U.S. Geological Survey home page

USGS Spectral Library Version 7 Sample Description

Kokaly, R.F., Clark, R.N., Swayze, G.A., Livo, K.E., Hoefen, T.M., Pearson, N.C., Wise, R.A., Benzel, W.M., Lowers, H.A., Driscoll, R.L., and Klein, A.J., 2017, USGS Spectral Library Version 7: U.S. Geological Survey Data Series 1035, 61 p., https://doi.org/10.3133/ds1035
For more information on the library, see: local link web link

TITLE: Marsh SCAM45%... CRMS121v28 DESCRIPT

DOCUMENTATION_FORMAT: PLANT

SAMPLE_ID: CRMS121v28

PLANT_TYPE: Mixed wetland species

PLANT: Chairmaker's bulrush, saltmeadow cordgrass, and wand lythrum

LATIN_NAME: Schoenoplectus americanus (Pers.) Volk. ex Schinz & R.Keller, Spartina patens (Ait.) Muhl, and Lythrum lineare L.

COLLECTION_LOCALITY: Coastwide Reference Monitoring System (CRMS) site 121 subplot v28. CRMS121 is located in southern Louisiana, approximately 37 kilometers southeast of New Orleans, Louisiana,in the western part of the Breton Sound hydrologic basin on the coast of the Gulf of Mexico.

COLLECTION_LATITUDE: 29.693955 deg. N

COLLECTION_LONGITUDE: 89.819528 deg. W

DATUM: NAD83

ORIGINAL_DONOR: Raymond F. Kokaly, USGS

SAMPLE_DESCRIPTION:

This spectrum is the average reflectance for a 2x2 m area of marsh covered by mixed species as detailed in the site vegetation description.

Collection Date
08-Jun-2010

Site Vegetation Description
The total vegetation cover on this site was 55%. The average height of herbaceous vegetation was 89 cm. The following table shows the percent cover by cover category:

 
Cover Category, Sub-Category                Cover (%) 
_____________________________      ____________________________ 
Vegetation, Total Cover                   55
 Vegetation, Tree                             0 
 Vegetation, Shrub                            0 
 Vegetation, Grass                           55
 Vegetation, Forb                             1 
Non-vegetation, Total Cover               45  
 Non-vegetation, Litter                      15 
 Non-vegetation, Bare                        15 
 Non-vegetation, Water                       15  
 Non-vegetation, Other                        0 
_____________________________      ____________________________ 

The following table shows the cover by shrub species in the plot:

 
Shrub Species                            Cover (%)
_____________________________________  ____________
Baccharis halimifolia L.                 solitary
_____________________________________  ____________

The following table shows the cover by grass species in the plot:

 
Grass Species                                                           Cover (%)
___________________________________________________________________  _____________
Schoenoplectus americanus (Pers.) Volk. ex Schinz & R.Keller             45
Spartina patens (Ait.) Muhl                                              10
___________________________________________________________________  _____________

The following table shows the cover by forb species in the plot:

 
Forb Species                                    Cover (%) 
____________________________________________  _____________ 
Lythrum lineare L.                                 1
Polygonum punctatum Ell.                          <1
Eupatorium capillifolium (Lam.) Small           solitary
____________________________________________  _____________ 

Field Observations
Unvegetated surface = 45% Water Level is 0.09 ft above marsh. Unvegetated Surface is bare ground and dead vegetation.

Site Classification
The area has been predominantly classified as intermediate marsh (see http://lacoast.gov/crms2/home.aspx).

Plot Location, Dimensions, and Vegetation Sampling
The coordinates of the southeast corner of the 2x2 m plot are 29.693955 N, 89.819528 W (in decimal degrees, datum is NAD83). Within the plot, vegetation species were identified and the percent cover of each species was visually estimated.

Spectral Measurement and Processing Methods
This spectrum is the average of 20 spectral measurements recorded throughout the plot. These spectra were collected using an ASD Field Spectrometer 3 (FS3) in reflectance mode, relative to a Spectralon reference panel. While walking on the edges of the plot, the fiber optic cable was pointed at nadir (straight down) at approximately shoulder height. The instrument was programmed to record 6 second averages of reflectance (thus, each recorded spectrum was an average of 60 individual measurements). The average spectrum was converted to absolute reflectance by multiplying by the reflectance spectrum of the Spectralon reference panel. The following channels were deleted from the spectrum (set to a value of -1.23e+34) because of atmospheric contamination or high levels of noise: 410-420, 768-796, 1002-1100, 1447-1622, 1651-1669, and 2077-2151 corresponding to wavelengths 0.759-0.769, 1.117-1.145, 1.351-1.449, 1.796-1.971, 2.000-2.018, and 2.426-2.500

General Site Description
The plot is located in southern Louisiana, approximately 37 kilometers southeast of New Orleans, Louisiana. It is in the western part of the Breton Sound hydrologic basin on the coast of the Gulf of Mexico. For additional information on the CRMS site see http://lacoast.gov/crms2/home.aspx

Project Background
This site was measured as part of joint work between the USGS Denver Spectroscopy Laboratory and the Coastal Restoration Assessment Branch of the USGS National Wetlands Research Center, Baton Rouge.

This spectrum was used in the following publication:
Kokaly, R.F., Couvillion, B.R., Holloway, J.M., Roberts, D.A., Ustin, S.L., Peterson, S.H., Khanna, S., and Piazza, S.C., 2013, Spectroscopic remote sensing of the distribution and persistence of oil from the Deepwater Horizon spill in Barataria Bay marshes, Remote Sensing of Environment, Volume 129, Pages 210-230. http://dx.doi.org/10.1016/j.rse.2012.10.028

IMAGE_OF_SAMPLE: in the site layout diagram, the subplot location is indicated by the matching number within the parentheses

Photo of site Photo of site

END_SAMPLE_DESCRIPTION.

COMPOSITIONAL_ANALYSIS_TYPE: None

COMPOSITION_DISCUSSION:

END_COMPOSITION_DISCUSSION.

TRACE_ELEMENT_ANALYSIS:

TRACE_ELEMENT_DISCUSSION:

END_TRACE_ELEMENT_DISCUSSION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1a2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns