Development of a methodology to assess future trends in low flows at the watershed scale using solely climate data

JOURNAL OF HYDROLOGY

卷:557

Article

Foulon, Etienne¹  Rousseau, Alain N.¹  Gagnon, Patrick² 

[1] INRS ETE, 490 Rue Couronne, Quebec City, PQ G1K 9A9, Canada

[2] Agr & Agri Food Canada, 2560 Blvd Hochelaga, Ste Foy, PQ G1V 2J3, Canada

关键词: Effective drought index;    7-Day low flow;    30-Day low flow;    HYDROTEL;    Trends;    Climate model;   

DOI  :  10.1016/j.jhydrol.2017.12.064

来源: Elsevier

【 摘 要 】

Low flow conditions are governed by short-to-medium term weather conditions or long term climate conditions. This prorripts the question: given climate scenarios, is it possible to assess future extreme low flow conditions from climate data indices (CDIs)? Or should we rely on the conventional approach of using outputs of climate models as inputs to a hydrological model? Several CDIs were computed using 42 climate scenarios over the years 1961-2100 for two watersheds located in Quebec, Canada. The relationship between the CDIs and hydrological data indices (HDIs; 7- and 30-day low flows for two hydrological seasons) were examined through correlation analysis to identify the indices governing low flows. Results of the Mann-Kendall test, with a modification for autocorrelated data, clearly identified trends. A partial correlation analysis allowed attributing the observed trends in HD's to trends in specific CDIs. Furthermore, results showed that, even during the spatial validation process, the methodological framework was able to assess trends in low flow series from: (i) trends in the effective drought index (EDI) computed from rainfall plus snowmelt minus PET amounts over ten to twelve months of the hydrological snow cover season or (ii) the cumulative difference between rainfall and potential evapotranspiration over five months of the snow free season. For 80% of the climate scenarios, trends in HDIs were successfully attributed to trends in CDIs. Overall, this paper introduces an efficient methodological framework to assess future trends in low flows given climate scenarios. The outcome may prove useful to municipalities concerned with source water management under changing climate conditions. (C) 2018 Elsevier B.V. All rights reserved.

【 授权许可】

Free