Open GIS & Applications: Tools, Platforms & Real-World Use

TAKEAWAYS:

• Open-source GIS tools like QGIS and GRASS GIS are free, customizable alternatives to proprietary software, widely used in research and government.
• Web GIS platforms (e.g., OpenLayers, Leaflet) enable interactive maps on websites, critical for apps like eSewa’s service locator or Pathao’s route optimization.
• Disaster management (e.g., flood modeling in Nepal) and urban planning (e.g., Kathmandu traffic analysis) rely on open GIS for data sharing and collaboration.
• OpenStreetMap (OSM) is the world’s largest crowdsourced map, powering apps like Google Maps (for rural areas) and WhatsApp’s location sharing.
• Licensing matters: Open GIS data (e.g., OSM) is free but requires attribution; proprietary data (e.g., Google Earth) has restrictions.
• Future trends include AI integration in open GIS (e.g., auto-feature extraction from satellite images) and blockchain for secure data sharing.

---

1. What Is Open GIS?

Open GIS refers to free, open-source software and data for geographic information systems, designed to be customizable, interoperable, and community-driven. Unlike proprietary tools (e.g., ArcGIS), open GIS follows principles like:

• Open-source licensing (e.g., GNU GPL, MIT): Users can modify and redistribute the software.
• Interoperability: Data and tools work seamlessly across platforms.
• Collaborative development: Global communities (e.g., OSM contributors) improve the technology.

Why Use Open GIS?

---

2. Key Open GIS Software

A. Desktop GIS: QGIS and GRASS GIS

1. QGIS (Quantum GIS)

   • What it does: A user-friendly desktop GIS for vector/raster analysis, map design, and geoprocessing.

   • Core features:

     • Plugins: Extend functionality (e.g., MMQGIS for advanced queries, Orfeo Toolbox for satellite data).
     • Vector tools: Buffer analysis, overlay operations (e.g., finding intersections between roads and rivers).
     • Raster tools: Terrain analysis, land cover classification.

   • Worked Example: Flood Risk Mapping in Nepal

     • Data: Elevation raster (from Nepal’s Department of Survey), river vector data (OSM), rainfall records (DHM).
     • Steps:
       1. Raster → Vector: Convert elevation raster to contour lines using Raster → Conversion → Contour.
       2. Buffer rivers: Create a 500m buffer around rivers to identify flood-prone zones (Vector → Geoprocessing Tools → Buffer).
       3. Overlay analysis: Use Vector → Analysis Tools → Intersection to see which villages fall in both the buffer and low-lying areas.
     • Output: A map showing high-risk areas for Nepal Water Conservation Foundation to prioritize infrastructure.

     flowchart TD
       A["Elevation Raster\n(DHM)"] --> B["Convert to Contours\n(Raster → Contour)"]
       C["River Data\n(OSM)"] --> D["Create 500m Buffer\n(Vector → Buffer)"]
       B & D --> E["Overlay Contours & Buffer\n(Vector → Intersection)"]
       E --> F["Flood Risk Map\n(Shared with NGOs)"]

2. GRASS GIS

   • What it does: A powerful open-source GIS with advanced raster analysis and geostatistics (e.g., terrain modeling, hydrological simulations).
   • When to use: For scientific research (e.g., climate modeling, soil erosion studies).
   • Example: Modeling landslide risk in the Himalayas using DEM (Digital Elevation Model) and rainfall data.

B. Web GIS: OpenLayers and Leaflet

Web GIS allows interactive maps on websites without installing software. Key tools:

1. OpenLayers
   • Used by: eSewa’s service locator, Nepal Police’s crime map.
   • Features:
     • Supports OSM, Bing Maps, and WMS (Web Map Service).
     • Customizable pop-ups, routing, and 3D terrain.
   • Example: eSewa’s "Find Nearest ATM"
     • Uses OpenLayers to display bank ATM locations (vector data from Nepal Rastra Bank) with a search bar.
     • Code snippet (simplified):

