Watershed Merging: A Simple and Effective Algorithm for Channel Network Identification and Extraction

Zhang, Yaoxin; Jia, Yafei

doi:10.1029/2019wr026943

Cited by 6 publications

(3 citation statements)

References 14 publications

(33 reference statements)

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“…Using the ArcMap Hydrological tools toolbox, the DEM is filled for sinks and analyzed for flow direction from each cell using the D8 algorithm. This determines the direction in which water flows from every cell based on the proven motion of water that it always flows from a point of high elevation to a point of low elevation [53]. From the flow direction, the drainage basins are then clearly distinguished using the Basin Tool, after which the flow directions of each basis are analyzed for areas of greatest flow accumulation, into which most cells pour.…”

Section: Methodsmentioning

confidence: 99%

Vulnerability and Adaptation to Flood Hazards in Rural Settlements of Limpopo Province, South Africa

Munyai

Chikoore

Musyoki

et al. 2021

Water

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Climate change has increased the frequency of extreme weather events such as heavy rainfall leading to floods in several regions. In Africa, rural communities are more vulnerable to flooding, particularly those that dwell in low altitude areas or near rivers and those regions affected by tropical storms. This study examined flood vulnerability in three rural villages in South Africa’s northern Limpopo Province and how communities are building resilience and coping with the hazard. These villages lie at the foot of the north-eastern escarpment, and are often exposed to frequent rainfall enhanced by orographic factors. Although extreme rainfall events are rare in the study area, we analyzed daily rainfall and showed how heavy rainfall of short duration can lead to flooding using case studies. Historical floods were also mapped using remote sensing via the topographical approach and two types of flooding were identified, i.e., those due to extreme rainfall and those due to poor drainage or blocked drainage channels. A field survey was also conducted using questionnaires administered to samples of affected households to identify flood vulnerability indicators and adaptation strategies. Key informant interviews were held with disaster management authorities to provide additional information on flood indicators. Subsequently, a flood vulnerability index was computed to measure the extent of flood vulnerability of the selected communities and it was found that all three villages have a ‘vulnerability to floods’ level, considered a medium level vulnerability. The study also details temporary and long-term adaptation strategies/actions employed by respondents and interventions by local authorities to mitigate the impacts of flooding. Adaptation strategies range from digging furrows to divert water and temporary relocations, to constructing a raised patio around the house. Key recommendations include the need for public awareness; implementation of a raft of improvements and a sustainable infrastructure maintenance regime; integration of modern mitigations with local indigenous knowledge; and development of programs to ensure resilience through incorporation of Integrated Development Planning.

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Section: Methodsmentioning

confidence: 99%

Vulnerability and Adaptation to Flood Hazards in Rural Settlements of Limpopo Province, South Africa

Munyai

Chikoore

Musyoki

et al. 2021

Water

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“…Since depression bottoms are thalwegs and depression borders are ridges, the preservation of depressions and the preservation of thalweg and ridge network structures are equivalent requirements. The relevance of thalweg and ridge networks has been recognized in the literature (e.g., Cayley, 1859; Chang et al., 1998; Lindsay & Seibert, 2012; Maxwell, 1870; Perron et al., 2009; Rak et al., 2019; Rana, 2006; Werner, 1972, 1988; Willett et al., 2014; Zhang & Jia, 2020). Werner (1972, 1988) provided a formal analysis of channel and ridge networks as interlocked tree structures.…”

Section: Introductionmentioning

confidence: 99%

“…Endorheic basins are appropriately identified in Barnes et al (2020Barnes et al ( , 2021. Zhang and Jia (2020) proposed a watershed merging method that connects depressions and flat areas without altering the observed topographic data. In these studies, however, exorheic and endorheic basins are not connected without altering the observed topographic data, or connections are not determined in a physically meaningful manner and the resulting channel network is not unequivocally defined.…”

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confidence: 99%

Thalweg and Ridge Network Extraction From Unaltered Topographic Data as a Basis for Terrain Partitioning

Moretti

Orlandini

2023

JGR Earth Surface

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Increasingly detailed observations of rocky and icy bodies in our solar system reveal dramatic diversity in surface topographic features (Black et al., 2017;Head et al., 2003). Earth topography helps scientists determine how rivers and streams drain through the landscape, where lowlands are prone to flooding, how plate tectonics or erosion are building or wearing away mountains, where hills may be prone to landslides, or how a volcanic eruption changed the shape of a mountain (Passalacqua et al., 2015;Robinson et al., 2017). Topography is also one of the factors that influences the existence of particular ecosystems (Frolking et al., 2009;Shugart et al., 2010). Therefore, topography is one of the factors that scientists can use to predict where certain plants or animals, such as endangered species, might be found. Planetary topography has been largely investigated in the last two decades (Perron et al., 2007;Smith et al., 1999). Black et al. ( 2017) compared topography at a range of scales with mapped river drainages to provide new insights into the topography-generating mechanisms on Earth, Mars, and Titan. As reported by Burr (2017), quantifying discrepancies between drainage networks and surrounding

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Application of 1D model for overland flow simulations on 2D complex domains

Zhang,

Al-Hamdan,

Bingner

et al. 2024

Advances in Water Resources

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Watershed Merging: A Simple and Effective Algorithm for Channel Network Identification and Extraction

Cited by 6 publications

References 14 publications

Vulnerability and Adaptation to Flood Hazards in Rural Settlements of Limpopo Province, South Africa

Vulnerability and Adaptation to Flood Hazards in Rural Settlements of Limpopo Province, South Africa

Thalweg and Ridge Network Extraction From Unaltered Topographic Data as a Basis for Terrain Partitioning

Application of 1D model for overland flow simulations on 2D complex domains

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