Chapter 1: introduction
Tamor-Kabeli Watershed General Context
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- Bu səhifədəki naviqasiya:
- Figure 7.3 – Physiographic regions of Nepal
- Protected areas, biological hotspots and forests
- 7.3.1 Current Developmental Status of the Tamor-Kabeli Watershed
- 7.3.2 Future Development Projections for the Tamor-Kabeli Watershed
- 7.3.2.1 Hydropower Development
- Table 7.1- Projects with a generation (construction) license (as of June 21, 2013)
- Project Capacity (MW) River
- Table 7.2 -Projects with survey license issued (as of June 21, 2013)
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7.3 Tamor-Kabeli Watershed General Context The KAHEP is located in the Kabeli River about 5.6 kilometers upstream from its confluence with the Tamor River. The Tamor is a major river in eastern Nepal and forms part of the Koshi River system. It has a total length of 198 km and has a drop of nearly 5,850 m from its head to the confluence with Arun at Tribeni. The average river gradient is 0.0295 (Shrestha H.M. 1983). The Tamor is a snow fed river and its hydrology is influenced both by monsoon rains and snowmelt. It originates from the Kanchenjunga area, home to Mount Kanchenjunga, the third tallest mountain in the world (8,586 meters). The Tamor and the Arun Rivers join the Sun Koshi at Tribeni to form the larger Sapta Koshi15 River network which flows through the Mahabharat Range and finally on to the Gangetic plain in India. The Tamor River basin covers four out of five physiographic regions of Nepal within a 200 km north to south direction and with elevation differences from 66 to 8,586 m above sea level. These physiographic regions are shown in Figure 7.3 and described below: Figure 7.3 – Physiographic regions of Nepal 
High Himalayan region: This region is always covered by snow with altitudes ranging from 3,000 to 8,586 meters (Mt. Kanchenjunga). The mountains are very steep with active glacier systems. The Tamor River catchment has a number of glacial lakes with a history of glacial lake outburst floods (GLOF). The GLOF of 1980 originating from Lake Nagma Pokhari had a flood surge reaching 20 m above the riverbed of Yangma Khola. It is estimated that the peak flow at Yangma Khola was about 8,500 m3/s decreasing to about 3,300 m3/s at the gauging station 690 at Mulghat. The geology consists of gneiss, schist, limestone and shale of different ages. Physical weathering predominates and soils are very stony. This region falls largely within the alpine and arctic climate regimes, so there are active glacier systems where there is enough precipitation in high catchments. The climate is dependent on elevation and location in the mountain massifs. Characteristic landforms are glaciers, cirque basins, moraines, U-shaped valleys and avalanche slopes. Bedrock in most of the areas is exposed at or near the surface including gneiss, schist and the Tethys sediments. Less than 1% of the region has soil and climate suited to crop production, only where irrigation is available. High Hills (or Mountain) region: The altitude of this region ranges from 2,000 to 2,500 m and it lies below the permanent snow line. It has a cool climate and receives heavy to moderate snow in winter. Mountain slopes are very steep but there are some flat valleys as well. Phyllite, schist, gneiss, and quartzite of different ages characterize the geology. Soil formation on the slopes is slow and they are rocky. This region borders the Middle Hills to the south and the high Himal to the north. Gneiss and garnetiferous mica schist are common. High river gradients and enhanced river down-cutting resulted in the formation of deep canyons since glaciation. Agriculturally this region is of lesser importance. After the snow melts, the mountains are covered with thick grasses and livestock like sheep, yak, and other mountain animals graze in this region. In the valleys, one crop a year (in summer) is harvested. The Kanchenjunga Conservation Area (KCA) is located within this region, and it is described under the Protected areas, biological hotspots and forest section below. Middle Hills (or Mountain) region: This region includes a wide range of physiography. Mountain peaks range up to 2,000 m with narrow river valleys. The mountains are the Mahabharat range. The geology consists of a complex of phyllite, schist, quartzite of Cambrian to Precambrian ages and granite and limestone of different ages. The climate ranges from warm subtropical to warm temperate. The higher peaks receive occasional snow whereas some lower parts receive occasional frost in winter, which causes damage to crops. Soils are extremely variable because of the differences in bedrock, geomorphology and microclimate. The southern margin mostly consists of a prominent belt of uplifted mountains known as Mahabharat Lekh. This belt is made up of deeply weathered granite, limestone, dolomite, shale, sandstone, slate and quartzite; it is intensively cultivated and is home for more than 60% of the population. Subtropical dense forest occupies the non-agricultural land. The dam and the powerhouse of the Kabeli-A hydropower project is located in this region. Tamor river fisheries are dependent upon the habitats (spawning and rearing) provided by rivers like Kabeli flowing through this region. The mean annual precipitation over the Project area is estimated to be 2,135 mm. Siwalik region: This region lies at the foot of the Mahabharat range. Altitudes range from 300 m to 1,800 m. The geology mainly consists