Salt Marsh Habitats, Rhode Island, 2012

This data set consists of salt marsh habitats for the state of Rhode Island derived from high resolution (0.5m) imagery collecting during June 2012. This data set utilized 4 Band multispectral aerial orthoimagery contributed to RIGIS by the Rhode Island Eelgrass Mapping Taskforce [(c) 2012 RIGIS] and LiDAR data collected through the LiDAR for the NorthEast project (2011).

To gauge the health and resilience of Rhode Island's coastal salt marshes and provide baseline data for detecting change over time.

Suggested bibliographic reference: RIGIS, 2017. Salt Marsh Habitats; saltmarsh12. Rhode Island Geographic Information System (RIGIS) Data Distribution System, URL: http://www.rigis.org, Environmental Data Center, University of Rhode Island, Kingston, Rhode Island (last date accessed: 20 June 2017).

Attributes for this product are as follows:

0 Background

1 Unclassified (Cloud, Shadow, etc)

2 Invasive Phragmites australis

3 High Marsh; S.patens-D.spicata

4 Mudflat/bare

5 Open Water

6 Dieoff Depression

7 Natural Pool

8 Salt Shrub

9 High Marsh; S.alterniflora

10 High Marsh; Mix

11 Low Marsh

12 Brackish Marsh, Native

13 High Marsh; J.gerardii

14 Wrack

Users must assume responsibility to determine the usability of these data.

None

Data set is not for use in litigation. While efforts have been made to ensure that these data are accurate and reliable within the state of the art, NOAA, cannot assume liability for any damages, or misrepresentations, caused by any inaccuracies in the data, or as a result of the data to be used on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty. This dataset is provided 'as is.’ The producer(s) of this dataset, contributors to this dataset, the Rhode Island Geographic Information System (RIGIS) consortium, the State of Rhode Island, and the University of Rhode Island do not make any warranties of any kind for this dataset, and are not liable for any loss or damage however and whenever caused by any use of this dataset. Please acknowledge both RIGIS and the primary producer(s) of this dataset in any derived products. Versions of the RIGIS logo suitable for both printed and web-based products are available at http://www.rigis.org/logos.

Version 6.2 (Build 9200) ; Esri ArcGIS 10.5.0.6491

According to accuracy assessment performed by the Narragasett Bay NERR , the overall accuracy for the classification is 82.7% and 0.804 Kappa. Each class accuracy is as follows: (Errors of Omission/Commission)

0 Background (N/A)

1 Unclassified (Cloud, Shadow, etc)(N/A)

2 Invasive Phragmites australis (100%/96%) 3 High Marsh; S.patens-D.spicata (80%/82%)

4 Mudflat/bare (100%/93%)

5 Open Water (95%/95%)

6 Dieoff Depression (78%/93%)

7 Natural Pool (91%/87%)

8 Salt Shrub (80%/100%)

9 High Marsh; S.alterniflora (85%/62%)

10 High Marsh; Mix (31%/56%)

11 Low Marsh (67%/100%)

12 Brackish Marsh, Native (0%/0%)

13 High Marsh; J.gerardii (75%/100%)

14 Wrack (100%/100%)

Given that development of this dataset was initiated several years after the collection of the imagery, some compromises were made in the assessment of it's accuracy. In an effort to evaluate the map using field data collected as close to the acquisition date of the imagery as possible, a subset of transects from the Rhode Island Salt Marsh Assessment (RISMA) were utilized. This restricted the ability to follow certain best practices associated with the accuracy assessment of maps derived from remotely sensed imagery. As such, we were unable to employ a stratified random sampling strategy or use an adequate number of samples for all of the categories included in the map. 237 accuracy assessment points were used but none of the classes have a minimum of 50 accuracy assessment points. While the accuracy assessment conducted does help inform us about the map's errors, there are shortcomings as an overall representation. It is hoped that a more complete field effort can be performed as part of a future update to this data.

< 2 meters CE95

There was no terrain correction in the geo-referencing procedure.

Tests for logical consistency indicate that all row and column positions in the selected latitude/longitude window contain data. Conversion and integration with vector files indicates that all positions are consistent with earth coordinates covering the same area. Attribute files are logically consistent.