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在和田地区新垦农地外围的流动沙地种植新疆杨乔木+沙拐枣灌木复合防护林,通过布设风速风向观测仪、沙尘通量梯度仪、温湿度和辐射等测定仪于林带前后,研究防护林网的防护效益,为营建绿洲外围防护林和合理开发利用荒漠区的土地资源提供理论依据。结果表明,防护林带的防风效能随着高度的增加而减弱,大于起沙风速(6m/s)时,新疆杨林带、沙拐枣林带在0.5m处的防风效能分别为67.2%和94.5%,在3m处的防风效能分别为31.3%和33.7%。随着风速的增大,沙拐枣林带和新疆杨林带的防风效能均减弱,新疆杨林带的减弱更为明显。防护林带有效地降低了地表风速,减轻地表风蚀。林带内的输沙量仅为外围的10%左右。此外,林带内的太阳辐射强度下降,温度降低,湿度显著增加。由此可见,防护林可以有效地起到防风固沙,改善区域小气候的作用。
In the hot sandy land of the newly reclaimed agricultural land in the Hetian area, planting the mixed forest of Populus deltoids + Shouzao jujube shrub in the periphery of the shelterbelt, the wind speed and wind direction observer, the sand dust flux gradiometer, the temperature, humidity and radiation were measured before and after the forest belts The protective benefit of shelterbelt network provides the theoretical basis for building perihelical shelterbelt of oasis and developing land resources of desert zone rationally. The results showed that the windbreaking effectiveness of the shelterbelt decreased with the increase of height. When the wind speed was higher than 6m / s, the windbreaking efficiencies at the Yanglin and Shakuguozao belts at 0.5m were 67.2% and 94.5% respectively, Windbreak resistance at 3 m was 31.3% and 33.7% respectively. With the increase of wind speed, the windbreaking efficiency of Shaandao jujube forest belt and Xinjiang poplar belt decreased, and the weakening of Yanglin belt in Xinjiang was more obvious. Shelterbelts effectively reduce the surface wind speed and reduce surface wind erosion. The amount of sediment in the belt is only about 10% of the periphery. In addition, the intensity of solar radiation in the forest belts decreases, the temperature decreases, and the humidity increases significantly. Thus, the shelterbelt can effectively play the role of windbreak and sand fixation and improvement of the regional microclimate.