyses was 40 acres in size.
Conservation Score
Conservation Themes
Working collaboratively, the consultant and CoH staff developed a list of data sources in Appendix 1
and organized them under different thematic areas. Each thematic area had a corresponding suitability
analysis. Each suitability analysis had a final score that was an input to a composite suitability analysis.
• Protecting Native Habitats & Wildlife
• Coastal Resources, wetlands, streams, and watersheds
• Hazards & Climate Change
• Landscape, Culture and History
• Prioritizing Agriculture & Food Security
The composite analysis used the five scores from the theme-based suitability analyses listed above.
This “nested” approach of developing thematic areas that roll up into a final score allowed planner to
look at trends that might be apparent within a particular theme but also allow a simplified “big picture”
of conservation priorities on the island.
During the development of the analysis, the consultant and planners modified the suitability grid cells,
removing grid cells that fell entirely within a permanent protected area (national or state parks) or areas
designated for conservation under the State Land Use system (many privately, owned but unlikely to
develop significantly under state law). This removed areas which were already conserved and put the
emphasis on finding areas that had a greater potential to be developed in the future.
Upon opening the analysis, the user has the option of choosing various “Saved Views” which set up the
ArcMap/CommunityViz interface. Saved Views assist users by arranging the screen display to match an
arrangement, appearance and map symbology. The saved views included in the analysis allowed the
user to examine the final results of each thematic area and the final composite score. The analysis lets a
user find specific information about suitability scores by querying one or more grid cells. CommunityViz
Analysis Documentation: Conservation & Urban Scores Report 3
has a set of functions that provide an easy way for a user to select a feature and get set of metrics,
displayed in either a table or chart. In this analysis, the metrics are displayed as indicators in a chart or
alternatively in a list. The image below illustrates how this process works.
In the example below, the user has selected an area west of Hilo (note pink highlighted grid cells). The
grid cells are showing the Composite Conservation Score on a scale from 0-100. Warmer colors
represent areas with higher scores. After running the “Update IsSelected Formulas” button on the
CommunityViz Scenario 360 Toolbar, the tool updates the indicator metrics shown in the charts. Each
chart contains the factors belonging to a particular theme, the bar graphs showing the average score
between 0-100 for each factor. Using this system, the user can identify what factors are contributing to
the conservation scores of any area of the island.
Figure 1 Screenshot of the Conservation Composite Scores in the CommunityViz analysis
Weighting the Suitability Analysis
By default, CommunityViz assigns a weight of five to all factors that are created with the tool. After the
development of a draft version, the consultant met with County planners to discuss potential criteria
that could influence weighting. The factors discussed included:
• Legal Criteria – What resources are protected by federal, state or county law? Criteria
considered included:
o Threatened and endangered species
o State land use system
o Coastal zone management
o State water code
o Historic Preservation Laws
o Important agricultural lands
• Data Quality
Analysis Documentation: Conservation & Urban Scores Report 4
o Scale. Data mapped at a coarser scale should be weighed less.
o Origin. Data that has been modeled or remotely sensed (e.g., mapped via satellite)
typically has a lower value than data mapped in person, in the field.
o Age. Older data should have a lower value compared to data that is more recent.
• Ecosystem Service Criteria. Ecosystem services is a concept that recognizes that natural
resources and healthy ecosystems provide benefits to people. While understood implicitly by
native people for millennia, modern societies have recognized the importance of ecosystem
services relatively recently. Ecosystem services can be classified using the following:
o Provisioning services are services that provide benefits such as food or raw materials.
o Regulating services regulate climate, cycle nutrients, and sequester carbon, among
other benefits.
o Habitat services provide habitat for migratory and resident species.
o Cultural services provide spiritual, recreational, scientific and educational benefits.
• Strategic Conservation Criteria
o Protected areas benefit from connectivity and buffering from intense human activities
o Conservation efforts in absence of complete information generally emphasize
protecting areas where the greatest diversity and abundance of species exist.
o Species imperilment is a key criterion to the protection of natural resources.
Conservation efforts should factor in concepts like rarity, endemism, and the threats
from long-term trends such as climate change and habitat loss. Resources with lower
levels of imperilment should receive lower weighting.
