نتایج جستجو برای: hydraulic gradient
تعداد نتایج: 154232 فیلتر نتایج به سال:
Using hydraulic geometry (HG) theory, we investigated three rivers typical of the Ecuadorian mountainous region with longitudinal slopes ranging from 0.8% to 10% and coarse bed material d50 3 54 mm values d90 up 908 mm. Extensive field measurements were performed characterize geometric properties at 33 sites. these data, at-a-station HG relationships obtained for top width, average flow depth, ...
In this research, the hydraulic behavior of two kinds of envelopes including synthetic envelope, PP450 and gravel envelope with USBR standard in two soil tank models with silty loam texture was investigated. Three water heads including 55, 75 and 105 cm (water logging) from drain level were used. The discharge of pipe drain in the steady state condition for gravel envelope and at 55, 75 and 105...
Abstract Internal erosion is susceptible to occur in conditions where there are cracks or pre-formed cavities at the interface between dam foundation and embankment. The initiation of internal related critical gradient ( I c ) hydraulic xy a certain position. addition repair materials improvement will change total head, especially on foundation, so value also simultaneously from upstream downst...
Nacrtak Opening-up of forests enables the application of rational forestry, which means more productivity and suitability for sustainable use. Therefore, forest roads are one of the most important tools needed. This study investigates tree damage caused by excavated materials during forest road construction in a karst region. Bending, crushing andwoundingwere defined as tree damage because of e...
Due to the diurnal and seasonal fluctuations in leaf-to-air vapor pressure deficit (D), one of the key regulatory roles played by stomata is to limit transpiration-induced leaf water deficit. Different types of plants are known to vary in the sensitivity of stomatal conductance (gs) to D with important consequences for their survival and growth. Plants that minimize any increase in transpiratio...
A range of continental-scale soil datasets exists in Europe with different spatial representation and based on different principles. We developed comprehensive pedotransfer functions (PTFs) for applications principally on spatial datasets with continental coverage. The PTF development included the prediction of soil water retention at various matric potentials and prediction of parameters to ch...
In hydraulic structures design, using cutoff walls is essential to reduce and control the resultant uplift force (U), seepage discharge (Q), exit gradient (i). This research investigates effectiveness of inclined double under structures, considering influence depths, locations, inclination angles upstream downstream by Finite Element Method (FEM). The results confirmed that installing a deeper ...
Whole vine (K(plant)) and individual root (K(root)) hydraulic conductances were measured in kiwifruit (Actinidia chinensis Planch. var. chinensis 'Hort16A') vines to observe hydraulic responses following partial root system excision. Heat dissipation and compensation heat pulse techniques were used to measure sap flow in trunks and individual roots, respectively. Sap flux and measurements of xy...
Process-based agricultural system models require detailed description of soil hydraulic properties that are usually not available. The objectives of this study were to evaluate the sensitivity of model simulation results to variability in measured soil hydraulic properties and to compare simulation results using measured and default soil parameters. To do so, we measured soil water retention cu...
The sessile lifestyle of plants constrains their ability to acquire mobile nutrients such as nitrate. Whereas proliferation of roots might help in the longer term, nitrate-rich patches can shift rapidly with mass flow of water in the soil. A mechanism that allows roots to follow and capture this source of mobile nitrogen would be highly desirable. Here, we report that variation in nitrate conce...
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