Evaluation and standardization of in situ measurements of soil hydraulic and solute transport properties

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Salt accumulation in irrigated arid lands constitutes a serious problem. For estimation of the dynamic solute transport using numerical simulation, evaluation and standardization of in situ measurement of soil hydraulic and solute transport properties are required. In this study, various in-situ practical measurements of field saturated hydraulic conductivity and unsaturated hydraulic conductivity were carried out using a constant head infiltrometer, a pressure infiltrometer, a tension disk permeameter, and a cone permeameter. Internal drainage method using profile probe, inverse analysis of hydraulic properties using genetic algorithms, transient evaporation method for the low water content range, modified multi-step outflow method and inverse method of multi-layer were developed for the estimation of hydraulic properties. Hydrodynamic dispersion in soils was estimated with four-electrode salinity probes. Simultaneous measurement of water flow, solute and heat transport properties by multi-functional heat pulse probe and TDR sensor with thermocouple was carried out to eliminate spatial variability in situ. A Web-Based-Common-Interface (WBCI) to enhance collaboration between data bases of Soil Information System (SIS) was developed. The WBCI may help in developing soil water and solute transport characteristics data base as well as solute transport characteristics data base and in situ measurement methods for analyzing transport phenomena in soils.