Search

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The calibration processes of current distributed hydrological model has been a critical issue in data-scared or ungauged regions. In this study, we setup a hydrological model, in which, the variable saturated zone concept originated from the real-time interactive basin simulator is applied for runoff generation and the grid water droplet method for flow concentration. We also proposed a method for parameter estimation based on the characteristics of underlying surface. Based on field infiltration experiments and parameter sensitivity analysis, the quantitative statistical relationships were built between two sensitive parameters (surface saturated hydraulic conductivity K0z, coefficient of attenuation of saturation hydraulic conductivity with depth f) and the topographic parameters and soil types. The overland confluence parameters were determined by field overland flow observation experiments. The proposed parameter estimation method was verified in selected basins. Our results showed that: ① The proposed method for K0z estimation contributes to a better modeling performance for flood simulation in Jiangwan experimental watershed, the average Nash- Sutcliffe efficiency coefficient increased from 0. 82 to 0. 86, and the average absolute values of peak and flood volume errors decreased by 2. 2% and 0. 95%, respectively, but the average absolute value of the peak present time error increased by 4% (still controlled within 2 h). ② Using the measured flood data of 14 basins such as Jiangwan to calibrate the parameter f, we established the quantitative relationship between the calibrated parameter f and the soil type data of different depths was built in 14 basins including Jiangwan, and further tested in other six basins. The parameter f estimated by the soil type data of different depths was very close to that determined by traditional model calibration processes, the average absolute relative error is 2. 8%, the average Nash-Sutcliffe efficiency coefficient of the flood simulation is 0. 83, and the average absolute values of flood peak error and flood volume error were 10. 07% and 6. 86%, respectively, and the average absolute peak present time error was 2. 61 h. Our results indicated that the proposed methods for determining sensitive runoff generation parameters are applicable in data-sparse areas and could provide a better or comparable parameter estimation and flood simulation than that determine by field measurements, model calibration, remote sensing data estimation, and other methods. [ABSTRACT FROM AUTHOR]

Low-slope bedrock meandering rivers widely exist in areas controlled by geological structures (the bed slope is less than 5‰). Flood has a great influence on riverbed sedimentation and erosion in bedrock meandering rivers, however, we have a poor understanding of dynamic structure of flood for bedrock meandering rivers. By geometrically generalizing bedrock meandering reaches, considering the Froude similarity and side wall roughness, a generalized model of a bedrock meandering channel is established in order to analyze the water surface profile distribution, time average flow fields and turbulence structure characteristics for bends under flood. The results show that under the flood flow, the minimum water surface transverse gradient, separation of flow on the convex bank, development of double circulation on the concave bank, velocity-dip-phenomenon and maximum secondary circulation intensity are caused at the upstream of the bend apex, and the maximum water surface transverse gradient and circulation splitting are caused at the downstream of the bend apex; the bed shear stress is distributed in the flow separation area at the convex bank as well as the center of the upstream of the bend apex, and the transverse momentum transport is concentrated at the upstream of the bend apex. The experiment results show an explanation in view of hydrodynamics in respect to bed erosion and sedimentation in bedrock meandering rivers. [ABSTRACT FROM AUTHOR]

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)