Catching up on our curves
It's been nearly 18 months since I managed to pop out a blog post, which has mostly been due to various family medical issues. Phew - there is a lot to catch up on and I'll try to do so over the next few weeks.
Firstly, I want to share a paper that we are all really proud of and excited by - the paper that presents Arc Hydro Hillslope! Lead by Dana Lapides and Anneliese Sytsma, this paper presents new tools for accounting for hillslope curvature when making flood routing predictions. You can find the full paper here: https://www.sciencedirect.com/science/article/pii/S1364815222001141
The tool works by accounting for how the contour length around a curving hillslope changes from the crest to the valley.
Then, it adjusts calculations of runoff timing and peak based on the effect of those curves. It works within ArcGIS so it's useful for planners who use this common package in their work. It helps us analyse hillslope properties and explore how they effect runoff and flood behaviour. For example, we can find how many hillslopes in a watershed are convergent, divergent, headwaters or uniform in curvature. One thing that surprised me was how many hillslopes are divergent, when a classical hydrological conceptual idea suggests that convergence is the norm.
And we can compare hydrographs accounting for curvature with those that do not. For example, when we account for the curvature in the watersheds, the time of concentration occurs earlier and the hydrograph peak is greater than if we did not account for the effect of those curves.
If you want to use these tools, you can install them into ARC GIS, specifically ArcGIS Pro 2.7 and higher. These tools are then available on through Esri's Arc Hydro Toolbox.