of tertiary mudstone, sandstone, siltstone and conglomerate. Soils vary depending on the materials from which they are developed. There are several inner valleys or duns, which are densely populated. Because of alluvial deposition, these valleys are very fertile. The landscape is very rugged and unstable, consisting of weakly consolidated Tertiary sediments with gentle to strongly sloping dip slope. Siwalik soils are unable to retain high precipitation, which frequently occurs, resulting in flash floods. The Tamor River emerges from the Middle Hills into the Siwalik region. The Terai region: Altitudes range from 66 m to 300 m in the lowest physiographic region of Nepal, the Terai. Although the Tamor basin does not include the Terai, the Tamor river does flow into the Sapta Koshi, which ends up in the Terai. The Tamor River introduces huge amounts of sediments into the Sapta Koshi River, supplying important nutrients for the fertile lands of the Terai region. Protected areas, biological hotspots and forests There are two important biological hotspots in the Tamor-Kabeli watershed: the Kanchenjunga Conservation Area (KCA), and Tinjure Milke Jaljale/Guranse Danda (TMJ) Forest, which provide biological diversity such as unique rhododendron forests, rare and endangered wildlife and bird species, medicinal and aromatic plants as well as spectacular panoramic views of the Himalaya range: Kanchenjunga, Makalu, and Kumbhakarna. Both KCA (25 km aerial distance from KAHEP) and TMJ (10 km aerial distance from KAHEP) are in a remote mountainous region and are accessible only by trekking over steep mountainous terrain from the KAHEP site: at least two days to KCA and one and half days to TMJ. The Kanchenjunga Conservation Area: The KCA is the main protected area in the watershed and is located in the Taplejung district, in the high hills region, at an altitude of 2000-2500 m. The landscape of the KCA comprises cultivated lands, forests, pastures, rivers, high altitude lakes and glaciers. It has an area of 2035 km2 representing high mountain physiographic regions, as follows: rocks and ice (65%); forests (14.1%); shrubs (10.1%); grassland (9.2%) and agricultural land (1.6%). The KCA comprises some of the most stunning scenery in all of Nepal and is a global hotspot for plant biodiversity, with twenty-three species of rhododendrons growing in the area. Rich forests support more than 250 species of birds and endangered wildlife. KCA is well known for its three river valleys (Simbua Khola, Ghunsa, and Tamor valleys) and has a lot of ethnic diversity and cultures. Approximately 5,000 people of about 11 ethnic communities live in the area. In 1998, the Department of National Parks and Wildlife Conservation (DNPWC) joined WWF Nepal to launch the Kanchenjunga Conservation Area Project (KCAP) in an effort to help ensure sustainable management of the region’s pristine ecosystem. KCA Management Council (KCAMC) was formed with the support of WWF Nepal in April 2003. In August 2006, the cabinet of the GoN passed a resolution to hand over management of KCA to the KCAMC. Tinjure Milke Jaljale/Guranse Danda (TMJ) Forest: The GoN is in the process of declaring the TMJ Guranse Danda Forest a protected forest that lies within the Tamor watershed. The TMJ ridge borders Taplejung, Terhathum and Sankhuwasabha districts. This is an area well known for its biodiversity, and is one of the largest natural rhododendron forests with the highest number of rhododendron species in the world. The TMJ represents middle and high mountain landscapes between two successfully protected areas of Nepal, KCA and Makalu-Barun National Park (MBNP) and is a popular tourist destination for mountaineering, trekking and rafting. It represents important global eco-regions including Eastern Himalayan Alpine Grasslands and Shrubs and Broadleaf Forest. It harbors more than 250 plant species including 17 endemic, nine endangered and 14 threatened species. Faunal diversity of the area includes rare, endangered and threatened species of mammals like snow leopard (Unciauncia), leopard cat (Felis bengalensis), clouded leopard (Neofelisnebulosa), musk deer (Moschuschrysogaster), pangolin (Manis species), etc. The TMJ landscape maintains contiguity/ connectivity and a wildlife corridor between the MBNP and the KCA. Other areas of ecological importance: Besides the protected areas described above, the main forest areas in the basin are located in the more remote parts, at higher altitudes/ridges/upper mountain slopes, and steep valley slopes, particularly along/near riverbanks. Based on the altitude, the types of forests in the basin include subtropical, temperate, sub-alpine and alpine forests. Subtropical forests below 2,000 m are: Shorearobusta – the dominant forest in the lower altitudes along the river valleys, and Schima-Castanopsis – the dominant forest in the upper subtropical range. The temperate forest is between 1,900 and 3,000 m, and may include East Himalayan Oak-Laurel forests at 1,900 – 2,600 m, and rhododendron and mixed rhododendron–maple forests at 2,600 – 3,000 m. The sub-alpine forest is between 3,000 and 4,000 m, and is rich in medicinal and aromatic herbs, and non-timber forest products (NTFPs), some of which have a very high market value. The NTFPs also have food and medicinal values. The alpine forest lies between 4,000 and 5,000 m and comprises dwarf rhododendron scrub and alpine meadows. Furthermore, even though it is not yet widely exploited, the Tamor River is a fair river for white-water rafting. With the river’s steep canyon walls in the upstream reaches and powerful and continuous rapids along the river stretch, rafting activities would have amazing views of Mt. Everest, Mt. Kanchenjunga and Mt. Makalu. 