scholarly journals Mixed Variational-Monte Carlo Assimilation of Streamflow Data in Flood Forecasting: the Impact of Observations Spatial Distribution

10.29007/39wq ◽  
2018 ◽  
Author(s):  
Giulia Ercolani ◽  
Fabio Castelli
Keyword(s):  
Monte Carlo ◽  
Spatial Distribution ◽  
River Basin ◽  
Flood Forecasting ◽  
Hydrologic Model ◽  
Variational Monte Carlo ◽  
Distributed Hydrologic Model ◽  
Streamflow Data ◽  
The Impact

A mixed variational-Monte Carlo scheme is employed to assimilate streamflow data at multiple locations in a distributed hydrologic model for flood forecasting purposes. The goal of this work is to assess the role of the spatial distribution of the assimilation points in terms of forecasts accuracy. The area of study is Arno river basin, and the strategy of investigation is to focus on one single nearly-flood event, performing various assimilation experiments that differ only in number and location of the assimilation sites.

scholarly journals Evaluation of a Distributed Streamflow Forecast Model at Multiple Watershed Scales

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1279
Author(s):  
Tyler Madsen ◽  
Kristie Franz ◽  
Terri Hogue
Keyword(s):  
Local Population ◽  
Model Performance ◽  
Forecast Model ◽  
Hydrologic Model ◽  
Laboratory Research ◽  
Discharge Data ◽  
Distributed Hydrologic Model ◽  
Verification Period ◽  
Silver Spring

Demand for reliable estimates of streamflow has increased as society becomes more susceptible to climatic extremes such as droughts and flooding, especially at small scales where local population centers and infrastructure can be affected by rapidly occurring events. In the current study, the Hydrology Laboratory-Research Distributed Hydrologic Model (HL-RDHM) (NOAA/NWS, Silver Spring, MD, USA) was used to explore the accuracy of a distributed hydrologic model to simulate discharge at watershed scales ranging from 20 to 2500 km2. The model was calibrated and validated using observed discharge data at the basin outlets, and discharge at uncalibrated subbasin locations was evaluated. Two precipitation products with nominal spatial resolutions of 12.5 km and 4 km were tested to characterize the role of input resolution on the discharge simulations. In general, model performance decreased as basin size decreased. When sub-basin area was less than 250 km2 or 20–40% of the total watershed area, model performance dropped below the defined acceptable levels. Simulations forced with the lower resolution precipitation product had better model evaluation statistics; for example, the Nash–Sutcliffe efficiency (NSE) scores ranged from 0.50 to 0.67 for the verification period for basin outlets, compared to scores that ranged from 0.33 to 0.52 for the higher spatial resolution forcing.

scholarly journals The impact of highways on population redistribution: the role of land development restrictions

2019 ◽  
Vol 20 (3) ◽  
pp. 783-808 ◽  
Author(s):  
Or Levkovich ◽  
Jan Rouwendal ◽  
Jos van Ommeren
Keyword(s):  
Spatial Distribution ◽  
The Netherlands ◽  
Population Growth ◽  
Land Development ◽  
Apparent Effect ◽  
Population Redistribution ◽  
Interaction Variables ◽  
Peripheral Areas ◽  
The Impact

Abstract We study the role of land development restrictions for the effects of highway expansion on the spatial distribution of population for the Netherlands. Introducing an IV approach to address multiple endogenous interaction variables, our findings show that new highways accelerated population growth in peripheral areas, but had no apparent effect in suburban municipalities, in line with the presence of development restrictions. Highway expansions caused a ‘leapfrog’ pattern in which suburban growth skipped development-restricted areas and expanded into farther located peripheral areas.

Ensemble flood forecasting with stochastic radar image extrapolation and a distributed hydrologic model

2009 ◽  
Vol 23 (4) ◽  
pp. 597-611 ◽  
Author(s):  
Sunmin Kim ◽  
Yasuto Tachikawa ◽  
Takahiro Sayama ◽  
Kaoru Takara
Keyword(s):  
Flood Forecasting ◽  
Hydrologic Model ◽  
Radar Image ◽  
Distributed Hydrologic Model

scholarly journals Climate-driven disturbances in the San Juan River sub-basin of the Colorado River

2018 ◽  
Vol 22 (1) ◽  
pp. 709-725 ◽  
Author(s):  
Katrina E. Bennett ◽  
Theodore J. Bohn ◽  
Kurt Solander ◽  
Nathan G. McDowell ◽  
Chonggang Xu ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Land Cover ◽  
River Basin ◽  
Colorado River ◽  
Hydrologic Model ◽  
San Juan ◽  
Forest Disturbances ◽  
San Juan River ◽  
The Impact

