[1] In drainage basin evolution models the implementation of sediment transport and sediment balance is constrained by numerical instabilities. In order to overcome these difficulties an implicit finite difference method is proposed. The method simultaneously adjusts the elevation at each node of the numerical grid, is unconditionally stable, and significantly reduces the computational time. Th...

Iran is well known for having countless historical and instrumental records of tectonic events. Shahriary catchment, as a study area, is part of the Zagros collision seismic province. This research aimed to introduce a new method which is useful in identifying the relative active tectonic events of an area. The research method was designed in order to calculate the relative active tectonic inde...

Topographically heterogeneous agricultural landscapes can complicate and accelerate agrochemical contamination of streams due to rapid transport of water and chemicals to poorly drained lower-landscape positions and shallow ground water. In the semiarid Palouse region, large parts of these landscapes have been tile drained to enhance crop yield. From 2000-2004 we monitored the discharge of a ti...

This paper explores the use of graphics processing units (GPUs) for combined numerical analysis and visualization. Using an implementation of the O’Callaghan and Mark (1984) drainage accumulation algorithm, it explores the advantages and challenges that this environment brings to real-time, frame-by-frame production of spatial modeling products and their visualization. Modern GPUs employ massiv...

Mesacanthus is a common and speciose genus of acanthodian fish from Lower Old Red Sandstone and Middle Old Red Sandstone assemblages (representing the Lower Devonian and Middle Devonian respectively) and is well represented in many palaeoichthyology collections in the UK. Based upon descriptions given during the 19th century, specimens of the genus Mesacanthus from the Orcadian Basin and Midlan...

Insect societies vary greatly in social organization, yet the relative roles of ecological and genetic factors in driving this variation remain poorly understood. Identifying how social structure varies along environmental gradients can provide insights into the ecological conditions favouring alternative social organizations. Here, we investigate how queen number variation is distributed along...

To sustain agricultural productivity, evaporation basins (or ponds) have been widely used for the disposal of agricultural drainage in areas requiring subsurface drainage in the San Joaquin Valley of California, USA. The drainage water contains elevated concentration of trace elements including selenium (Se) and arsenic (As). Unlike Se, little information is available about As, a potentially hi...