145 research outputs found

    Influence of initial soil moisture and vegetation conditions on monsoon precipitation events in northwest México

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    Land surface conditions including soil moisture and vegetation states are expected to play important roles in the development of the daytime boundary layer and the formation of convective precipitation. For areas with an in-phase seasonality of radiation and precipitation, such as the North American Monsoon (NAM) region, diagnosing the direct contributions of each effect is difficult given the co-occurrence of high soil moisture and vegetation greening during the warm season. In this study, we use the WRF-Hydro modeling system to simulate the interactions between the land surface and atmosphere within a large watershed in northwest México subject to the influence of the NAM. After testing the coupled simulations against a bias-corrected reanalysis product for two summer periods in 2004 and 2013, we conduct a series of storm-scale modeling experiments that separately vary the initial soil moisture and vegetation conditions. Results reveal that both soil moisture and vegetation anomalies can positively affect convective precipitation, although their influence on boundary layer development is different. We then diagnose the specific land-atmosphere mechanisms by which the land surface states positively influence convective precipitation. Under high land surface anomalies, such as initial soil moisture equal to field capacity or the maximum vegetation greening state, storm-scale (48 h) precipitation accumulations can be increased up to 26 mm. As a result, improvements in how land surface conditions are initialized either through remote sensing or sensor networks are critical for enhancing precipitation prediction systems in the NAM region

    A meteo-hydrological modelling system for the reconstruction of river runoff: the case of the Ofanto river catchment

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    Abstract. A meteo-hydrological modelling system has been designed for the reconstruction of long time series of rainfall and river runoff events. The modelling chain consists of the mesoscale meteorological model of the Weather Research and Forecasting (WRF), the land surface model NOAH-MP and the hydrology–hydraulics model WRF-Hydro. Two 3-month periods are reconstructed for winter 2011 and autumn 2013, containing heavy rainfall and river flooding events. Several sensitivity tests were performed along with an assessment of which tunable parameters, numerical choices and forcing data most impacted on the modelling performance.The calibration of the experiments highlighted that the infiltration and aquifer coefficients should be considered as seasonally dependent.The WRF precipitation was validated by a comparison with rain gauges in the Ofanto basin. The WRF model was demonstrated to be sensitive to the initialization time and a spin-up of about 1.5 days was needed before the start of the major rainfall events in order to improve the accuracy of the reconstruction. However, this was not sufficient and an optimal interpolation method was developed to correct the precipitation simulation. It is based on an objective analysis (OA) and a least square (LS) melding scheme, collectively named OA+LS. We demonstrated that the OA+LS method is a powerful tool to reduce the precipitation uncertainties and produce a lower error precipitation reconstruction that itself generates a better river discharge time series. The validation of the river streamflow showed promising statistical indices.The final set-up of our meteo-hydrological modelling system was able to realistically reconstruct the local rainfall and the Ofanto hydrograph

    A meteo-hydrological modelling system for the reconstruction of river runoff: the case of the Ofanto river catchment

    Get PDF
    A meteo-hydrological modelling system has been designed for the reconstruction of long time series of rainfall and river runoff events. The modelling chain consists of the mesoscale meteorological model of the Weather Research and Forecasting (WRF), the land surface model NOAH-MP and the hydrology-hydraulics model WRF-Hydro. Two 3-month periods are reconstructed for winter 2011 and autumn 2013, containing heavy rainfall and river flooding events. Several sensitivity tests were performed along with an assessment of which tunable parameters, numerical choices and forcing data most impacted on the modelling performance. The calibration of the experiments highlighted that the infiltration and aquifer coefficients should be considered as seasonally dependent. The WRF precipitation was validated by a comparison with rain gauges in the Ofanto basin. The WRF model was demonstrated to be sensitive to the initialization time and a spin-up of about 1.5 days was needed before the start of the major rainfall events in order to improve the accuracy of the reconstruction. However, this was not sufficient and an optimal interpolation method was developed to correct the precipitation simulation. It is based on an objective analysis (OA) and a least square (LS) melding scheme, collectively named OA+LS. We demonstrated that the OA+LS method is a powerful tool to reduce the precipitation uncertainties and produce a lower error precipitation reconstruction that itself generates a better river discharge time series. The validation of the river streamflow showed promising statistical indices. The final set-up of our meteo-hydrological modelling system was able to realistically reconstruct the local rainfall and the Ofanto hydrograph

    Modeling the Hydrologic Influence of Subsurface Tile Drainage Using the National Water Model

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    Subsurface tile drainage (TD) is a dominant agriculture water management practice in the United States (US) to enhance crop production in poorly drained soils. Assessments of field-level or watershed-level (105 km2) impacts of TD on hydrology. The National Water Model (NWM) is a distributed 1-km resolution hydrological model designed to provide accurate streamflow forecasts at 2.7 million reaches across the US. The current NWM lacks TD representation which adds considerable uncertainty to streamflow forecasts in heavily tile-drained areas. In this study, we quantify the performance of the NWM with a newly incorporated tile-drainage scheme over the heavily tile-drained Midwestern US. Employing a TD scheme enhanced the uncalibrated NWM performance by about 20–50% of the fully calibrated NWM (Calib). The calibrated NWM with tile drainage (CalibTD) showed enhanced accuracy with higher event hit rates and lower false alarm rates than Calib. CalibTD showed better performance in high-flow estimations as TD increased streamflow peaks (14%), volume (2.3%), and baseflow (11%). Regional water balance analysis indicated that TD significantly reduced surface runoff (−7% to −29%), groundwater recharge (−43% to −50%), evapotranspiration (−7% to −13%), and soil moisture content (−2% to −3%). However, TD significantly increased soil profile lateral flow (27.7%) along with infiltration and soil water storage potential. Overall, our findings highlight the importance of incorporating the TD process into the operational configuration of the NWM.This aritcle is published as Valayamkunnath, Prasanth, David J. Gochis, Fei Chen, Michael Barlage, and Kristie J. Franz. "Modeling the hydrologic influence of subsurface tile drainage using the National Water Model." Water Resources Research 58, no. 4 (2022): e2021WR031242. https://doi.org/10.1029/2021WR031242. This article is a U.S. Government work and is in the public domain in the USA
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