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At least 721 records · Page 40Linked to original sources
USGS2002

Effects of water use diversion regulation and conservation on sediemtn transport with comparisons from the United States

Too much sediment and too little water are related problems in China’s Yellow River Basin. Sediment yield in the basin averages about 2,100 t/(km 2 ·a), greatest is of the world’s large rivers although the Yellow River ranks 31st in mean flow. A quarter of the sediment deposited in the 780-km lower reach, causing bed levels to rise an average of a meter per decade wang and other. Sediment aggradation along this reach is concentrated between dikes, resulting in average river-bed elevations 5 m higher, and at Xinxiang as much as 10 m higher, than surrounding bottomlands. The dikes, which have breached nearly 1,600 times in the last 24 centuries, reduce the threat of flooding for 85-million people on 120,000 km 2 in five provinces of northeastern China (Decun, undated). This paper addresses some environmental and social factors related to this problem, and provides descriptions of two United States rivers that exhibit some analogous responses, albeit not to the extent of those associated with the Yellow River, “China’s Sorrow”.

Yellow River↗
USGS2014

Waterfowl populations of conservation concern: learning from diverse challenges, models, and conservation strategies

There are 30 threatened or endangered species of waterfowl worldwide, and several sub-populations are also threatened. Some of these species occur in North America, and others there are also of conservation concern due to declining population trends and their importance to hunters. Here we review conservation initiatives being undertaken for several of these latter species, along with conservation measures in place in Europe, to seek common themes and approaches that could be useful in developing broad conservation guidelines. While focal species may vary in their life histories, population threats and geopolitical context, most conservation efforts have used a systematic approach to understand factors limiting populations and o identify possible management or policy actions. This approach generally includes a priori identification of plausible hypotheses about population declines or status, incorporation of hypotheses into conceptual or quantitative planning models, and the use of some form of structured decision making and adaptive management to develop and implement conservation actions in the face of many uncertainties. A climate of collaboration among jurisdictions sharing these birds is important to the success of a conservation or management programme. The structured conservation approach exemplified herein provides an opportunity to involve stakeholders at all planning stages, allows for all views to be examined and incorporated into model structures, and yields a format for improved communication, cooperation and learning, which may ultimately be one of the greatest benefits of this strategy.

Wildfowl↗
USGS1973

Method for estimating the diversion potential of streams in eastern Massachusetts and southern Rhode Island

A simple method is proposed for estimating the probable magnitude and frequency of streamflow that is in excess of predetermined minimum streamflows required downstream in eastern Massachusetts and southern Rhode Island. Regional curves relate these annual volumes of streamflow excess to the average annual discharge and the median 7-day annual minimum flow of the site. Use of the curves is illustrated by a hypothetical example.

Massachusetts, Rhode Island↗