Site Analysis for Monarch Waystation Garden using GIS

Background Information ABOUT PROJECT: Presented here is a spatial analytical study carried out to assess a suitable Monarch waystation habitat in College Station, Texas. The goal of this project is to convert an undeveloped land into a neighborhood park based on parameters that are deemed suitable habitat of Monarch butterflies.

 Total project budget: $150,000

 Estimated cost to develop the park: $40,000/acre  Proposed target area for the new park: 3.0 acre  Funds saved for research; site survey; and overhead project costs: $30,000

Image Source: http://blog.hmns.org/

Here is a brief introduction about the project and the estimated break-up of research grant available to us.

Background Information PARAMETERS FOR SPATIAL ANALYSIS:

Our site selection needs to depend upon many parameters, mainly two categories: Topographic and Landuse, that are required to grow and sustain these species over a long time in an urban environment.

South Central Region Milkweed Species suitable for Monarch butterfly:

Topographic Parameters:  Dry, well-drained soil types and 2 - 6% slope  Good sun exposure for at least 6 hours a day  Minimum 500 feet offset from Floodplains Landuse Parameters:  Located within Undeveloped land use parcels adjacent to existing Residential uses.

 Should be within 600 feet from at least one road.  At least 100 square feet needed for an effective way station.

Top Right: Green Antelopehorn Milkweed, Asclepias viridis -utexas.edu Top Left: Antelopehorns Milkweed, Asclepias asperula -wildflower.org Bottom Left: Zizotes Milkweed, Asclepias oenotheroides -monarchwatch.org

The images shown above are some of the native or commonly found species in our study area that we want to grow in our new park. And we are analysing, using the GIS, certain parameters that are critical for being able to grow and sustain these species, over a long period of time, in an urban environment.

MAP - 1

Methods in GIS - 1

Texas boundary map derived from State Plane Zones shape file sourced from Texas State Parks and Wildlife Department (TPWD) website. DISSOLVE tool was used to derive a continuous Texas state boundary.

Observed Monarch sighting data was mapped alongwith Texas boundary data. The sightings data was then INTERPOLATED to visualize estimated sightings throughout Texas state.

But let us first have a look at the journey pattern of Monarchs across the Texas region to get an idea of. Observed Monarch sightings were mapped and were used to estimate Spatial Trend of their migration. The map presented here indicates relatively less concentrations but greater spread in and around College Station. The two images above just show some steps involved in working with GIS.

MAP - 2

Methods in GIS - 2

Landuse attribute data was QUERIED for all Residential and Undeveloped and Unplatted land parcels.

Source: City of College Station Open Data

Presented here is the process of analysis as carried out in ArcGIS: an idea of rationale for the study; and the tools employed towards locating our ideal site. The first analytical step - Undeveloped landuse parcels were located within the College Station city limits and visualized along side Residential and other uses to facilitate further analysis.

MAP - 2

MAP - 3

Methods in GIS - 3

Top Left: Soil raster image displayed in ArcGIS Bottom Left: Soil image was RECLASSIFIED to obtain suitable slopes (2-6%) and Well-Drained soil types, and CONVERTED to polygons to EXTRACT suitable sites.

Second step involved analysing for SLOPES AND SOILS: The map here shows extracted suitable slopes and soil type layers out of the Soil raster image. The extracted layers were intersected to obtain our required topography layer. The screenshots above give an idea of how the tools were executed in ArcGIS and the visual process involved.

MAP - 3

Methods in GIS - 4 This screen shot shows the process involved in clipping the previous layer by using Undeveloped Landuse and Buffered Floodplain layers.

The result is the Green layer (Sites_Slopes): Good soil type+good slope+Undeveloped land+500ft from floodplain.

Methods in GIS - 5

DISTANCE FROM ROADS: Parcels obtained in previous steps were QUIRIED with resect to city road data.

Sites were selected that were within 600 feet from selected public roads.

We get the Yellow layer as a result. You can see how the Yellow parcels relate to Blue road types.

Methods in GIS SUN EXPOSURE: Southfacing slopes featuring high sun exposure were extracted from DEM data and intersected with suitable sites as obtained in previous steps. Observe the Magenta polygons, and how they overlap with South-facing polygons in Black.

MAP - 4

Methods in GIS a

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BEST SITES: The sites obtained in previous steps account for all required conditions for growing milkweed for sustained time period and hence are good possible sites for waystation park. Refer map and the screenshots here representing all good sites and their adjacent landuse conditions.

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MAP - 5

Recommendations  Low-rise single family units  Away from High-speed roads and Freeways  Possibility of future expansion: Inclusion in a larger neighborhood park accessible to local community  Total park area proposed = 3 acre  Proposed Location for Waystation = 2 acre

FINAL MAP

Recommendations & Final Map Presented here is the Final Map for the proposed location of the waystation park, underlayed with aerial image of the neighbouring areas.

The proposed location is ideally located alongside vegetated land parcels that are currently in Undeveloped Unplatted status. It is suggested that the vegetated area and proposed park be integrated in future to create a new neighborhood level park accessible to the local communities.

Such a strategy will enhance community environment and can prove useful for long-term upkeep and expansion of waystation area in future as funds become available.