The Churia range, also called Siwaliks, corresponds to the outermost range of the Himalayas. It rises steeply from the Tarai plains along its northern border. At places, the Churia range is separated from the Mahabharat range by valleys known as duns or Inner Tarai. At some other places, it bifurcates, forming a dun between them. The Churia hills are geologically young, and are composed of unconsolidated loose materials originating from soft rocks such as mudstone, sandstone, siltstone and shale. Covering 33 districts, they border the Mahabharat range in the north and the Bhabar in the south. The gentle slope and flatland immediately to the south of the Churia hills is called Bhabar (broadly included in the Tarai region). Consisting mainly of gravel, it comprises about 18 per cent of the total land area of the Tarai region. 

Not only are the Churia hills structurally weak, but they also lie in a high volume precipitation zone. Forest degradation and agricultural interventions pose great threats to the environment in these areas. The erosion hazards are particularly very high in the Churia hills compared to other mountain areas of the country. Any human activity causing destruction of the vegetative cover leads to erosion in the Churia. This, in