نتایج جستجو برای: rivers

تعداد نتایج: 19001  

2011
Liyuan Yang Ji Shen Enfeng Liu Wei Zhang

Based on water quality monitoring data of four inflow rivers of Nansihu Lake in 2006, 2007 and 2008, the water qualities were evaluated according to the method of comprehensive water quality identification index, with the indicators of dissolved oxygen, CODMn, biochemical oxygen demand and ammonia nitrogen. The results show that the rivers has been in the state of serious pollution, in which th...

Journal: :Bulletin of environmental contamination and toxicology 1998
D T Gundersen M D Krahling J J Donosky R G Cable S D Mims

The paddlefish (Polyodon spathula) is a primitive fish that is found in several large rivers of the Mississippi River drainage. The status of paddlefish populations in these large rivers is debatable due to several factors including habitat loss, contaminants and commercial fishing (Sparrowe 1986; Gundersen and Pearson 1992). The roe of female paddlefish is used to make domestic caviar and comm...

Journal: :The Bulletin of the American Academy of Psychiatry and the Law 1990
J R Ciccone J F Tokoli C D Clements T E Gift

This article examines the impact of the New York court decision, Rivers v. Katz, which in June 1986 dramatically changed the state procedure for responding to involuntarily committed psychiatric patients who formally refused psychopharmacologic treatment. The court rejected the medically administered review process that had been used to respond to involuntarily committed psychiatric patients wh...

Journal: :Science 2005
James P M Syvitski Charles J Vörösmarty Albert J Kettner Pamela Green

Here we provide global estimates of the seasonal flux of sediment, on a river-by-river basis, under modern and prehuman conditions. Humans have simultaneously increased the sediment transport by global rivers through soil erosion (by 2.3 +/- 0.6 billion metric tons per year), yet reduced the flux of sediment reaching the world's coasts (by 1.4 +/- 0.3 billion metric tons per year) because of re...

2003
G. Caldarelli P. De Los Rios M. Montuori

Erosion by flowing water is one of the major forces shaping the surface of Earth. Studies in the last decade have shown, in particular, that the drainage region of rivers, where water is collected, exhibits scale invariant features characterized by exponents that are the same for rivers around the world. Here we show that from the data obtained by the MOLA altimeter of the Mars Global Surveyor ...

2011
V. I. Babkin

Contents 1. Introduction 2. Primary stage of the occurrence of river systems 3. Development of rivers in the Paleozoic 4. Change of hydrography in the Mesozoic 5. Modification of river systems in the Cenozoic 6. Water balance change of the river basins in the Mesozoic-Cenozoic 7. Features of dynamics of the hydrographic network and channel deformations 8. Hydrography and water resources of the ...

2002
William Roark

We have used a variety of approaches to introduce quantitative concepts into our introductory geology classes, some of which rely on using case studies of local rivers to improve student interest and appreciation of quantitative methods in scientific problem solving. Fortunately, there are rivers in most parts of the country, so these approaches are easily transferable and applicable in many ar...

Journal: :Science 2004
Luke J Reusser Paul R Bierman Milan J Pavich E-an Zen Jennifer Larsen Robert Finkel

The direct and secondary effects of rapidly changing climate caused large rivers draining the Atlantic passive margin to incise quickly into bedrock beginning about 35,000 years ago. Measured in samples from bedrock fluvial terraces, 10-beryllium shows that both the Susquehanna and Potomac Rivers incised 10- to 20-meter-deep gorges along steep, convex lower reaches during the last glacial cycle...

2012
Anahit M. Manvelyan

Taking into account the importance of Lake Sevan and Lake Sevan basin’s rivers for Armenian economy, the main goals of our investigations were the documentation of water quality and the biodiversity of invertebrates developed in Lake Sevan basin’s rivers and selected tributaries. Moderately satisfied ecological condition for the biodiversity of Lake Sevan basin’s rivers has been established, an...

G Zamora Echenique R.N Singh V.F Navarro Torres

Hydrographically Bolivian Poopó Lake is located in the basin of Desaguadero River and it has over a dozen main tributary rivers and other smaller rivers with lower flow. The mine water discharge from the abandoned and current mining activities polluted these rivers by carrying heavy metals, dissolved and suspended solids which in turn polluted the Poopó Lake which is considered as an important ...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید