Mountains and Nepal

Mountain is a topographical feature that rises more than 300m above the surrounding. There is a difference between mountain and hill. Hill is a land surface lower than a mountain that rises prominently above the surrounding lands to elevations less than 300 m. This region is represented by Siwalik and Mahabharat range in Nepal. Mountain environment is of great importance in Nepal. Nepal is predominantly a mountainous country. The Himalaya extends over a length of approximately 2400 km from the Indus to the Brahmputra. The central sector of Himalaya about 800 km lies in the kingdom of Nepal. The hills and the Himalayas constitute over 78% of the total geographical area of Nepal (145,305 sq. km.). Nepal justifies its position as elevationally highest country in the world with average altitude of 4500 m, and most of majestic peaks of the world are located here.
The global elevation mean is 975 m and the earth surface has about 0.5 percent area above 4000 m, 3.3 percent area between 2000 to 4000 m and 25.3 percent land between 0 to 2000 m altitude. Nepal is privileged in having the proud summit Mt. Everest / Sagarmatha. There are nine peaks above 8000 m, 127 peaks above 7000 m, and 1311 peaks above 6000 m making the Nepal Himalaya an unique topography in the world. Mountains are religiously, aesthetically, biologically and culturally very significant to man. Mountains are regarded as source of aspiration and places of vital apiritual values. About 10% of global population inhabit in the mountain areas and about 40% population harvest direct or indirect benefits from mountains. Nepal is the world's fastest tourism growing country in the world, particularly for mountaineering and trekking. Mountains are rich in biodiversity, thus they provide us a large number of wildlife, sound ecosystem and maintain gaseous and water cycle of our nature.

In Nepal, mountains are affected by certain factors. Lets first take a look at the climatic factors. Heavier rainfall is brought about by the south-west monsoon from the Bay of Bengal which begins by mid-June and continues till mid-September. First, it reaches the eastern part of the country which gets the highest amount of rainfall. Gradually the rainfall decreases towards the west. All parts of the country also receives winter shower in late March. The southern slope of the Mahabharat receives maximum annual rainfall (5550 mm at Lumle) and the rainfall is minimum (295 m manually at Jomsom) in the inner Himalayan Valleys (Stainton, 1972). Similarly, the temperature varies from extrene hot in the tropical plains to artic frost in the mountain regions. High humidity is marked during rainy months in the Terai. The Kathmandu Valley comprises a relative humidity of more than 80% during the months of July and August. The different vegetational zones of the country represent distinctly the soil composition of different types (Bhatt, 1977, 1981). Terai region is characterized by alluvial soil which is transported by the river systems, having well stratified, rounded and smooth particles. The Siwalik zone is composed of unstable soil with sand, stone, shale and boulder. The Mahabharat zone is conspicuously characterized by parent rocks of limestone, dolomite and quartz. The trans-Himalayan zone consists of an accumulation of the sedimentation of Paleozoic era. On the basis of altitude Nepal is divided into following zones:

(i) Tropical zone (upto 1000 m)

(ii) Subtropical zone (1000 m to 2100 m)

(iii) Temperate zone (2100 m to 3000 m)

(iv) Sub-alpine and alpine zones (3000 m to 5000 m)

(i) Tropical Zone [upto 1000 m]: It is characterized by the high temperature, abundant rainfall and virtually continuous growing season. This zone extend from east to west and include Terai, Siwalik hills and Dun valleys. It is characterized by different kinds of deciduous trees dominated by sal forest (Shorea robusta). The other tree species associated with sal forest are Adina cordifolia (Karma), Terminalia bellirica (barro), T. chebula (harro), Syzygium cumini (Jamun), Butea monosperma (plans) etc. Dalbergia sisso (sisi) and Acacia catechu (Khair) are the common decidous species along the riverside terraces. Riverine forest includes Albizzia procera (Siris), Bombax ceiba (Simal), Cassia fistula (amaltas) etc. The common mammalian fauna of tropical zoneare hog deer (cervus porcinus), spotted deer (Axis axis), wild boar (Sus scrofa), leopard (Panthera pardus), wild dog (Cuon alpinus), sloth bear, Jackel, monkey etc. The threatened unique species are the grat one-horned rhinoceros (Rhinoceros unicornis), tiger (Panthera tigris) and wild elephant (Elephas maximus).

