Evaluating DEM source and resolution uncertainties in the Soil and Water Assessment Tool

Lin, Shengpan; Jing, Changfeng; Coles, Neil; Chaplot, Vincent; Moore, Nathan; Wu, Jiaping

doi:10.1007/s00477-012-0577-x

Cited by 94 publications

(60 citation statements)

References 26 publications

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“…Several researchers have concluded that the DEM grid size influences the slope gradient and slope length factors (Gao 1997;Lin et al 2013;Mukherjee et al 2013). The average of slope gradient decreased with increasing DEM grid size (Gao 1997;David and McCabe 2000;Thompson et al 2001;Wang and Wang 2009).…”

Section: Introductionmentioning

confidence: 93%

Effects of DEM grid size on predicting soil loss from small watersheds in China

Cao

Liu

et al. 2014

Environ Earth Sci

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The topography (slope gradient and slope length) has an important effect on soil erosion by water. Slope gradient and slope length factor are the parameters of the universal soil loss equation that is commonly used to predict soil erosion. These factors are usually extracted from the digital elevation model (DEM). Thus the DEM grid size will influence topographic factors and therefore soil loss calculation. The purpose of this study was to investigate the effect of DEM grid size on the topographic factors and therefore soil loss prediction on a typical watershed in northeast of China. The site for the case study was Dontaigou watershed which is located at Huairou district, Beijing, China. Contour lines of 2 m interval digitized from 1:2,000 scale of topographic maps were used to generate DEM with grid size of 2 m. The DEMs with grid sizes of 3-30 m, at 1 m intervals, were created using the nearest neighbor resampling method. In total, 29 DEMs with different grid sizes were obtained. Four different scenarios of the channel initiation threshold were used to extract the drainage channel and let the slope length cutoff. Chinese soil loss equation was used to predict the soil loss. The results show that DEM grid size had different effects on the topographic factor. The average calculated slope steepness factor decreased with the increase of the DEM grid size in a linear decay function. The average slope length factor increased with DEM grid size when the drainage channel was not considered. It slightly decreased with DEM grid size and then increased when the drainage channel suitable for DEM grid size was used. However, comparing different grid sizes, the LS factor and the soil loss prediction of DEM grid size less than or equal to 10 m were close to those of 2 m DEM. The channel initiation threshold had effects on the extraction of slope length and then slope length factor. We found that the effect of DEM grid size on predicting soil loss depends on selection of suitable channel initiation threshold.

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Section: Introductionmentioning

confidence: 93%

Effects of DEM grid size on predicting soil loss from small watersheds in China

Cao

Liu

et al. 2014

Environ Earth Sci

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“…During the last decade, the first CTI product at 1 km resolution from HYDRO1k global data set released by US Geological Survey (USGS) in 2000 has become the most commonly applied global data set for large-scale applications (Kleinen et al, 2012;Lei et al, 2014;Ringeval et al, 2012;. However, HYDRO1k has been proven to potentially overestimate inundation extent due to a lack in quality of the underlying digital elevation model (DEM) (Grabs et al, 2009;Lin et al, 2010Lin et al, , 2013Sørensen and Seibert, 2007). With recent advances in the development of DEMs (Danielson and Gesch, 2011;Lehner et al, 2008), there is both a requirement and an opportunity to investigate uncertainties caused by CTI parameter.…”

Section: Introductionmentioning

confidence: 99%

Modeling spatiotemporal dynamics of global wetlands: comprehensive evaluation of a new sub-grid TOPMODEL parameterization and uncertainties

