Multiscale temporal variability and regional patterns in 555 years of conterminous U.S. streamflow

Abstract

The development of paleoclimate streamflow reconstructions in the conterminous United States (CONUS) has provided water resource managers with improved insights into multidecadal and centennial scale variability that cannot be reliably detected using shorter instrumental records. Paleoclimate streamflow reconstructions have largely focused on individual catchments limiting the ability to quantify variability across the CONUS. The Living Blended Drought Atlas (LBDA), a spatially and temporally complete 555 year long paleoclimate record of summer drought across the CONUS, provides an opportunity to reconstruct and characterize streamflow variability at a continental scale. We explore the validity of the first paleoreconstructions of streamflow that span the CONUS informed by the LBDA targeting a set of U.S. Geological Survey streamflow sites. The reconstructions are skillful under cross validation across most of the country, but the variance explained is generally low. Spatial and temporal structures of streamflow variability are analyzed using hierarchical clustering, principal component analysis, and wavelet analyses. Nine spatially coherent clusters are identified. The reconstructions show signals of contemporary droughts such as the Dust Bowl (1930s) and 1950s droughts. Decadal‐scale variability was detected in the late 1900s in the western U.S., however, similar modes of temporal variability were rarely present prior to the 1950s. The twentieth century featured longer wet spells and shorter dry spells compared with the preceding 450 years. Streamflows in the Pacific Northwest and Northeast are negatively correlated with the central U.S. suggesting the potential to mitigate some drought impacts by balancing economic activities and insurance pools across these regions during major droughts.

Impact of different types of ENSO conditions on seasonal precipitation and streamflow in the Southeastern United States

“…Therefore, ENSO signal reflected in streamflow is not the same as that reflected in precipitation for the SEUS (Wang et al, ). Regional patterns revealed in different areas in the United States show that a spatial pattern in the SEUS is identified (Ho et al, ). Similar to precipitation, weak signal is reflected in seasonal streamflow at the JJA season (results not shown) which is the typical onset season for ENSO phenomena.…”

A Clustering Preprocessing Framework for the Subannual Calibration of a Hydrological Model Considering Climate‐Land Surface Variations

“…Clustering algorithms have poor performance when classifying high‐dimensional data sets on account of the intense computation of the covariance matrices (T. T. G. Zhao, Liu, et al, ). The information redundancy of the clustering indices impairs the robustness of the clusters (Ho et al, ). As such, PCA (Section S1.2) is conducted to eliminate the multicollinearity and the redundant information among the clustering indices.…”

Six Centuries of Upper Indus Basin Streamflow Variability and Its Climatic Drivers

“…This underlying principle has allowed the use tree rings to develop reconstructions of past flow and flow extremes, including for one gauge on the UIB (Cook et al, ). These paleohydrologic records from tree rings have found a wide variety of applications, from placing instrumental mean discharge in a long‐term context (Stockton & Jacoby, ); to being used as forecasting, planning, and research tools by water managers (Meko & Woodhouse, ); and understanding continental‐scale streamflow covariability and clustering (Ho et al, ).…”