资源环境科技发展态势分析平台

Realistic stochastic simulation of hydro-environmental fluxes in space and time, such as rainfall, is challenging yet of paramount importance to inform environmental risk analysis and decision making under uncertainty. Here, we advance random field simulation by introducing the concepts of general velocity fields and general anisotropy transformations. This expands the capabilities of the so-called Complete Stochastic Modeling Solution (CoSMoS) framework enabling the simulation of random fields preserving: (1) any non-Gaussian marginal distributions, (2) any spatiotemporal correlation structure, (3) general advection expressed by velocity fields with locally varying speed and direction, and (4) locally varying anisotropy. We also introduce new copula-based spatiotemporal correlation structures and provide conditions guaranteeing their positive definiteness. To illustrate the potential of CoSMoS, we simulate random fields with complex patterns and motion mimicking rainfall storms moving across an area, spiraling fields resembling weather cyclones, fields converging to (or diverging from) a point, and colliding air masses. The proposed methodology is implemented in the freely available CoSMoS R package.