A 400-year reconstruction of spring–summer precipitation and summer low flow from regional tree-ring chronologies in North-Eastern Austria

Abstract

Atmospheric and streamflow drought back to 1600 were reconstructed with provenance-verified regional Pinus-sylvestris and Pinus-nigra chronologies of earlywood, latewood and ring width, detrended by signal-free regional curve standardization, from the Weinviertel, a dry region in Eastern Austria. Linear regression models with Weinviertel latewood indices as predictor variables were used to estimate regional April–August precipitation totals (R2 = 0.47) and seven-day minimum flow from May to October (best fit: R2 = 0.65). As a novelty, the well-known dendrochronology quality measure “Expressed Population Signal” in a modified version is used to define a scaling factor for empirically estimating the reconstructions’ time-varying reliability.For the detection of drought years in the reconstructed time series, four stages of drought of increasing intensity were defined as conditions below median, and below the 33rd, 20th, and 5th percentile—representing 2-year, 3-year, 5-year and 20-year recurrence intervals.The method for the extension of time series of low flows into the past is applicable in the Weinviertel and can be a useful source of historical hydrological and meteorological information restricted by the uncertainties coming along with proxy records. Of the analyzed period back to 1600, the 19th century is the driest one closely followed by the 18th century, sharing the overall driest period from 1775 to 1813. The phase with the longest continuous atmospheric dry period is 1807–1811. The longest hydrological drought lasted from 1832 to 1839.