Showing papers by "Faisal Hossain published in 2018"

Global Estimates of River Flow Wave Travel Times and Implications for Low‐Latency Satellite Data

Abstract: Earth-orbiting satellites provide valuable observations of upstream river conditions worldwide. These observations can be used in real-time applications like early flood warning systems and reservoir operations, provided they are made available to users with sufficient lead time. Yet the temporal requirements for access to satellite-based river data remain uncharacterized for time-sensitive applications. Here we present a global approximation of flow wave travel time to assess the utility of existing and future low-latency/near-real-time satellite products, with an emphasis on the forthcoming SWOT satellite mission. We apply a kinematic wavemodel to a global hydrography data set and find that global flowwaves traveling at their maximum speed take a median travel time of 6, 4, and 3 days to reach their basin terminus, the next downstream city, and the next downstream dam, respectively. Our findings suggest that a recently proposed ≤2-day data latency for a low-latency SWOT product is potentially useful for real-time river applications. Plain Language Summary Satellites can provide upstream conditions for early flood warning systems, reservoir operations, and other river management applications. This information is most useful for time-sensitive applications if it is made available before an observed upstream flood reaches a downstream point of interest, like a basin outlet, city, or dam. Here we characterize the time it takes floods to travel down Earth’s rivers in an effort to assess the time required for satellite data to be downloaded, processed, and made accessible to users. We find that making satellite data available within a recently proposed ≤2-day time period will make the data potentially useful for flood mitigation and other water management applications.

100 Years of Progress in Hydrology

Abstract: The focus of this chapter is progress in hydrology for the last 100 years. During this period, we have seen a marked transition from practical engineering hydrology to fundamental developme...

Understanding Model-Based Probable Maximum Precipitation Estimation as a Function of Location and Season from Atmospheric Reanalysis

Abstract: Extreme precipitation events bring huge societal and economic loss around the world every year, and they have undergone spatially heterogeneous changes in the past half-century They are fu

A highly sensitive and selective spectrofluorimetric method for the determination of manganese at nanotrace levels in some real, environmental, biological, soil, food and pharmaceutical samples using 2-(α-pyridyl)-thioquinaldinamide

Abstract: A very simple, ultra-sensitive and highly selective non-extractive spectrofluorimetric method is presented for the determination of manganese at nano-trace levels using 2-(α-pyridyl)-thioquinaldinamide (PTQA). PTQA has been proposed as a new analytical reagent for the direct non-extractive spectrofluorimetric determination of manganese(VII). This novel fluorimetric reagent, PTQA becomes oxidized in a slightly acidic (0.0125–0.05 M H2SO4) solution with manganese(VII) in absolute ethanol to produce a highly fluorescent oxidized product (λex = 319 nm; λem = 373 nm). Constant and maximum fluorescence intensities were observed over a wide range of acidity (0.0125–0.05 M H2SO4) for the period between 5 min and 24 h. Linear calibration graphs were obtained for 0.01–800 μg L−1 of Mn, having a detection limit of 1 ng L−1; the quantification limit of the reaction system was found to be 10 ng L−1 and the RSD was 0–2%. A large excess of over 60 cations, anions and complexing agents do not interfere in the determination. The developed method was successfully used in the determination of manganese in several standard reference materials (alloys, steels, hair and sediments) as well as in some environmental waters (potable and polluted), biological samples (human blood, urine and hair), soil samples, food samples (vegetables, fruits, tea, rice, and wheat), fertilizer samples and pharmaceutical samples (multivitamin-mineral tablets and syrup), solutions containing both manganese(II) and manganese(VII) speciation and complex synthetic mixtures. The results of the proposed method for assessing biological, food and vegetables samples were comparable with AAS and ICP-MS and were found to be in excellent agreement.

Sensitivity of initial-condition and cloud microphysics to the forecasting of monsoon rainfall in South Asia

Abstract: Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, USA Correspondence F. Hossain, Department of Civil and Environmental Engineering, University of Washington, Seattle, WA 98195, USA. Email: fhossain@uw.edu Funding information National Aeronautics and Space Administration, Grant/Award number: NNX16AO68H; NASA Earth and Space Fellowship, Grant/Award number: NNX16AO68H; NASA, Grant/Award number: NNX15AC63G The main objective of this study is to assess the impact of using different initialization techniques and cloud microphysics of a numerical atmospheric model to improve the forecasting of Indian summer monsoon rainfall (ISMR). A total of six intense precipitation events over the Ganges–Brahmaputra–Meghna (GBM) and Indus River basins were tested to identify the most suitable combination of parameterization and initialization techniques. The global forecast system (GFS)-based numerical weather prediction (NWP) forecast fields were dynamically downscaled by the mesoscale model of weather research and forecasting (WRF). The performance of four types of initial conditions with three cloud microphysics was assessed using a model resolution of up to 9 km. A main conclusion is that the model initialized using hot start in the study involves more uncertainty, probably due to poor-quality data assimilation, and it cannot exceed the performance of cold-start initialization. The study findings provide evidence that the finer resolution initial condition is promising in higher resolution models. In the case of cloud microphysics, the performance of WRF single moment 5 class (WSM5) was sufficient for South Asian monsoon systems within this scale of the model resolution. The findings provide a general guideline for flood forecasters for the WRF model set-up for forecasting the ISMR from publicly available GFS-based NWP forecast fields.

A scalable open-source Web-analytic framework to improve satellite-based operational water management in developing countries

Abstract: Two software development hurdles to advancing real-world operationalization of satellite datasets for water management are addressed in this study. First, a simple, easy-to-build and open-source web portal connecting to a back-end complex model is developed for resource-constrained developing nations. Second, to enhance the skill of satellite-based predictions, an innovative and dynamic web analytics-based correction system is developed to reduce the uncertainty of satellite estimates. The correction system comprises dynamic precipitation bias correction and streamflow correction. Dynamically web crawled in-situ hydrologic data pertaining to the region are used to estimate satellite estimation bias. These corrected datasets are finally shared through the web portal. On average, these dynamic correction techniques reduced root mean squared error in streamflow by 80–90% for the case of South Asian river basins. The take-home message is that it is now possible to build cost-effective operational web portals based on satellite data and non-proprietary software.

Viscometric Studies of Molecular Interactions in Binary Liquid Mixtures of Isomeric Xylenes with Methanol

Abstract: Dynamic viscosities (ηexp) for the binary mixtures of methanol with isomeric (o-, m-, and p-derivatives) xylenes were measured at T = (303.15, 308.15, 313.15, 318.15, and 323.15) K and atmospheric pressure (p = 101 kPa). The viscosity deviation (Δη) that has been derived from the ηexp was correlated using a Redlich–Kister-type equation. The ηexp values were compared with the calculated viscosities (ηcal) obtained using generalized correlation models, such as Bingham, Arrhenius, Kendall–Monroe, Grunberg–Nissan, and Andrade/DIPPR. The changes in the ηexp of solvent mixtures rather than in the pure fluids, or deviations from ηcal, have been discussed in terms of the molecular interactions and structural effects due to the component molecules. Furthermore, the quantum chemical density-functional theory calculations were used to predict the optimized geometry and total energies of the pure fluids and their binary mixtures.