Publications

The IKONOS spacecraft acquired images on July 3, 17, and 25, and August 13, 2001 of Brookings SD, a small city in east central South Dakota, and on May 22, June 30, and July 30, 2000, of the rural area around the EROS Data Center. South Dakota State University (SDSU) evaluated the Brookings scenes and the USGS EROS Data Center (EDC) evaluated the other scenes. The images evaluated by...

Landsat-7 and Landsat-5 have orbits that are offset from each other by 8 days. During the time that the sensors on both satellites are operational, there is an opportunity for conducting analyses that incorporate multiple intra-annual high spatial resolution data sets for characterizing the Earth's land surface. In the current study, nine Landsat thematic mapper (TM) and enhanced...

A wide range of urban ecosystem studies, including urban hydrology, urban climate, land use planning, and resource management, require current and accurate geospatial data of urban impervious surfaces. We developed an approach to quantify urban impervious surfaces as a continuous variable by using multisensor and multisource datasets. Subpixel percent impervious surfaces at 30-m...

How have changes in land management practices affected vegetation patterns in the greater Yellowstone ecosystem? This question led us to develop a deterministic, successional, vegetation model to “turn back the clock” on a study area and assess how patterns in vegetation cover type and structure have changed through different periods of management. Our modeling spanned the closing...

A group of satellite radar interferograms that span the time period from 1991 to 2000 shows that Westdahl volcano, Alaska, deflated during its 1991-1992 eruption and is reinflating at a rate that could produce another eruption within the next several years. The rates of inflation and deflation are approximated by exponential decay functions having time constants of about 6 years and a...

Over the past decade, many investigators have published techniques for deriving phenological parameters, especially the start of the growing season (SOS), from time-series satellite imagery. The principal satellite sensor for these studies is the advanced very high resolution radiometer (AVHRR). This study investigates the characteristics of four of the primary methods for identifying...

The comparison between a spatially distributed crop index and reported yield was evaluated. The crop index was generated by a crop water balance model that simulates the reduction of crop yield (as a percentage of the potential) due to water deficit. This model is currently operational as a monitoring and forecasting tool for region-wide food security analyses in drought prone countries...

No abstract available.

The U.S. Geological Survey (USGS) has done a progress review on improving access to its spatial data holdings over the Web. The USGS EROS Data Center has created three major Web-based interfaces to deliver spatial data to the general public; they are Earth Explorer, the Seamless Data Distribution System (SDDS), and the USGS Web Mapping Portal. Lessons were learned in developing these...

This paper presents the use of GIS to assess human vulnerability due to cyclonic storm in India. Human vulnerability is conceptualized here as the exposure to hazard by external activity (e.g. cyclone) and coping capacity of the people to reduce the risk. The assessment looks at the potential exposure to people impacted by cyclonic activity in 32 Indian states and locates the vulnerable...

Sizeable areas of the Southern African Region experienced widespread flooding in 2000. Deployment of hydrologic models can help reduce the human and economic losses in the regions by providing improved monitoring and forecast information to guide relief activities. In this study, we describe a hydrologic model developed for wide-area flood risk monitoring for the Southern African region...

The National Elevation Dataset (NED) contains the best publicly available elevation data merged into a seamless dataset for the entire United States. In some cases these data contain unwanted artifacts, limiting the quality of standard hydrologic derivatives. The Elevation Derivatives for National Applications (EDNA) project is an interagency effort with the goal of developing a more