Aquifer recharge is water that moves from the land surface or from the vadose zone into the saturated zone. Quantitative estimation of recharge rate contributes to the understanding of large-scale hydrologic processes. It is important for evaluating the sustainability of groundwater supplies, though it does not equate with a sustainable rate of extraction. Where contamination of an aquifer is a concern, estimating the recharge rate is a first step toward predicting solute transport to the aquifer. Recharge often occurs episodically in response to storms and other short-term, high-intensity inputs. For a given amount of infiltration, such temporal c oncentration enhances recharge because it entails shorter residence times for water in the portions of the soil from which evapotranspiration takes place. Similarly, a larger fraction of infiltrated water will become recharge if it is concentrated in narrow channels such as fingers or macropores, not only because this tends to hasten its passage through the unsaturated zone, but also because the water then occupies less of the volume of soil from which evapotranspiration takes place. Artificial recharge by ponding or injection is becoming a widely-used means of water storage.
Highlights:
Darcian method for recharge quantification
Development of basic method; Palouse Site, Washington
Nimmo, J. R., Stonestrom, D. A., and Akstin, K. C., 1994, The feasibility of recharge rate measurements using the steady state centrifuge method: Soil Science Society of America Journal, v. 58, p.49-56.
(PDF).
Western Mojave Desert, beneath ephemeral streams
Nimmo, J.R., Deason, J.A., Izbicki, J.A., and Martin, P., 2002, Evaluation of unsaturated-zone water fluxes in heterogeneous alluvium at a Mojave Basin site: Water Resources Research, v. 38, no. 10, p.33-1 - 33-13.
(PDF).
Glassboro Study Area, New Jersey
Baehr, A.L., Kaufman, L.J., Perkins, K.S., and Nolan, B.T., 2003, Estimating spatial variability of recharge in Southern New Jersey from unsaturated-zone measurements: U.S. Geological Survey Water-Resources Investigations Report 02-4288, 31 p.
(PDF).
Water-table fluctuation and lysimeter methods; Mahantango Creek watershed, Pennsylvania
Heppner, C.S., Nimmo, J.R., Folmar, G.J., Gburek, W.J., and Risser, D.W., 2007, Multiple-Methods Investigation of Recharge at a Humid-Region Fractured Rock Site, Pennsylvania, USA: Hydrogeology Journal.
(PDF)
Episodic aquifer recharge
Development of Episodic Master Recession (EMR) method for investigating effects of the time distribution of precipitation (including storm intensity, seasonality, inter-storm interval)
Nimmo, J.R., Horowitz, C., and Mitchell, L., 2015, Discrete-storm water-table fluctuation method to estimate episodic recharge: Groundwater, v.53, no. 2, doi: 10.1111/gwat.12177.
(PDF).
Application to a complex karst-dominated unsaturated zone
Alloca, V., De Vita, P., Manna, F., Nimmo, J.R., 2015, Groundwater recharge assessment at local and episodic scale in a soil
mantled perched karst aquifer in southern Italy: Journal of Hydrology, 529, p. 843-853.
(PDF).
Water balance and tracer analysis; recharge dependences on crop type, irrigation, and cultural practice in the North China Plain
Wang, B., Jin, M., Yang, L., Wang, W., and Nimmo, J.R., 2008, Estimating Aquifer Recharge by Applied Tracer Method in Hebei Plain: Journal of Hydrology, v. 356, p. 209-222.
(PDF).
Using the source-responsive approach , we incorporated of preferential flow into the widely-used water-balance method for recharge estimation. It permits realistic accounting for water storage and fluxes for those cases where preferential flow is a significant component
Nimmo, J.R., 2010, Theory for Source-Responsive and Free-Surface Film Modeling of Unsaturated Flow: Vadose Zone Journal, v. 9, no. 2, p. 295–306. (PDF)
Cuthbert, M.O., Mackay, R., and Nimmo, J.R., 2013, Linking soil moisture balance and source-responsive models to estimate diffuse and preferential components of groundwater recharge: Hydrology and Earth System Sciences, v. 17, no. 3, doi: 10.5194/hess-17-1003-2013, p. 1003-1019. (PDF).
Tracers and unsaturated zone hydraulics, Mississippi
Perkins, K.S., 2011, Measurement and Modeling of Unsaturated Hydraulic Conductivity, in Hydraulic Conductivity - Issues, Determination and Applications, Lakshmanan Elango (Ed.), InTech Publishing, ISBN: 978-953-307-288-3.
(PDF).
Review and encyclopedia articles on aquifer recharge
Nimmo, J.R., Stonestrom, D.A., and Healy, R.W., 2003, Aquifer Recharge, in Stewart, B.A., and Howell, T.A., eds., Encyclopedia of Water Science: Agropedia, Marcel Dekker, New York, p. 22-25.
(PDF Nimmo, J.R., Healy, R.W., and Stonestrom, D.A., 2005, Aquifer Recharge, in Anderson, M.G., and Bear, J., eds., Encyclopedia of Hydrological Science: Chichester, UK, Wiley, p. 2229-2246.
(PDF).
Effects of soil disturbance on recharge
Nimmo, J.R., and Perkins, K.S., 2008, Effect of soil disturbance on recharging fluxes--Case study on the Snake River Plain, Idaho National Laboratory, USA: Hydrogeology Journal, v. 16, no. 5, p. 829-844.(PDF).
Large-scale infiltration experiment to investigate recharge and preferential flow through a 200-m thick unsaturated zone, Idaho National Laboratory
Nimmo, J.R., Perkins, K.S., Rose, P.A., Rousseau, J.P., Orr, B.R., Twining, B.V., and Anderson S.R., 2002, Kilometer-scale rapid transport of naphthalene sulfonate tracer in the unsaturated zone at the Idaho National Engineering and Environmental Laboratory: Vadose Zone Journal, v. 1, p. 89-101.(PDF).
