Estimating Groundwater Recharge Using the Oklahoma Mesonet

Transcription

1 Estimating Groundwater Recharge Using the Oklahoma Mesonet Briana Sallee and Tyson E. Ochsner, Oklahoma State University; Christopher A. Fiebrich and Bradley G. Illston, University of Oklahoma; and Christopher R. Neel, Oklahoma Water Resources Board

2 Groundwater Supply Challenges Oklahoma basins facing the most significant water supply challenges (OCWP, 2012)

3 Aquifer Water Balance Basics At steady state Recharge = Discharge + Pumping + Effective GW management requires reliable recharge estimates. Active root zone Drainage Recharge Water table Pumping Discharge

4 Recharge Data Drought Recharge data for Oklahoma are sparse and often decades old. Existing recharge estimates often don t reflect recent climate conditions. How can the Mesonet platform be used for recharge estimation? Effective regional recharge rates across Oklahoma, (Pettyjohn et al., 1983)

5 Our Approach With OWRRI funding, we determined Mesonet soil properties (Scott et al., 2013). Soil properties + Mesonet soil moisture data drainage estimates Working hypothesis: drainage recharge Approach: estimate recharge using several independent methods, then compare with Mesonet-based drainage rates. Mesonet soil profiles Drainage Recharge Water table

6 Unsaturated zone chloride mass balance: sampling locations OG RS Fig. 1. Major aquifers of Oklahoma (shaded regions) and Mesonet site locations (red dots). The Ogallala (OG) and Rush Springs (RS) aquifers are identified and proposed coring locations are circled. Reproduced from OWRB draft report.

7 Geoprobe drilling at Ft. Cobb Russell Neill (US EPA) preparing to drill at the Fort Cobb Mesonet site. December 10, 2013

8 uz-cmb recharge estimates Table 1: Average annual precipitation, unsaturated zone pore water chloride concentrations, and recharge estimates based on steady-state, unsaturated zone chloride mass balance method for eight Mesonet sites in western Oklahoma. Mesonet Site Precip. Chloride Recharge mm yr -1 ppm mm yr -1 Fort Cobb Freedom Woodward Arnett Slapout / /1.4 Hooker Goodwell Boise City

9 Saturated zone chloride mass balance: 2013 GMAP sampling locations The baseline water quality network of sampling sites within Group A aquifers of GMAP. Reproduced from 2013 Groundwater Report: Beneficial Use Monitoring Program (OWRB, 2014)

10 sz-cmb recharge estimates Table 2: Average groundwater chloride concentrations and recharge estimates based on steady-state, chloride mass balance method for five Oklahoma aquifers. Aquifer GW chloride Recharge ppm mm yr -1 Gerty Sand Elk City 9 25 Ogallala Northwest Rush Springs Canadian River

11 Kim and Jackson (2012) statistical model

12 Mesonet-based drainage estimates Table 3: Median annual precipitation and median annual drainage at 60 cm for the Mesonet sites above some major Oklahoma aquifers from The range of previously published recharge values for each aquifer is included for comparison. Aquifer Sites Precip. Drainage Recharge mm mm mm Roubidoux Arkansas River n/a Garber-Wellington Vamoosa-Ada Rush Springs Antlers Ogallala

13 Take Home Messages Water resource managers in Oklahoma need reliable recharge estimates. Results thus far indicate good potential for estimating recharge using the Oklahoma Mesonet soil moisture data. Reconciling recharge estimates from various methods is a key challenge. Buffalo Springs, Chickasaw National Recreation Area, Sulphur, OK. Source: Brian Wright

14 Thanks to: