Calibration of Spatially Distributed Hydrological Processes and Model Parameters in SWAT Using Remote Sensing Data and an Auto-Calibration Procedure: A Case Study in a Vietnamese River Basin

Abstract

Abstract:In this paper, evapotranspiration (ET) and leaf area index (LAI) were used to calibrate the SWAT model, whereas remotely sensed precipitation and other climatic parameters were used as forcing data for the 6300 km 2 Day Basin, a tributary of the Red River in Vietnam. The efficacy of the Sequential Uncertainty Fitting (SUFI-2) parameter sensitivity and optimization model was tested with area specific remote sensing input parameters for every Hydrological Response Units (HRU), rather than with measurements of river flow representing a large set of HRUs, i.e., a bulk calibration. Simulated monthly ET correlations with remote sensing estimates showed an R 2 = 0.71, Nash-Sutcliffe Efficiency NSE = 0.65, and Kling Gupta Efficiency KGE = 0.80 while monthly LAI showed correlations of R 2 = 0.59, NSE = 0.57 and KGE = 0.83 over a five-year validation period. Accumulated modelled ET over the 5-year calibration period amounted to 5713 mm compared to 6015 mm of remotely sensed ET, yielding a difference of 302 mm (5.3%). The monthly flow at two flow measurement stations were adequately estimated (R 2 = 0.78 and 0.55, NSE = 0.71 and 0.63, KGE = 0.59 and 0.75 for Phu Ly and Ninh Binh, respectively). This outcome demonstrates the capability of SWAT model to obtain spatial and accurate simulation of eco-hydrological processes, also when rivers are ungauged and the water withdrawal system is complex.

Multi-site calibration and validation of SWAT with satellite-based evapotranspiration in a data-sparse catchment in southwestern Nigeria

“…10). Nevertheless, the high overall average soil moisture validation R 2 agrees with a previous study that validated a hydrological model with ESA CCI SM in West Africa (Poméon et al, 2018). The multicalibration and validation results show the SWAT model to perform satisfactorily in the study area.…”

“…Any one of these three PET equations can be chosen to run in SWAT, but they vary in the amount of input data required. The Hargreaves method (Hargreaves and Samani, 1985) is temperature based and requires only average daily air tem-perature as input in Eq. 2:…”

“…The Priestley-Taylor equation (Priestley and Taylor, 1972) is a radiation-based method and it provides PET estimates for low advective conditions. The P-T method requires solar radiation, air temperature and relative humidity as input (Eq.…”

“…In this study, we do not consider runoff-measured data for an independent validation because they are not available for the study basin, and this is the main reason we considered AET derived from satellite products as an alternative option for the SWAT model calibration and validation. We believe using available AET products (GLEAM and MOD16), which have been tested in the past in various calibration and validation studies undertaken by a number of scientists (Roy et al, 2017;Herman et al, 2017;López López et al, 2017;Ha et al, 2018;Poméon et al, 2018), is one solution to setting up a hydrological model that will be used as a decision support tool in such a data-scarce region.…”

Linking Earth Observations for Assessing the Food Security Situation in Vietnam: A Landscape Approach

“…Nam Dinh province is part of the coastal area of northern Vietnam and located in the southern part of the Red River delta (Ha et al, 2018). The province has a total area of 1,676 km 2 and 72 km of coastline.…”