After meeting internally and some initial revisions, county planners proposed the weighting system
included in the table below. The analysis called, “Hawaii_Suitability6.mxd” was provided to county
planners. The analysis was built on CommunityViz 5.2 for ArcGIS 10.4 but will work with the current
production version of ArcGIS 10.7 as of this writing. A more complete version of the table below is
included in Appendix 2.
Suitability Factor Name Weight
Protecting Native
Habitats & Wildlife
Nature Conservancy Assessment of Habitat Quality 10
Nature Conservancy Assessment of Biodiversity 10
Native Vegetation 8
Proximity to Protected Areas 6
Proximity to State Land Use Designated Conservation
Areas 5
Critical Habitat 3
Threatened and endangered plant species 2
Coastal Resources,
wetlands, streams,
and watersheds
Anchialine pools 10
Watersheds Priority 3 9
Watersheds Priority 4 8
Watersheds Priority 1 7
Watersheds Priority 2 6
Analysis Documentation: Conservation & Urban Scores Report 5
Streams Diverse Resources 5.5
Streams Riparian Resources 5
Streams Aquatic Resources 4.5
Streams with Cultural Resources 4
All streams (complements the other stream assessment
layers) 3
State Coastal Management Zone 2
USGS Wetlands 1
Hazards & Climate
Change
USGS volcano hazard areas 10
Tsunami risk areas 8.5
Sea, Lake and Overland Surges from Hurricanes (SLOSH) 7
Sea level rise areas 5
Wildfire risk 4
Steep slopes 3
FEMA flood areas 1
Landscape, Culture
and History
Exceptional and Important Views 10
Important Viewsheds 8
Na Ala Hele Trails 6
Archaeology Polygon 4
Historic Sites 2
Historic Districts 1
Prioritizing
Agriculture & Food
Security
Active Agricultural Land 10
Indigenous agricultural lands 7
Agricultural land of importance 4
Composite Score
Protecting Native Habitats & Wildlife 10
Coastal Resources, wetlands, streams, and watersheds 8
Hazards & Climate Change 6
Landscape, Culture and History 4
Prioritizing Agriculture & Food Security 2
The conservation score analysis reveals various conservation hotspots across the island. Many of these
areas are proximate to the County’s existing conservation areas and coastline. The importance of the
island’s perennial streams and wetland areas is also apparent. Forest areas, in particular areas with high
ratios of native species to non-native species appear in the wetter windward sides of the island
(Hamakua, Hilo, Kau and Puna) as well as the highlands of South Kona.
Analysis Documentation: Conservation & Urban Scores Report 6
Figure 2 Conservation Scores map
Urban Score
The Urban Suitability Analysis was developed as part of an earlier technical task that focused on
identifying areas that would be most suitable for future urban growth. This is documented in the
Alternative Future Scenarios Technical Report. This task culminated in the creation of the Priority
Development Zone (PDZ) future growth scenario. The scenario tested the potential of shifting urban
growth to areas in and around existing villages, towns and urban clusters. The development of the
Urban Score helped planners identify the boundaries of the PDZs and was employed again here for the
purpose of identifying potential conflicts between areas that are appropriate for future urban growth
and areas with a high conservation value.
The urban score was developed using eight factors described below. No weighting was assigned and
the default score of 5 assigned by CommunityViz was maintained.
Suitability Factor Name Weight
Urban Score
Density of Existing Commercial Development 5
Density of Existing Residential Development 5
Proximity to Existing Facilities (school, park, or community
center)
5
Proximity to Existing Utilities (Water, Wastewater) 5
Intersection Density 5
Analysis Documentation: Conservation & Urban Scores Report 7
Road Density 5
Mixed Use Score (An assessment of the existing mix of
housing and nonresidential activities)
5
US Census Defined Urban Area 5
Overlap with County Zoning allowing Urban Uses 5
The urban score reveals a handful of hotspots on the island. This reflects the predominantly rural nature
of development in CoH. The analysis confirms that there are just a few places on the island that are
truly urbanized and have utilities to support dense urban growth: Hilo, Honoka’a, Kailua-Kona,
Keauhou, Waikoloa, and Waimea.
