Grain size data from the Carmel River, central California, 2013 to 2021 (ver. 2.0, March 2022)

Grain-size measurements were made at four to six transects per site using a 0.5 by 0.5 m sampling frame, with approximately 100 sediment-particle counts per transect. Each transect was defined by coordinates on the left and right sides of the river, and sediment grain sizes were measured at five equally spaced locations within the bankfull channel on the transect defined by those endpoint coordinates (see accompanying file within this data release for transect endpoint coordinates). Grain-size diameters were measured using a gravelometer. We report grain-size values to the next size class up in this spreadsheet, that is, the size gradation that the sediment grain passed through on the gravelometer frame, with the data being analogous to the percent passing in sieve analyses. Not all study sites were measured in all study years. The Rancho San Carlos (SC) site was not yet established in water year 2013; was established in water year 2014. Only one runoff event reached the site in 2014, and it happened just before the cross section was established. That flow was just enough to wet the channel from bank to bank, and it generated virtually no sediment transport or geomorphic work. Therefore, the grain-size measurements for the SC site during water year 2014 (on date 2014-03-07) were assumed to represent water-year 2013 values.

Changes to version 2.0 of these data include adding grain-size measurements for 2018, 2019, 2020, and 2021; adding horizontal coordinates for approximate spatial reference; and reshaping the data file to facilitate grain-size distribution analysis. Data were pivoted, so that each site occupies one row and the counts for the grain-size are represented in a separate column.