When
Where
Available in person in Harshbarger 110 or via zoom (see email link)
Abstract
Surface water resources of the Colorado River Basin (CRB) are stressed by rapidly increasing demand from nearly all elements of society including declining supply due to current demands, accelerating demands of growing regional populations, and ambitious agricultural, industrial and mining proposals for the future. Water availability in the CRB is already impacted by reductions in source supply due to environmental change, especially the pace of climate change. Under these conditions, water resource management will require plausible projections of future supplies. Unfortunately those projections cannot be based entirely on current system state dynamics, but must take into account the almost certain non-stationarity of future states. That non-stationarity is likely to occur on multiple scales of space and time that are currently rarely seen in the CRB, if ever. In this talk I will outline a spectral approach to analyzing streamflow records of the CRB that identifies both normal trends in current records and anomalies that could become more common in the future. The basic elements of the analysis are (1) singular value decompositions (SVD) of the space-time correlation structure exhibited by regional streamflow data, (2) extreme value statistics that are derived from the current annual data and (3) are then projected dynamically into the future based on nonlinear stochastic dynamics. In this talk I will focus on elements 1 & 2 and give details of the data, data structures and data transformations that have proved most useful so far in identifying trends and anomalies.