Figure 3 Urban Scores map
Comparing Urban Score and Conservation Score
If the urban score suggests where future growth might most appropriately be located, what conflicts
might arise with areas that also have high conservation value? This was the question that CoH Planners
wanted to address as the final step of the analysis process. To address this, the analysis then compared
areas with both high conservation and urban scores by adding one score to the other to create a
“conflict score”. After a few iterations of the process, the consultant and planners agreed that only
Analysis Documentation: Conservation & Urban Scores Report 8
areas with scores higher than 40 should be added to each other. This removed areas with relatively low
scores in both assessments. This set a minimum score of 80 and theoretical maximum score of 200
(each score being on a scale of 1-100). The Conflict Score can be revisited by changing the formula in
the “SuitabilityCompositeConflict” attribute in the Suitability Grid layer (e.g., choose a higher threshold
than 40).
The result of this step reveals that are a limited number of areas (144 grid cells or about 5,760 acres)
where high urban scores and conservation score coexist. The largest of these areas is an area in Hilo
that includes the waterfront and a forested corridor along the Wailuku River surrounding upland
(mauka) areas, west of the city. One of the highly ranked themes in the Conservation Score includes
Hazards & Climate Change. The Hilo waterfront is an extremely vulnerable place with a tragic history of
tsunami inundations. Upland areas to the west may be slightly less vulnerable but steep slopes and high
conservation values imply incompatibility with future urban growth. Other areas that have high conflict
scores include coastal areas near Kailua-Kona, South Kohala Beach Areas, and Laupahoehoe. These
areas have similar profiles in conservation and conflict: high vulnerability to hazards and proximity to
fragile coastal resources while having high suitability for urban development due to the presence of
existing towns and villages and their services. That many of the most urban areas have relatively low
conservation scores makes sense, these areas having been developed and most of their conservation
value reduced.
Figure 4 Conservation Score map, with highlights in pink showing areas with both high Conservation Score and Urban
Scores
Analysis Documentation: Conservation & Urban Scores Report 9
This map is interesting to contrast against a similar analysis of conflict using an alternative to the Urban
Score. The Trend Growth Scenario also used the CommunityViz suitability tool to guide the location of
future residential growth as has been occurring according to recent trends. Informed by a statistical
analysis and described in greater detail in the Trend Scenario and Land Use Allocation Technical
Report, the Trend Residential Suitability was used to orient residential growth in the Trend Scenario
(nonresidential growth was guided by a separate suitability analysis). The Trend Scenario showed a
much more dispersed growth pattern, in particular orienting growth into rural and undeveloped areas
of Puna, North and South Kona, Kau and South Kohala. As with the other suitability scores, the Trend
Residential Growth was on a scale of 0-100. Using this score instead of the Urban Score results in a
much larger areas of conflict (2,091 grid cells or 83,640 acres). Large areas in Ocean View, Puna, North
and South Kona. While the Urban Score and Conservation Conflict areas are limited to a few coastal
areas, many areas of the county’s interior show conflict in this assessment.
Figure 5 Conservation Score map, with highlights in pink showing areas with both high Conservation Score and Trend
Suitability Scores
Analysis Documentation: Conservation & Urban Scores Report 10
Appendix 1
Data Used or Considered For Conservation Analysis
• Hawaii Statewide Assessment of Forest Conditions and Resource Strategy (2010).
Biodiversity/Habitat Quality summaries completed by The Nature Conservancy
• Carbon Assessment of Hawaii Land Cover Map 2015 (CAH Land Cover)
• Protected Areas (PAD US 2015)
• Hawaii State Land Use
• USFWS Critical Habitat
• Threatened and endangered plant species (1992)
• Anchialine Pool Sites
• Thermal Springs
• USGS Volcano Hazard Zones
• NOAA Tsunami risk areas
• NOAA Sea, Lake and Overland Surges from Hurricanes (SLOSH)
• SLR-XA 3.2 feet
• Wildfire Hazard
• Digital Elevation Model derived steep slopes (slope as percent) (Placeways 2015)
• Exceptional and Important View Areas Point Locations (2014)
• Viewsheds (Placeways 2015)
• Streams with Assessed Resources (cultural/diverse/riparian/aquatic) layer
• USGS Streams layer (all streams)
• State Coastal Management Areas
• Watershed Priority Areas (I, II, III, IV)
• Impaired marine waters
• Restricted Watersheds
• GW Recharge (optional?)
