Lake Apopka North Shore - St. Johns River Water Management District

Lake Apopka North Shore – St. Johns River Water Management District

Invasive Species Plant Program

In cooperation with Deborah Stone, Invasive Plant Program Supervisor, St. John’s River Water Management District, a prototype test is now under design and development, which intends to determine the effectiveness of UAS technologies to support the Florida Invasive Species Partnership (FISP) – Cooperative Invasive Species Management Areas (CISMA) in the identification and management of invasive species. The Lake Apopka North Shore area represents approximately 20,000 acres in area (see below).

The following areas (see right) were identified by Deborah Stone, who supervised the entire session.

The first prioritized areas contain West Indian marsh grass, para grass (aka cogon grass). St. Johns Water Management District is doing restoration work here so it would be nice to pinpoint any new populations of these species. This area is old farmland being restored to marsh, so it is pretty much impossible to get through on the ground/by boat.

The following Waypoint Maps were programmed for initial image capture, for the purpose of determining best altitude and camera resolution for effective species identification.

The northern mapping area covered 67 acres and was flown at approximately 260 ft. altitude. Camera resolution was set at 3.5 cm/pixel. The UAV captured 486 images.

Environmental conditions: Full sun/no clouds, steady winds at 5-7 mph, 69 degrees F.

The blue circle represents the Homepoint, or launch location. The orange circles indicate flight boundaries. Straight lines indicate flight path; the bright vs. shaded lines demonstrate multiple battery runs, since this mission required 2 batteries to complete. The UAV was returned to Homepoint at the end of battery 1 charge, and the Abandonment Point’s latitude/longitude was recorded by GPS. Following battery change, the UAV flew to the Abandonment Point, then resumed the mission. The small green dot in the NW corner represents the first waypoint and image capture, the small red circle in the SE corner represents the last image capture.

The southern mapping area covered 71 acres and was flown at approximately 260 ft. altitude. Camera resolution was set at 3.5 cm/pixel. The UAV captured 513 images.

Environmental conditions: Full sun/no clouds, winds at 7-10 mph with occasional gusts to 15mph, 72 degrees F.

There are a broad range of invasive species present. To list a few:

New/somewhat new:

– West Indian marsh grass (Hymenachne amplexicaulis)

– Brazilian pepper (Schinus terebinthifolius)

Well established:

– Para grass (Bracharia mutica),

– Wild Taro (Colocasia esculenta)

– Water Lettuce (Pistia stratiotes)

– Water Hyacinth (Eichornia crassipes)

Nearby but not known here yet:

– Old World Climbing Fern (Lygodium microphyllum)

Native but bad:

– Carolina Willow (Salix caroliniana)

– Cattail (Typha spp)

The orthomosaic was processed from both areas simultaneously, approximately 1,000 images (link to the processing report). The orthomosaic is a 1.41 GB geotiff, and can be directly imported into GIS software. The image may be downloaded here, or click the image below. Additionally, a .zip, Google Earth KML file is available – the entire package of approximately 1,000 actual-size images are compressed into one .sitx 4.06 GB file and may be downloaded by request (info@trilliumlearning.com) . Keep scrolling to the bottom of this page for NDVI – Normalized Difference Vegetation Index/NIR – Near Infra-Red imagery.