Forecast of winter low flows in a cold-region river under the impact of climate warming
| Autor: | Amruthur S. Ramamurthy, Aneesh Kochukrishnan, S. Samuel Li |
|---|---|
| Rok vydání: | 2022 |
| Předmět: |
Watershed
River ecosystem 010504 meteorology & atmospheric sciences Global warming Ensemble average Flow (psychology) 0207 environmental engineering Representative Concentration Pathways 02 engineering and technology Geotechnical Engineering and Engineering Geology 01 natural sciences 6. Clean water Freezing point 13. Climate action Climatology General Circulation Model General Earth and Planetary Sciences Environmental science 020701 environmental engineering 0105 earth and related environmental sciences |
| Zdroj: | Cold Regions Science and Technology. 194:103448 |
| ISSN: | 0165-232X |
| Popis: | Changes in winter low flow (WLF) in cold-region rivers affect engineering design, water quality, and river ecosystem health. This paper aims to quantify to what extent WLF will change under climate warming and to propose a practical forecasting model for WLF predictions. The new concept of cumulative watershed temperature (CWT) is used as a convenient lumped surrogate for complicated hydrological processes that influence WLF. Statistical analyses of century-long flow data from the Fraser River in British Columbia, Canada show a strong dependence of WLF on CWT. In winter season, time series of CWT and WLF are shown to each divide into a falling and a rising limb at the data point of their lowest values, being −358 °C and 827 m3/s (historical averages), respectively. The falling and rising limbs describe the cumulative freezing and thawing effects of air temperatures fluctuating around the freezing point on WLF changes. The correlation between CWT and WLF (time series) data points on the rising limbs forms the forecasting model, expressing WLF as a function of CWT in terms of their z-scores. The model takes input of Global Circulation Model (GCM) projections of temperature increases by the end of 21st century under different Representative Concentration Pathways (RCPs), and predicts changes of Fraser River WLF from the historical average. RCP4.5 causes a 22.6% increase (ensemble average from six GCMs). RCP8.5 increases WLF by 20% (for some future years) to 44% (for others). The methods reported in this paper can be adapted to other cold regions. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect