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Natural Hazards: Tools and Methodologies

Research

Forecasting

Monitoring

Monitoring helps researchers understand the consequences of multiple environmental and anthropogenic stressors on ecosystems. An understanding of responses to these changes is important when prescribing restoration and management strategies that will enhance the sustainability of ecological systems. New tools and methodologies based on long-term data sets are developed to strengthen the capacity to assess the sustainability of ecosystems with and without restoration and protection investments. These data predict the potential consequences of disturbance events and climate change to these systems.

 

Steyer, G.D., Couvillion, B.R., and Barras, J.A., 2013, Monitoring vegetation response to episodic disturbance events by using multitemporal vegetation indices: Journal of Coastal Research, Special Issue No. 63 - Understanding and Predicting Change in the Coastal Ecosystems of the Northern Gulf of Mexico, p. 118-130, http://dx.doi.org/10.2112/SI63-011.1

Normalized Difference Vegetation Index (NDVI) derived from MODerate-resolution Imaging Spectroradiometer (MODIS) satellite imagery and land/water assessments from Landsat Thematic Mapper (TM) imagery were used to quantify the extent and severity of damage and subsequent recovery after Hurricanes Katrina and Rita of 2005 within the vegetation communities of Louisiana's coastal wetlands. Field data on species composition and total live cover were collected from 232 unique plots during multiple time periods to corroborate changes in NDVI values over time.

 

Kokaly, R.F., Heckman, D., Holloway, J., Piazza, S., Couvillion, B., Steyer, G.D., Mills, C., and Hoefen, T.M., 2011, Shoreline surveys of oil-impacted marsh in southern Louisiana, July to August 2010: U.S. Geological Survey Open-File Report 2011-1022, 124 p., http://pubs.usgs.gov/of/2011/1022/

This report describes shoreline surveys conducted in the marshes of Louisiana in areas impacted by oil spilled from the Deepwater Horizon offshore oil drilling platform in the Gulf of Mexico. Three field expeditions were conducted on July 7-10, August 12-14, and August 24-26, 2010, in central Barataria Bay and the Bird’s Foot area at the terminus of the Mississippi River delta. This preliminary report includes locations of survey points, a photographic record of each site, field observations of vegetation cover and descriptions of oil coverage in the water and on plants, including measurements of the distance of oil penetration from the shoreline.

 

Ramsey, E.W. III, Rangoonwala, A., Middleton, B.A., and Lu, Z., 2009, Satellite optical and radar data used to track wetland forest impact and short-term recovery from Hurricane Katrina: Wetlands, v. 29, n. 1, p. 66-79, http://dx.doi.org/10.1672/08-103.1

Satellite Landsat Thematic Mapper (TM) and RADARSAT-1 (radar) satellite image data collected before and after the landfall of Hurricane Katrina in the Pearl River Wildlife Management Area on the Louisiana-Mississippi border, USA, were applied to the study of forested wetland impact and recovery. We documented the overall similarity in the radar and optical satellite mapping of impact and recovery patterns and highlighted some unique differences that could be used to provide consistent and relevant ecological monitoring.

Tools and Methods

 

Ramsey, E.J., III, 2013, Emergency response mapping of surge flooding and damage to coastal resources with satellite radar and optical data [Presentation]: U.S. Geological Survey http://www.nwrc.usgs.gov/hurricane/isaac/files/Mapping.pptx, http://www.nwrc.usgs.gov/hurricane/isaac/files/Mapping.pdf

A rare example of the synergistic application of optical and radar satellite imagery in an emergency response situation evolved during and after the landfall of Hurricane Ike at Galveston, Texas, on 13 September 2008. In terms of environmental monitoring, optical satellite imagery offers important information that can be combined with radar imagery to provide a more complete understanding of environmental impacts.

 

Ramsey, E.W. III, Nelson, G.A., Echols, D., and Sapkota, S.K., 2002, The National Vegetation Classification Standard applied to the Remote Sensing Classification of two semiarid environments: Environmental Management, v. 29, n. 5, p. 703-715, http://dx.doi.org/10.1007/s00267-001-0048-5

The National Vegetation Classification Standard (NVCS) was implemented at two US National Park Service (NPS) sites in Texas, the Padre Island National Seashore (PINS) and the Lake Meredith National Recreation Area (LMNRA), to provide information for NPS oil and gas management plans. Because NVCS landcover classifications did not exist for these two areas prior to this study, we created landcover classes, through intensive ground and aerial reconnaissance, that characterized the general landscape features and at the same time complied with NVCS guidelines. The created landcover classes were useful for the resource management and were conducive to classification with optical remote sensing systems, such as the Landsat Thematic Mapper (TM).

 

Ramsey, E.W. III, Sapkota, S.K., Barnes, F.G., and Nelson, G.A., 2002, Monitoring the recovery of Juncus roemerianus marsh burns with the normalized difference vegetation index and Landsat Thematic Mapper data: Wetlands Ecology and Management, v. 10, n. 1, p. 85-96, http://dx.doi.org/10.1023/A:1014362616119

Nine atmospherically corrected Landsat Thematic Mapper images were used to generate mean normalized difference vegetation indices (NDVI) at 11 burn sites throughout a coastal Juncus roemerianus marsh in St. Marks National Wildlife Refuge, Florida. Time-since-burn, the time lapse from the date of burn to the date of image collection, was related to variation in mean NDVI over time.

 

USGS National Wetlands Research Center, 2000, Fire ecology in the southeastern United States: U.S. Geological Survey Fact Sheet 018-00, 4 p., http://www.nwrc.usgs.gov/factshts/018-00/018-00.htm

Fire has played an important role in the structure of natural ecosystems throughout North America. As a natural process, fire helps clear away dead and dying plant matter and increases the production of native species that occur in fire prone habitats. It also reduces the invasion of exotic species and the succession to woody species in pitcher plant bogs, pine savannas, coastal prairies, marshes, and other natural plant communities of the southeastern United States. Today we use fire as a management tool to maintain and restore the ecological structure of natural plant and animal communities. USGS studies the effects of fire on native species to better understand the influence fire has on the structure of their communities and ecosystems.

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