Due to recent rainfall extremes and tropical cyclones that form over the Bay of Bengal during the pre- and post-monsoon seasons, the Nagavali and Vamsadhara basins in India experience frequent floods, causing significant loss of human life and damage to agricultural lands and infrastructure. This study provides an integrated hydrologic and hydraulic modeling system that is based on the Soil and Water Assessment Tool model and the 2-Dimensional Hydrological Engineering Centre-River Analysis System, which simulates floods using Global Forecasting System rainfall forecasts with a 48-h lead time. The integrated model was used to simulate the streamflow, flood area extent, and depth for the historical flood events (i.e., 1991-2018) with peak discharges of 1200 m3/s in the Nagavali basin and 1360 m3/s in the Vamsadhara basin. The integrated model predicted flood inundation depths that were in good agreement with observed inundation depths provided by the Central Water Commission. The inundation maps generated by the integrated modeling system with a 48-h lead time for tropical cyclone Titli demonstrated an accuracy of more than 75%. The insights gained from this study will help the public and government agencies make better decisions and deal with floods.
Adding fibers into cement to form fiber-reinforced soil cement material can effectively enhance its physical and mechanical properties. In order to investigate the effect of fiber type and dosage on the strength of fiber-reinforced soil cement, polypropylene fibers (PPFs), polyvinyl alcohol fibers (PVAFs), and glass fibers (GFs) were blended according to the mass fraction of the mixture of cement and dry soil (0.5%, 1%, 1.5%, and 2%). Unconfined compressive strength tests, split tensile strength tests, scanning electron microscopy (SEM) tests, and mercury intrusion porosimetry (MIP) pore structure analysis tests were conducted. The results indicated that the unconfined compressive strength of the three types of fiber-reinforced soil cement peaked at a fiber dosage of 0.5%, registering 26.72 MPa, 27.49 MPa, and 27.67 MPa, respectively. The split tensile strength of all three fiber-reinforced soil cement variants reached their maximum at a 1.5% fiber dosage, recording 2.29 MPa, 2.34 MPa, and 2.27 MPa, respectively. The predominant pore sizes in all three fiber-reinforced soil cement specimens ranged from 10 nm to 100 nm. Furthermore, analysis from the perspective of energy evolution revealed that a moderate fiber dosage can minimize energy loss. This paper demonstrates that the unconfined compressive strength test, split tensile strength test, scanning electron microscopy (SEM), and mercury intrusion porosimetry (MIP) pore structure analysis offer theoretical underpinnings for the utilization of fiber-reinforced soil cement in helical pile core stiffening and broader engineering applications.
采用西藏自治区39个国家级气象站的24h积雪观测资料作为实况,对2019年10月1日至2020年4月30日ECMWF、GRAPESGFS 20时起报小时积雪产品利用双线性差值方法插值到站点上,并进行了检验评估。结果表明,在西藏区域两家模式积雪预报产品基本趋势与实况一样,但整体上ECMWF表现为漏报,GRAPESGFS表现为空报,相比ECMWF模式GRAPESGFS模式的误差更大一些,并在一月份降雪集中的地区两家模式的预报质量比其余月份偏低显著。两家模式在空间上表现为西藏大部分区域积雪预报是偏多,但常年降雪较多及积雪较厚的区域积雪预报结果偏少,同时喜马拉雅山脉沿线和北部个别区域预报结果偏少明显,跟西藏气候带和地理地貌分布较吻合,因此模式和客观预报改善该区域的参数配置,将大幅度提高整体的预报水平。
采用西藏自治区39个国家级气象站的24h积雪观测资料作为实况,对2019年10月1日至2020年4月30日ECMWF、GRAPESGFS 20时起报小时积雪产品利用双线性差值方法插值到站点上,并进行了检验评估。结果表明,在西藏区域两家模式积雪预报产品基本趋势与实况一样,但整体上ECMWF表现为漏报,GRAPESGFS表现为空报,相比ECMWF模式GRAPESGFS模式的误差更大一些,并在一月份降雪集中的地区两家模式的预报质量比其余月份偏低显著。两家模式在空间上表现为西藏大部分区域积雪预报是偏多,但常年降雪较多及积雪较厚的区域积雪预报结果偏少,同时喜马拉雅山脉沿线和北部个别区域预报结果偏少明显,跟西藏气候带和地理地貌分布较吻合,因此模式和客观预报改善该区域的参数配置,将大幅度提高整体的预报水平。