SSN2 review
Specialized R modeling for stream-network data, with prediction and diagnostics.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
SSN2 is an open-source R package for researchers and analysts working with spatial stream-network data. It fits linear and generalized linear models that account for network structure, water-flow direction, stream distances, and Euclidean spatial dependence. The package is aimed at statistical analysis of streams rather than broad GIS tasks, making it a fit for people whose work centers on modeling connected waterways and their spatial relationships.
Its modeling workflow includes prediction at unobserved stream locations, calculation of hydrologic distance matrices, and support for tail-up, tail-down, and Euclidean spatial dependence. Users can also perform leave-one-out cross-validation, simulate spatially autocorrelated variables on stream networks, and inspect fitted-model diagnostics and empirical semivariograms. These capabilities give the package a focused set of tools for fitting, checking, and interpreting stream-network models; the same specialization means it is not a substitute for a general-purpose GIS application.
SSN2 is open source and has a free plan. Its official documentation describes installation in R and local data processing, so it suits analysts comfortable working in that environment. Email and community support channels are listed. The package is described as a desktop deployment, with no integrations or broader platform coverage specified. Researchers seeking stream-network statistical modeling at no cost should consider it; teams looking for a wider GIS feature set or platform ecosystem should look elsewhere.
SSN2 pros and cons
- Where it wins
- Fits linear and generalized linear models for stream networks
- Predicts values at unobserved locations and calculates hydrologic distances
- Includes cross-validation, simulation, and model diagnostics
- Where it doesn't
- Focused on stream-network statistics, not general-purpose GIS
- Requires working with R and local data processing
- Desktop deployment limits the listed platform coverage
SSN2 fact sheet, pricing and score →
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
Last updated · How we research and update