An Investigation of Hydrologic Scale: Natural Variability Modeling, and Data Collection

问题尺度对观测和解释水文现象的方式有重要影响。最近的水文研究清楚地表明，实验室结果可能不能充分反映现场尺度的行为，在一个尺度上开发的模型可能在其他尺度上无效，小尺度的变化可能会产生大尺度的后果。该研究项目旨在帮助水文学家更清楚地了解尺度效应及其与实际水文调查的相关性。它考察了自然变率与基于科学水文学的模型和数据收集程序之间的复杂关系。该项目的第一阶段回顾了描述时间和空间尺度范围内自然变异性的随机方法。第二阶段研究了对水文数量进行依赖尺度估算的新技术。研究的最后阶段考虑如何使用现场数据来提高这些估计的准确性。项目中采用的随机方法提供了一种量化模型分辨率、采样努力和估计精度之间重要的尺度相关权衡的方法。该方法在地下水流动和输送中的应用说明了这一点。

Problem scale has a significant effect on the way that hydrologic phenomena are observed and explained. Recent hydrologic research has clearly demonstrated that laboratory results may not adequately reflect field scale behavior, that models developed at one scale may not be valid at other scales, and that small scale variability may have large scale consequences. This research project is designed to help hydrologists obtain a clearer understanding of scale effects and their relevance to practical hydrologic investigations. It examines the complex relationship between natural variability and the models and data collection programs that from the basis for scientific hydrology. The first phase of the project reviews stochastic methods for describing natural variability over a range of time and space scales. The second phase examines new techniques for deriving scale-dependent estimates of hydrologic quantities. The final phase of research considers how field data can be used to improve the accuracy of these estimates. The stochastic approach adopted in the project provides a way to quantify important scale-dependent tradeoffs between model resolution, sampling effort, and estimation accuracy. This approach is illustrated with applications to groundwater flow and transport.