Improving hydrological information acquisition from DEM processing in floodplains

Getirana, Augusto; Bonnet, Marie‐Paule; Filho, Otto Corrêa Rotunno; Mansur, Webe João

doi:10.1002/hyp.7167

Cited by 41 publications

(26 citation statements)

References 57 publications

(71 reference statements)

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“…The relatively flat landscapes are usually beyond the required vertical resolution required to accurately identify realistic drainage flow paths (Callow et al, 2007;Getirana et al, 2009). Thus, further research is needed to explore more precise methods for subcatchment delineation to assist in the identification of the primary factors influencing water pollution at the different monitoring sites.…”

Section: Performance and Uncertainty Of The Modeling Systemmentioning

confidence: 99%

Impacts of land use and population density on seasonal surface water quality using a modified geographically weighted regression

Chen

Mei

Dahlgren

et al. 2016

Science of The Total Environment

163

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• The modified GWR models had higher R 2 and reflected the actual spatial features.• A manual variable excluding-selecting method is explored to avoid multicollinearity.• Influences of the dominant indicator on water quality varied with space and seasons.• Protection policies need consider sitespecific conditions and seasonal variations. G R A P H I C A L A B S T R A C Ta b s t r a c t a r t i c l e i n f o As an important regulator of pollutants in overland flow and interflow, land use has become an essential research component for determining the relationships between surface water quality and pollution sources. This study investigated the use of ordinary least squares (OLS) and geographically weighted regression (GWR) models to identify the impact of land use and population density on surface water quality in the Wen-Rui Tang River watershed of eastern China. A manual variable excluding-selecting method was explored to resolve multicollinearity issues. Standard regression coefficient analysis coupled with cluster analysis was introduced to determine which variable had the greatest influence on water quality. Results showed that: (1) Impact of land use on water quality varied with spatial and seasonal scales. Both positive and negative effects for certain land-use indicators were found in different subcatchments. (2) Urban land was the dominant factor influencing N, P and chemical oxygen demand (COD) in highly urbanized regions, but the relationship was weak as the pollutants were mainly from point sources. Agricultural land was the primary factor influencing N and P in suburban and rural areas; the relationship was strong as the pollutants were mainly from agricultural surface runoff. Subcatchments located in suburban areas were identified with urban land as the primary influencing factor during the wet season while agricultural land was identified as a more prevalent influencing factor during the dry season. (3) Adjusted R 2 values in OLS models using the manual variable excluding-selecting method averaged 14.3% higher than using stepwise multiple linear regressions. However, the corresponding GWR models had adjusted R 2~5 9.2% higher than the optimal OLS models, confirming that GWR models demonstrated better prediction accuracy. Based on our findings, water resource protection policies should consider site-specific land-use Contents lists available at ScienceDirectScience of the Total Environment j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / s c i t o t e n v conditions within each watershed to optimize mitigation strategies for contrasting land-use characteristics and seasonal variations.

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Section: Performance and Uncertainty Of The Modeling Systemmentioning

confidence: 99%

Impacts of land use and population density on seasonal surface water quality using a modified geographically weighted regression

Chen

Mei

Dahlgren

et al. 2016

Science of The Total Environment

163

View full text Add to dashboard Cite

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“…Getirana et al . () propose an approach (namely simply FB approach) that is based on a ‘double DEM burning’ process in floodplains. Yamazaki et al .…”

Section: Introductionmentioning

confidence: 97%

“…However, the D8 approach, which is based on the slopes of neighbouring cells, has the limitations of extracting watershed drainage networks from DEMs of flat areas. The most common problems include the absence of existing river segments and the presence of artificial parallel river segments (Turcotte et al, 2001;Getirana et al, 2009;Metz et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Watershed delineation using hydrographic features and a DEM in plain river network region

Lai

et al. 2015

Hydrol. Process.

