Decadal Climate Variability Impact on Watershed Based Budget planning by the U.S. Army Corps
U.S. Army Corps of Engineers – Institute for Water Resources; June 2015 – October 2015
Vikram Mehta, CRCES
Katherin Mendoza, CRCES
J. Rolf Olsen, U.S. Army Corps of Engineers – Institute for Water Resources
Harvey Hill, U.S. Army Corps of Engineers – Institute for Water Resources
The Missouri River Basin (MRB) and the Mississippi River Basin (MsRB) produce 70% of wheat and 96% of corn produced in the U.S.A. Sixty percent of the grains produced in the MRB and the MsRB are transported on the Mississippi River to ports on the Gulf of Mexico. The U.S. Army Corps of Engineers (USACE) annually spends $1.5 billion on maintaining navigability of the Mississippi and other inland waterways. Using a variety of observed data from 1961 to 2013 Current Era, associations between natural decadal climate variability (DCV) phenomena – the Pacific Decadal Oscillation (PDO), the tropical Atlantic sea-surface temperature (SST) gradient (TAG) variability, the West Pacific Warm Pool SST variability, and decadal variability of the interannual El Niño-Southern Oscillation phenomenon – and hydro-meteorology, crop production and prices; and river flow, cargo tonnage shipped, and mud volume dredged in the Middle Mississippi River (MMR) to maintain navigability are described.
Precipitation, river flow, and wheat production were generally above average in the positive phase of the PDO and the negative phase of the TAG variability; and were generally below average in the opposite phases of the PDO and the TAG variability. Corn production suffered both in very dry and very wet conditions. There was, sometimes but not always, an inverse relationship between crop production and price. There are also demonstrable associations among DCV phases; and tonnage of shipped cargo and volume of mud dredged from the MMR in some high- and low-flow epochs. Statistics of persistence and transition probabilities of phases of observed DCV indices imply that it may be possible to predict the DCV phases and their possible impacts on river flow, crop yields and production, and navigation conditions in the Mississippi River one to two years in advance.