Watershed is regarded as a very complex system of natural, social, economic and ecological dimensions and like any similar systems, exploitation of its resources requires a comprehensive and coordinated planning and management. Given the importance of watershed management projects for the development and management of natural resources, the enhancement of the efficiency of these activities is e...

The aim of the present work was to evaluate the possibilities of using sub-basin data for calibration of the Soil and Water Assessment Tool (SWAT) model in a small ungauged basin (46 ha) and its response. This small basin was located in the viticultural Anoia-Penedès region (north-east Spain), which suffers severe soil erosion. The data sources were: daily weather data from an observatory locat...

Modes of tropical climate variability, such as the El Niño– Southern Oscillation (ENSO), the Indian Ocean Basinwide Mode (IOBM), the Indian Ocean Dipole (IOD), and the Atlantic Equatorial Mode (AEM) (sometimes referred to as the Atlantic Zonal Mode, or Atlantic Niño) interact most readily via the atmosphere. Sea surface temperature anomalies (SSTAs) in the tropics drive changes in the Walker Ci...

garra rufa , a bottom dwelling freshwater fish and native to the middle east, is distributed in the southwestern of iran and the tigris basin. considering the importance of length-weight relationships data of a species in different habitats, the length-weight relationship of g. rufa from 13 rivers in the persian gulf and the tigris basins was explored. the value of exponent b ranged from 2.74 t...

Recent trends in sea ice have raised the question of how much is associated with greenhouse warming, and how much is the result of oscillations within the climate system. To address this issue, we investigate the effect of changes in latitudinal temperature gradients on circulation and sea ice at high latitudes in a set of experiments with the GISS GCM. Sea surface temperature gradients are inc...

A basin boundary can undergo sudden changes in its character as a system parameter passes through certain critical values. In particular, basin boundaries can suddenly jump in position and can change from being smooth to being fractal. e describe these changes ("metamorphoses") and f&nd that they involve certain special unstable orbits on the basin boundary which are aceessibIe from inside one ...

this study was conducted to determine taxonomic and zoogeographic features of fishes from the kor and helleh river basins in southwestern iran. the specimens were collected from 2004 to 2007. twenty four species belonging to 20 genera, 9 families, and 6 orders from the kor river basin and 21 species belonging to 19 genera, 8 families, and 6 orders from helleh basin were identified. ichthyofauna...

Intermontane basins in the Trans-Pecos region of westernmost Texas and northern Chihuahua, Mexico, are target areas for disposal of interstate municipal sludge and have been identified as possible disposal sites for low-level radioactive waste. Understanding ground water movement within and between these basins is needed to assess potential contaminant fate and movement. Four associated basin a...