Hydroelectric Exploitation and Sustainable Development of the Yalong River
Total Page:16
File Type:pdf, Size:1020Kb
UNHYDRO 2004 Beijing HYDROELECTRIC EXPLOITATION AND SUSTAINABLE DEVELOPMENT OF THE YALONG RIVER Chen Yunhua: Professorial Senior Engineer,General Manager of Ertan Hydropower Development Company Ltd. Abstract: The middle and lower reaches of the Yalong River are China’s few river basins with favorable conditions for hydropower development. The abundant water resources of the Yalong have environment-friendly features in all perspectives. With the river running through Ganzi Tibetan Autonomous Prefecture and Liangshan Yi Autonomous Prefecture of Sichuan Province in China’s Southwest, development of the Yalong will greatly promote economic development and social advancement of the minority areas. Only when a river basin is developed and managed by a vigorous and responsible company can a harmony between environment and development be achieved to the maximum extent, and a successful implementation of the strategies for sustainable development be assured. Ertan Hydropower Development Company Ltd. (EHDC) has been authorized by the Central Government to exploit the hydropower resources of the Yalong River. This is a glorious mission and historical responsibility for the Ertaners. EHDC has been making a plan for ecological protection of the river basin with corresponding solutions, which will be demonstrated in the overall planning of the basin. Through construction of Ertan Hydroelectric Project, outstanding achievements and successful experience have been obtained in resident resettlement and environment protection. The development- oriented policies brought practical opportunities to the affected people, and the environment management efforts have started to show their effects. Hydropower development has proved to have more benefits than disadvantages in terms of environmental impacts. With the successful completion of Ertan Project as a new start, EHDC is looking into the future, and will follow the development guideline of “basin, cascading, rolling and comprehensiveness”, and persistently pursue after environment- friendliness and sustainable development. We are confident that the Yalong river basin will become a successful example in China and even in the world for execution of sustainable development strategies in hydroelectric development. The Yalong river, originated from the southern foot of the Bayankala Mountains in Yushu Prefecture of Qinghai Province, stretches from northwest to southeast, passing by Ganzi Tibetan Autonomous Prefecture and Liangshan Yi Autonomous Prefecture of Sichuan Province, and joins the Jinsha River near the city of Panzhihua. It belongs to the Yangtze river water system, and is the biggest tributary of the Jinsha. From its headstream to confluence, the main stream of the Yalong is 1,571km, which covers a catchment area of 136,000km2, creates a natural fall of 3,830m, and gives a multi-year average inflow of 1,890m3/s and an annual runoff of 59.6 billion cubic meters at its confluence. Stretching to the southeast of Qinghai-Tibetan Plateau and lying between the Jinsha and Dadu rivers, the Yalong river Basin is a long but narrow strip of land which is 950km from south to north and 135km from east to west. In the east, north and west, the basin is surrounded by mountains of over 4,000m above sea level. 1 THE UNIQUE WATER RESOURCES OF THE YALONG RIVER 1.1 Summary The Yalong river has abundant hydropower resources, with a big natural fall and large constant inflows. It has a technically developable capacity of 34.62GW, which represents an annual power generation of 184.04TWh. Out of which, the main stream of the river has a hydropower reserve of 33.40GW, and a technically developable capacity of 28.56GW, representing an annual power generation of 151.64TWh, and accounting for roughly 24% and 5% of the total generation of Sichuan Province and the whole country respectively. So it is a unique treasury of clean energy. 1 UNHYDRO 2004 Beijing Twenty-one cascade schemes have been planned along the main stream of the Yalong, utilizing 2,813m of its natural fall. With proper combination of the sizes of the cascade schemes and good regulation performance of the reservoirs, the reservoir capacity factor of the Yalong river is 0.32. Lianghekou, Jiping and Ertan are the controlling reservoirs, which add up to a total regulation capacity of 15.8 billion m3. The middle/lower section of the Yalong river (from Lianghekou to the confluence) flows through Ganzi Tibetan Autonomous Prefecture, Liangshan Yi Autonomous Prefecture, and Panzhihua Municipality. With concentrated distribution of power projects as planned, small quantity of land acquisition and resettlement, and minor inundation losses, projects in this section of the river have high economic performance, favorable development conditions, and prominent benefits in terms of power generation and other areas. It will also play an important role in promoting economic development and social progress of the minority areas. Therefore, it is one of the best among China’s 12 hydropower sources. Recent development activities will focus on this section of the river, which accommodates Jinping (I & II), Guandi, Ertan (completed), and Tongzilin. Ertan Hydropower Station was built between 1991 and 2000, with an installed capacity of 3,300MW. Before completion of Ertan, the hydropower resources of the Yalong river had not been well recognized by the public. Construction of Ertan opened the prelude for development of the Yalong river Basin, and unveiled the mysterious river, making people surprised at its rich resources, unique environment-friendliness and superior development conditions. 