Cultivation is intensive. The valley areas have fertile and rich soil. There is intensive cultivation on terraced hill slopes, but irrigation facilities are deficient. The Siwalik Range which forms the southern foothills of the Himalayas, slopes down into a boulder bed called 'bhadhar'. The transitional belt running along the entire length of the state is called the terai and bhabhar area. It has rich forests, cutting across it are innumerable streams which swell into raging torrents during the monsoon.