Numerical simulation of the impact of reforestation on winter meteorology and environment in a semi-arid urban valley, Northwestern China
刊物全称
Science of the Total Environment
论文作者
Ye Yu,Jianjun He,Suping Zhao,Na Liua,Jinbei Chen,Hongjun Mao,Lin Wu
发表年度
2016
刊物类别
SCI
卷
569–570
期
404–415
影响因子
3.976
通讯作者
Yu, Y
请求全文
关键词
Land use change, Air pollution, WRF, Mountain-valley circulation, Complex terrain, Lanzhou
摘要
Since 1999 Chinese government has made great effort to reforest the south and north mountains surrounding urban Lanzhou - a city located in a river valley, Northwestern China. Until 2009 obvious land use change occurred, with 69.2% of the reforested area been changed from grasslands, croplands, barren or sparsely vegetated land to closed shrublands and 20.6% from closed shrublands, grasslands, and croplands to forests. Reforestation changes land-surface properties, with possible impact on the evolution of atmospheric variables. To understand to what extent the local meteorology and environment could be affected by reforestation in winter, and through what processes, two sets of simulations were conducted using the Weather Research and Forecasting model (WRF) and the FLEXible PARTicle (FLEXPART) dispersion model for a control case with high-resolution remotely sensed land cover data for 2009 and a scenario assuming no reforestation since 1999. Results suggested that the changes in albedo, surface exchange coefficient and surface soil heat conductivity related to reforestation led to the changes in surface net radiation and surface energy partitioning, which in turn affected the meteorological fields and enhanced the mountain-valleywind circulation. Replacement of shrublands and grassland with forest in the south mountain through reforestation play a dominant role in the enhancement of mountain-valley wind circulation. Reforestation increased the amount of air exchanged between the valley and the outside during the day, with the largest hourly increase of 10% on calm weather days and a monthly mean hourly increase of 2% for the study period (Dec. 2009). Reforestation affected the spatial distribution of pollutants and slightly improved the urban air quality, especially in the eastern valley. Results from this study provide useful information for future urban air quality management and reforestation plan, and some experience for cities with similar situations in the world.
- 上一条: Climatic characteristics of thunderstorm days and the influence of atmospheric environment in Northwestern China 2018-10-11
- 下一条: Seasonal and interannual variation of radiation and energy fluxes over a rain-fed cropland in the semi-arid area of Loess Plateau, northwestern China 2018-10-11
- Climatic characteristics of thunderstorm days and the influence of atmospheric environment in Northwestern China 2018-10-11
- Integrated modeling of urban–scale pollutant transport: application in a semi–arid urban valley, Northwestern China 2018-10-11
- Numerical Model-Based Artificial Neural Network Model and Its Application for Quantifying Impact Factors of Urban Air Quality 2018-10-11
- A study of variation characteristics of Gobi broadband emissivity based on field observational experiments in northwestern China 2018-10-11
- Seasonal and interannual variation of radiation and energy fluxes over a rain-fed cropland in the semi-arid area of Loess Plateau, northwestern China 2018-10-11