1) Why modular beats monoliths
Traditional GIS workflows tend to accrete into a single giant project or “model” that is hard to test, slow to run, and fragile to change. In contrast, SpaceIndex & the GeoLayers suite break a problem into small, composable apps—each excellent at one thing—chained together by open formats and shareable links.
- Speed: load only what you need; precompute heavy bits; keep the UI snappy.
- Auditability: each step has inputs, parameters and an export—easy to review.
- Resilience: swap a step (e.g., a different reprojector) without rewriting everything.
2) The modular architecture
Here’s how the GeoLayers stack maps to common planning tasks:
- GeoAnalyst: the map canvas—add layers, style, measure, analyze, export PNG/PDF with legend, share links.
- GIS Tools: focused utilities (reproject, spatial join, buffers, CSV→points, COG, contours, lint & fix GeoJSON).
- Planning Suite: controls finder, parking/loading, SDP checklists, consent/rezoning wizards.
- Apps: envelope visualizer, sun/shade, bulk & yield, pro-forma lite, EIA screening overlays, etc.
CSV addresses → (CSV→Points) → Join with zoning → Suitability scoring → Envelope visualize → Export & share
Each arrow is an open format handoff (GeoJSON/CSV/COG), not a hidden internal state.
3) Auditability & transparency
Every module emits inspectable outputs (e.g., a GeoJSON with the derived fields and a JSON of parameters). Share-links compress state into the URL hash so peers can reproduce results with the same toggles and weights.
4) Data & interoperability
- Vectors: GeoJSON, Shapefile, KML/GPX, TopoJSON.
- Rasters: GeoTIFF & Cloud-Optimized GeoTIFF (COG).
- CRS: EPSG registry via the CRS Finder; batch reprojection with grid-shift warnings for SA CRSs.
Because formats are open, results move cleanly between desktop GIS, web apps and code notebooks.
5) Collaboration & governance
- Share links: pass a scenario as a URL for review—no attachments required.
- Templates: start from a playbook (TOD, flood-safe growth, housing); standardise across teams.
- Checks & lists: SDP Checklist provides a shareable, pre-ticked compliance record.
6) Performance & scaling
Heavy operations can run on tiled rasters/vectors (COG, vector tiles), while the browser handles interaction. Simplify geometries or sample rasters to keep views responsive; switch to vector tiles for national coverage.
7) Migration path from traditional GIS
- Keep your data in current stores; export task outputs to open formats.
- Swap one step: e.g., do Spatial Join or Reproject in the web tool; keep the rest.
- Adopt templates for repeated analyses; socialise share-links as the review artifact.
- Host frequently used overlays/apps on GeoLayers for a single source of truth.
8) Example: from question to map
Question: “Where can we add 1,000 units near transit without hitting flood/wetland constraints?”
- Load transit stops and flood/wetland layers in GeoAnalyst.
- Run the Suitability template (near transit + access to services; mask constraints).
- Use the Envelope Visualizer on top parcels to test height/setbacks.
- Export the map (PNG/PDF with legend) and share a link for sign-off.
9) Checklist: when to choose modular
- You need stakeholder-visible, explainable steps.
- Multiple quick scenarios with small parameter changes.
- Mixed skill teams (not everyone has desktop GIS).
- Desire to reuse steps across projects.
Traditional GIS still shines for deep cartography, power-user edits and bespoke scripts. Use both—modular where it accelerates, desktop where it specialises.