| Lower Liasan | |
|---|---|
| Municipality | Tambulig |
| Province | Zamboanga del Sur |
| PSGC code | PH0907328019 |
| Population (2020 est.) | 390 |
| Area | 2.5 km² |
| Cell towers | 0 |
| Coverage status | Dead zone: no towers from any source |
| Typhoons since 1980 | 10 (within 100 km) |
Lower Liasan is a barangay of Tambulig, Zamboanga del Sur, Philippines, with an estimated population of 390 (WorldPop 2020, corrected zonal estimate). It is classified as a connectivity dead zone: neither the national tower registry nor crowdsourced signal data records any cell tower within the barangay. Household income in the area is estimated at ₱17,070 per month; a Starlink satellite subscription (₱4,099/month) would represent approximately 24% of that income.
| Indicator | Value | Source |
|---|---|---|
| Registered cell towers (NTC) | 0 | NTC registry |
| Crowdsourced towers (OpenCelliD) | 0 | OpenCelliD |
| Coverage classification | Dead zone: no towers from any source | Cross-validation |
| Median download (where tested) | 18.5 Mbps | M-Lab |
| Backbone proximity | 25 to 50 km from the backbone | Submarine Cable Map / PeeringDB / DICT |
Estimated household income: ₱17,070/month (modeled from PSA poverty incidence, 39.0% for the municipality). Starlink (₱4,099/month) would consume about 24% of household income, well above common affordability benchmarks.
| Indicator | Value | Source |
|---|---|---|
| Mean elevation | 186 m | FABDEM |
| Mean slope | 16.8° | FABDEM |
| Tree canopy height | 26.0 m | ETH Global Canopy 2020 |
| Travel time to nearest city | 29 min | Malaria Atlas Project |
Since 1980, 10 tropical cyclones have passed within 100 km (NOAA IBTrACS). Satellite records show 0 observed flood event(s) (Global Flood Database). Lightning density is 0.23 strokes/km²/year (WGLC).
Annual average night-time radiance (NASA VIIRS), a proxy for electrification and economic activity:
NTC tower registry · OpenCelliD · WorldPop 2020 (100 m, corrected zonal statistics) · PSA Small Area Estimates · NASA VIIRS · NOAA IBTrACS v04 · Global Flood Database · ETH Global Canopy Height · FABDEM · Malaria Atlas Project · WGLC lightning climatology · Microsoft Global ML Building Footprints · Starlink Philippines published pricing. Methodology: data fused at barangay level using PSGC boundaries (2023).