Abstract. Accelerated climate change and associated forest disturbances in the southwestern USA are anticipated to have substantial impacts on regional water resources. Few studies have quantified the impact of both climate change and land cover disturbances on water balances on the basin scale, and none on the regional scale. In this work, we evaluate the impacts of forest disturbances and climate change on a headwater basin to the Colorado River, the San Juan River watershed, using a robustly calibrated (Nash–Sutcliffe efficiency 0.76) hydrologic model run with updated formulations that improve estimates of evapotranspiration for semi-arid regions. Our results show that future disturbances will have a substantial impact on streamflow with implications for water resource management. Our findings are in contradiction with conventional thinking that forest disturbances reduce evapotranspiration and increase streamflow. In this study, annual average regional streamflow under the coupled climate–disturbance scenarios is at least 6–11 % lower than those scenarios accounting for climate change alone; for forested zones of the San Juan River basin, streamflow is 15–21 % lower. The monthly signals of altered streamflow point to an emergent streamflow pattern related to changes in forests of the disturbed systems. Exacerbated reductions of mean and low flows under disturbance scenarios indicate a high risk of low water availability for forested headwater systems of the Colorado River basin. These findings also indicate that explicit representation of land cover disturbances is required in modeling efforts that consider the impact of climate change on water resources.

scholarly journals Spatial Distribution of Picophytoplankton in Southeastern Coast of Peninsular Malaysia Using Flow Cytometry

2021 ◽  
Vol 29 (3) ◽  
Author(s):  
Roswati Md Amin ◽  
Md Suffian Idris ◽  
Nurul Asmera Mudiman ◽  
Noor Hazwani Mohd Azmi ◽  
Hing Lee Siang
Keyword(s):  
Flow Cytometry ◽  
Spatial Distribution ◽  
Distribution Patterns ◽  
Southwest Monsoon ◽  
Peninsular Malaysia ◽  
Percentage Contribution ◽  
Southeastern Coast ◽  
Ocean Productivity ◽  
The Impact

The distribution of picocyanobacteria from two genera, Synechococcus and Prochlorococcus, and picoeukaryotes in surface water (0.5 m) was investigated by flow cytometry in the southeastern coast of Peninsular Malaysia during the Southwest monsoon in August 2014. During the cruise, Synechococcus cells were predominant throughout the study area, contributing as much as 50% to the total picophytoplankton population, whereas picoeukaryotes and Prochlorococcus constituted only 31% and 19% of the population, respectively. Spatially, Synechococcus and picoeukaryotes were more dominant in coastal waters, while Prochlorococcus appeared to be more highly abundant in offshore waters. Furthermore, the percentage contribution of each population to total picophytoplankton also exhibited different spatial distribution patterns along a coastal-offshore gradient. The percentage contribution of Synechococcus was spatially constant throughout the study area, while the fraction contributed by picoeukaryotes showed a reduced contribution from coastal to offshore waters. In contrast, Prochlorococcus exhibited an increased proportion to total picophytoplankton across a coastal-offshore gradient, suggesting the increasing importance of this population in offshore waters of the study area. As revealed by Canonical Correlation Analysis, the abundance of Synechococcus and picoeukaryotes increased significantly with reducing dissolved oxygen levels and pH, and with increasing total chlorophyll. In contrast, temperature was the only factor influencing the abundance of Prochlorococcus significantly increased with decreasing water temperature in the study area. Overall, results of the present study provide valuable information on the role of regional environmental factors in the distribution and dominance of picophytoplankton communities that are not only critical for the ocean productivity but also the impact on the carbon cycle in the study area.

scholarly journals Integrating remote sensing-derived evapotranspiration and ground-monitored discharge data for the improvement of hydrological modelling: A case study of the Sekong River Basin

2021 ◽  
Author(s):  
Raksmey Ang ◽  
S. Shrestha ◽  
Salvatore Virdis ◽  
Saurav KC
Keyword(s):  
Remote Sensing ◽  
Model Calibration ◽  
Hydrological Model ◽  
Hydrologic Model ◽  
Physically Based Model ◽  
Physically Based ◽  
Streamflow Data ◽  
The Impact ◽  
Streamflow Simulation ◽  
Calibration Approach

This study analyses the efficiency of integrating remotely sensed evapotranspiration into the process of hydrological model calibration. A joint calibration approach, employing both remote sensing-derived evapotranspiration and ground-monitored streamflow data was compared with a conventional ground-monitored streamflow calibration approach through physically-based hydrological, Soil and Water Assessment Tool (SWAT) model setups. The efficacy of the two calibration schemes was investigated in two modelling setups: 1) a physically-based model with only the outlet gauge available for calibration, and 2) a physically-based model with multiple gauges available for calibration. Joint calibration was found to enhance the skill of hydrological models in streamflow simulation compared to ground-monitored streamflow-only calibration at the unsaturated zone in the upstream area, where essential information on evapotranspiration is also required. Additionally, the use of remote sensing-derived evapotranspiration can significantly improve high flow compared to low flow simulation. A more consistent model performance improvement, obtained from using remote sensing-derived evapotranspiration data was found at gauged sites not used in the calibration, due to additional information on spatial evapotranspiration in internal locations being enhanced into a process-based model. Eventually, satellite-based evapotranspiration with fine resolution was found to be competent for calibrating and validating the hydrological model for streamflow simulation in the absence of measured streamflow data for model calibration. Furthermore, the impact of using evapotranspiration for hydrologic model calibration tended to be stronger at the upstream and tributary sub-basins than at downstream sub-basins.

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