Study on the trend of Northern river-type reservoir eutrophication

Author(s):  
X.L. Meng ◽  
G.L. Fan ◽  
J.W. Li ◽  
P. Wang
Keyword(s):  
2010 ◽  
Author(s):  
Kannan M. Munisamy ◽  
Ahmad Kamal ◽  
Norshah Hafeez Shuaib ◽  
Mohd. Zamri Yusoff ◽  
Hasril Hasini ◽  
...  

1994 ◽  
Vol 51 (4) ◽  
pp. 974-980 ◽  
Author(s):  
Stanley D. Rice ◽  
Robert E. Thomas ◽  
Adam Moles

We compared the impact of exposure to seawater on three sockeye salmon (Oncorhynchus nerka) stocks: one that normally migrates to sea as underyearlings (sea-type) and two with the more common life history strategies of 1 (river-type) or 2 (lake-type) yr of freshwater residence prior to seaward migration. Innate differences in survival, ability to regulate tissue chlorides, and oxygen consumption when first introduced into salt water were more evident in April and May when fish were less than 50 mm in length. In fish longer than 50 mm, the only significant differences among the stocks were in saltwater growth. Between June and August, sea-type fish showed faster growth than river-type fish which in turn grew faster than lake-type fish. When introduced into salt water in October, virtually no growth occurred in any stock, regardless of fish size. River-type and lake-type sockeye, which normally overwinter 1 and 2 yr, respectively, in freshwater, can be reared in seawater if underyearlings are raised to a length of 50 mm before release into salt water, similar to the normal life history of sea-type underyearlings. Early life history appears to be influenced more by habitat than by genetics.


2020 ◽  
Vol 12 (5) ◽  
pp. 773 ◽  
Author(s):  
Gino Caspari

The Valley of the Kings in Tuva Republic, southern Siberia, is arguably one of the most important archaeological landscapes in the eastern Eurasian steppes. Nonetheless, little information exists about the spatial characteristics and preservation conditions of this burial ground consisting of large “royal” mounds. We map the large monuments of the Uyuk Valley’s northern river terrace and assess their state of preservation based on high-resolution optical satellite data. The burial site consists of several hundred mounds, over 150 of them with diameters of more than 25 m, the largest monuments are bigger than 100 m in diameter. This makes the Valley of the Kings in Tuva Republic one of the largest Early Iron Age burial sites in the Eurasian steppes. Unfortunately, around 92% of the large monuments are in bad condition, mostly due to looting.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Pei-yin Yuan ◽  
Ping-yi Wang ◽  
Yu Zhao

Large-scale landslides often occur in river-type reservoirs, and landslide-generated waves affect navigation channels and the navigation of ships. Thus, such waves cause widespread regional disasters. This study establishes a mechanical model of landslide-generated waves via field investigations and data collection, reveals the mechanism and process of landslide-generated waves, and investigates the propagation characteristics of landslide-generated waves along a sloping wave. The feasibility of the model is verified via (i) regularity analysis, (ii) comparative analysis of the effect of landslide-generated waves of mountain river channel reservoirs on the movement characteristics of navigation vessels and stationary vessels, (iii) deviation from the equilibrium position, and (iv) an in-depth study of the influence of large-scale landslide-generated waves on ships in different navigation positions in a river channel. Countermeasures are proposed for a sailing ship to tackle a sudden landslide-generated wave; these measures can provide a theoretical basis for ships to sail safely through large-scale landslide-generated waves.


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