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Mathematical modeling of natural groundwater recharge
Author(s) -
Krishnamurthi N.,
Sunada D. K.,
Longenbaugh R. A.
Publication year - 1977
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/wr013i004p00720
Subject(s) - groundwater recharge , infiltration (hvac) , richards equation , hydraulic conductivity , water content , water table , soil science , vadose zone , hydrology (agriculture) , groundwater , streamflow , groundwater model , moisture , finite difference , geotechnical engineering , environmental science , mathematics , geology , aquifer , soil water , mathematical analysis , meteorology , geography , drainage basin , cartography
A mathematical model is presented to determine natural groundwater recharge by using transient soil moisture data measured as a function of vertical position. The model is based upon the finite difference form of the Richards equation. The assumption is made that moisture content varied in the linear range of pressure‐moisture and conductivity‐moisture relations to obtain a solution to a particular field problem. The parameters of the model, estimated by a linear model of the moisture data, characterize the hydraulic properties of soil and their spatial variability. The finite difference form of the mathematical model is solved by iteration using the Newtonlike method, ensuring computational speed and accuracy. The model and the computer program are verified by using the first‐order approximate one‐dimensional solution of the infiltration equation for homogeneous soil. Application of the model to the High Plains of Colorado provides monthly recharge rates which correlate adequately with the time series data of water table elevations and events of precipitation and ephemeral streamflow.