3 resultados para Gullies

em Queensland University of Technology - ePrints Archive


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"The extended drought periods in each degradation episode have provided a test of the capacity of grazing systems (i.e. land, plants, animals, humans and social structure) to handle stress. Evidence that degradation was already occurring was identified prior to the extended drought sequences. The sequence of dry years, ranging from two to eight years, exposed and/or amplified the degradation processes. The unequivocal evidence was provided by: (a) the physical 'horror' of bare landscapes, erosion scalds and gullies and dust storms; (b) the biological devastation of woody weeds and animal suffering/deaths or forced sales, and; (c) the financial and emotional plight of graziers and their families due to reduced production in some cases leading to abandonment of properties or, sadly, deaths (e.g. McDonald 1991, Ker Conway 1989)."--Publisher website

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Two ultrasound survey methods were used to determine the presence and activity patterns of New Zealand long-tailed bats (Chalinolobus tuberculatus) in the city of Hamilton. First, 13 monthly surveys conducted at 18 green spaces found C. tuberculatus in only one urban forest reserve, Hammond Bush, where they were found consistently throughout the year. Bat activity was strongly related to temperature. Second, twice-yearly citywide surveys conducted over 2 years determined the distribution and habitat associations of C. tuberculatus. Bats were found only in the southern part of the city and were strongly associated with the Waikato River. Bat activity was negatively correlated with housing and street light density and positively correlated with topographical complexity. In Hamilton, topographical complexity indicates the presence of gullies. Gullies probably provide foraging and roosting opportunities and connect the river to distant forest patches. These results suggest that urban habitats can be useful for bats if gullies can link these to distant habitat fragments.

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There is a growing interest to autonomously collect or manipulate objects in remote or unknown environments, such as mountains, gullies, bush-land, or rough terrain. There are several limitations of conventional methods using manned or remotely controlled aircraft. The capability of small Unmanned Aerial Vehicles (UAV) used in parallel with robotic manipulators could overcome some of these limitations. By enabling the autonomous exploration of both naturally hazardous environments, or areas which are biologically, chemically, or radioactively contaminated, it is possible to collect samples and data from such environments without directly exposing personnel to such risks. This paper covers the design, integration, and initial testing of a framework for outdoor mobile manipulation UAV. The framework is designed to allow further integration and testing of complex control theories, with the capability to operate outdoors in unknown environments. The results obtained act as a reference for the effectiveness of the integrated sensors and low-level control methods used for the preliminary testing, as well as identifying the key technologies needed for the development of an outdoor capable system.