BACKGROUND The Camarones River Valley, located in the extreme north of Chile, is characterized by high environmental arsenic levels and an arid desert. It has been inhabited by humans for the past 7,000 years. Evidence exists for chronic arsenic poisoning in both prehispanic and present populations residing in the area. Chronic arsenic exposure causes multi-systemic problems and can induce cong...

–I developed a classification system for streams in Michigan’s Upper Peninsula (UP) using a landscape-based approach that was originally developed for Lower Peninsula (LP) Michigan streams. Multiple linear regression, cluster analysis, and graphical techniques were used to examine stream attribute data (stream size, temperature, hydrology, gradient, water chemistry, valley type, fish community,...

The windings of rivers have long fascinated their human observers. For example, Aboriginal legend explains the sinuous pattern of the modern Finke River (Fig. 1) as the creation of the immense and powerful Rainbow Serpent as he emerged during the Dreamtime from deep waterholes. Recently in PNAS (1), a new theory for the general origin of such sinuous flow patterns was published, which follows f...

The Illinois River is a major contributor of nitrate-N to the Mississippi River and the Gulf of Mexico, where nitrate is a leading cause of summertime benthic hypoxia. Corn-soybean production on tile-drained land is a leading source of nitrate-N in this river system, in addition to municipal wastewater discharge. We calculated annual nitrate-N loads in the Illinois River at Valley City from 197...

Study of Landsat imagery prompted Cannon (1) to suggest that Sithylemenkat Lake in central Alaska occupies a meteorite impact crater. In support of his thesis, he cites physiographic, structural, geochemical, and aeromagnetic evidence from various published sources. We believe, on the basis of our previous work in the area (2-4), that Cannon has largely misinterpreted these published data, whic...

At the commencement of this paper it was stated that the | Bara river crossed the Mahmaud tract obliquely towards the I north-east. In tlii3 course it flows about a mile to the south of the city, which, with cantonments, it will be remembered, occupies the north-eastern verge of that elevated tract. Its level at this part, however, is too low to admit of its water being drawn off for the use of...

The results of the retrospective global radioactive contamination mapping of the Enisey-river catchment are presented. The maps of spatial , J 7 Cs distributions of 1964, 1974, 1986, 2000 are compiled using the geoinformation technologies in the Institute of Global Climate and Ecology. The territory of mapping is 2600000 km. The mapping is done from the airbome-gamma-spectrum data obtained at t...

This paper represents a contribution to the study of hazard caused by the interaction between landslides and river courses. The effects of such interferences are often catastrophic and could include the formation of upstream lakes, potential dam failure, river bed dynamics and morphological alterations. These scenarios could be substantially reduced if it was possible to predict the eventuality...

tehran city has been subject of critical environmental challenges during the course of 20th. century namely: massive population growth, broad expansion, reduction in urban open/green spaces, increasing in energy consumption and waste production. releasing industrial wastewater into river valleys have led to considerable changes in structure of city's natural landscape. the natural structur...