Are climate models that allow better approximations of local meteorology better for the assessment of hydrological impacts? A statistical analysis of droughts

Abstract

Abstract. This work studies the benefit of using more reliable local climate scenarios to analyse hydrological impacts. It assumes that more reliable local scenarios are defined with the statistically corrected Regional Climate Model (RCM) simulations when they provide better approximations to the historical basic and drought statistics. The paper analyses if the best solutions in terms of their approximation to the local meteorology also provide the best hydrological assessments. A classification of the corrected RCM simulations attending to both approximations is performed. It has been applied in the Cenajo Basin (southeast Spain), where we demonstrate that the best approximations of the historical meteorological statistics provide also the best approximations of the hydrology ones. The selected RCMs were used to generate future (2071–2100) local scenarios under the RCP 8.5 emission scenario. The two selected RCMs predict significant changes of mean precipitation (−31.6 and −44.0 %) and mean temperature (+26.0 and +32.2 %). They also predict higher frequency (from 5 events in the historical period to 20 and 22 in the future), length (4.8 to 7.4 and 10.5 months), magnitude (2.53 to 6.56 and 9.62 SPI) and intensity (0.48 to 1.00 and 0.94 SPI) of extreme meteorological droughts.

Analysis of the Potential Ompact of Climate Change on Climatic Droughts, Snow Dynamics and the Correlation between Them

“…A simple definition is to consider it as a water deficit in relation to normal conditions [21]. Depending on the nature of the water deficit, droughts can be categorized into four types: meteorological, hydrological, agricultural and socioeconomic [22,23,24]. Meteorological, hydrological and agricultural droughts are based on the same concept, i.e.…”