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Precise estimation of unsaturated hydraulic properties of porous media is indispensable in various study areas, such as analyzing the moisture flow, the drying process occurring from the surface, and the pollutant migration beneath the ground surface. Although many empirical/theoretical models describing the unsaturated hydraulic properties have been proposed by several previous researchers, the best model for the different types of soil/rock may not be identical. Thus, the model selection process and the estimation technique of the parameters included in the models should be developed. In the present study, the inverse technique based on the transient evaporation change was investigated to select the model and estimate the model parameters. The experimental work was based on a relatively low permeable soft rock and a relatively high permeable sandy soil (Toyoura standard sand). Experimental equipment was developed to precisely measure the evaporation rate for the high permeable sandy soil. The Genetic Algorithm (GA) was adopted in the inverse technique as an optimization tool. In order to simplify the problem, only the drying process from the saturated condition was considered. It was established that the information concerning the transient evaporation change could be used for the model selection and parameter estimation. Further, the saturation distribution could be used for the selection of the models. The present study provides important information for the development of the model selection process.  相似文献   
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The Pranhita-Godavari Basin in central eastern India is one of the Proterozoic "Purana" basins of cratonic India.New geochronology demonstrates that it has a vast depositional history of repeated basin reactivation from the Palaeoproterozoic to the Mesozoic.U-Pb laser ablation inductively coupled plasma mass spectrometry dating of detrital zircons from two samples of the Somanpalli Group—a member of the oldest sedimentary cycle in the valley-constrains its depositional age to ~1620 Ma and demonstrates a tripartite age provenance with peaks at ~3500 Ma,~2480 Ma and ~1620 Ma,with minor age peaks in the Eoarchaean(~3.8 Ga) and at ~2750 Ma.These ages are consistent with palaeocurrent data suggesting a southerly source from the Krishna Province and Enderby Land in East Antarctica.The similarity in the maximum depositional age with previously published authigenic glauconite ages suggest that the origin of the Pranhita-Godvari Graben originated as a rift that formed at a high angle to the coeval evolving late Meosproterozoic Krishna Province as Enderby Land collided with the Dharwar craton of India.In contrast,detrital zircons from the Cycle III Sullavai Group red sandstones yielded a maximum depositional age of 970±20 Ma and had age peaks of ~2550 Ma,~1600 Ma and then a number of Mesoproterozoic detrital zircons terminating in three analyses at ~970 Ma.The provenance of these is again consistent with a southerly source from the Eastern Ghats Orogen and Antarctica.Later cycles of deposition include the overlying Albaka/Usur Formations and finally the late Palaeozoic to Mesozoic Gondwana Supergroup.  相似文献   
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