Speaker: Jaivime Evaristo

Title: Environmental Isotope Applications in Critical Zone science

Time: 9:00 am on May 28th, 2018 (Monday)

Venue: Conference room 307 in College of Natural Resources and Environment

Short summary of the presentation:

It is possible to estimate and predict the fate and transport of water and solutes using a range of tools. Oftentimes, however, technical limitations lead to large uncertainties in model predictions. Moreover, poor understanding of solute multi-isotope variability hampers our ability to derive robust geospatial models of solute spatial variability from regional to continental scales. This status quo needs to change, especially in light of mounting pressures on scientists and practitioners alike to make rigorous predictions on water routing and solute (or pollutant) transport. In this seminar, I will present recent progress made towards achieving greater clarity and understanding of the phenomenon that is ecohydrological compartmentalization. I will begin with testing the generality of ecohydrological compartmentalization and end with unscrambling the possible process controls behind the partitioning of subsurface moisture between root water uptake and groundwater recharge based on results from a controlled drought-rewetting experiment at the Biosphere 2-Tropical Rainforest mesocosm. Insights from data synthesis, laboratory and field experiments suggest a radically different way of looking at the terrestrial water cycle-a purposeful use of chemistry to track raindrops rather than just the hydrometrics of input and output over defined space and time scales. An appreciation of the difference between the mass flux of water (i.e. velocity, represented by the age distribution of water in storage) and the speed with which an incoming parcel of water propagates through the flow domain (i.e. celerity, represented by stream hydrographs) is therefore warranted. With these insights I will outline a research collaboration agenda with Northwest A&F University (NWAFU) that (1) implements the concepts of ecohydrological compartmentalization for improving process representations in hydrological models, and (2) identifies opportunities for using a multi-isotope approach in tracing sources and sinks of water and nutrients in the Loess Plateau.

Brief introduction of Jaivime Evaristo:

Jaivime Evaristo, Ph.D., assistant professor at the University of Nevada, USA. Dr. Evaristo focuses on ecohydrology, especially on ecohydrological separation. He has done a lot of work related to plant water source and catchment-scale water cycle, which emphasizes the application of isotope technique. The hypothesis of two water world hypothesis was verified by comparing isotopic compositions of precipitation, soil water, xylem water, river water and groundwater, which has been published in Nature. In addition, he has published some important papers on Hydrological Processes and other journals. Welcome to attend the report.

College of Natural Resources and Environment

28th May 2018