• NWI Wetlands
• FEMA Coastal V-zones (coastal waters)
• Sensitive Ecological Areas
• Scenic Beauty Sites/Viewsheds?
• Na ala Hele Trail
• University of Hawaii Hilo Agriculture Assessment (2015)
• The potential of indigenous agricultural food production under climate change in Hawaiʻi (2019)
Modeled layers representing areas with potential for different methods of indigenous
agriculture: dryland, loi and agroforestry
• Agricultural Lands of Importance.
Additional Location Sensitive Data
• Archeological Points/polygons
• Historic Object/Buildings/structures
• Historic Districts
• T&E Plant species
Analysis Documentation: Conservation & Urban Scores Report 11
Appendix 2
Theme, Factor and Data Matrix for Conservation Score Suitability Analysis
This matrix contains all of the factors created for Conservation Score Suitability Analysis, including the
CoH assigned rank, CommunityViz assumption weight (0-10), the name of the assumption in the
CommunityViz analysis and the GIS layer name that the factor is based on.
Suitability Factor Name Rank CommunityViz Model Weight CommunityViz Assumption
Name Layer Name
Protecting Native
Habitats & Wildlife TNC Habitat Quality 1 10 HAB_TNCHabQual
hi_hq_combo_int_prj_clip_reclas
s.tif
Protecting Native
Habitats & Wildlife TNC Biodiversity 1 10 HAB_TNCBiodiv
hi_biodiv2010_int_prj_clip_reclas
s.tif
Protecting Native
Habitats & Wildlife Native Vegetation 2 8 HAB_NativeVeg Weight CAH_HabStatusPrj2clip.tif
Protecting Native
Habitats & Wildlife
Proximity to Protected
Areas 3 6 HAB_ProxProtectedArea Weight PADUS_CoH_Protected
Protecting Native
Habitats & Wildlife
Proximity to SLU
Conservation Areas 4 5 HAB_ProxSLUconserv Weight SLU_Conservation
Protecting Native
Habitats & Wildlife Critical Habitat 5 3 Hab_CriticalHabitat CriticalHabitat
Protecting Native
Habitats & Wildlife
Threatened and
endangered plant
species 6 2 HAB_TEveg Weight teplant_n83_prj
Coastal Resources,
Wetlands, Streams,
and Watersheds Anchialine pools 1 10 WET_Anchialine Weight AnchialinePoolsPrj
Coastal Resources,
Wetlands, Streams,
and Watersheds Watershed Priority 3 2 9 WET_WatershedP3 Weight Watersheds
Coastal Resources,
Wetlands, Streams,
and Watersheds Watershed Priority 4 2 8 WET_WatershedP4 Weight Watersheds
Coastal Resources,
Wetlands, Streams,
and Watersheds Watershed Priority 1 2 7 WET_WatershedP1 Weight Watersheds
Coastal Resources,
Wetlands, Streams,
and Watersheds Watershed Priority 2 2 6 WET_WatershedP2 Weight Watersheds
Coastal Resources,
Wetlands, Streams,
and Watersheds
Streams Diverse
Resources 3 5.5 WET_StreamsDiverse Weight
StreamsDiverseResources_strms
div_n83_prj
Coastal Resources,
Wetlands, Streams,
and Watersheds
Streams Riparian
Resources 4 5 WET_StreamsRiparian Weight strmsrip_n83_prj
Analysis Documentation: Conservation & Urban Scores Report 12
Coastal Resources,
Wetlands, Streams,
and Watersheds
Streams Aquatic
Resources 5 4.5 WET_StreamsAquatic Weight
StreamsAquaticResources_strms
aq_n83_prj
Coastal Resources,
Wetlands, Streams,
and Watersheds
Streams with Cultural
Resources 6 4 WET_StreamsCultural Weight
StreamsDiverseResources_strms
div_n83_prj (where resource is
