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At least 1,243 records · Page 69Linked to original sources
USGS2008

Methods for Processing and Summarizing Time-Series Temperature Data Collected as Part of the National Water-Quality Assessment Program Studies on the Effects of Urbanization on Stream Ecosystems

Temperature data and summary statistics are presented for 256 sites in 9 metropolitan areas as part of the U.S. Geological Survey National Water-Quality Assessment Program studies of the effects of urbanization on stream ecosystems. The computer program (GRAN) that was developed to derive uniform data granularity and calculate temperature statistics (means, standard deviations, rates of change, degree days) is described, as are the methods used to estimate missing daily mean temperatures, degree days (annual and summer periods), and 7-day running averages of daily mean temperatures.

Data Series↗
USGS2008

Watershed influences and in-lake processes - A regional-scale approach to monitoring a water-supply reservoir, Lake Houston near Houston, Texas

Created in 1954 by an impoundment on the San Jacinto River, Lake Houston currently (2008) supplies about 20 percent of the total source water for the city of Houston. Houston historically has relied on ground water as the major source of supply. As a result of regulations to limit ground-water withdrawals because of associated land subsidence (effective in 2010), the lake will become the primary source of water supply for the city in the future. Since 1983 the U.S. Geological Survey (USGS), in cooperation with the City of Houston, has collected water-quality and lake-level data at Lake Houston, as well as discharge and intermittent water-quality data at its major inflowing tributaries. Previous studies indicate that Lake Houston is shallow, eutrophic, light limited and has a variable hydrologic regime with water residence times ranging from 12 hours to 400 days. Spring Creek, a tributary that drains the western, more urban, part of the Lake Houston watershed, contributes more sediment and nutrients than East Fork San Jacinto River, a tributary that drains the more rural, eastern part of the watershed. This fact sheet explains the importance of monitoring for management of the resource and describes ongoing research in the Lake Houston watershed by the USGS and the City.

Texas↗
USGS2011

Understanding processes affecting mineral deposits in humid environments

Recent interdisciplinary studies by the U.S. Geological Survey have resulted in substantial progress toward understanding the influence that climate and hydrology have on the geochemical signatures of mineral deposits and the resulting mine wastes in the eastern United States. Specific areas of focus include the release, transport, and fate of acid, metals, and associated elements from inactive mines in temperate coastal areas and of metals from unmined mineral deposits in tropical to subtropical areas; the influence of climate, geology, and hydrology on remediation options for abandoned mines; and the application of radiogenic isotopes to uniquely apportion source contributions that distinguish natural from mining sources and extent of metal transport. The environmental effects of abandoned mines and unmined mineral deposits result from a complex interaction of a variety of chemical and physical factors. These include the geology of the mineral deposit, the hydrologic setting of the mineral deposit and associated mine wastes, the chemistry of waters interacting with the deposit and associated waste material, the engineering of a mine as it relates to the reactivity of mine wastes, and climate, which affects such factors as temperature and the amounts of precipitation and evapotranspiration; these factors, in turn, influence the environmental behavior of mineral deposits. The role of climate is becoming increasingly important in environmental investigations of mineral deposits because of the growing concerns about climate change.

Fact Sheet↗