太阳辐射对青藏高原不同路面类型表面热状况及其下伏多年冻土的影响

分析了青藏高原地区太阳辐射的特点,实测了不同路面类型获得的太阳总辐射和净辐射,计算了路表有效辐射,最终得出水泥混凝土路面和沥青路面的太阳辐射反射系数。利用实际断面地温监测数据分析了太阳辐射对于不同路面类型及其下伏多年冻土的影响,最后由太阳总辐射及大气温度反演了路表温度,并进行了验证,从而得出了一个计算路面表面温度的参数化方法。研究指出,青藏高原地区的总辐射及净辐射均很高,对冻土的稳定不利。路面太阳辐射的反射系数与太阳辐射强度及测试的位置无关,但与路面颜色的深浅关系密切;水泥混凝土路面的反射系数大约在0.48左右,沥青路面的反射系数大约在0.20左右;在相同太阳辐射强度下,沥青路面吸收的太阳辐射能量更多,其下伏的冻土也更容易受到热扰动而退化。

Influence of Solar Radiation on Surface Thermal Regime of Different Pavement Types and Its Permafrost Underlying Embankment on the Qinghai-Tibetan Plateau

The character of solar radiation on the Qinghai-Tibetan plateau was analyzed and total solar radiation and net solar radiation of different pavement types were measured.Through counting available radiation of pavement surface,the reflection coefficient of cement concrete pavement and asphalt concrete pavement were calculated.The influence of solar radiation on pavement types and the permafrost underlying the embankment was analyzed by utilizing the measure data of ground temperature.Finally,the total solar radiation and atmosphere temperature were linked to retrieve the pavement surface temperature,which basically agreed with the observed one,and a parameterization method for calculating the pavement surface temperature was set up.It is concluded that total solar radiation and net solar radiation on the Qinghai-Tibetan plateau are higher than other areas in China and are unfavorable to permafrost.The reflection coefficient of cement concrete pavement and asphalt concrete pavement have nothing to do with the intensity of solar radiation and the measure location,but are related to pavement color.The reflection coefficient of cement concrete pavement is about 0.48.The reflection coefficient of asphalt concrete pavement is about 0.20.The asphalt concrete pavement under the same intensity of solar radiation absorbed more energy and the permafrost underlying its embankment is easier to receive the thermal agitation.