Both environmental heterogeneity and mode of dispersal may affect species co-occurrence in metacommunities. Aquatic invertebrates were sampled in 20-30 streams in each of three drainage basins, differing considerably in environmental heterogeneity. Each drainage basin was further divided into two equally sized sets of sites, again differing profoundly in environmental heterogeneity. Benthic inv...

the present study reports range extansion of moenkhausia oligolepis to the pindaré river drainage, of the mearim river basin, and itapecuru river basin, maranhão state, northeastern brazil. this species was previously known only from venezuela, guianas, and the amazon river basins. in addition, we present some meristic and morphometric data of the specimens herein examined and discuss on its di...

there is a need to analyze and map rainfall erosivity to assess soil erosion at the regional scale. the objectives of this study were to develop a regional model to estimate seasonal erosivity from seasonal rainfall data and to study temporal and spatial distribution of rainfall erosivity for the gorganrood drainage basin in the northeast of iran. six gauging stations with a high temporal resol...

there is a need to analyze and map rainfall erosivity to assess soil erosion at the regional scale. the objectives of this study were to develop a regional model to estimate seasonal erosivity from seasonal rainfall data and to study temporal and spatial distribution of rainfall erosivity for the gorganrood drainage basin in the northeast of iran. six gauging stations with a high temporal reso...

In this present study, Remote Sensing (RS) and Geographical Information System (GIS) techniques are used to update drainage and surface water bodies to evaluate linear, relief and aerial morphometric parameters and to prioritize the watersheds of the Markandeya River Sub-Basin (MRSB), located in Belgaum district of Karnataka state,India. The Markandeya River Sub-Basin has sub-dendritic to dendr...

With regard to the importance of instantaneous peak discharge estimation for watershed management study, and due to the lack of and unqualified climatic and hydrologic data for estimation and measurement in countries such as Iran, researchers were obliged to establish a link between constant parameters (geomorphologic) and variables (hydrologic) to present models with minimum dependence on clim...

Lakes have long been recognized as being rich storehouses of environmental information. A lake basin collects water, but also sediment, much of which has been weathered and transported via fluvial processes from the near and far reaches of its drainage basin. The amount of water held in a lake is recorded on the landscape in coastal erosional and depositional landforms created at the water’s ed...

A key component of a sediment yield prediction is an estimate of the sediment deposition between erosion sources and a drainage basin outlet. This technical note presents methods requiring a minimum of data which can be used to assess the importance of sediment deposition within the river system of a basin. The methods were applied to a 4123 km basin in the Philippines. Results indicated that s...

This paper describes TerraHidro that is a distributed hydrologic modeling platform. TerraHidro is general purpose water resources system that presents a new concept to represent water flows based on graph structure, in the geographic information system (GIS) context. The drainage extractions and Amazonian basin delimitations using TerraHidro have been compared with ArcGis Hydro Tools regarding ...

Despite the arid to hyperarid climate of the Great Sahara of North Africa, pluvial climates dominated the region. Radar data shed some light on the postulated Trans-African Drainage System and its relationship to active and inactive tributaries of the Nile basin. Interpretations of recent elevation data confirm a source of the river water from the Red Sea highlands did not connect the Atlantic ...