Computational simulations of wildfire spread typically employ empirical rate-of-spread calculations under various conditions (such as terrain, fuel type, weather). Small perturbations in conditions can often lead to significant changes in fire spread (such as speed and direction), necessitating a computationally expensive large set of simulations to quantify uncertainty. Model emulation seeks alternative representations of physical models using machine learning, aiming to provide more efficient and/or simplified surrogate models. We propose a dedicated spatio-temporal neural network based framework for model emulation, able to capture the complex behaviour of fire spread models. The proposed approach can approximate forecasts at fine spatial and temporal resolutions that are often challenging for neural network based approaches. Furthermore, the proposed approach is robust even with small training sets, due to novel data augmentation methods. Empirical experiments show good agreement between simulated and emulated firefronts, with an average Jaccard score of 0.76.
翻译:野火扩散的计算模拟通常在各种条件下(如地形、燃料类型、天气)采用经验性分布率计算,条件中的小扰动往往会导致火灾传播发生重大变化(如速度和方向),需要计算昂贵的大规模模拟来量化不确定性。模型模拟寻求使用机器学习的物理模型的替代表示,目的是提供更有效率和(或)简化的替代模型。我们提议为模型模拟建立一个专门的空-时神经网络框架,以便能够捕捉火传播模型的复杂行为。拟议方法可以将预测的时空分辨率大致地与对以神经网络为基础的方法往往具有挑战性的细微分辨率相近。此外,由于新的数据增强方法,拟议的方法即使是小型培训,也十分健全。经验实验表明模拟和模拟的防火前线之间达成了良好的一致,平均计价为0.76。