TROPICAL GEOGRAPHY ›› 2016, Vol. 36 ›› Issue (5): 840-849.

### Analysis on the Source Area of Forest Site in Phoenix Mountain of Zhuhai

LIU Wei1,2，WEI Zhigang1,2，ZHENG Zhiyuan1,2，ZHU Xian1,2

1. （1．State Key Laboratory of Earth Surface Processes and Resource Ecology，Beijing Normal University，Beijing 100875，China；2．Center for Zhuhai Regional Climate-Environment-Ecology Prediction and Early Warning Co-innovation，Future Earth Research Institute，Beijing Normal University，Zhuhai 519087，China）
• Received:2015-11-05 Online:2016-09-05 Published:2016-09-05

Abstract:

Based on the data of CO2 flux and interaction between land and atmosphere from the observing tower in Phoenix Mountain of Zhuhai, the study computes the source area of corresponding time in evergreen broadleaved forest in the mountain, and analyzes the change rule with different atmospheric stability conditions, different seasons and different time using K-M model. We develop a series of standards, which can judge the uniform lever and certify the applicability of the K-M model by computing the ratio between the projected area and the surface area. The results show that the distribution of source areas is similar to that of the main wind direction in stable atmospheric condition, and not completely similar to the main wind direction distribution in unstable atmospheric condition. In winter, the source area is mainly distributed in the northern and eastern directions. In spring, before the onset of the monsoon, the source area distribution is similar to that in winter. After the onset of the monsoon, the distribution of the source area is relatively concentrated in the southwest and southeast directions. The rule is similar to that of the distribution of wind direction. As for daily variation, the area range at night is larger than that in the day. The maximum range more likely appears at night. With the monsoon onset, the time delays from T02:00 to 04:00. The cause is probably that the atmosphere in different seasons reaches the most stable condition in different time. The minimum range of the source area occurs in the period between T 07:00-09:00, when the turbulent activity is the strongest.