Get_Drought_metrics: Get_drought_metrics

In sarahforte/CESIfun: Calculating flood and drought metrics, executing trend tests using specific parameters

Description

The function takes in a character representing the station number within 1014 RHBN_U stations and a vector of numerics or a character, calculates four drought metrics: dr_threshold: the lower threshold that was calculated in Threshold_build function from above; dr_days:days under the lower threshold within a year; dr_events:independent drought events over a year; dut_ma_dur: the maximum consecutive duration under the threshold within a year;

Usage

Get_Drought_metrics(station, year = "all")

Arguments

station	a character representing a station we want the flood metrics to be calculated at;
year	a vector of numeric representing the list of years we want thew flood metrics to be calculated at, defaulted to 'all' indicating all the years at the station;

Details

The four metrics will then be calculated based on only the time within a year between the last and first bday calculated from the previous bday_calculation() function, and the result will be recorded in a table and returned. In order to measure the independence between drought events, we set the following constraints: 1. t >= 5 2. the excess volume, Vabove / min(Vbelowi, Vbelowj)>=0.1 where t is the time between events, Vabove is the amount that exceeds the threshold, Vbelowi and Vbelowj are the volumes below during events i and j.

Value

A dataframe of the format: || STATION_NUMBER || Year || dr_days || dr_events || dr_threshold || dut_max_dur ||

References

WMO World Meteorological Organization (2008). Manual on Low-Flow Estimation and Prediction. 1339 Operational Hydrology.

sarahforte/CESIfun documentation built on Dec. 22, 2021, 10:16 p.m.