Aerial photographs from the Yampa and Little Snake Rivers in northwest Colorado used to characterize channel changes occurring between 1954 and 1961

Aerial photographs of the Yampa and Little Snake Rivers acquired in 1954 and 1961 were used to examine channel changes occurring along these two rivers during this time period. In addition, these data were used to develop and test a generalizable new approach to characterizing the uncertainty associated with analyses of channel change based on time series of remotely sensed data, which we term the Spatially Distributed Probabilistic (SDP) method. This technique accounts for errors introduced during: 1) image co-registration and geo-referencing; 2) interpreting the location of the channel boundary; and 3) digitizing the channel boundary. The method provides a probability distribution of channel locations and can be used to calculate error bounds associated with polygons of erosion and deposition and thus net sediment flux. The Yampa and Little Snake Rivers were used as a case study to illustrate an application of the new SDP method and this data release provided all of the data needed to perform an SDP analysis for this example. The data sets available here include: 1) air photo mosaics from 1954, 1961, and 2017, with the most recent coverage used as a base for geo-referencing the older photos; 2) test points used to quantify spatially varying co-registration error; and 3) active channel polygons digitized from the 1954 and 1961 air photos and used to create polygons of erosion and deposition. Software for implementing the SDP method and an example script that illustrates how to perform this type of analysis using data from the Yampa and Little Snake Rivers as a case study is available from the Center for Colorado River Studies at Utah State University.