关键词: 风电场, 植被生长, 灰腾梁, 草地

Abstract:

With increasing environmental problems and a growing shortage of energy resources, wind as a renewable energy source is increasing in attention from various sectors. Currently, China′s energy policies are gradually turning to utilizing wind energy. Although there are many positive environmental benefits that wind energy provides, researchers around the world have recently begun to investigate environmental negative effects of wind energy development, and they are identifying the pros and cons of wind energy. Current investigations largely focus on vegetation, soil and animal disturbance due to wind farm construction, as well as focusing on possible impacts to the surrounding land surface temperature and local climate change. Existing research indicates that in wind farm areas both near-surface air humidity and surface sensible heat flux decrease. These changes can indirectly change meteorological elements, for example cloud cover and precipitation. The construction and operation of wind farms significantly reduces wind speed in the leeward direction which affects local air temperatures (both increasing and decreasing temperatures). These elements could have an impact on the growth state of local vegetation. In this article, remote sensing techniques are used to investigate the scope and impact intensity of the Huitengliang wind farm, Inner Mongolia, on local vegetation. This investigation will provide a reference for wind farm construction, conservation and restoration of vegetation and environmental improvement. Utilizing MOD13Q1-NDVI data in 2000-2014, vegetation change in a 50 km buffer area around the Huitengliang wind farm, Inner Mongolia, was analyzed. Combining meteorological data in this analysis, the impact of wind direction on vegetation growth was discussed. Compared with the construction phase (2000-2008), the operation phase (2008-2014) has a more obvious impact on the growth of vegetation. However, the results showed that vegetation impact was uneven: 1) The influencing mechanisms of a wind farm on vegetation differ within and outside of the farm area. Within the wind farm area, the wind farm is not conducive to vegetation growth, while it is helpful to vegetation growth in windward/leeward area; 2) Compared with the wind farm construction stage, the proportion of vegetation restoration in the buffer area and the farm area during the operational phase of the wind farm increased by 26.66% and 13.14%, respectively. The proportion of vegetation restoration in the windward and leeward areas, however, increased by 51.83% and 41.07%, respectively, over the same time period. This indicates that the proportion of vegetation restoration in the windward/leeward areas, especially in the windward area, is much higher than in the buffer or farm areas; 3) A zone 30-40 km from the center of the wind farm, on the windward side, is likely to be the area of greatest vegetation impact from the wind farm.

Key words: wind farm, vegetation change, Huitengliang, grassland