نتایج جستجو برای: river basins

تعداد نتایج: 92307  

Journal: :Computers & Geosciences 2006
Qiuming Cheng Connie Ko Yinhuan Yuan Yong Ge Shengyuan Zhang

This paper introduces two parsimonious models for predicting runoff for ungauged basins from the observed river flow data in gauged basins and precipitation data from rain gauging stations in the same area. The models assume the runoff is related to the precipitation subject to variance of drainage basins. The runoff can be modeled as a function of precipitation and parameters determined by bas...

1999
A. P. Mehta C. Reichhardt C. J. Olson Franco Nori

River basins as diverse as the Nile, the Amazon, and the Mississippi satisfy certain topological invariants known as Horton’s laws. Do these macroscopic (up to 103 km) laws extend to the micron scale? Through realistic simulations, we analyze the morphology and statistical properties of networks of vortex flow in flux-gradient-driven superconductors. We derive a phase diagram of the different n...

2012
Arjen Y. Hoekstra Mesfin M. Mekonnen Ashok K. Chapagain Ruth E. Mathews Brian D. Richter

Freshwater scarcity is a growing concern, placing considerable importance on the accuracy of indicators used to characterize and map water scarcity worldwide. We improve upon past efforts by using estimates of blue water footprints (consumptive use of ground- and surface water flows) rather than water withdrawals, accounting for the flows needed to sustain critical ecological functions and by c...

Journal: :Environmental monitoring and assessment 2014
Daniel M Evans Stephen H Schoenholtz Parker J Wigington Stephen M Griffith William C Floyd

Research on relationships between dissolved nutrients and land-use at the watershed scale is a high priority for protecting surface water quality. We measured dissolved nitrogen (DN) and ortho-phosphorus (P) along 130 km of the Calapooia River (Oregon, USA) and 44 of its sub-basins for 3 years to test for associations with land-use. Nutrient concentrations were analyzed for spatial and seasonal...

2009
Marloes H. N. Bakker

The objectives of this study were (1) to quantify river floods shared by more than one country, that is, transboundary river floods and (2) to grasp more fully the degree of vulnerability of people to such events on a global, international river basin (IRB) and country level. To these ends, publicly available data were combined to identify such events and the resultant losses of life, flood-rel...

1975
R Quirós

Environmental changes in large river basins are subject to forces external to the water and to biological issues. Before 1960, the Plata River Basin was almost undeveloped. The regulation of the Parana for hydroelectricity has been increasing since the early 1970s. Water in reservoirs of the upper Parana Basin currently comprises more than 70 percent of the mean annual discharge at its confluen...

2013
Zuzana Musilová Lukáš Kalous Miloslav Petrtýl Petra Chaloupková

The headwaters of five large African river basins flow through the Bié Plateau in Angola and still remain faunistically largely unexplored. We investigated fish fauna from the Cuanza and Okavango-Zambezi river systems from central Angola. We reconstructed molecular phylogenies of the most common cichlid species from the region, Tilapia sparrmanii and Serranochromis macrocephalus, using both mit...

2016
Jamie Pittock David Dumaresq Andrea M. Bassi Marko Keskinen Olli Varis

An increasing global population and growing wealth are raising demand for energy and food, impacting on the environment and people living in river basins. Sectoral decision-making may not optimize socio-economic benefits because of perverse impacts in other sectors for people and ecosystems. The hydropower–food supply nexus in the Mekong River basins is assessed here in an influence model. This...

2006
K. - E. Lindenschmidt U. Herrmann I. Pech U. Suhr H. Apel A. Thieken

Assessing and mapping damage risk of floods for large river basins is still in its infancy. Damage risk is understood to be the combination of flood hazard and the vulnerability of communities to a flood of a particular return period. Risk is calculated and mapped for two communities in which dykes are not located for flood protection: Meissen on the Elbe River and Döbeln in the Mulde catchment...

H. Zareian H.R. Esmaeili R. Zamanian Nejad S. Vatandoust

This paper provides information on the geographic distributions of two cyprinid species: Hemiculter leucisculus (Basilewsky, 1855) and Alburnus caeruleus Heckel, 1843, in the world and the entire drainage systems in Iran. The new distribution records were taken from Maroon River (Jarrahi River system) and Chardaval River (Karkheh river system), both in Tigris River basin showing wide and narrow...

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