PANAJI
Soil erosion in Goa is occurring at rates nearly five times higher than the permissible limit, raising serious concerns over land degradation and ecological sustainability in the State.
A recent scientific assessment using the Revised Universal Soil Loss Equation has found that the average soil loss in Goa stood at 58.11 tonnes per hectare per year (t/ha/yr) in earlier years, before declining slightly to 51.79 t/ha/yr in 2024. However, both figures remain significantly higher than the national tolerance limit of 11.2 t/ha/yr, indicating that soil is being lost at an unsustainable pace.
The study, titled ‘Estimation of Soil Erosion in Goa using RUSLE, Remote Sensing and GIS’ and published in the Indian Geotechnical Journal, analysed soil loss patterns between 2020 and 2024. It attributes the high erosion rates to heavy rainfall, undulating terrain, and changes in land use, including the loss of natural vegetation.
The findings suggest that current erosion levels are roughly 4.5 to 5 times above the acceptable threshold, as identified by the Indian Council of Agricultural Research (ICAR), meaning topsoil is being depleted far faster than it can naturally regenerate.
Data inputs for the study included satellite imagery from Landsat 8, Digital Elevation Models, and rainfall records. Key factors influencing erosion-such as rainfall intensity, slope, soil type, vegetation cover and conservation practices were mapped through thematic layers.
The report underscores the urgent need to protect natural land cover and implement soil conservation measures, including afforestation and sustainable land-use planning. “Since these results are above the sustainable threshold, there is a necessity of safeguarding natural land cover to mitigate soil erosion and an urgent need for conservation and protection measures in Goa to preserve the natural landscape and effectively minimize soil erosion,” the study noted.
Earlier, in 2023, the ICAR-Central Coastal Agricultural Research Institute had highlighted that Goa’s unique undulating topography with slopes ranging from 0 to 280 per cent and an average slope of 14.41 per cent combined with heavy annual rainfall exceeding 3,000 mm, makes the state particularly vulnerable to soil erosion.
ICAR has observed that soil erosion losses in Goa range from moderate levels (<15 t/ha/yr) to extremely severe (>80 t/ha/yr), while the national average soil loss stands at 15.59 t/ha/yr, still above the permissible limit of 11.2 t/ha/yr.