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Watershed delineation is a required step when conducting any spatially distributed hydrological modelling. Automated approaches are often proposed to delineate a watershed based on a river network extracted from the digital elevation model (DEM) using the deterministic eight‐neighbour (D8) method. However, a realistic river network cannot be derived from conventional DEM processing methods for a large flat area with a complex network of rivers, lakes, reservoirs, and polders, referred to as a plain river network region (PRNR). In this study, a new approach, which uses both hydrographic features and DEM, has been developed to address the problems of watershed delineation in PRNR. It extracts the river nodes and determines the flow directions of the river network based on a vector‐based hydrographic feature data model. The river network, lakes, reservoirs, and polders are then used to modify the flow directions of grid cells determined by D8 approach. The watershed is eventually delineated into four types of catchments including lakes, reservoirs, polders, and overland catchments based on the flow direction matrix and the location of river nodes. Multiple flow directions of grid cells are represented using a multi‐direction encoding method, and multiple outflows of catchments are also reflected in the topology of catchments. The proposed approach is applied to the western Taihu watershed in China. Comparisons between the results obtained from the D8 approach, the ‘stream burning’ approach, and those from the proposed approach clearly demonstrate an improvement of the new approach over the conventional approaches. This approach will benefit the development of distributed hydrological models in PRNR for the consideration of different types and multiple inlets and outlets of catchments. Copyright © 2015 John Wiley & Sons, Ltd.

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“…The problem of these erroneous parallel streams has been addressed using surface reconditioning techniques such as the AGREE method of Hellweger and Maidment (), which alters the surface of the DEM in the areas adjacent to streams so that they slope towards the channel. More recently, Getirana and colleagues (Getirana et al ., , ) have proposed a 'double DEM burning' method that also applies a secondary gradient within the adjacent floodplain areas. Surface reconditioning can impact extensive areas within DEMs, potentially significantly altering modeled drainage patterns (Callow et al ., ).…”

Section: Stream Burning Methodsmentioning

confidence: 99%

The practice of DEM stream burning revisited

Lindsay

2016

Earth Surf Processes Landf

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Stream burning is a common flow enforcement technique used to correct surface drainage patterns derived from digital elevation models (DEM). The technique involves adjusting the elevations of grid cells that are coincident with the features of a vector hydrography layer. This paper focuses on the problematic issues with common stream burning practices, particularly the topological errors resulting from the mismatched scales of the hydrography and DEM data sets. A novel alternative stream burning method is described and tested using five DEMs of varying resolutions (1 to 30 arc‐seconds) for an extensive area of southwestern Ontario, Canada. This TopologicalBreachBurn method uses total upstream channel length (TUCL) to prune the vector hydrography layer to a level of detail that matches the raster DEM grid resolution. Network pruning reduces the occurrence of erroneous stream piracy caused by the rasterization of multiple stream links to the same DEM grid cell. The algorithm also restricts flow within individual stream reaches, further reducing erroneous stream piracy. In situations where two vector stream features occupy the same grid cell, the new tool ensures that the larger stream, designated by higher TUCL, is given priority. TUCL‐based priority minimizes the impact of the topological errors that occur during the stream rasterization process on modeled regional drainage patterns. The test data demonstrated that TopologicalBreachBurn produces highly accurate and scale‐insensitive drainage patterns and watershed boundaries. The drainage divides of four large watersheds within the study region that were delineated from the TopologicalBreachBurn‐processed DEMs were found to be highly accurate when compared with the official watershed boundaries, even at the coarsest grid resolutions, with Kappa index of agreement values ranging from 0.952 to 0.921. The corresponding Kappa coefficient values for a traditional stream burning method (FillBurn) ranged from 0.953 to 0.490, demonstrating a significant decrease in mapping accuracy at coarser DEM grid resolutions. Copyright © 2015 John Wiley & Sons, Ltd.

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Improving hydrological information acquisition from DEM processing in floodplains

Cited by 41 publications

References 57 publications

Impacts of land use and population density on seasonal surface water quality using a modified geographically weighted regression

Impacts of land use and population density on seasonal surface water quality using a modified geographically weighted regression

Watershed delineation using hydrographic features and a DEM in plain river network region

The practice of DEM stream burning revisited

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