Landscape Impact And Assessment System Construction Of The Small Hydropower Rundle Development In Baisha River Drainage Area

Taking the Baisha river which was the first level tributaries of the Tianquan river as the study object, the impact to landscape elements, landscape structure and landscape function of the small hydropower rundle development in Baisha river drainage area were analyzed by the numbers in this study. Then, the comprehensive landscape impact assessment system of small hydropower rundle development in Baisha river drainage area was elementary analyzed. Finally, the landscape impact of the small hydropower rundle development in Baisha river drainage area was assessed by using the comprehensive assessment system designed before. The results were as follows:1. Landscape impact of the small hydropower rundle development in Baisha river drainage areaThe area of grassland, rivers, woodland, farmland and other natural or semi-natural landscapes transfered in Baisha river drainage area. Hydropower, factory and other artificial landscape rose. Woodland was the absolute advantage matrix around the small hydropower rundle development. Porosity of the matrix increased, but the value was not high, so the impact of the small hydropower rundle development to the matrix was not significant.After the rundle development of the small hydropower in Baisha river drainage area, the number and the density of overall patch decreased, the average patch size increased. The trend of patch connectivity was increasing and the fragmentation was decreasing. The results showed that the correlation of the index change between overall patch and woodland was high. The index change of the woodland had something to do with the small hydropower rundle development in Baisha river drainage area. But the patch index change of grassland, factories and neighborhoods had noting to do with the small hydropower rundle development in Baisha river drainage area.The ecological flows discharged were low. The river width shrunk significantly. Water erosion and the curvature of the river reduced, and its heading changed. Some area appeared dehydrated, feculent and stench. The impact of the hydropower to the river pH value was not remarkable on operation period, but it could increase the biology salt content and the warm function of Water. But it could also reduce the dissolved oxygen content of Water. The quoted channel and the tail channel of the neighboring hydropower linked up so close that the quality of the natural breach also reduced. With the development of the small hydropower rundle, it caused the dehydration in some sections of river, and this weakened the isolation function of the river. And the dam weakened longitudinally connection of the river. While, the quoted channel blocked the crosswise relationship between two sides habitats of the river.In the area of the middle reaches of the river, the quoted channel partially passing through the woodland caused the woodland overall ecology value division. The rundle development indirectly caused the path to extend, weakening relation between the land and the aquatic animals in the path region, as well as the ecology supporting capacity of the river course to the land animals.The development of small hydropower rundle had the remarkable contribution to the increasing of landscape diversity, landscape dominance, landscape uniformity, landscape separating degree as well as the landscape reduction of fragmentation. But the impact of the small hydropower rundle development was not remarkable to the stability of the Baisha river drainage area. The edge contrast of the hydropower was generally low in upstream area, and generally high in middle and low reaches of the river. The hydropower edge contrast had something to do with its area and position.The Landscape function of the river and the woodland were mainly impact by the small hydropower rundle development in Baisha river drainage area. As the decreasing of the ecological flows, the ground water level lowed and the water environment quality changed badly. It not only affected the adjustment function of the river bank vegetation belt, but also disturbed the normal transmission of the matter, energy and the information in river landscape habitat. The width of river corridor changing narrow also caused certain species become the invasion, posing the threat to some low ecology position species. In addition, small hydropower producing noise in operation period also impacted the aquatic animals. The shape of hydropower could also affect the biology proliferation and the process of looking for food.The small hydropower rundle development had either positive or negative impact to some single environment function, but the impact was not remarkable to the overall environment function of the river landscape. And the small hydropower rundle development had positive impact to most single environment function, which could also improve the overall environment function of the woodland landscape.2. The comprehensive landscape impact assessment system to the rundle development of the small hydropowerBased on the analysis of landscape impact of small hydropower rundle development in Baisha river drainage area, the assessment scope was determined. Then, the landscape impact content was decomposed, and 25 assessment factors were filtered. And the assessment factor graduation and its significant degree were determined. Through the consult general graduation standard, the composite index grouping method and the analogy similar appraisal achievement, the judgment standard system was determined. Finally, the comprehensive landscape impact assessment system to the development of the small hydropower rundle was constructed.Landscape value loss assessment system of the small hydropower rundle development was initially constructed. The river landscape value loses mainly included the fishery production, soil erosion, the silt filling up, water purification and cultural entertainment function. The woodland landscape value loses mainly included the woodland production, the water source self-control, the silt drains, the fixing up coal and put out the oxygen, occupying value loss and renewing expense.3 Landscape impact assessment of the small hydropower rundle development in Baisha river drainage areaUsing the assessment system, the landscape impact assessment of the small hydropower rundle development in Baisha river drainage area was carried out. The results indicated that the assessment conclusion was comprehensive and objective in the course of using the assessment system. The landscape rank showed good after the small hydropower rundle development in Baisha river drainage area. So the landscape impact of the small hydropower rundle development in Baisha river drainage area was not remarkable.Using the initially constructed landscape value loss assessment system of the small hydropower rundle development, the value loss assessment was carried out. And the result showed that the landscape value loss was 20749977 Yuan after the development of small hydropower rundle in Baisha river drainage area.Landscape protective measures was proposed. It was suggested the landscape restoration should be carried out. First, guarantee the water amount for landscape ecology using by increasing the water amount, enhancing the water quality, reducing the non-landscape water; Second, apply the ecological engineering technology, such as landscape conservation of water and soil as well as the ecology restoration.