1. The structure of lotic macroinvertebrate communities may be strongly influenced by land-use practices within catchments. However, the relative magnitude of influence on the benthos may depend upon the spatial arrangement of different land uses in the catchment. 2. We examined the influence of land-cover patterns on in-stream physico-chemical features and macroinvertebrate assemblages in nine...

Semi-arid ecosystems form the stage for a plethora of vegetation patterns; a feature that has been captured in terms of mathematical models since the beginning of this millennium. To study these patterns, we use a reaction-advection-diffusion model that describes the interaction of vegetation and water supply on gentle slopes. As water diffuses much faster than vegetation, this model operates o...

various methods have been used to economically design wastewater and stormwater collection systems. in this article, discrete differential dynamic programming (dddp) which is a subsection of dynamic programming (dp) was used. for each pipe network, various alternatives such as depth and slope of pipe laying and various diameters could be considered to satisfy hydraulic and engineering constrain...

A corridor is one of the new classes of airspace introduced with Next Generation Air Transportation System (NextGen). A well-designed corridor may reduce the airspace complexity, increase airspace capacity and decrease controller workload. This paper develops a computer simulation model for constructing risk-capacity tradeoff curves of en-route corridor concepts. Keywords-corridor; simulation, ...

The Heihe River Basin (HRB) is the second largest inland river basin in China, characterized by high diversity in geomorphology and irrigated agriculture in middle reaches. To improve the knowledge about the relationship between biotic and hydrological processes, this study used Global Inventory Modeling and Mapping Studies Normalized Difference Vegetation Index (NDVI) data (1982-2006) to analy...

Using an analysis of the first full year of CALIPSO lidar measurements, this paper derives unprecedented, altitude-resolved seasonal distributions of desert dust transported over the Tibetan Plateau (TP) and the surrounding areas. The CALIPSO lidar observations include numerous large dust plumes over the northern slope and eastern part of the TP, with the largest number of dust events occurring...

Aims Factors limiting distributions of species are fundamental to ecology and evolution but have rarely been addressed experimentally for multiple species. The conspicuous linear distribution patterns of plant species confined to river corridors in the Central European lowlands constitute an especially long-standing distribution puzzle. We experimentally tested our novel hypothesis that the tol...

An analysis of channel head locations provides insight into controls on drainage density, the response of landscapes to climatic change, and the delineation of source areas for channel network simulations. Channel heads and colluvial deposits were mapped in a roughly 2 km 2 area near San Francisco, California, and, although channel heads are located within colluvial deposits in hollows, many su...