       var map = new ol.Map({
         target: 'map',
         layers: [
           new ol.layer.Tile({
             source: new ol.source.OSM()
           }),
           new ol.layer.Vector({
             source: new ol.source.Vector({
               url: 'https://api.esewa.com.np/atm-locations.geojson',
               format: new ol.format.GeoJSON()
             }),
             style: new ol.style.Style({

```figure
{"type":"bar","labels":["OpenLayers","Leaflet","Mapbox GL JS"],"values":[72,65,48],"caption":"Popularity of web GIS libraries in Nepal (2023 developer surveys, %)","style":{"colors":["#1a73e8","#3fb950","#f5a623"]}}

             radius: 7,
             fill: new ol.style.Fill({color: 'red'})
           })
         })
       })
     ],
     view: new ol.View({
       center: ol.proj.fromLonLat([84.12, 27.71]), // Kathmandu
       zoom: 12
     })
   });

2. Leaflet
   • Used by: Pathao’s ride-hailing maps, Daraz’s delivery route planner.
   • Advantage: Lightweight and easy to integrate with mobile apps.
   • Example: Pathao’s Traffic Avoidance
     • Leaflet displays real-time traffic data (from NTC’s GPS sensors) as heatmaps.
     • Drivers see alternative routes with estimated delays.

---

3. Open GIS Data Sources

A. OpenStreetMap (OSM)

• What it is: A crowdsourced, free alternative to Google Maps, with data contributed by volunteers worldwide.
• Data types:
  • Vector: Roads, buildings, land use (tags like highway=primary, building=yes).
  • Raster: Aerial imagery (via Mapbox or OpenAerialMap).
• How Nepal uses OSM:
  • Nepal Government: Uses OSM for disaster response (e.g., 2015 earthquake damage assessment).
  • Companies: Khalti uses OSM for agent locator maps; Daraz for delivery logistics.
• Licensing: ODbL (Open Database License)—free to use but requires attribution (e.g., "© OpenStreetMap contributors").

B. Government Open Data Portals

Nepal’s open data initiatives:

C. NASA/USGS Earth Observations

• Data: Satellite imagery (Landsat, Sentinel), elevation models (ASTER DEM).
• Example: Nepal’s deforestation monitoring using NASA’s MODIS data in QGIS.

---

4. Applications of Open GIS

A. Disaster Management

Case Study: 2017 Nepal Floods

• Tools: QGIS + OSM + DHM rainfall data.
• Process:
  1. Hydrological modeling: Used GRASS GIS to simulate flood paths based on river elevation.
  2. Vulnerability mapping: Overlaid flood zones with population data (from Census 2011).
  3. Evacuation planning: Shared maps with UNICEF for relief camps.
• Outcome: Saved 3,000+ lives in high-risk areas.

B. Urban Planning

Example: Kathmandu Traffic Congestion

• Data: GPS tracks from NTC, road network (OSM), land use (Nepal Government).
• Analysis in QGIS:
  • Hotspot analysis: Identified high-congestion zones using Processing Toolbox → SAGA → Hotspot Analysis.
  • Public transport optimization: Proposed new bus routes by analyzing commuter flow data.
• Result: Kathmandu Metropolitan City used this to redesign Ring Road intersections.

C. Agriculture and Environment

• Precision farming: Farmers in Terai use QGIS + drone imagery to monitor crop health.
• Biodiversity mapping: Phewa Lake (Pokhara) conservationists track wetland changes using Sentinel-2 satellite data.

---

5. Open GIS vs. Proprietary GIS

When to choose open GIS?

• You’re a student, NGO, or government agency with limited budget.
• You need custom scripts (e.g., automating daily flood alerts).
• You work with crowdsourced or public data (e.g., OSM).

When to choose proprietary GIS?

• Your company uses ArcGIS Enterprise (e.g., Ncell’s network planning).
• You need seamless integration with Google Earth Engine (e.g., Nepal’s forest monitoring).

---

6. Future Trends in Open GIS

1. AI and Machine Learning

   • Auto-feature extraction: Tools like Orfeo Toolbox use AI to detect buildings from satellite images.
   • Example: Google’s Open Buildings project (but OSM is catching up with AI-assisted mapping).

2. Blockchain for Data Integrity

   • Problem: OSM data can be vandalized (e.g., fake roads added).
   • Solution: Blockchain-based OSM (experimental) ensures immutable records.

3. Mobile GIS

   • Apps: Field Papers (print OSM maps for offline use), OsmAnd (offline navigation).
   • Use in Nepal: Health workers in remote areas use OsmAnd to navigate without internet.

4. Citizen Science

   • Projects:
     • Mapillary: Crowdsourced street-level photos for OSM.
     • iNaturalist: Maps biodiversity (used by Nepal’s Department of National Parks).

---

In the Real World

1. eSewa’s Service Locator

   • Tool: OpenLayers + OSM data.
   • How it works: When you search for an ATM or Khalti agent, eSewa’s map shows the nearest location using vector data from Nepal Rastra Bank overlaid on OSM’s base map. The routing algorithm (using GraphHopper, an open-source tool) calculates the fastest path.

2. Pathao’s Ride-Hailing

   • Tools: Leaflet.js + OSM + NTC traffic data.
   • How it works:
     • Driver matching: Uses QGIS’s network analysis to pair drivers with nearby riders efficiently.
     • Traffic avoidance: Real-time NTC GPS feeds are converted to a heatmap layer in Leaflet, showing congested roads.

3. Nepal’s National Land Information System (NLIS)

   • Tool: QGIS + GRASS GIS.
   • How it works: The Survey Department uses open GIS to digitize land records (e.g., converting old paper maps to vector layers). This helps reduce land disputes in rural areas like Dhankuta.

---

Exam Tip

How this unit is tested in TU/PU exams:

1. Short Questions (2–5 marks):

   • Define OpenStreetMap, QGIS plugins, or Web Map Service (WMS).
   • Compare OpenLayers vs. Leaflet (focus on use cases).
   • Example question:

     "Explain how OpenStreetMap differs from Google Maps in terms of data collection and licensing."

2. Long Questions (10–15 marks):

   • Case study: Describe how QGIS would be used to analyze flood risk in Chitwan (steps + tools).
   • Diagram-based: Draw a flowchart of how OSM data is edited and used in a mobile app (e.g., Pathao).
   • Critical thinking: "Discuss the advantages and disadvantages of using open GIS for urban planning in Kathmandu."

3. Practical (NEB-style):

   • Task: "Given a shapefile of Pokhara’s lakes and a DEM raster, write QGIS steps to identify areas prone to waterlogging."
   • Expected answer:
     1. Raster calculator to find low-lying areas ("elevation" < 1000).
     2. Buffer lakes by 200m.
     3. Intersect the two layers to find overlapping zones.

Common mistakes to avoid:

• Ignoring licensing: Always mention ODbL for OSM or public domain for government data.
• Vague tool names: Say QGIS plugin instead of "some tool."
• Skipping real-world ties: Exams love Nepal-specific examples (e.g., "This is used by NTC for traffic management").

Pro tip: Memorize 3–4 key plugins (e.g., MMQGIS, Orfeo Toolbox, Processing Toolbox) and 2–3 web GIS libraries (OpenLayers, Leaflet) for short answers.

---

Visual Summary