et al. 2016

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Abstract.Simulations of the spatiotemporal dynamics of wetlands are key to understanding the role of wetland biogeochemistry under past and future climate. Hydrologic inundation models, such as the TOPography-based hydrological model (TOPMODEL), are based on a fundamental parameter known as the compound topographic index (CTI) and offer a computationally cost-efficient approach to simulate wetland dynamics at global scales. However, there remains a large discrepancy in the implementations of TOPMODEL in landsurface models (LSMs) and thus their performance against observations. This study describes new improvements to TOPMODEL implementation and estimates of global wetland dynamics using the LPJ-wsl (Lund-Potsdam-Jena Wald Schnee und Landschaft version) Dynamic Global Vegetation Model (DGVM) and quantifies uncertainties by comparing three digital elevation model (DEM) products (HYDRO1k, GMTED, and HydroSHEDS) at different spatial resolution and accuracy on simulated inundation dynamics. In addition, we found that calibrating TOPMODEL with a benchmark wetland data set can help to successfully delineate the seasonal and interannual variation of wetlands, as well as improve the spatial distribution of wetlands to be consistent with inventories. The HydroSHEDS DEM, using a riverbasin scheme for aggregating the CTI, shows the best accuracy for capturing the spatiotemporal dynamics of wetlands among the three DEM products. The estimate of global wetland potential/maximum is ∼ 10.3 Mkm 2 (10 6 km 2 ), with a mean annual maximum of ∼ 5.17 Mkm 2 for 1980-2010. When integrated with wetland methane emission submodule, the uncertainty of global annual CH 4 emissions from topography inputs is estimated to be 29.0 Tg yr −1 . This study demonstrates the feasibility of TOPMODEL to capture spatial heterogeneity of inundation at a large scale and highlights the significance of correcting maximum wetland extent to improve modeling of interannual variations in wetland area. It additionally highlights the importance of an adequate investigation of topographic indices for simulating global wetlands and shows the opportunity to converge wetland estimates across LSMs by identifying the uncertainty associated with existing wetland products.

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“…The quality of DEMs have been shown to vary from one source to another, which could have an impact on model parameters thereby compromising the quality of model results (Wu et al 2008;Lin et al 2013). However, Lin et al (2013) investigated the impact of DEM spatial resolution on SWAT model results and reported that, the latter had a significant impact on water quality and sediment load simulation but simulated streamflow was not sensitive to DEM spatial resolution. Given that the purpose of this study was streamflow simulation, a DEM with spatial resolution of 90 m was used.…”

Section: Spatial Datamentioning

confidence: 99%

Effect of single and multi-site calibration techniques on hydrological model performance, parameter estimation and predictive uncertainty: a case study in the Logone catchment, Lake Chad basin

Nkiaka

Nawaz

Lovett

2017

Stoch Environ Res Risk Assess

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Understanding hydrological processes at catchment scale through the use of hydrological model parameters is essential for enhancing water resource management. Given the difficulty of using lump parameters to calibrate distributed catchment hydrological models in spatially heterogeneous catchments, a multiple calibration technique was adopted to enhance model calibration in this study. Different calibration techniques were used to calibrate the Soil and Water Assessment Tool (SWAT) model at different locations along the Logone river channel. These were: single-site calibration (SSC); sequential calibration (SC); and simultaneous multi-site calibration (SMSC). Results indicate that it is possible to reveal differences in hydrological behavior between the upstream and downstream parts of the catchment using different parameter values. Using all calibration techniques, model performance indicators were mostly above the minimum threshold of 0.60 and 0.65 for Nash Sutcliff Efficiency (NSE) and coefficient of determination (R 2 ) respectively, at both daily and monthly time-steps. Model uncertainty analysis showed that more than 60% of observed streamflow values were bracketed within the 95% prediction uncertainty (95PPU) band after calibration and validation. Furthermore, results indicated that the SC technique outperformed the other two methods (SSC and SMSC). It was also observed that although the SMSC technique uses streamflow data from all gauging stations during calibration and validation, thereby taking into account the catchment spatial variability, the choice of each calibration method will depend on the application and spatial scale of implementation of the modelling results in the catchment.

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Evaluating DEM source and resolution uncertainties in the Soil and Water Assessment Tool

Cited by 94 publications

References 26 publications

Effects of DEM grid size on predicting soil loss from small watersheds in China

Effects of DEM grid size on predicting soil loss from small watersheds in China

Modeling spatiotemporal dynamics of global wetlands: comprehensive evaluation of a new sub-grid TOPMODEL parameterization and uncertainties

Effect of single and multi-site calibration techniques on hydrological model performance, parameter estimation and predictive uncertainty: a case study in the Logone catchment, Lake Chad basin

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