Construction of large-scale hydropower development on the ecological impact and recovery _ network to write papers

Write papers Network: Abstract: Xiangjiaba hydropower station construction, for example, a comprehensive analysis of the construction of hydropower construction on the natural environment, and proposed ecological restoration measures.

Keywords: hydropower station construction, construction impacts, ecological restoration

Last Xiangjiaba Hydropower Station is the Jinsha River hydropower station, a construction time from January 2006 to December 2008, two construction time from January 2009 to December 2012, although the authorities to Xiangjiaba power plant construction process planning and implementation of a large number of effective environmental protection measures, due to things is the constant practice to get in-depth, inevitable during the construction period, there were many environmental problems can not be ignored, leading to the area decline in environmental quality and ecological environment there has been deterioration.

First, the study area
(A location
Xiangjiaba hydropower station is located in the lower reaches of the Jinsha River valley exit Xiangjiaba is the Jinsha River downstream of a cascade development of the last steps, the left bank of the dam site is located in Yibin County, Sichuan Province, Yunnan Province Shuifu in the right bank of the reservoir involved in Yunnan Province Shuifu, Suijiang, Yongshan, Yibin, Sichuan, Ping Shan, Leibo total of six counties.

(B) topography
Xiangjiaba dam site is located in Yunnan-Guizhou Plateau and Sichuan Basin hilly region south of the junction, cross the mountain to the downstream slope, valley slope is relatively weak and gentle, open terrain, terrain.

(C climatic conditions
Xiangjiaba reservoir area belongs to subtropical monsoon climate, and climate of the plateau to the Sichuan Basin, with the climate in Yunnan is characterized by the transition. Sufficient heat within the region, abundant rainfall, four distinct seasons, water, heat is also synchronized, high temperature and humidity in summer, warm in winter, long frost-free period, benefit sub-tropical forest, crop growth due to the unique topographical conditions, combined with terrain elevation and the poor, the level of climate zones and vertical distribution of the more obvious, the upstream temperature is higher than the downstream region, precipitation is just the opposite.

(D environment
Severely damaged due to human activities, vegetation destroyed most of the Central Plains vegetation, existing vegetation, mainly in secondary forest mainly of vegetation types can be divided into five types, and broad-leaved forest and broad-leaved woodland, coniferous forest, shrub , shrub, farmland vegetation. Xiangjiaba dam area of ​​the main types of vegetation to shrubs, grass-based, high forest vegetation cover less. Xiangjiaba hydropower station construction disturbance on terrestrial state and the effects of erosion
1, construction disturbance effects on terrestrial state
Xiangjiaba hydropower project the impact of construction on the main terrestrial state: during construction, project construction, construction site layout, yard, excavation and construction activities such as filling residue field, direct damage to existing vegetation, the construction area occupied by After the existing vegetation, will be completely transformed into man-made structures, so that the already relatively homogeneous landscape ecological structure to further simplify the project will directly take to completely destroy the original vegetation type, vegetation, biological productivity will change, loss of production 7391.53t, loss of vegetation production to orchards, forests, a large proportion of grass management, accounting for 83.24%, agricultural land accounted for 12.86%.

2, construction disturbance on the effects of erosion
(1 project covers an area of ​​the effects of erosion. Project area on the effects of erosion features: destruction of the original vegetation, reduce soil erosion force, remodeling or destruction of the original topography in the rainy season, splash erosion has occurred, rill erosion of soil erosion.

(2 excavation and backfill of the effects of erosion. Earthwork excavation, especially the cut so that the original vegetation, surface composition of the material, topography and soil structure damage, disturbance, bare ground, losing the original vegetation of the anti- red, solid soil capacity, while excavation backfill the exposed surface and the formation of steep slope to the destruction of the natural stable, easy to produce erosion, collapse, thus increasing the amount of soil erosion.

(3 project spoil the impact of soil erosion. Because of construction spoil generated if appropriate Landang slope, slope protection and other protective measures, debris surface for a long time without vegetation cover in the flood and rain erosion gullies , the resulting residue washed the body, collapse, causing serious soil erosion.

