The tRIBS Distributed Hydrologic Modeling System, Version 6.0.0, is a major release focused on simplifying the user experience and streamlining the codebase. It is not backwards compatible with previous versions: the main input file, the text-based input and output formats, and several parameter conventions have all changed. Example input files are available in the Model Benchmark Repository. Users working through the pytRIBS Python package should upgrade to pytRIBS 1.0.0, which supports the v6.0.0 input and output formats; earlier versions of pytRIBS are not compatible with this release.
Nearly all text-based input and output is now CSV with a single header row, replacing the previous fixed-width and count-header formats. Station and gridded forcing files no longer carry centroid latitude, longitude, or UTC offset; these moved to the main input file as UTCOFFSET, CENTROIDLAT, and CENTROIDLONG. Point and gridded rainfall both standardize on mm/hr, and relative humidity is the only accepted humidity forcing. Land use parameters are now validated at startup, so models carrying out-of-range values stop with a descriptive message rather than running on.
The snow module was refactored with dynamic snow density via compaction, liquid water routing by holding capacity and conductivity, and a selectable precipitation phase-partitioning scheme, all configured through a new optional snow parameter file (.spf). Canopy interception is handled exclusively by the Rutter water-balance method, with the legacy Gray (1970) formulation removed. Root zone depth became a land use parameter, supplied through the land use table or a raster, replacing the model-wide ROOTZONEDEPTH keyword, and a new static gridded land use option (OPTLANDUSE = 2) supplements the existing dynamic and tabular modes. Evapotranspiration, unsaturated zone, and snowpack calculations received several mass-balance corrections, and channel transmission losses were reworked, with conductivity now specified in mm/hr. Initial groundwater depth and depth to bedrock are now interpreted as vertical depths rather than slope-normal, which will change results for existing model setups.
Parallel simulations are now self-contained: METIS is vendored into the source tree and compiled into the parallel binary, and the stream-reach graph is built and partitioned in-process at startup for however many MPI processes the run was launched with, retiring the standalone MeshBuilder tool and its external gpmetis and Perl-script workflow. A new partition-only mode (PARALLELMODE = 2) writes the partition file and reports load balance and edge cuts without running a simulation, and parallel outputs are merged on the head node rather than written per-processor. The restart module was rewritten to save a minimal, portable state that can hot start any simulation on the same mesh, with no dependence on simulation time or the original processor count. Optional GDAL support (-DWITH_GDAL=ON) allows tRIBS to read GeoTIFF, NetCDF, and other GDAL-supported raster formats. The legacy rainfall forecasting mode, stochastic storm generator, and RIBS-output compatibility mode were removed, an optional monthly stomatal resistance scaling file (RSPARAMFILE) was added, and internal performance optimizations reduced typical wall-clock time by 15 to 20%.