1.2 Natural Features of Environment-friendliness To some extent, all environmental impacts caused by construction of hydropower projects can be summarized into two categories – hydrological impact and land inundation resulted from dams. Hydrological impact is reflected by the influence in silt discharge, water quality, water temperature, aquatic plants and fish resources in the reservoir area and the downstream course. Reservoir inundation is represented by the impact on biodiversity, loss of farm land and forest, resettlement of people, and loss of historical, cultural or natural relics. The unique characteristics of the resources of the Yalong river are not only reflected in their superior technical and economic indicators, but are also and more particularly demonstrated by the nature of all-perspective environment-friendliness. The Yalong river has a deeply-cut narrow river course, with steep slopes and high mountains along the river. The relative height of the mountains is normally 500-1,500m, and the slopes are usually 30- 45° or above (60-70° in the big Jinping River Bend), which form a typical “V” valley. The special features and poor conditions have led to scarce population and little farm land. Therefore, dam construction will only need to move a small population and inundate a small quantity of farm land. Distribution of vegetation types in the valley is closely related to the sea level and relative height, with the steep slopes dotted with scarce trees, bushes and grass clusters adapted to hot and dry valley- type climate. The planned reservoir areas have already been disturbed by human activities, particularly the excessive felling of the forest over the past decades. As a result, none of the forest resources along the river with easy access are left over, and the remaining trees only cover a small area in a scattered manner, which are generally common species of low protection values or economic values. With low precipitation, and dry and hot climate, the valley areas amid the high mountains are not suitable for human-beings or plants. Further upstream, due to excessive grazing and unbalanced existence of the natural species of wild lives, the plateau grassland has been badly destroyed, resulting in sharp deterioration of its functions for retaining of soil and water. Hydropower development will give the destroyed ecology a chance for alleviation and restoration. The planned reservoir areas do not involve any natural reserves. Due to scarce population, there are few cultural relics in the Basin, and no relics of significance have been discovered in the reservoir areas. On the contrary, formation of the reservoirs will create a number of natural forest parks, which, like a series of emeralds, will constitute an ecological zone in the upstream of the Yangtze river. Small resettlement and low inundation losses are outstanding features of the hydropower projects on the Yalong river. In this respect, it is the best among China’s 12 planned hydropower sources. The unique environment-friendly feature has made it possible to minimize, through more effective mitigation measures, the adverse environmental impacts resulted from construction of dams, and has 2 UNHYDRO 2004 Beijing created an opportunity to improve the heavily destroyed ecology, to raise the environmental benefits, and to promote economic development and social progress through protection and restoration of the basin environment in the process of hydropower development. Primary Facts of Major Projects Lianghekou Jinping-I Jinping-II Guandi Ertan Tongzilin Capacity (MW) 3,000 3,600 4,400 1,800/2,400 3,300 450/600 Mean Annual Generation 116.87 166.20 210.81 87.13 170.00 25.66 (TWh) Farmland Inundated (ha.) 492.90 508.50 0 45.40 2,182 4.10 Unit Inundation of Farmland 0.1643 0.1413 0 0.0189 0.6612 0.0068 (ha./MW) Unit Inundation of Farmland 0.0422 0.0306 0 0.0052 0.1284 0.0016 (ha./GWh) Forest Inundated (ha.) 2,480 People Resettled 4,925 3,641 0 298 45,812 2,420 People Resettled per MW 1.6417 1.0114 0 1.1242 13.8824 4.0333 People Resettled per GWh 0.4214 0.2191 0 0.0342 2.6948 0.9431 1.3 The River Calls – the Minority People Are Eager for Development The dominant residents affected by Ertan hydroproject and to be affected by the upstream power projects are Tibetan and Yi minorities, and there are totally 19 minorities in the whole basin of the Yalong river.