摘要
为了理解京津风沙源治理工程区植被对沙尘天气的影响,该文采用沙尘天气气象数据和归一化植被指数NDVI(normalized difference vegetation index)时间序列,分析了京津风沙源治理工程区(二期)2000-2013年沙尘天气发生日数和植被NDVI的时空格局,探究了沙尘天气与当年春季、前一年植被生长季NDVI之间的关系,揭示了植被对沙尘天气影响的时间格局和空间异质性特征。结果表明,2000-2013年,京津风沙源治理工程区(二期)沙尘天气发生日数呈显著下降趋势,同时区域植被NDVI显著增加;沙尘天气发生日数与当年5月、前一年8月的NDVI的相关性最强;约60.99%区域沙尘天气发生日数与当年5月NDVI显著相关,主要分布在典型草原中区、浑善达克沙地和农牧交错区;约19.59%的地区植被NDVI对沙尘天气的影响具有一定的滞后性,主要分布在鄂尔多斯高原东部、典型草原西区、燕山丘陵山地水源区北部。
Sand-dust weather is a weather phenomenon where wind and dust are rolled into the air by strong winds making theair cloudy and visibility reduction. In meteorology, it is divided into three levels of dust, sand and sandstorms according to theintensity of sand-dust weather. Vegetation plays a significant role on controlling the sand-dust weather occurrence. In the pastdecades, sand-dust weather has a serious impact on people＇s lives and the socioeconomic development in cities of Beijing andTianjin, and Hebei province. In order to improve the air quality in Beijing and Tianjin and the surrounding areas, and mitigatethe hazards of wind and sand, China launched the Beijing-Tianjin Sandstorm Source Control Project in 2002. Previous studiesshowed that since implementation of the project, the overall ecological conditions in the region have been improved, anddesertification lands and dust weather have been significantly reduced. However, how the vegetation related to the sandstormweather in the Beijing-Tianjin Sandstorm Source Region （BTSSR） is still unclear. Therefore, we took BTSSR as the study area,which covers 138 counties in six administrative regions （i.e. province, autonomous regions or municipalities） in Beijing,Tianjin, Hebei, Shanxi, Inner Mongolia and Shaanxi Provinces. The data used in this study mainly included numbers ofsand-dust weather days （SWD） from China Meteorological Data Service Center （http：//data.cma.cn/） and SPOT/VGTNormalized Difference Vegetation Index （NDVI） S10 data from Cold and Arid Regions Science Data Platform ofEnvironmental and Ecological Science Data Center for West China （http：//westdc.westgis.ac.cn/）. We used the linear trendmethod to analyze the intra- and inter-annual patterns of sand-dust weather occurrence and vegetation dynamics from 2000 to2013. The correlation analysis was utilized to explore the relationship between SWD and the monthly NDVI ofconcurrent/antecedent year. The spatiotemporal pattern of impacts of the vegetation on sand-dust weather was further revealed.The results showed that SWD in BTSSR was high in the west and low in the east. The average SWD of BTSSR was up to 15days in 2000. The SWD in BTSSR were mainly occurred in spring, which accounted for up to 75.5% of the total. Themaximum SWD appeared in 2001, it lasted about 25 days and after that the number of days for SWD decreased significantlytill 2013. The NDVI was high in the east and low in the west. The annual NDVI in BTSSR increased smoothly from 2000 to2013. Correlation analysis showed that the SWD had a more significant correlation with NDVI in concurrent May （R2=0.55,P〈0.01） and antecedent August （R2=0.50,P〈0.01）. The BTSSR was classified into four sub-regions based on the lag effects ofvegetation on the SWD. We found that in 19.59% of the BTSSR, the concurrent SWD was significantly correlated with NDVIof the antecedent year, which was mainly located in the sandy zones with vegetation cover of desert grassland and deciduousbroad-leaved forest. In the typical steppe such as eastern part and central of typical grassland, the SWD was mainly controlledby the vegetation in the concurrent year. Vegetation, regardless of whether it is alive or withered, they can effectively block theeffect of strong winds on the exposed surface, and at the same time reduce wind speed by increasing surface roughness. Themain inhibitory effect of dust weather was the remnants of vegetation and withered vegetation in the antecedent year, such asthat in Erdos plateau and Horqin sandy. We suggested that in the future, targeted prevention and management measures basedon the time-delay characteristics of vegetation impact on sand-dust weather need to be conducted. The results are of greatsignificance to the development and management of vegetation construction in BTSSR.
作者
崔晓
赵媛媛
丁国栋
信忠保
高广磊
于明含
Cui Xiao;Zhao Yuanyuan;Ding Guodong;Xin Zhongbao;Gao Guanglei;Yu Minghan(Key Laboratory of State Forestry Administration on Soil and Water Conservation,School of Soil and Water Conservation,BeijingForestry University,Beijing 100083,China;Yanchi Ecology Research Station of the Mu Us Desert,Yanchi 751500,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2018年第12期171-179,310,共10页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家重点研发计划项目(2016YFC0500802)
国家自然科学基金项目(41401095)
关键词
植被
沙尘
NDVI
京津风沙源区
时空格局
vegetation
dust
NDVI
Beijing-Tianjin Sandstorm Source Region
spatiotemporal pattern
