Physical Properties of Rivers: Calculating Recurrence Interval and Exceedance Probability

Physical Properties of Rivers: Calculating Recurrence Interval and Exceedance Probability This lesson was adapted from educational material written by Dr. Kateri Salk for her Fall 2019 Hydrologic Data Analysis course at Duke University. This is the first part of a two-part exercise focusing on the physical properties of rivers. Introduction Rivers are bodies of freshwater flowing from higher elevations to lower elevations due to the force of gravity. One of the most important physical characteristics of a stream or river is discharge, the volume of water moving through the river or stream over a given amount of time. This exercise will introduce the concepts of Recurrence Intervals and Exceedance Probability for the prediction of streamflow discharge. Learning Objectives After successfully completing this exercise, you will be able to: 1. Execute queries to pull a variety of National Water Information System (NWIS) and Water Quality Portal (WQP) data into R. 2. Calculate recurrence interval and exceedance probability from daily discharge data.河流物理特性：重现期与超越概率计算 本课程改编自凯特丽·萨尔克（Kateri Salk）博士为其2019年秋季杜克大学水文数据分析课程编写的教学材料，为聚焦河流物理特性的两部分练习的第一部分。 引言 河流是受重力作用由高海拔向低海拔流动的淡水水体。溪流或河流最重要的物理特性之一为流量（discharge），即单位时间内流经河道的水体体积。本练习将介绍重现期（Recurrence Interval）与超越概率（Exceedance Probability）的概念，用于河道流量预测。 学习目标 成功完成本练习后，你将能够： 1. 执行查询操作，将多种美国国家水文信息系统（National Water Information System, NWIS）与水质门户（Water Quality Portal, WQP）数据导入R环境。 2. 基于日流量数据计算重现期与超越概率。