On the probabilistic structure of water age
On the probabilistic structure of water age
复制标题
论水时代的概率结构
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
S. Calabrese
中科院分区：
文献类型：
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作者：
A. Porporato;S. Calabrese
近年来，水文系统中水的年龄分布重新引起了人们的关注，特别是在流域对降雨输入的响应方面。这一贡献的目的是首先提请注意人口动力学、流体力学和随机地下水中关于年龄分布的现有理论，特别是McKendrick-von Foerster方程及其推广和解。第二个也是更重要的目标是澄清，当用时变随机过程模拟水文通量时，年龄分布本身必须被视为随机函数。一旦获得了它们的概率结构，就可以用它来表征真实系统中年龄分布的可变性，从而帮助量化现场确定水龄的内在不确定性。我们参考一个随机存储模型来说明这些概念，该模型已被用作土壤水分和径流动力学的最小模型。
The age distribution of water in hydrologic systems has received renewed interest recently, especially in relation to watershed response to rainfall inputs. The purpose of this contribution is first to draw attention to existing theories of age distributions in population dynamics, fluid mechanics and stochastic groundwater, and in particular to the McKendrick‐von Foerster equation and its generalizations and solutions. A second and more important goal is to clarify that, when hydrologic fluxes are modeled by means of time‐varying stochastic processes, the age distributions must themselves be treated as random functions. Once their probabilistic structure is obtained, it can be used to characterize the variability of age distributions in real systems and thus help quantify the inherent uncertainty in the field determination of water age. We illustrate these concepts with reference to a stochastic storage model, which has been used as a minimalist model of soil moisture and streamflow dynamics.