Environmental disaster has struck Kerala once again. Unusually heavy rains have caused landslides in Kottayam and Idukki.
High loss of life due to such disaster must lead to a serious review of the land-use pattern in Kerala.
With a population density of 860 persons/sq. km against an all-India average of 368 persons/sq. km (Census 2011), Kerala experiences very high pressure on the land.
Brief on Landslides:
A landslide is defined as the movement of a mass of rock, debris or earth down a slope.
Landslides are a type of mass wasting (a geomorphic process) which denotes any down-slope movement of soil and rock under the direct influence of gravity.
The important causes of Landslides are slow weathering of rocks as well as soil erosion, earthquakes and volcanic activity.
Land-use change: Settlement of the highlands instead of Coastal plains:
- Historically, most of the settlements were concentrated in the coastal plain, the adjoining lowlands and parts of the midlands.
- However, this scenario has altered now, with significant land-use change across topographic boundaries.
- Population growth, agricultural expansion, economic growth, infrastructure development, particularly road construction and intra-State migration have all led to settlement of the highlands.
- Kerala is experiencing high growth of residential buildings. The Census records that during the decade between 2001 and 2011, the population grew by 5% whereas the number of houses grew by 19.9%.
- Such a pace of construction has serious implications for the geo-environment.
- Not only the locations for siting settlements but also the demand for construction materials, with the attendant quarrying and excavations, is altering the landscape through terracing, slope modification, rock quarrying, and the construction of roads. The basin characteristics of all rivers have been altered.
- This has resulted in gross disturbance of the character of the terrain evolved through weathering and formation of soil under natural vegetation cover. Consequently, the water-absorbing capacity of the river catchment is lost, contributing to increasing surface run-off and reduction in ground water recharge.
- Road construction in hilly areas, even when cutting across the toe of the slope, is destabilising and creates conditions conducive to landslides.
On the unchecked land use pattern in the hilly districts:
It is important that for the hilly districts of Idukki and Wayanad, both the local and State authorities should rely on scientific reports on the landslide vulnerabilities to reach decisions on land allocations for various constructions.
While deciding on it, local soil properties and slope stability should be important factors to be considered rather than political expediency.
The incidents of landslides in the State have increased exponentially over the last several years.
Consequence of Hesitancy in implementation of Gadgil Committee recommendations:
- Construction on hill slopes prone to disintegration during heavy rain is a threat not only to those who choose to live in the buildings but also to those who are in the path of the debris that gets dislodged in a landslide.
- It is clear by now that in parts of the State the hills have been overbuilt, posing a danger to life.
- Interestingly, the extremely complicated rules for registration of purchase and sale of property in Kerala are not matched by a due diligence of building plans.
- It is not even clear that the authorities responsible for the oversight of construction are sufficiently aware of the nature of the problem.
- While the idea of a construction-free Coastal Regulation Zone, instituted by the Government of India and applicable to the entire country, is fairly well recognised in the State, the Government of Kerala has been timid in enforcing similar regulation in its own backyard.
- The hesitancy towards the implementation of the recommendations by the Western Ghats Ecology Expert Panel, commonly known as the Gadgil Committee, on protection of the Western Ghats is the best example of this. We can now see how prescient they were.
Review of two projects must be done:
- While evolving a land-use protocol to be observed in all cases without exception cannot be delayed any further, it is understandable that it may take time.
- However, the most recent landslide in Kerala should lead the government to immediately review two major projects with a potential to lower ecological security.
- The first of these is the Silver Line project, a light railway connecting the two extremities of the State.
- Its potential to usurp agricultural land and cause ecological disturbance is well known. The claim that it is vital to the development of the State, reportedly made by the government in the Legislature, is debatable.
- After all, a railway line exists across the entire length of the State already, and how much a saving of a few hours’ travel time can contribute to the gross domestic product is not clear at all.
- While infrastructure for growth is necessary, Kerala’s deficit is less with respect to transportation than what it is to power generation, urban infrastructure and a well-trained workforce.
- As the Kochi Metro network was being expanded, a prominent entrepreneur of the city rightly observed that it needs a sewage disposal system more than it needs a rapid transit network.
- Overnight, tree-lined roads have been converted to bare tarmac exposed to the sun. The loss of vegetation and tree cover is sure to have an impact on local climate and water retention, impacting its availability.
Way Ahead steps:
- Climate change, population growth and related economic aspects should have compelled Kerala to move towards a more integrated, catchment-based approach to the management of land and water, if necessary, through environmental legislation.
- A key component of this integrated catchment-based approach is the recognition that only by strengthening the natural processes, the rivers would be able to find their pathways for flood waters.
- For that to happen, the immediate need is to develop flood zonation maps for various catchment areas.
- By now, the State should have developed macro- and micro-level flood vulnerability maps based on flood histories.
- These maps should have been used to issue both long-term and short-term warnings to the local population.
- For the long term, these maps available locally should be used for land zonation and thus help the residents to move out in exchange for land elsewhere. The same procedure should be followed also in the case of landslides.
- We need to follow the land zonation map in identifying the areas vulnerable to landslides and discourage building houses in such places.
It is important to bring in restrictions on machine-mediated quarrying activities. A blueprint that demarcates areas suitable for habituation and those to be left untouched should help strictly implement the basic tenets of land zonation.
A comprehensive master plan on land utilisation strategy based on a clear environmental vision needs to be prepared at macro and micro-levels to ensure that encroachment is minimal.
These documents should contain clear guidelines for constructions, including recommended designs of houses, that will match with local landscape and scenery.