The size and shape of the stones in dry gravel river beds are of interest in geology and river hydraulics. The topography of a bed surface can be measured by three-dimensional laser scanning. A method is described for fitting ellipsoids to the surfaces of individual stones to estimate their size, shape and orientation in the river bed. Different cost functions are evaluated and the methods are ...

This paper describes the usage of linked models for assessment of water quality in a river basin. River water quality model QUAL2K and the Wennerblom (Älvsborg) diffused pollution model were simultaneously applied for water quality and land-based pollution estimations. A software tool was developed to control the data flow between these models and databases. This tool provides automatic formati...

The abundance of cladocerans recorded in plankton samples from the littoral regions of two environments (Baía River and Guaraná lake), the Upper Paraná River floodplain and some limnological variables important in controlling their abundance were investigated at three sites in the lake and two in the river, from March/93 to January/94. Abundance was highest in the lake, chiefly during high wate...

The Haihe River basin is one of the most developed regions in China. With the rapid economic development and associated increases in water demand, the river basin has been enduring increasing water stress. Water for the ecosystem use has been compromised and the environment has been deteriorating. Water shortage has become a bottleneck to the further development of the economy and grain product...

Important characteristics of an appropriate river basin model, intended to study the effect of climate change on basin response, are the spatial and temporal resolution of the model and the rainfall input. The effects of input and model resolution on extreme discharge of a large river basin are assessed to give some indication on appropriate resolutions. A simple stochastic rainfall model and a...

The Berg River redfin (Pseudobarbus burgi) is a critically endangered endemic cyprinid from South Africa. We investigated mitochondrial DNA control region variation among specimens representative of five populations drawn from two adjacent river systems. Phylogenetic analyses, a minimum spanning network, and an analysis of molecular variance underscore the pronounced genetic separation of redfi...

Rivers can be treated as transportation networks which supply or collect and remove certain resources from the surrounding environment. A positive feedback between environment and river network both reshapes the configuration of the terrain and produces dynamically stable web of river channels. Anastomosing rivers exemplify such interactions very clearly. In case of this specific type of river,...

Average methylmercury levels in five Savannah River tributary streams, sampled 11 times over 2 years (0.170 ng/l), were nearly twice as high as in the Savannah River (0.085 ng/l). Total mercury levels in the tributaries (2.98 ng/l) did not differ significantly from the river (2.59 ng/l). All of the tributaries drained extensive wetlands that would be expected to support comparatively high rates...

[1] The generation of synthetic river flow samples that can reproduce the essential statistical features of historical river flows is useful for the planning, design, and operation of water resource systems. Most river flow series are periodically stationary; that is, their mean and covariance functions are periodic with respect to time. This article develops model identification and simulation...

Large-Scale Particle Image Velocimetry (LSPIV) is an effective method for the measurement of the river surface flow velocity. For the wide cross-section river, in the near-field area of river surface image there are small and clear targets. But the flow tracers are almost invisible in the far-field area because of the resolution limit of one single video camera, which makes it difficult to comp...