(ii) Sub-tropical Zone: Sub-tropical zone lies between 1000m and 2100m. It includes Siwalik hills and the southern slope of Mahabharat range. It is characterized by moderately warm and humid climate. The central and eastern regions of this zone are represented by chilaune-katush (Schima wallichaina and Castanopsis indica) forest. However, in western Nepal this zone is characterized by the occurrence of Pinus roxurghii. We

t ravines and gullies have almost always a belt of Alnus nepalensis. The associated tree species are Acer oblongum, Michelia kisopa, Myrica esculanta, F. semicordata, etc. The most common mammalian fauna of subtropical zone are leopard (Panthera pardus), wild dog (Cuon alpinus), fox, wild boar, Jackal, wolf, monkey, etc.

(iii) Temperate Zone: This zone includes principally the Mahabharat range which lies almost parallel and north to Siwalik hills from east to west. The region falls between the altitude 2100 m and 3000 m and is represented by a cool and humid climate. This zone is characterized by laurel, evergreen oak, mixed broad-leaved deciduous and Rhododendron forests in the eastern and central Nepal, while in western Nepal, it is a zone of distinct evergreen coniferous forests and deciduous mixed forests. Laurel and evergreen oak forests are found in the lower part of this zone. The mammalian fauna of temperate zone are leopard (Panthera pardus), wolf (Canis lupus), ghoral (Naemorhedus goral), wild

boar, Himalayan black bear, langur (Presbytis entellus) etc.

(iv) Sub-alpine and Alpine Zone: The slopes above 3000 m to the timber line at about 4000 m, come under the sub-alpine zone. Between the timberline (4000 m) and the snowline (5000m), the mountainous country of Nepal comes under the Alpine Zone. The climate is extremely cold, dry and windy. The sub-alpine zone is characterized by Abies spectabilis at lower level and birch-rhododendron (Beutal utilis-Rhododendron companulatum) forests at upper level near the timber line. The rimber line is estimated to be 4100m in eastern Nepal, while it goes down to 3,800m and 3,650 m in central and western Nepal respectively. Alpine zone vegetation consists of mainly grasses, herbs and dwarf shrubs. Some of the well known ones are Juniperus spp. and Rhododendron spp. on exposed slopes. Other associated species are Acontinum, Anaphalis, Meconopis, Potentilla, Primula, Saxifraga. The different species of Rhododendron are R. fulgens, R. wightii, R. lepidotum, R. nivale

etc. The alpine zone experiences heavy snowfall in winter. During the summer, alpine fields are used for grazing the shep and yaks. The alpine herbs remain quite prominent upto 5200 m. Beyond this altitude the palces are covered with continuous snow and no traces of important vegetation can be seen except mosses and lichens at scattered places. The mammal species include the snow leopard (Panthera uncia), red panda (Ailurus fulgens), musk deer (Moschus moschiferus), blue sheep (Pseudois nayaur), wild boar (Sus scrofai), Himalayan black bear (Selenarctos thibetanus), Ghoral (Naemorhedus ghoral).

Pollution is the major problem in mountainous region of Nepal. Degradation of quality of environment which includes air, water and soil is known as pollution. Odum (1971) stated that pollution is an undesirable change in the physical, chemical or biological

characteristics of our air, land and water that may or will harmfully affect human life, industrial progress, living conditions, and cultural assets. Southwick (1976) defined that pollution is the unfavorable alteration of our environment, largely as a result of human activities. A clean and unpolluted environment is the basic necessity for the happy and healthy life of man. Due to man himself the present day environment around the globe is rapidly becoming unsuitable for hu

man survival. They are destroying the very environment on which they survive. The process of urbanization and industrialization has, no doubt, made the human life more comfortable, on this planet. There has also been rapid advancement in the field of agricultur

e. By developing new varieties of wheat, rice and other crop plants, man has succeeded in increasing the yield from the manyfold. Better irrigational facilities, use of chemical fertilizers, pesticides and insecticides, no doubt, have accelerated the green revolution. Increasing human population produces a strain on the resources and availability of energy and materials. Use of fuels, fertilizers, agrochemicals (pesticides) and disposal of waste materials introduce many unwanted substance in the environment. These substances gradually degrade the quality of air, water and soil, which is called pollution. Environmental pollution and population explosion, if not checked in time, will be potentially dangerous to the very survival of man on this little planet. The three major types of pollution are:

(i) Air pollution

(ii) Water pollution

(iii) Soil pollution