Structural hillslope connectivity is driven by tectonics more than climate and modulates hydrologic extremes and benefits

This resources includes the Python scripts to calculate Index of Connectivity maps and MATLAB scripts for generating the plots used in the manuscript. This resource also includes the following Word/PDF files: (1) the text file of the manuscript, (2) the figures file, and (3) the supplemental information file. These files describe the process the authors undertook to create a structural connectivity map of the contiguous United States (CONUS). The exact methods are described in the text file. To download connectivity raster maps, visit the following link: https://apps.cuahsi.org/connectivity-map.

The abstract for the manuscript is shown below:

Structural hydrologic connections, formed by the coaction of tectonic and climatic processes, facilitate the transfer of matter from upland source zones to receiving waters. Recent global analyses disagree whether tectonic or climatic processes control river structure, but similar large-scale investigation of structural connectivity of hillslopes has not been performed. Here, we model hillslope connectivity for CONUS (75 billion calculations at 10-m resolution), explore connectivity drivers using earthquake-hazard and land-surface modeling, and relate the strength of connectivity to cataloged hydrologic extremes (landslides and floods) and benefits (wetlands). We show that tectonics is a first-order control of structural hillslope connectivity as indicated by strong Spearman correlation with river steepness (ρ = 0.84) and seismic activity (ρ = 0.48). Climate is a weaker influence with wind speed showing some correlation (ρ = 0.43) and precipitation less so (ρ = -0.31). Highly connected basins were strongly associated with the occurrence of landslides (ρ = 0.69) while poorly connected basins were correlated with greater wetland density (ρ = -0.50). However, structural connectivity did not explain the occurrence of floods (ρ = -0.12), indicating that some hydrodynamic processes may not be well-represented by static landscape variables alone. Understanding the dominant controls and spatial extent of hillslope connectivity has implications for how limited resources for watershed management should be distributed to maximize ecosystem benefits.