7.3.1 Current Developmental Status of the Tamor-Kabeli Watershed As the watershed develops, linear infrastructure such as highways, roads and transmission lines have already started landscape fragmentation. As of today, development activities in the Tamor-Kabeli basin have been ad-hoc and mostly guided by individual efforts of interested groups and developers. Hydroelectric power is the only sector where some level of government regulation is currently in place, but even this level has been limited to providing hydropower development licenses. The Sapta Koshi basin, which includes the Tamor-Kabeli watershed, has a theoretical hydropower potential close to 22,350 MW16. There are only two projects under operation, the Sunkoshi (10 MW) and the Khimti (60 MW); the Upper Tamakoshi (456 MW) is under construction. These are the only major hydropower plants in the Sapta Koshi basin, but there are also some mini-hydroelectric power plants. Among numerous water resource projects in the basin, perhaps the best known is the Koshi Barrage, a bi-national multipurpose irrigation, flood control and hydropower generation sluice project across the Koshi River in Nepal, near the Nepal–Indian border, some 170 km south of the Kabeli project site. It was built between 1958 and 1962 and has 52 gates controlled by Indian officials as per the Koshi treaty. As of today, the Tamor basin has no major hydropower plants or dams in operation. However, the Koshi barrage, as the first structure constructed on the Koshi River, has probably already created a barrier to long distance fish migration in the larger Koshi basin, including the Tamor-Kabeli river systems. Other sectors have no known development plans for the near future. Planning initiatives of the local bodies (including District and Village Development Committees – VDCs) are limited to resolving immediate needs of the communities (related to water supply, trail development, extension of rural motorable roads, small irrigation, etc.) and lack medium to long term strategic objectives. Knowledge of the current environmental and social conditions at the basin level is limited, but there seems to be wide and unregulated natural resource extraction by local communities, including a recent increase in illegal fishing using electric shock and poison. Most of the secondary information available covers the district administrative boundaries, which do not coincide with the natural basin boundaries. Modern development and infrastructure works, so far, have been limited and therefore have generated only limited impacts on the natural environment. Rural roads supported/constructed by the districts and the earthen roads opened on community initiatives of the basin VDCs, have in recent years added to erosion, downstream sedimentation and changes in land use, including some isolated cases of economic displacement of affected people. Mechi Highway, passing approximately north-south through the Tamor basin and through the southern border of the Kabeli basin, has also had limited impact on land use, forest resources and soil erosion. The planned Mid-Hill Highway17 corridor passes approximately east-west through the Tamor and Kabeli basins. The increased access due to highways, if unmanaged, is expected to further increase resource extraction for livelihood. As of today, opening of new highways in the region has created unplanned market centers that provide access to much needed commodities to local people, but at the same time has resulted in new settlement and population encroachment along the highway. These encroachments not only generate additional sources of domestic pollution (e.g., garbage, waste water) but increase pressure on the existing natural resource base (e.g., water supply, land, forests, fish, etc). A coherent integration of the highway projects with other agricultural/horticultural based cottage industries along with the new hydropower development projects may help local communities reduce their reliance on unregulated and unsustainable exploitation of natural resources, diversify sources of livelihoods, and slow down or reverse the current environmental degradation trend of the basin. This will also reduce pressure on the Kanchenjunga Conservation Area, which as stated above, is located within the Tamor-Kabeli watershed.
Future development in the Tamor-Kabeli watershed can be broadly divided into three groups:
7.3.2.1 Hydropower Development Considering the license status and difficulties with financial arrangements, the KAHEP will probably be the first hydropower plant to be developed in the Kabeli River and likely to be one of the few, if not the only new project to be constructed in the Tamor Watershed in the next 5 to 7 years. As of June 21, 2013, DOED had issued 24 licenses to hydropower developers in the Tamor basin, which are in various stages of development. These projects range from 2 to 415 MW, totaling 918 MW. These licenses are grouped into the following three categories:
Table 7.1- Projects with a generation (construction) license (as of June 21, 2013)
Source DOED 2013 * Developer has applied for a downgrade from 57 to 54 MW ** Developer has applied for a downgrade from 415 to 280 MW Table 7.2 -Projects with survey license issued (as of June 21, 2013)
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