GFPLAIN250m, a global high-resolution dataset of Earth’s floodplains

Abstract

Identifying floodplain boundaries is of paramount importance for earth, environmental and socioeconomic studies addressing riverine risk and resource management. However, to date, a global floodplain delineation using a homogeneous procedure has not been constructed. In this paper, we present the first, comprehensive, high-resolution, gridded dataset of Earth’s floodplains at 250-m resolution (GFPLAIN250m). We use the Shuttle Radar Topography Mission (SRTM) digital terrain model and set of terrain analysis procedures for geomorphic floodplain delineations. The elevation data are processed by a fast geospatial tool for floodplain mapping available for download at https://github.com/fnardi/GFPLAIN. The GFPLAIN250m dataset can support many applications, including flood hazard mapping, habitat restoration, development studies, and the analysis of human-flood interactions. To test the GFPLAIN250m dataset, we perform a consistency analysis with floodplain delineations derived by flood hazard modelling studies in Europe.

Global Relationships Between River Width, Slope, Catchment Area, Meander Wavelength, Sinuosity, and Discharge

“…However, the choice of mean annual flow may have prevented us from finding direct relationships between discharge and meander wavelength and discharge sinuosity. Additionally, exploring relationships between our centerline locations and basin and floodplain characteristics such as those cataloged by Shen et al (2017) and Nardi et al (2019) may lead to further insight on meander formation, flood wave propagation (e.g., Allen & Pavelsky, 2018), and refinement of local digital elevation models (Shastry & Durand, 2019). Furthermore, our data set may be improved by using techniques such as hydrography-driven coarsening applied to high-resolution digital elevation models as described by Moretti and Orlandini (2018), which may lead to improved estimates of catchment areas and slopes, particularly in mountainous areas and in areas where high-resolution topographic data sets exist, for example, local LiDAR or 1 arc-second SRTM data.…”

“…Furthermore, our data set may be improved by using techniques such as hydrography-driven coarsening applied to high-resolution digital elevation models as described by Moretti and Orlandini (2018), which may lead to improved estimates of catchment areas and slopes, particularly in mountainous areas and in areas where high-resolution topographic data sets exist, for example, local LiDAR or 1 arc-second SRTM data. Additionally, exploring relationships between our centerline locations and basin and floodplain characteristics such as those cataloged by Shen et al (2017) and Nardi et al (2019) may lead to further insight on meander formation, flood wave propagation (e.g., Allen & Pavelsky, 2018), and refinement of local digital elevation models (Shastry & Durand, 2019).…”

“…Responding to the need for better understanding of rivers at continental and global scales, recent studies have explored existing remote sensing data to trace river networks (e.g., Allen & Pavelsky, 2015;Lehner et al, 2008;Lehner & Grill, 2013;Yamazaki et al, 2014), extract basin and floodplain parameters and features (Nardi et al, 2019;Shen et al, 2017), map the extent of flooding and flood risk (Andreadis et al, 2017;Brakenridge, 2018;Van Dijk et al, 2016), and estimate discharge (e.g., Brakenridge et al, 2007;Gleason & Wang, 2015;Tarpanelli et al, 2013;Tourian et al, 2013;Tourian et al, 2017). However, additional information about rivers can be extracted from currently available satellite imagery, particularly descriptors of shapes of rivers and meanders.…”

Will the Surface Water and Ocean Topography (SWOT) Satellite Mission Observe Floods?

“…While associating waterbodies with flood events could potentially allow us to extend the window of significance beyond flood duration, as well as extract information on river width and floodplain extent from global databases (e.g., Allen & Pavelsky, ; Nardi et al, respectively), water surface slope, meander wavelength, sinuosity, and discharge from Frasson et al (), flood wave travel time from Allen et al (), and others, such association is difficult to be automated without extensive manual intervention. Therefore, we present two case studies where we show the timing of SWOT passes with respect to flood hydrographs and display relevant SWOT swaths over the study areas, illustrating how spatial coverage may be during real flood events.…”

Exploring the role of risk perception in influencing flood losses over time

“…Since very ancient times, many human settlements established in close proximity to rivers and their floodplains offer fertile land and easy movement, thereby promoting cultural organization and fostering economic growth (Nardi et al 2019). Indeed, rivers played a fundamental role in the economic development of societies, as illustrated by ancient major cultures, such as those that settled in Mesopotamia within the Tigris-Euphrates river system.…”