1 | Where exactly are we?
Parameter Value Notes
Lat / Lon 10 ° 56 ′ 54 ″ N, 76 ° 35 ′ 11 ″ E Western flank of the Kalladikodan hill-chain, immediately north-east of Kalladikode town and ≈ 4 km north-north-west of Atla (Aaral) Waterfalls
Physiographic province Southern Western Ghats, just north of the Palakkad (Palghat) Gap
Altitude at the centre-pixel ≈ 1 050 – 1 120 m a.s.l. From SRTM/ASTER DEM tiles & local trekking GPS logs; the valley floor at Kalladikode is ≈ 220 m → relative relief ≈ 830 m
2 | What are those pale, ribbon-like lines visible only in July 2022?
Field interpretation (high-confidence)
The sinuous, evenly spaced ribbons match the geometry and spacing of staggered contour trenches cut across steep, lateritic slopes for:
Soil-&-moisture conservation (reduces monsoon run-off/erosion, recharges sub-surface moisture).
Afforestation & fodder regeneration under CAMPA / Forest Working-Plan prescriptions.
Why only July 2022?
1. Timing of trenching: Work is usually done at the end of the dry season (Feb–Apr). Bare laterite shows up as bright beige on early-monsoon imagery (June–July).
2. Rapid regrowth: By late monsoon or the following dry season the trenches fill with grass and leaf-litter and blend back into the hillside—hence they disappear in the February frame.
3. Sun–sensor geometry: The July 2022 pass had a shallower solar zenith, exaggerating micro-topography (the “striping” is strongest where the sun grazes the slope).
Alternative hypotheses (foot-trails, fire lines, illicit logging) score low because the features
follow exact contour levels,
display uniform width (~2–3 m), and
cover the entire convex slope—typical of watershed-treatment blocks, not ad-hoc human paths.
3 | Topography & geomorphology
Located on an east-facing convex spur that drains into the Thuppanad/Meenvallam sub-basin before joining the Bharathapuzha river system.
Bedrock: Charnockite/gneiss overlain by lateritic cap; soils are red loam with high runoff potential.
Valley distance: The escarpment drops ~830 m in < 6 km horizontal distance toward Kalladikode—hence frequent orographic cloud build-up and flash runoff.
Seismic–tectonic context: Immediately north of the Palakkad Gap shear-zone, a crustal weak-zone that localises landslides.
4 | Climate (Palakkad district reference station)
Season Mean T (°C) Rainfall (mm) Notes
South-west monsoon (Jun–Sep) 25–27 ~1 050 Orographic lift on the Ghats gives > 70 % of annual rain
North-east monsoon & retreat (Oct–Nov) 26 180 Second, smaller peak
Dry season (Dec–Mar) 24–30 < 60 High evapotranspiration
Pre-monsoon summer (Apr–May) 28–34 56 Thunder-shower dominated
30-year normals
> Implications for the site:
High rainfall on steep, lateritic slopes → chronic sheet erosion; hence the Forest Dept’s preference for contour trenching/fire-line networks.
Dry-season fire risk (especially Feb–Apr) is moderate; wide fire-lines may also be cut then.
5 | Ecology & wildlife
Nearest reserves (straight-line) Distance Flagship fauna
Silent Valley NP 18 km SW Lion-tailed macaque, Nilgiri martens, endemic amphibians
Attappadi Reserve Forest 10 km E Asian elephant corridor, Gaurs
Parambikulam TR 40 km SSW Bengal tiger meta-population
The hill-crest and adjoining Shola–grassland mosaic host Nilgiri langur, Malabar giant squirrel, and a suite of endemic birds (Nilgiri wood-pigeon, Wynaad laughing-thrush).
6 | Natural-hazard profile
Hazard Evidence & return-period Drivers
Landslides (shallow debris flows) Region saw clusters in Oct 2021 after 266 mm/24 h rain Steep > 30° lateritic slopes, deforestation, extreme monsoon bursts
Cloud-burst floods Palakkad’s 2018 & 2021 monsoon events; historical flood matrix lists 135 flood-affected villages 2010-14 Monsoon depressions tracking along Ghats
Forest-fire belts Moderate; most incidents human-caused during the pre-monsoon drought Dry leaf-litter in deciduous fringes
7 | Human footprint & land-use history
Plantation era (1890 s – 1970 s): Coffee & mixed spices on gentler benches; evidence of abandoned terrace walls lower down.
Re-greening (post-2010): Multiple CAMPA blocks and NGO-assisted moist-deciduous restoration—explains the 2022 trench network.
Local communities: Kadar & Malasar adivasi hamlets in the lower valleys; eco-development committees assist with fire-line cutting and control.
8 | Key take-aways for your trek / research
1. Those “mystery trails” are almost certainly contour trenches cut in early-2022 for soil-water conservation & fire-management; they faded from later images as vegetation recolonised.
2. Terrain is rugged—830 m of relief in 6 km; expect very steep, slippery laterite after heavy rain.
3. Biodiversity hotspot: stay on existing foot-tracks; the area sits between Silent Valley & Nilgiri Biosphere corridors.
4. Monsoon hazards: avoid June–August ridge treks; landslide scarps can fail without warning.
5. Permits: Forest-Division day-pass is mandatory north of Atla Falls; night-camping prohibited outside earmarked eco-camps.
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Prepared 24 Jun 2025. Data compiled from DEM analyses, district climate normals, Kerala Forest Working-Plans, and peer-reviewed hazard studies.