Every year in the ridgetop city of Aizawl, landslides destroy buildings, roads and lives. These disasters result from a combination of the steep terrain, intense rainfall, and construction activity that undercuts slopes. A strong earthquake, though infrequent, will also trigger landslides--thousands at the same time. 

 

More than 300,000 people live in Aizawl today, with an expected 820,000 by 2031. They live in multi-story buildings packed onto slopes with unstable geology. Urban growth pushes unauthorized development onto ever more fragile areas, where it increasingly triggers landslides. 

 

The Aizawl Municipal Corporation is taking action aimed at preventing landslide disasters. We helped the city draft new regulations that control where and how people can excavate to build on slopes. The regulations require a professional geologist's inspection and approval of proposed slope modifications.

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Local geologists and engineers took part in our intensive classroom training and field courses that focused on how to investigate hazards, inspect excavations, and monitor early-stage landslides. Now they are prepared to implement the new rules with confidence. University professors and geology students also took part, and their ongoing training will serve the district for many years.

 

We created landslide hazard maps at 1:5000 scale for the entire Aizawl municipal district. They pinpoint hazards such as steep slopes with adverse bedding, jointed sandstone and shale layers, and historic or incipient landslides.These are the first community hazard maps at such a large scale in India.

 

The maps are an essential tool for enforcing the new regulations. They're big enough to identify landslide risk at the parcel level, and they mark zones connected to policy action.

 

With new site development regulations, trained local experts, and large-scale landslide hazard maps, the city can anticipate preventable disasters--and take action to protect people from harm.

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Project funded by reinsurer Munich Re​​