3 research outputs found

    Scalability of a multi-physics system for forest fire spread prediction in multi-core platforms

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    Advances in high-performance computing have led to an improvement in modeling multi-physics systems because of the capacity to solve complex numerical systems in a reasonable time. WRF-SFIRE is a multi-physics system that couples the atmospheric model WRF and the forest fire spread model called SFIRE with the objective of considering the atmosphere-fire interactions. In systems like WRF-SFIRE, the trade-off between result accuracy and time required to deliver that result is crucial. So, in this work, we analyze the influence of WRF-SFIRE settings (grid resolutions) into the forecasts accuracy and into the execution times on multi-core platforms using OpenMP and MPI parallel programming paradigms

    A Dynamic Data Driven Application System for Vehicle Tracking

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    AbstractTracking the movement of vehicles in urban environments using fixed position sensors, mobile sensors, and crowd-sourced data is a challenging but important problem in applications such as law enforcement and defense. A dynamic data driven application system (DDDAS) is described to track a vehicle's movements by repeatedly identifying the vehicle under investigation from live image and video data, predicting probable future locations, and repositioning sensors or retargeting requests for information in order to reacquire the vehicle. An overview of the envisioned system is described that includes image processing algorithms to detect and recapture the vehicle from live image data, a computational framework to predict probable vehicle locations at future points in time, and a power aware data distribution management system to disseminate data and requests for information over ad hoc wireless communication networks. A testbed under development in the midtown area of Atlanta, Georgia in the United States is briefly described

    Anthropogenic modification of the natural fire landscape and its consequences for vegetation patterns on the Cape Peninsula

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    Understanding the spatial probability of fire and how urban development may alter natural patterns is particularly important in areas where alternate ecosystem states occur at fine spatial scales. The Cape Peninsula, South Africa, is a one such region where fire-sensitive forest patches occur interspersed in a sea of fire-dependent fynbos. Fire is believed to be an important determinate of forest distribution, with absence or occurrence of fires potentially allowing patch contraction and expansion. In this thesis I use a series of computer models to determine the extent to which anthropogenic development and land transformation have altered the spatial variation in fire likelihood, or the 'burn probability', and its consequence for the distribution of forest on the Cape Peninsula. The two multi-model, fire behaviour simulation systems I use are FlamMap and FARSITE. FARSITE is a deterministic simulation package used globally for discrete event simulation. In an effort to assess the viability of using the FARSITE model for fire prediction in fynbos and the determinants of model accuracy, I predicted fire area for a historical fire on the Cape Peninsula using a variety of fuel models and wind conditions. Following this validation, FlamMap was used to simulate the burn probability of the Cape Peninsula under natural conditions – no urban development present – and transformed conditions – where urban areas mapped as non-burnable fuel models. I then determined changes in forest distribution documented over the last 50 years relative to changes in burn probability as a result of urbanisation. My results show that an increase in urbanisation on the Cape Flats has produced a significant urban shadow effect due to the interruption of natural fire catchments. This urban shadow effect has resulted in an overall increase in area of fire refuges on the Peninsula and expansion of forest, particularly on the more mesic eastern slopes at Kirstenbosch and Newlands. The results strongly support that urban-mediated changes to fire patterns are drivers of forest expansion in this region, and adds further evidence to support the significance of fire in determining biome boundaries in the fynbos
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