oa A New Device For Measuring The Two Soil Moisture Characteristic Curves: Application To Native Soils In The State Of Qatar

This paper presents a new device [TypoSoilTM] for characterizing the hydrostructural properties of the soil medium organization. It intended to simultaneously and continuously measure both the shrinkage [V(W)] and the water potential [h(W)] characteristic curves for 8 cylindrical soil samples (~100 〖"cm" 〗^"3" ) at the same time during evaporation from the saturation to dry state. No other device makes similar measurements that are crucial to research the fundamental equations of the hydrostructural behavior of soils. This device makes part of a complete chain of measurements of the hydrostructural properties of the soil medium including also the soil swelling curve [V(t)] and the unsaturated hydraulic conductivity curve [K(W)]. Twelve soil samples were prepared, and analyzed by TypoSoilTM. These samples included three replicates of reconstituted and undisturbed soil cores of two native soils in the state of Qatar, named locally "Rodah soil" and "Sabkha soil". The obtained results indicated a good procedure for the soil samples preparation, and consistent measurement of the TypoSoilTM. Minor variations were observed among SWCC and SSCC of the three replicates of each soil type showing the trustworthiness of measurement. The results will help us to make an accurate hydro-functional typology of these kinds of soils in arid countries. This information is also needed for understanding and simulating the soil hydraulic behavior under agronomical practices (irrigation), or for planning some remediation techniques of the Sabkha soils. The quality of results confirmed also the thermodynamic theory behind the exploitation of these curves to extract the hydrostructural characteristic parameters.