Expanding SWOT discharge series using the drainage area ratio method

This resource contains five R-markdown scripts that process and analyze the connections between MERIT Hydro River reaches of the Mississippi River for Surface Water and Ocean Topography (SWOT) satellite observable rivers. The first code calculates the cumulative amount of urban land area for each reach in the basin. The second code relates the reaches, linking them based on drainage area ratios between 0.01 and 100. It filters these relationships based on whether a SWOT measurement could be donated from one location to the other via the drainage area ratio method, dam locations, and the amount of urban area between locations. Then, the potential increase in SWOT observations throughout the basin is calculated. The third code takes 373 gauges in the river basin and calculates Kling-Gupta Efficiency (KGE) values assessing the potential of using the drainage area ratio method among the gauges. The fourth assesses the impact dams, reservoirs, and urban area have on KGE values obtained. Finally, the fifth code expands simulated SWOT time series using the qualified drainage area ratio method and compares the expansion to daily discharges by first transforming each time series into a Log Pearson Type III distribution. KGE values between quantiles of each distribution are calculated and the Kolmogorov-Smirnov and Student t significance tests are performed. These codes and their associated text files serve as the resources for the study, "Leveraging river network topology and regionalization to expand SWOT-derived river discharge time series in the Mississippi River Basin" (doi:10.3390/rs13081590).