Table B2.10.

Typical uses of GIS

Required dataPotential data sources
Planning of new roads
Land use and infrastructure for route corridor selectionPublished small-scale topographical maps if available digitally. If not they may require to be digitized. Large scale remote sensing can be used to update existing maps using GIS. Surveyed cadastral maps can form a separate mapping layer
Small-scale topographical data for route corridor selectionPublished small-scale topographical maps if available digitally. If not they may require to be digitized
Large-scale topographical data for alignment design and design of cross-sectionsProject-derived photogrammetry or LiDAR and site survey
Geology for route corridor selectionPublished small-scale geological maps. Usually not available digitally. Can be digitised into GIS and augmented by remote sensing data
Landslide locations for route corridor selectionRemote sensing can be interpreted on-screen or digitised, scanned and geo-referenced into GIS. Landslide locations from field observations can be geo-referenced into GIS
Detailed information on rock and soil types for alignment design and design of cross-sectionsProject-derived field mapping and ground investigation. Not usually digitized, but scanned and geo-referenced into GIS
Detailed information on landslides for alignment design and design of cross-sections
Drainage details (catchment areas, rivers, streams etc)Digitized from topographical maps, less commonly from remote sensing
Information on rainfall and seismicityCan be stored and analysed using GIS
Slope management along existing roads (see Part D)
Locations of cut and fill slopes, retaining walls and drainage structuresInventory of earthworks and structures and their condition can be collected and stored and analysed using GIS in both spreadsheet and graphical format
Condition of cut and fill slopes, retaining walls and drainage structures
Soil and rock types in earthworksProject-derived field mapping, slope inventory and ground investigation. Not usually digitized, but scanned and geo-referenced into GIS
Landslide locationsProject-derived field mapping, supplemented with remote sensing can be digitized or scanned and geo-referenced into GIS
Landslide and slope stabilityLandslide inventories can be stored as spreadsheets, geo-referenced and analysed in GIS
Locations of slope monitoring sitesMonitoring locations can be surveyed and stored in GIS as a separate mapping layer
Results of slope monitoringMonitoring spreadsheets can be stored, geo-referenced and analysed in GIS
Hazard and risk data for maintenance managementAssessment of hazard and risk can be derived from mapping and inventories, stored and analysed in GIS for prioritizing maintenance