The INCA (Integrated Nitrogen CAtchment) model is a semi-distributed, dynamic nitrogen model which simulates nitrogen fluxes in catchments. Sources of nitrogen can be atmospheric deposition, the terrestrial environment or direct discharges. The model can simulate nitrogen processes in six land use classes. There are three components included; the hydrological model, the catchment nitrogen proce...

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...

Rainbow trout native to the McCloud River, California, USA (Oncorhynchus mykiss stonei) are thought to represent a relic, nonanadromous trout adapted to harsh, fragmented environments. These fish, commonly named McCloud River 'redband' trout, survive in their most primitive form in a small, spring-fed stream, Sheepheaven Creek, in the upper McCloud River drainage. Turn-of-the-century fisheries ...

Fish reproductions were studied in two river basins (Corumbataí and Jacaré-Pepira basins) in the State of São Paulo, southeastern Brazil. In the Corumbataí basin, four sites were sampled: Cabeça River, Lapa Stream, Passa-Cinco River, and Corumbataí River; in the Jacaré-Pepira basin, three sites were sampled: Tamanduá Stream, Jacaré-Pepira River, and Agua Branca Stream. A total of 12 bimonthly s...

fish biodiversity investigation in urmia basin which is a part of irano-anatolian hot spot aimed to determine the state of fish in this endorheic basin. based on the obtained results, freshwater fish species of the urmia basin comprise 29 species in 25 genera, 7 families, 5 orders and one class. the most diverse order is the cypriniformes with 23 species (79.31%) followed by salmoniformes and p...

Cambarus (Puncticambarus) callainus, new species, is a stream-dwelling crayfish endemic to the Big Sandy River basin in Kentucky, Virginia, and West Virginia. Within the basin, C. callainus occurs in the Levisa, Tug, and Russell fork watersheds. The new species is morphologically and genetically most similar to Cambarus veteranus, which is endemic to the Upper Guyandotte River basin of West Vir...

Despite obvious limitations, such simple indices can reveal important features of streamflow and how they compare with those of other streams in the same basin. These simple indices can also give clues regarding the timing of historic, momentous events, such as the abrupt decrease of the monthly maximum flow in the Little Red River record (1%1) shown in Figure 1 with records of other selected s...

Stream terraces of the Salt River form the interpretive backbone of Plio-Pleistocene landscape evolution of central Arizona, because they represent the base level of all tributary streams. This paper presents a new addition to T.L. Péwé’s Salt River Terrace sequence (in decreasing topographic position and age: Sawik, Mesa, Blue Point, and Lehi) that has been unrefined for the last 30 years. The...

Management of river salt loads in a complex and highly regulated river basin such as the San Joaquin River Basin of California presents significant challenges for current Information Technology. Computerbased numerical models are used as a means of simulating hydrologic processes and water quality within the basin and can be useful tools for organizing Basin data in a structured and readily acc...

The Iguaçu River basin is a tributary to the upper Paraná River in southern Brazil, and is considered an important aquatic ecoregion that, although having few species of fish, 51-71% of these are apparently endemic. Ancistrus abilhoai is one of three recently described species for this basin and is currently considered endemic to the basin. In this study, we present the chromosomal structure of...