Development of streamflow drought severity–duration–frequency curves using the threshold level method

Abstract

Abstract. This study developed a streamflow drought severity-duration-frequency (SDF) curve that is analogous to the well-known depth-duration-frequency (DDF) curve used for rainfall. Severity was defined as the total water deficit volume to target threshold for a given drought duration. Furthermore, this study compared the SDF curves of four threshold level methods: fixed, monthly, daily, and desired yield for water use. The fixed threshold level in this study is the 70th percentile value (Q 70 ) of the flow duration curve (FDC), which is compiled using all available daily streamflows. The monthly threshold level is the monthly varying Q 70 values of the monthly FDC. The daily variable threshold is Q 70 of the FDC that was obtained from the antecedent 365 daily streamflows. The desired-yield threshold that was determined by the central government consists of domestic, industrial, and agricultural water uses and environmental in-stream flow. As a result, the durations and severities from the desired-yield threshold level were completely different from those for the fixed, monthly and daily levels. In other words, the desired-yield threshold can identify streamflow droughts using the total water deficit to the hydrological and socioeconomic targets, whereas the fixed, monthly, and daily streamflow thresholds derive the deficiencies or anomalies from the average of the historical streamflow. Based on individual frequency analyses, the SDF curves for four thresholds were developed to quantify the relation among the severities, durations, and frequencies. The SDF curves from the fixed, daily, and monthly thresholds have comparatively short durations because the annual maximum durations vary from 30 to 96 days, whereas those from the desired-yield threshold have much longer durations of up to 270 days. For the additional analysis, the return-period-duration curve was also derived to quantify the extent of the drought duration. These curves can be an effective tool to identify streamflow droughts using severities, durations, and frequencies.

Quantifying human impacts on hydrological drought using a combined modelling approach in a tropical river basin in central Vietnam

“…The threshold approach (Zelenhasić and Salvai, 1987) is widely used to determine hydrological drought in temperate regions, where the discharge is usually greater than zero (Tallaksen et al, 2009;van Huijgevoort et al, 2012; and Sung and Chung, 2014). It defines drought events based on a threshold value and provides information about its onset, duration, and severity (Stahl, 2011;Hisdal et al, 2004).…”

“…Here the break days are 1 September and 1 January, which are the starting dates of the wet and dry seasons, respectively. Furthermore, lower than average flow in wet seasons contributed to the development of drought in the following season (Sung and Chung, 2014). A binary approach has been considered to identify whether it is a dry day or normal day based on the daily low-flow varying threshold.…”

“…Its specific objectives were to (1) simulate discharge to obtain naturalized streamflow time series by applying a distributed hydrological response unit (HRU) (Pfenning et al, 2009) based rainfallrunoff model -J2000 (Krause, 2002;Fink et al, 2013); (2) model reservoir storage and operation for eight major hydropower reservoirs in order to simulate daily release rates, hydropower production, and storage using the HEC-ResSim model (USACE, 2007); (3) simulate reservoir-impacted reconstructed streamflow for downstream stations at the two main river branches; and (4) quantify to which extent hydrological drought duration and severity can be attributed to hydropower reservoir operation or climate variability by applying the variable threshold method approach (Tallaksen et al, 2009;Sung and Chung, 2014) to reconstructed and naturalized streamflow time series.…”

Analysis of streamflow droughts using fixed and variable thresholds

“…On the other hand, when droughts are defined as below normal water availability (Mishra & Singh, 2010), then less severe events that occur during the wet period are mainly captured by the variable thresholds, which is a more wise choice in this case (Heudorfer & Stahl, 2017). Additionally, in the TLM, drought characteristics are defined in all possible hydrological variables in a uniform manner (Heudorfer & Stahl, 2017) and they can also be directly determined if the threshold is set using drought affected sectors (Sung & Chung, 2014). Hence, TLM is quite attractive in the scientific community and it has been used in various applications (Hisdal & Tallaksen, 2003;Keyantash & Dracup, 2002;Tigkas, Vangelis, & Tsakiris, 2012;Van Huijgevoort et al, 2012;Wu, Soh, Samal, & Chen, 2008).…”

Persistence Characteristics of Floods and Droughts of the Ganges-Brahmaputra-Meghna Basins Using Flood Duration Curve and Drought Duration Curve

“…However, he didn't define the threshold limit and gives no advice how to determine its value [6]. After that, based on the typical drought characteristics (water deficit and duration) and threshold levels, many researchers proposed different approaches to define drought [7][8][9][10].…”