cultural)
Coastal Resources,
Wetlands, Streams,
and Watersheds
All streams
(complements the
other stream
assessement layers) 7 3 WET_StreamsAll Weight Streams_All_DARprj
Coastal Resources,
Wetlands, Streams,
and Watersheds
State Coastal
Management Zone 8 2 WET_SCZM Weight StateCoastalZoneManagement
Coastal Resources,
Wetlands, Streams,
and Watersheds Thermal Springs X X WET_ThermalSpr Weight ThermalSpringsPrj_Buffer
Coastal Resources,
Wetlands, Streams,
and Watersheds USGS Wetlands 10 1 WET_Wetlands Weight HI_WetlandsPrj
Hazards & Climate
Change
USGS volcano hazard
areas 1 10 HAZ_VolcanoHaz Weight VolcanoHazardZones
Hazards & Climate
Change Volcano buffer area X X HAZ_VolcanoBuf Weight volbndbuf_n83
Hazards & Climate
Change Tsunami risk areas 3 8.5 HAZ_Tsunami Weight Hawaii_Tsunami_Prj
Hazards & Climate
Change
Sea, Lake and Overland
Surges from Hurricanes
(SLOSH) 4 7 HAZ_SLOSH Weight HI_Cat4_SLOSH_HiTidePrj6.tif
Hazards & Climate
Change Sea level rise areas 5 5 HAZ_SLR Weight
slr_exposure_area_3_pt_2_ft_prj
2
Hazards & Climate
Change Wildfire risk 6 4 HAZ_WildfireHaz Weight WildfireRisk_WHA2015_prj2
Hazards & Climate
Change Steep slopes 7 3 HAZ_Slope Weight HawaiiSlopePerc
Hazards & Climate
Change FEMA flood areas 8 1 HAZ_Flood Weight Flood_Zones
Hazards & Climate
Change Marine waters X X HAZ_MarineWaters Weight
Landscape, Culture
and History
Exceptional And
Important Views 1 10 LCH_ExcImpViews Weight ExceptionalAndImportantViews
Landscape, Culture
and History Important Viewsheds 2 8 LCH_Viewshed Weight ViewshedMaxValue
Landscape, Culture
and History Na Ala Hele Trails 3 6 LCH_NaAlaHele Weight NaAlaHeleTrailsPrj
Landscape, Culture
and History Archaeology Polygon 4 4 LCH_ArchSite Weight Archaeology Polygon
Landscape, Culture
and History Historic sites 5 2 LCH_HistPoint Weight
Historic Object Point, Historic
Structure Point, Historic Building
Point
Analysis Documentation: Conservation & Urban Scores Report 13
Landscape, Culture
and History historic districts 6 1 LCH_HistDist Weight Historic District Polygon
Landscape, Culture
and History Natural Beauty Sites X X LCH_NatBeautySite Weight Natural Beauty SitesPrj
Prioritizing
Agriculture & Food
Security
Active Agricultural
Land 1 10 AG_ActiveAg Weight 2015AgBaseline_Prj2
Prioritizing
Agriculture & Food
Security
Indigenous agricultural
lands 2 7 AG_IndigAg Weight
Hawaii_Agro_Final10prj_Rcls3.tif
, Hawaii_Dry_Final10prj_Rcls3.tif,
Hawaii_Loi_Final10prj_Rcls3.tif
Prioritizing
Agriculture & Food
Security
Agricultural land of
importance 3 4 AG_AgLandofImp Weight AgLandofImportance
Composite
Suitability
Protecting Native
Habitats & Wildlife 1 10 HAB_CompWeight
Protecting Native Habitats &
Wildlife
Composite
Suitability
Coastal Resources,
wetlands, streams, and
watersheds 2 8 WET_CompWeight
Coastal Resources, wetlands,
streams, and watersheds
Composite
Suitability
Hazards & Climate
Change 3 6 HAZ_CompWeight Hazards & Climate Change
Composite
Suitability
Landscape, Culture and
History 4 4 LCH_CompWeight Landscape, Culture and History
Composite
Suitability
Prioritizing Agriculture
& Food Security 5 2 AG_CompWeight
Prioritizing Agriculture & Food
Security