The bald eagle (Haliaeetus leucocephalus) population in North America declined greatly after World War II due primarily to the eggshell thinning effects of p,p'-DDE, a biodegradation product of DDT. After the banning of DDT in the United States and Canada during the early 1970s, the bald eagle population started to increase. However, this population recovery has not been uniform. Eagles nesting...

— Information Inputs to making decisions about recreational use of rivers are described. Major recre­ ational decisions and possible Inputs to them are Iden­ tified. A future scenario for recreational use of rivers Is given and the needed research on Information Inputs Is Identified within the context of the scenario. So much planning and management infor­ mation is being generated by river res...

Rivers provide a special suite of goods and services valued highly by the public that are inextricably linked to their flow dynamics and the interaction of flow with the landscape. Yet most rivers are within watersheds that are stressed to some extent by human activities including development, dams, or extractive uses. Climate change will add to and magnify risks that are already present throug...

human activities in the fields of agriculture, municipal and industry introduce significant amounts of nutrients and organic materials into the rivers and streams resulting in their contamination. computer models such as qual2kw are used extensively for water quality management of rivers and streams. the qual2kw model is a one dimensional, non-uniform, steady water quality model, which has been...

the morphological river evolution at long-time (centuries and even millennia) and large spatial scale (watersheds of several square kilometres) can be described by means of simplified 1d models, able to simulate the variation of bed elevation and grain size composition at non-detailed scales, involving a reduced computational effort. the erosion and deposition phenomena acting along rivers can ...

Mapping a rivers course and width provides valuable information to help understand the ecology, topology and health of a particular environment. Such maps can also be useful to determine whether specific surface vessels can traverse the rivers. While rivers can be mapped from satellite imagery, the presence of vegetation, sometimes so thick that the canopy completely occludes the river, complic...

River length has been the particular interest of people. Topographic data, which are obtained from field survey or digitizing from topographies, can serve as ideal data source for river length calculating. The topographic data are vector-based data, which represent river entities as polygonal line. Depending on data scale, rivers are represented in topographic data as single-line (narrow) or do...

In Java and Kalimantan in Indonesia, river water plays important roles in human life; for example, for transportation, and economic activities of the inhabitants. However, industrial, agricultural and domestic water is discarded into rivers directly in many developing countries, including Indonesia, since drainage systems have not been completely constructed. In this study, to evaluate the wate...

most previous laboratory studies of local scour at bridge abutments were performed in rectangular channels in which the distributions of flow velocity and bed shear stress were considered uniform in the transverse direction. in reality however, bridge abutments are usually located in the floodplain zone of rivers where velocity and shear stress distributions are directly affected by the lat...