River basin hydrosalinity modeling
ABSTRACT Tanji, K.K., (1981). River basin hydrosalinity modeling. Agric. Water Manage., 1981. Hydrologic-salinity modeling at the river sub-basin and basin spatial scales in the Western U.S.A. are evaluated. In the past two decades, significant advances have been made in basin hydrosalinity modeling. These models are providing increased understanding of the complexity of water and salt flows in large-scale systems. Most models, however, have been developed for specific problems and do not lend themselves for application to a wide variety of salinity problems. Much more work is needed in the areas of field verification of models and increasing their utility for management and policy-making decisions.
Quality of percolating waters: II. A computer method for predicting salt concentrations in soils at variable moisture contents
The San Luis Project, a major new unit in the Central Valley Project, is currently
 under construction. It will transport Feather River water to the west side of the
 San Joaquin Valley. The State of California Water Plan envisions a program of cyclic
 use of ground water during periods of deficiency, and storage of excess surface water
 when supplies are plentiful. Recharge of underground storage basins will involve the
 percolation of water through substrata, and the quality of the percolating water will
 be influenced by salts present in the substrata.
 A series of papers in this issue present a method of predicting the quality of percolating
 waters in substrata (Part III), utilizing field data obtained from substrata profiles
 in the west side of the San Joaquin Valley (Part I). Theoretical considerations and
 approximations (Parts II and III) are formulated in the computer programs, for calculating
 simultaneously the major physicochemical reactions that occur during recharge.
Estimating Soil and Saturation Extract Composition by a Computer Method
Five soil samples were salinized with NaCl and CaSO₄.2H₂O. They were extracted at 1:1 and saturation moisture content, and the chemical composition of the soils and extracts was determined. Exchange constants, for Na-Ca and Mg-Ca exchange, in combination with chemical data derived from samples at 1:1 moisture content were used in a computer program to predict soil and extract composition at saturation. The computer procedure, developed by Dutt, proved very satisfactory in estimating chemical makeup at saturation.