Xiangjiaba Hydropower Station construction area of ​​damage to the surface of the tables:
Second, the measures taken in response
(A terrestrial state environmental protection measures
Terrestrial ecological environment protection include:
1, vegetation protection vegetation protection and include three aspects: (1 moist valley forest economy. Humid valley is flooded reservoir area "orchards, forests, artificial woodland 'largest area of ​​vegetation types to protect this vegetation type, and so that ecological protection and agricultural economic development, to be Suijiang County in Yunnan and Sichuan Pingshan Longqiaoxiang establish moist valley forest economy, (2 to create a forest soil and water conservation or water conservation forest. soil erosion mainly due to destruction of vegetation, so prevent soil erosion, in addition to Engineering measures to restore water area of ​​vegetation is also an important measure in the upstream of the reservoir and construction of water source protection areas around the forest; (3 construction of basic farmland. soil and water conservation is inseparable from the construction of basic farmland, the hills built on the terraced mountains of China's rural areas is now widely used approach. Links to free download http://www.hi138.com
2, restoration of vegetation, mainly of measures based on the steep slopes on both sides of the river artificial seed resistance to dry heat and barren slope Liu, Coriaria, additional hedges along the dry slopes to reduce soil erosion, development of production of lac host trees, erosion easy to produce the purple soil region mountains spread Trema or jute bags with afforestation, the development of greenhouse vegetables, the development of cash crops and other feed materials.

(B) soil erosion conservation measures
1, the hub of the dam area: the main project design to protect the use of reinforced concrete lining, concrete lining protection, hanging close shotcrete, drainage and slope intercept slope drainage, slope anchor, backfill mined-out area and slope finishing and other measures to reinforce rock, soil and water conservation from the point of view of protection to satisfy the requirements in the construction and operation of soil erosion does not occur during the hazards. In addition, to beautify the environment, combined with the plant landscape planning, both banks are set up in the box grid of reinforced concrete beams, box beams within the cell filling with new soil to sow grass seed to restore vegetation.

2, road control area: dig square sections are set in the embankment on both sides with mortar rubble inside and outside drains, excavation slope according to slope angle, length and geological factors such as grass or take masonry or grid Spray plant vegetation slope. filled square section of side slope control in 1:1.5, the outer slope toe foot care using mortar rubble retaining wall block, both sides are using dry stone slope protection.

3, quarry areas: Engineering measures include construction of drainage at the foot of the slope type of drainage ditches, and yard drains connected to the surrounding layout, and in order to prevent the platform and the ground after the casing soil erosion hazards, the platform, the ground outside dry stone blocks, built into a stone-faced terraces, plant design measures for the restoration of vegetation, nearby relocation of farmers to address local land issues, planning for the exploitation of the plains and the platform casing formed. After casing the ground by the migration of farmers to cultivate close to the platform after casing sow grass seed, planting local Suitable shrubs, restore vegetation.

4, spoil the market control areas: Engineering measures: slope protection, slope protection and drainage treatment. Drainage design uses a combination of light and shade, residue field four weeks to set cut-off drains, the road base construction debris retaining dams and slope using mortar protection beams and stones sash and sash within the casing to sow the seeds green beam of plant design measures: the slag due to slag field mainly by gravel, gravel, etc., lack of soil, so after the introduction of the project in the spoil on the first casing, and then sow grass seed to green.

5, the construction business areas: the main project design, the site preparation before, according to the site terrain conditions, the first to ditch water, such as the pond area in the advance wave Gully water treatment, in the construction camp site preparation, in have laid the perimeter drainage, backfill, excavation slope to slope treatment, to ensure that construction camps slope stability, erosion from rain and surface runoff. In addition, according to the soil and water conservation master plan after the completion of the project, planting trees, restore vegetation.

References:
[1] Jinsha River hydropower Xiangjiaba Environmental Impact Report [R]. Changsha: Central South China Hydropower Engineering Consulting Group Survey and Design Institute, 2005.

[2] Jinsha River Soil and Water Conservation Xiangjiaba Hydropower Report [R]. Changsha: Central South China Hydropower Engineering Consulting Group Survey and Design Institute, 2006.

[3] Tseng, Chen Fangqing Hsu years large-scale water conservancy and hydropower project disturbed the ecological restoration of vegetation - to Xiangjiaba hydropower project as an example [J]. Yangtze River Resources and Environment, 2009,18, (11): 1074-- 1079.

Links to free download http://www.hi138.com