7,147 research outputs found
Scaling gridded river networks for macroscale hydrology: Development, analysis, and control of error
A simple and robust river network scaling algorithm (NSA) is presented to rescale fineāresolution networks to any coarser resolution. The algorithm was tested over the Danube River basin and the European continent. Coarseāresolution networks, at 2.5, 5, 10, and 30 min resolutions, were derived from higherāresolution gridded networks using NSA and geomorphometric attributes, such as river order, shape index, and width function. These parameters were calculated and compared at each resolution. Simple scaling relationships were found to predict decreasing river lengths with coarserāresolution data. This relationship can be used to correct river length as a function of grid resolution. The lengthācorrected width functions of the major river basins in Europe were compared at different resolutions to assess river network performance. The discretization error in representing basin area and river lengths at coarser resolutions were analyzed, and simple relationships were found to calculate the minimum number of grid cells needed to maintain the catchment area and length within a desired level of accuracy. This relationship among geomorphological characteristics, such as shape index and width function (derived from gridded networks at different resolutions), suggests that a minimum of 200ā300 grid cells is necessary to maintain the geomorphological characteristics of the river networks with sufficient accuracy
Global system of rivers: Its role in organizing continental land mass and defining landātoāocean linkages
The spatial organization of the Earth\u27s land mass is analyzed using a simulated topological network (STNā30p) representing potential flow pathways across the entire nonglacierized surface of the globe at 30āmin (longitude Ć latitude) spatial resolution. We discuss a semiautomated procedure to develop this topology combining digital elevation models and manual network editing. STNā30p was verified against several independent sources including map products and drainage basin statistics, although we found substantial inconsistency within the extant literature itself. A broad suite of diagnostics is offered that quantitatively describes individual grid cells, river segments, and complete drainage systems spanning orders 1 through 6 based on the Strahler classification scheme. Continental and globalāscale summaries of key STNā30p attributes are given. Summaries are also presented which distinguish basins that potentially deliver discharge to an ocean (exorheic) from those that potentially empty into an internal receiving body (endorheic). A total of 59,122 individual grid cells constitutes the global nonglacierized land mass. At 30āmin spatial resolution, the cells are organized into 33,251 distinct river segments which define 6152 drainage basins. A global total of 133.1 Ć 106 km2 bear STNāSOp flow paths with a total length of 3.24 Ć 106 km. The organization of river networks has an important role in linking land mass to ocean. From a continental perspective, lowāorder river segments (orders 1ā3) drain the largest fraction of land (90%) and thus constitute a primary source area for runoff and constituents. From an oceanic perspective, however, the small number (n=101) of large drainage systems (orders 4ā6) predominates; draining 65% of global land area and subsuming a large fraction of the otherwise spatially remote lowāorder rivers. Along river corridors, only 10% of land mass is within 100 km of a coastline, 25% is within 250 km, and 50% is within 750 km. The global mean distance to river mouth is 1050 km with individual continental values from 460 to 1340 km. The Mediterranean/Black Sea and Arctic Ocean are the most landādominated of all oceans with land:ocean area ratios of 4.4 and 1.2, respectively; remaining oceans show ratios from 0.55 to 0.13. We discuss limitations of the STNā30p together with its potential role in future global change studies. STNā30p is geographically linked to several hundred river discharge and chemistry monitoring stations to provide a framework for calibrating and validating macroscale hydrology and biogeochemical flux models
The evolutionary loss of lipogenesis in insect parasitoids: Molecular mechanisms and ecological aspects
Financial incentives and job choice
Berg, G.J. van den [Promotor]Hochguertel, S. [Copromotor]Bloemen, H.G. [Copromotor
I Warned You! Applicant Reactions to Different Types of Warnings Against Faking on Personality Tests: An Organizational Justice, Trust and Affect-Based Perspective
Abstract
Despite their widespread use in employee selection procedures, personality measures are susceptible to applicant faking. Explicit warnings, often included in test instructions to deter faking behavior, inform applicants that items are included on the test to detect faking, and that those caught faking, will be removed from the applicant pool (i.e., invalidation warnings). The current research examined the effectiveness of another warning type informing applicants that faking is not in their best interest, as it is likely to get them into a job for which they are a poor fit (i.e., job fit warnings). Results for Study 1 supported the application of The Theory of Planned Behavior (Ajzen, 1991) to the context of applicant faking on personality tests; invalidation warnings appear to function by lessening applicantsā perceived ability to fake successfully without being caught. Moreover, the positive job fit warnings were just as effective as the negative invalidation warnings at lessening applicant faking behaviors. Positive job fit warnings also elicited much more positive reactions from applicants than did the negative invalidation warnings and thus, appear to have greater utility than the negative invalidation warnings. Study 2 revealed that combining the negative invalidation warning with the positive job fit warning minimized the adverse reactions to the negative invalidation warning, resulting in more positive applicant reactions. Additionally, this combination warning was slightly more effective in deterring applicant faking behavior than either single-consequence warning alone. Taken together, organizations may benefit most by utilizing the negative invalidation + positive job fit combination warning
River Discharge, in State of the Climate in 2008
The global mean temperature in 2008 was slightly cooler than that in 2007; however, it still ranks within the 10 warmest years on record. Annual mean temperatures were generally well above average in South America, northern and southern Africa, Iceland, Europe, Russia, South Asia, and Australia. In contrast, an exceptional cold outbreak occurred during January across Eurasia and over southern European Russia and southern western Siberia. There has been a general increase in land-surface temperatures and in permafrost temperatures during the last several decades throughout the Arctic region, including increases of 1Ā° to 2Ā°C in the last 30 to 35 years in Russia. Record setting warm summer (JJA) air temperatures were observed throughout Greenland
U.S. River Discharge for 2008 in State of the Climate in 2008
The global mean temperature in 2008 was slightly cooler than that in 2007; however, it still ranks within the 10 warmest years on record. Annual mean temperatures were generally well above average in South America, northern and southern Africa, Iceland, Europe, Russia, South Asia, and Australia. In contrast, an exceptional cold outbreak occurred during January across Eurasia and over southern European Russia and southern western Siberia. There has been a general increase in land-surface temperatures and in permafrost temperatures during the last several decades throughout the Arctic region, including increases of 1Ā° to 2Ā°C in the last 30 to 35 years in Russia. Record setting warm summer (JJA) air temperatures were observed throughout Greenland
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