2. OVERVIEW
• Professor Nicholas Robinson – Pace Law School
• Investigation of the Ossining portion of the Pocantico River Watershed
• New initiative to deal with hazards brought about by climate change
• Analyze GIS data and digital elevation models of the area in order to locate potential storm water
detention basins
• Also, locate potential flood zones in the area
3. POCANTICO RIVER
• Western Central Westchester County, NY
• 9 miles long (14km)
• Tributary of the Hudson River
• Rises in the town of New Castle
• Flows southwest past Briarcliff Manor
• Outlet at Sleepy Hollow
4. POCANTICO RIVER WATERSHED
• Portions of Mount Pleasant, Ossining, and Tarrytown
• 16 square mile watershed
• 436 acres of mapped freshwater wetlands
• 11 dams
• 14,866 people live within the watershed
• Largely suburban
• Contains parks, forests and wildlife, highways, utilities, and institutions
5. GEOGRAPHIC INFORMATION SYSTEMS (GIS)
• System designed to capture, store, manipulate, analyze, manage, and present all types of spatial or
geographical data
• Geographic information science – the science underlying geographic concepts, applications, and
systems.
• Many applications – engineering, planning, management, etc.
• Mapping and analyzation of map data
6. ARCGIS
• Esri – GIS software company
• ArcGIS
• Many different programs
• Creating and using maps
• Analyzing mapped information
• Sharing and discovering data
• ArcMap
• Mapping and design tool
• Analyze geospatial data
• 2 dimensional
• ArcScene
• 3 dimensional
7. LIDAR – WHAT IS IT?
• Remote sensing technology that measures distance by illuminating a target with a laser and analyzing
the reflected light
• Elevation levels of land
• Combination of “light” and “radar”
• High resolution maps
• “Combines laser focused imaging with radar’s ability to calculate distances by measuring the time for a
signal to return.”
• DEM – Digital Elevation Model
8. LIDAR - HISTORY
• Originated in early 1960s
• First used in meteorology by the National Center for Atmospheric Research to measure clouds.
• 1971 during the Apollo 15 mission, when astronauts used it to map the surface of the moon.
• Ultraviolet, visible, or near infrared light to create images.
• Make digital elevation models for use in geographic information systems
9. THE INVESTIGATION
• Professor Nick Robinson – Pace Law School
• Member of the Pocantico River working group and lives in Sleepy Hollow
• Sleepy Hollow planning committee for years
• Concerned about flooding
• Isolate the Ossining portion of the Pocatinco River Watershed and locate the low points of elevation in
which storm water can be detained
• Locate the points in elevation where the area may flood
• Create several maps to illustrate the findings
10. LEGISLATION
• Governor Cuomo - $128 million in hazard mitigation grant
• Projects advance for federal action
• 10 projects have progressed to the next stage of federal action (approx. $128 million)
• Hazard Mitigation Grant Program (HMGP) proposals
11. LEGISLATION
• A call for projects to be funded by the HMGP
• Assist local governments and non-profit organizations rebuild stronger, more sustainable communities
• Extreme weather causes hazards
• Preparing for future storms to protect the safety of citizens
• Precautionary measures
12. • Ossining Portion of Pocantico River Watershed
outlined in red.
• World Imagery
13. • Digital Elevation Model of the Study Area
• Dark areas represent low points
• Light areas represent high points
• Downhill slope
15. • Blue = Natural storm water detention areas
• Pink = Flood zone
• Properties vs areas of storm water
detentions/flood zones
16. • Green = Blue = Natural storm water detention
areas
• Purple = Flood zone
• Elevation levels displayed for analyzation
17.
18. • Storm water detention area number 1 (North)
• Google Maps
19. STORM WATER DETENTION AREA #1 (NORTH)
• Most suitable area for a natural storm water detention
basin
• Little to no zoning parcels and properties
• Highly vegetated to absorb water
• Can be developed into a man-made wetland or vernal
pool
• Bio filter
20.
21. STORM WATER DETENTION BASIN #2 (ATHLETIC FIELDS)
• Suitable area for storm water detention
• Little to no zoning parcels and properties
• Baseball fields will absorb water and drain it into
the ground
• Flat land will attract water to the area
• Development can be done to close off the
region
• To trap water more effectively so it does not
continue down hill
• Increase surrounding vegetation to absorb and
slow water flow
22.
23. STORM WATER DETENTION BASIN #3 (SOUTH)
• Not a suitable area for storm water detention
• Too many zoning parcels and properties
• Residential area
• People will be suspect to flooding
• Non-permeable ground material (concrete,
asphalt)
• Although the water may be trapped here, there
is no where for it to drain
• Therefore, it will continue downhill and flood
the lower level properties
24. • Storm water detention area number 2 (Athletic
Fields)
• Storm water detention area number 3 (South)
• Google Maps
27. FLOOD ZONE (SOUTHEAST)
• Highly susceptible to flooding
• Lowest point of elevation in the study area
• Bottom of the slope
• Club Fit – health and fitness club
• Large parking lot
• Commercial and residential area
• Flooding of the nearby highway
• Developments must be implemented to divert
water and prevent flooding
29. MEASUREMENTS
Name Length (miles) Area (sq. miles)
North Top 0.21 0.013
North Middle 0.24 0.017
North Bottom 0.19 0.013
Athletic Fields 0.37 0.045
South 0.32 0.013
Flood Zone 1.18 0.15
31. CITY ENGINE
• Program used to translate and view maps in interactive 3D form
• Created by Esri
• The Study Area City Engine:
http://www.arcgis.com/apps/CEWebViewer/viewer.html?3dWebScene=2c996c1b022e4e50ba329ac1ce852e6e
32. CONCLUSION
• Storm water detention area #1 (North)
• Most suitable for storm water detention
• Storm water detention area #2 (Athletic Fields)
• Second most suitable for storm water detention
• Storm water detention area #3 (South)
• Not suitable for storm water detention
• Flood Zone (Southeast)
• Highly vulnerable to flooding
