Multi-Proxy, Multi-Season Streamflow Reconstruction with Mass Balance Adjustment

Abstract

Dendrohydrology, the study of past hydroclimate using tree rings, has been largely motivated by water resources management. The field traces back to Hardman and Reil (1936), who recognized that instrumental records were too short to understand drought trends and demonstrated that better understanding could be gained from exploring the links between tree rings and streamflow. Their work was motivated by contemporary droughts in California that affected irrigation. At the same time, Hawley (1937) found strong correlations between tree rings and streamflow in Tennessee, USA, and was probably the first to show the lagged relationship of streamflow to tree rings. Also to understand droughts, Schulman (1945) established a tree ring chronology for the Colorado River Basin, this time motivated by the war effort-to examine Hoover Dam's hydropower production reliability to meet wartime demand. While these early works stopped at studying tree ring indices, dendrohydrology took a big step when Stockton (1971), leveraging advanced multivariate techniques (Fritts et al., 1971), showed that reconstructing streamflow record back in time was feasible-long term surface water availability could now be quantified directly. Soon, multiple streamflow reconstructions were developed across the Colorado River Basin (Stockton & Jacoby, 1976), revealing the

Time to Use Dendrohydrological Data in Water Resources Management?

“…For example, oxygen isotopes often correlate well with peak flow (Xu et al 2019), while ring widths tend to capture the response to droughts (Gallant and Gergis 2011). One could therefore leverage the correlation between multiple proxies and different target variables to reconstruct subannual flows-a concept recently demonstrated by Rao (2020) and Nguyen et al (2020a). Because more sampling sites and proxies are being developed (e.g., blue intensity, latewood density), we have an opportunity for creating models that bank on large multiproxy networks to reconstruct subannual streamflow.…”