Geography of Sikkim

The thumb-shaped state of Sikkim is characterised by wholly mountainous terrain. Almost the entire state is hilly, with the elevation ranging from 280 metres (920 feet) to 8,585 metres (28,000 feet). The summit of the Kanchenjunga is the highest point. For the most part, the land is unfit for agriculture because of the precipitous and rocky slopes.

However, certain hill slopes have been converted into farm lands using terrace farming techniques and is used for cultivation. Numerous snow-fed streams in Sikkim have carved out river valleys in the west and south of the state. These streams combine into the Teesta and its tributary, the Rangeet. The Teesta, described as the “lifeline of Sikkim“, flows through the state from north to south. About a third of the land is heavily forested.

The lofty Himalayan ranges surround the northern, eastern and western borders of Sikkim in a crescent. The populated areas lie in the southern reaches of the state, in the Lower Himalayas. The state has twenty-eight mountain peaks, twenty-one glaciers, 227 high altitude lakes, including the Tsongmo Lake, Gurudongmar and Khecheopalri Lakes, five hot springs, and over 100 rivers and streams. Eight mountain passes connect the state to Tibet, Bhutan and Nepal.

Geology

The hills of Sikkim mainly consist of gneissose and half-schistose rocks, making their soil brown clay, and generally poor and shallow. The soil is coarse, with large amounts of iron oxide concentrations, ranging from neutral to acidic and has poor organic and mineral nutrients. This type of soil tends to support evergreen and deciduous forests.

A large portion of the Sikkim territory is covered by the Precambrian rock and is much younger in age than the hills. The rock consists of phyllites and schists and therefore the slopes are highly susceptible to weathering and prone to erosion. This, combined with the intense rain, causes extensive soil erosion and heavy loss of soil nutrients through leaching. As a result, landslides are frequent, isolating the numerous small towns and villages from the major urban centres.