Getting the Tnc Resilient Land Mapping Tool to actually work
The tool is built on a fairly standard QGIS plugin architecture with some pre-packaged raster layers from the Nature Conservancy's Open Land Initiative. It runs on QGIS 3.28 and newer. You'll need to install the plugin from the official repository, but honestly the whole process is a bit more fiddly than it should be because of dependency mismatches. I had a project last year where someone tried running it on QGIS 3.34 and the Python geoprocessing backend kept throwing an error about missing GRASS modules. The fix was reinstalling the GRASS plugins through the QGIS plugin manager, then restarting QGIS before loading the TNC tool. Takes about five minutes once you know what you're doing. Once installed, the plugin adds a dock panel with tabs for land cover classification, resilience scoring, and output configuration. The core workflow is: load your base geospatial data (usually shapefiles or GeoTIFFs), run the land use classification pass, apply the resilience index layers, and export your results. The tool ships with a default set of terrain and vegetation layers that cover most of the continental United States, but if you're working outside those regions you'll need to supply your own raster inputs or the tool will just skip those areas. One thing nobody really mentions in the docs is that the default classification thresholds are calibrated for temperate climates. I ran into this when a colleague was doing work in the Sonoran Desert and the tool classified large swaths of sagebrush habitat as "resilient urban" because the spectral signatures overlapped with built-up areas in the training data. The workaround was exporting the default training samples, editing them manually in the classification editor to include desert scrub categories, and re-running the classifier. It added about forty-five minutes to the workflow but saved us from having to redo the whole project. Another quirk: the tool will silently use cached intermediate files if you run it twice without clearing them. So if your results look identical to a previous run even though you changed parameters, go check the cache folder in your temporary directory and delete it before rerunning.
What the resilience scoring actually measures
The scoring system combines twelve input variables across four categories: hydrological connectivity, vegetation health indices, soil stability, and anthropogenic pressure. Each category gets weighted and the tool calculates a composite score from zero to one hundred. Higher scores indicate greater ecological resilience, lower scores flag areas where intervention might be needed. The default weights are reasonable for broad-scale assessments but they skew toward riparian zones because the hydrological layer has higher spatial resolution than the anthropogenic data. If your study area is arid or semi-arid, the hydrological signal can dominate the composite score even when land use pressure is the real concern. I've seen cases where two areas with very different degradation profiles ended up with nearly identical resilience scores because the default weighting mask that difference out. The workaround is either adjusting the category weights manually in the configuration panel or running the tool in modular mode where you can isolate individual layers and score them separately before combining them. Modular mode is underdocumented but it's the most useful feature in the tool. You access it through the advanced settings tab by toggling "enable layer-level processing" and then the output will include individual score rasters for each category instead of just the composite.
Output formats and common export issues
Results can be exported as GeoTIFF, GeoPackage, or shapefile. The recommended format is GeoPackage because it handles the attribute tables cleanly and avoids the coordinate reference system bugs that sometimes show up with shapefile exports. There's also an option to export as a MapInfo TAB file if you're working with legacy GIS systems, but that conversion has been flagged as problematic in version 2.4.1 and earlier. Make sure you're on at least version 2.5.0 before exporting to Tab. Another practical note: the tool's default export resolution is 30 meters, which works for regional assessments but is too coarse if you're doing site-level planning. You can change the output cell size in the export dialog, but lowering it below fifteen meters significantly increases processing time and memory usage. On a typical workstation with 32 GB RAM, a fifteen meter export over a fifty thousand hectare area takes about twenty minutes and uses roughly twelve gigabytes of temporary disk space. The biggest limitation is that the tool requires reasonably clean input data. If your source shapefiles have topology errors, overlapping polygons, or mixed CRS definitions, the classification pass will either fail or produce garbage output without any warnings. I spent a full day once trying to debug results that turned out to be wrong because someone in the pipeline had projected a layer to WGS84 but left the datum untransformed, so the coordinates were technically in lat/lon but the tool interpreted them as a different projection entirely. Always run a topology check on your inputs before feeding them into the tool. A quick check with QGIS's built-in validator catches most of these issues in under ten minutes. The second limitation is the climate model layer. The tool pulls precipitation and temperature projections from WorldClim, which are updated every few years but haven't been refreshed in the current release. For work that depends on future climate scenarios, the data might be a year or two behind the latest publications. That's fine for strategic planning but not for projects that need the most current projections. In that case you'd be better off running the classification step in the tool and then swapping in your own climate rasters manually before computing the final resilience scores. It's a two-step process but it keeps the output current.
Get the Full Details
The tool is available through the QGIS Plugin Manager under the search term "TNF Resilient Land Mapping" or directly from the Nature Conservancy's GitHub releases page. Install it, test it on a small parcel first, and don't skip the input validation step.
