摘要
根据巴丹吉林沙漠与腾格里沙漠交汇处的民勤绿洲荒漠过渡区的长期连续实测资料 ,分析了该地区的辐射特征 ,研究了热量平衡各分量的变化特征及热量平衡规律。在绿洲荒漠过渡区 ,其太阳辐射、净辐射和反射辐射具有明显的日进程和季节变化规律 ;太阳辐射月总量最大值 (12 0 2 3 3kW·m- 2 )出现在 8月份 ,最小值(5 2 0 6 5kW·m- 2 )出现在 11月份 ;流动沙丘表面的反射率高于有植被覆盖的红柳和白刺灌丛沙丘表面的反射率 ,在植被生长季节更为明显 ,反射率日最大值分别为流动沙丘 (37 5 % ) >白刺沙丘 (2 9 7% ) >红柳沙丘 (2 7 9% ) ;流动沙丘表面接受的净辐射是植被覆盖区的 5 0 %～ 70 %左右。在绿洲荒漠过渡区生态系统的热量平衡中 ,占比例最大的是潜热通量 ,其次为感热通量和土壤热通量。随着荒漠化程度的加深 ,生态系统反射率增加 ,净辐射减少 ,而且热量平衡中感热通量和土壤热通量所占比例增加 ,而潜热通量比例减小。
Based on the long term data and information collected from transitional region between oasis and desert at the transitional belt between Badanjilin desert and Tenggeli desert, research on the radiation change characteristics and heat balance law were carried out. All factors of radiation balance in the plot have obvious diurnal and seasonal pattern. The maximum of overall radiation is 12 023.3 kW·m -2 in August and the minimum is 5 206.5 kW·m -2 in November. The albedo rate on the vegetation covered surface (such as Tamarix ramosissima,Nitraria tangutorum) is lower than that on the uncovered shifting sand dune, especially at growth season; is sequence of maximum is shifting sand dune(37.5%)>Nitraria tangutorum sand dune(29.7%)>Tamarix ramosissima(27.9%). The net radiation on the shifting sand dune surface is 50%～70% of that on the uncovered shifting sand dune. The biggest proportion in the heat balance is the potential heat flux, followed by sensible heat flux and soil heat flux. With desertification becoming·more serious, while the albedo rate is to increase, net radiation is to decrease in ecosystem; Moreover, the proportion of soil heat flux in heat balance increases, but that of potential heat flux decreases.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2004年第3期26-32,共7页
Scientia Silvae Sinicae
