| Under the influence of the global warming,Hulunbeier grasssland is bearing a severe stress. In this paper, we do the experiment in the degraded grassland of Hulun Lake Basin. On the premise of "maximum wind erosion control while minimizing excessive moisture consumption", the research discussed most reasonable barrier using method of field observation and biomass survey. The research’s purpose is sovling the problem of configuration mode and providing scientific basis for ecological construction of degraded grassland in Hulun Lake Basin. The main conclusions are as follows:(1) The evaluation of windbreak and sand fixation effect of the five windshields of Ⅰ,Ⅱ,Ⅲ,Ⅳ and V need to be considered comprehensively. The effects of different windshields on the surface soil water content and near surface evaporation, and cost were obtained in the Hulun Lake Basin area. Comparing the Ⅰ, Ⅱ and Ⅲ, the more suitable was the Ⅱ; Comparing the Ⅲ,Ⅳ and Ⅴ,the more appropriate is the IV There are 27m / s windy weather in the Hulun Lake Basin, so it is especially important to set the appropriate windshield in the area of the tuyere or where wind appear frequently.(2) To compare and evaluate of the wind-prevention and sand-fixing effect of the three kinds of square sand barrier,the windspeed,the surface soil moisture and the near-surface evaporation were considered. Materials and labor costs also were considerd. Although the 1m × 1m wind prevention and sand fixation effect is the best,but compared with 1.5m × 1.5m, the difference between the two is not obvious, and 1.5m × 1.5m’s cost is low. So under the premise of governance needs of the Hulun Lake Basin sandy area, and in consideiration of resources economically, 1.5m × 1.5m is the best choice.(3) To compare and evaluate of the wind-prevention and sand-fixing effect of the three kinds of band-shaped sand barrier, the windspeed, the surface soil moisture and the near-surface evaporation were considered. The linewidth of lm is the best.However, due to the change of the wind direction in the area, the wind-prevention and sand-fixing effect of the band-shaped sand barrier is significantly smaller than that of the square sand barrier. Therefore, the configuration of the band-shaped sand barrier is not considered.(4) The Hulun Lake Basin is a region that is more affected by climate change,so it should be more concerned. The average annual temperature of the three regions of Manchuria,Xinbaerhuzuoqi and Xinbaerhuyouqi in the Hulun Lake Basin showed a slight decrease trend in 2005-2016 years, and the climatic inclination rates were-1.13, -0.3,3 and -0.11 (℃/ 10a). The precipitation in 2013-2016 years showed a decreasing trend, and the precipitation in July and August was very few. The number of high winds in the region increased from 2014 to 2016.The high amount of evaporation, the hign number of wind days and other factors are unfavorable factors for ecological restoration. Therefore, in the ecological restoration process, the appropriate species should have the speciality of drought tolerance, cold resistance and other characteristics. |
