scholarly journals Evaluating the effects of land use and cover change on the decrease of surface wind speed over China in recent 30 years using a statistical downscaling method

2016 ◽  
Vol 48 (1-2) ◽  
pp. 131-149 ◽  
Author(s):  
Jian Wu ◽  
Jinlin Zha ◽  
Deming Zhao
2019 ◽  
Vol 11 (3) ◽  
pp. 345-356 ◽  
Author(s):  
Yupeng Li ◽  
Yaning Chen ◽  
Zhi Li

2016 ◽  
Vol 41 (1) ◽  
pp. 46-67 ◽  
Author(s):  
Jinlin Zha ◽  
Jian Wu ◽  
Deming Zhao

The changes of near-surface wind speed (SWS) were induced by the combination effects from anthropogenic activities and natural climate changes, thus the research of the long-term changes and cause of SWS is very important to recognize the effects from natural changes and anthropogenic activities to SWS. Some studies have shown that land use and cover change (LUCC) over China was very distinct in the last 30 years. However, the possible effects of LUCC to the slowdown in SWS are still uncertain. The European Centre for Medium-Range Weather Forecasts Reanalysis from January 1989 onward (to be extended back to January 1979) (ERA-Interim hereafter) dataset includes little information about LUCC, so the effects of LUCC on SWS in China during 1979–2010 have been estimated by using the difference between SWS per the ERA-Interim dataset and that from 492 meteorological stations. The results show the following. (1) The effects of LUCC on the SWS are distinct, and could have caused a decrease in the SWS of 0.12 m s–1 per decade, which could account for decreases of 0.57 and 0.30 m s–1 wind speed for large and small cities, respectively. In addition, a decrease of 0.1 m s–1 in the SWS could be induced by a 10% rise in the urbanization rate. (2) The impacts of LUCC on the SWS in the Beijing-Tianjin-Tangshan region, the Yangtze River Delta region and the Pearl River Delta region are more significant than those for the entire region. (3) The bias in the ERA-Interim dataset could cause a 51% error in the estimation for the entire region during the study period, but had a non-significant effect on the decreasing trend in the SWS. The decrease rate of SWS induced by LUCC based on the traditional observation minus reanalysis method had an error of 0.01 m s–1 decade–1. (4) The results of different methods to quantify the impacts of LUCC on the SWS are also compared in this study.


2013 ◽  
Vol 52 (3) ◽  
pp. 570-587 ◽  
Author(s):  
Fang-Yi Cheng ◽  
Yu-Ching Hsu ◽  
Pay-Liam Lin ◽  
Tang-Huang Lin

AbstractThe U.S. Geological Survey (USGS) land use (LU) data employed in the Weather Research and Forecasting (WRF) model classify most LU types in Taiwan as mixtures of irrigated cropland and forest, which is not an accurate representation of current conditions. The WRF model released after version 3.1 provides an alternative LU dataset retrieved from 2001 Moderate Resolution Imaging Spectroradiometer (MODIS) satellite products. The MODIS data correctly identify most LU-type distributions, except that they represent western Taiwan as being extremely urbanized. A new LU dataset, obtained using 2007 Système Probatoire d’Observation de la Terre (SPOT) satellite imagery [from the National Central University of Taiwan (NCU)], accurately shows the major metropolitan cities as well as other land types. Three WRF simulations were performed, each with a different LU dataset. Owing to the overestimation of urban area in the MODIS data, WRF-MODIS overpredicts daytime temperatures in western Taiwan. Conversely, WRF-USGS underpredicts daytime temperatures. The temperature variation estimated by WRF-NCU falls between those estimated by the other two simulations. Over the ocean, WRF-MODIS predicts the strongest onshore sea breezes, owing to the enhanced temperature gradient between land and sea, while WRF-USGS predicts the weakest onshore flow. The intensity of the onshore breeze predicted by WRF-NCU is between those predicted by WRF-MODIS and WRF-USGS. Over Taiwan, roughness length is the key parameter influencing wind speed. WRF-USGS significantly overpredicts the surface wind speed owing to the shorter roughness length of its elements, while the surface wind speeds estimated by WRF-NCU and WRF-MODIS are in better agreement with the observed data.


2014 ◽  
Vol 599-601 ◽  
pp. 1605-1609 ◽  
Author(s):  
Ming Zeng ◽  
Zhan Xie Wu ◽  
Qing Hao Meng ◽  
Jing Hai Li ◽  
Shu Gen Ma

The wind is the main factor to influence the propagation of gas in the atmosphere. Therefore, the wind signal obtained by anemometer will provide us valuable clues for searching gas leakage sources. In this paper, the Recurrence Plot (RP) and Recurrence Quantification Analysis (RQA) are applied to analyze the influence of recurrence characteristics of the wind speed time series under the condition of the same place, the same time period and with the sampling frequency of 1hz, 2hz, 4.2hz, 5hz, 8.3hz, 12.5hz and 16.7hz respectively. Research results show that when the sampling frequency is higher than 5hz, the trends of recurrence nature of different groups are basically unchanged. However, when the sampling frequency is set below 5hz, the original trend of recurrence nature is destroyed, because the recurrence characteristic curves obtained using different sampling frequencies appear cross or overlapping phenomena. The above results indicate that the anemometer will not be able to fully capture the detailed information in wind field when its sampling frequency is lower than 5hz. The recurrence characteristics analysis of the wind speed signals provides an important basis for the optimal selection of anemometer.


2020 ◽  
Vol 12 (2) ◽  
pp. 155-164
Author(s):  
He Fang ◽  
William Perrie ◽  
Gaofeng Fan ◽  
Tao Xie ◽  
Jingsong Yang

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