Publications

Launched in 1982 and 1984 respectively, the Landsat-4 and -5 Thematic Mappers (TM) are the backbone of an extensive archive of moderate resolution Earth imagery. However, these sensors and their data products were not subjected to the type of intensive monitoring that has been part of the Landsat-7 system since its launch in 1999. With Landsat-4's 11 year and Landsat-5's 20+ year data...

This report presents an analysis of Ethiopian rainfall from 1960 through 2004, based on 186 gauges in Ethiopia and 373 gauges from surrounding countriesi. Substantial post1997 declines in March-September rainfall have been observed in the northeast, southeast and southwestern portions of the country, a result corroborated by several independent data sourcesii. The observed rainfall...

A data set of the fractional green vegetation cover (FGREEN) for the Conterminous USA was evaluated for regional and seasonal variation. The value of FGREEN was derived monthly for the three most dominant land cover classes per 20 km by 20 km grid cell within the study area. At this grid cell resolution (comprised of 400 1-km pixels), 97 percent of the grid cells included three or fewer...

A new land cover database of Greater Mesoamerica has been prepared using moderate resolution imaging spectroradiometer (MODIS, 500 m resolution) satellite data. Daily surface reflectance MODIS data and a suite of ancillary data were used in preparing the database by employing a decision tree classification approach. The new land cover data are an improvement over traditional advanced...

No abstract available.

This book has presented what is known about the extent and causes of amphibian population declines in the United States and what can be done about them. It has also examined life history and natural history features needed to manage for amphibians, with a current assessment of their distribution. In assembling the literature for this project, and with a quick look at the species accounts...

This section features the Caudata, which includes the families Ambystomatidae, Amphiumidae, Cryptobranchidae, Dicamptodontidae, Plethodontidae, Proteidae, Rhyacotritonidae, Salamandridae, and Sirenidae. It provides information on their historical versus current distribution, historical versus current abundance, life history features, and conservation.

This section features the Anura, which includes the families Ascaphidae, Bufonidae, Dendrobatidae, Hylidae, Leptodactylidae, Microhylidae, Pelobatidae, Pipidae, Ranidae, and Rhinophrynidae. It provides information on their historical versus current distribution, historical versus current abundance, life history features, and conservation.

Many species of amphibians have declined substantially in distribution or number of populations in the United States and globally, and a variety of anthropogenic and natural factors have been suggested as causal agents in these declines. Evidence for the causal action of these agents derives from many types of sources, all of which are important in seeking to understand amphibian...

Periodic epidemics of malaria are a major public health problem for many sub-Saharan African countries. Populations in epidemic prone areas have a poorly developed immunity to malaria and the disease remains life threatening to all age groups. The impact of epidemics could be minimized by prediction and improved prevention through timely vector control and deployment of appropriate drugs...

Aim  Extrapolation of tower CO2 fluxes will be greatly facilitated if robust relationships between flux components and remotely sensed factors are established. Long-term measurements at five Northern Great Plains locations were used to obtain relationships between CO2fluxes and photosynthetically active radiation (Q), other on-site factors, and Normalized Difference Vegetation Index...

This report presents a science strategy for the geographic research of the U.S. Geological Survey (USGS) for the years 2005-2015. The common thread running through the vision, mission, and science goals presented in the plan is that USGS geographers will provide national leadership to understand coupled human-environmental systems in the face of land change and will deliver pertinent...