Chilean basins have long been exposed to nutrient discharges from human activities and land use changes. A historical seasonal NO(3)(-)-N and PO(4)(3-)-P database of the last 23 years of the main nine rivers of central-southern region of Chile was analysed. Generalized additive models indicated that annual trends in NO(3)(-)-N and PO(4)(3-)-P are nonlinear. River basins such as Bío-Bío, Bueno, ...

Infectious diseases have become a rising challenge to mankind in a globalizing world. Yet, little is known about the inland transmission of infectious diseases in history. In this study, we based on the spatio-temporal information of 5559 plague (Yersinia pestis) outbreaks in Europe and its neighboring regions in AD1347-1760 to statistically examine the connection between navigable rivers and p...

Flow-rate measurement in rivers under different conditions is required for river management purposes including water resources planning, pollution prevention, and flood control. This study proposed a new discharge estimation method by using a mean velocity derived from a 2D velocity distribution formula based on Tsallis entropy concept. This procedure is done based on several factors which refl...

pollution deriving from trace elements (cd, cu, ni, pb, zn, hg, as and cr) in sediment samples(collected in 2009), belonging to rivers located in catalonia and the basque country (spain), was assessedaccording to sediment quality guidelines. sediment samples were ranked in terms of a pollution index thattakes into account the presence of multiple pollutants such as trace elements. while only ab...

Sediment transfer from continents to oceans via rivers is one of the important processes regulating river-bank stabilization, soil formation, biogeochemical cycling of elements, crust evolution and many other earth-related processes. Due to changes in continental positions during the geologic past, water flow and sediment loads in rivers have also shown variations during different time periods....

This paper was motivated by the 25th anniversary of the publication of Marc Reisner's book, Cadillac Desert: The American West and its Disappearing Water. Dams are ubiquitous on rivers in the United States, and large dams and storage reservoirs are the hallmark of western U.S. riverscapes. The effects of dams on downstream river ecosystems have attracted much attention and are encapsulated in t...

Title of Document: POPULATION GENETICS OF THE EASTERN OYSTER IN CHESAPEAKE BAY Colin Rose, Doctor of Philosophy, 2008 Directed By: Professor Matthew P. Hare Department of Biology The eastern oyster, Crassostrea virginica, plays an important role in the ecology of Chesapeake Bay. Its large population size, long larval dispersal stage and potential for high variance in reproductive success is rep...