Yao Y.B.,China Meteorological Administration Key Laboratory of Arid Climate Change and Reducing Disaster |
Yao Y.B.,Gansu Province Key Laboratory of Arid Climate Change and Reducing Disaster |
Yao Y.B.,Lanzhou Institute of Arid Meteorology |
Wang R.Y.,China Meteorological Administration Key Laboratory of Arid Climate Change and Reducing Disaster |
And 6 more authors.
Journal of Arid Land | Year: 2013
This paper, using a revised Penman-Monteith model, computed the terrestrial surface humidity index of the Loess Plateau (China) based on climatic factors of monthly mean temperature, maximum temperature, minimum temperature, relative humidity, precipitation, wind speed and sunshine duration observed on the plateau from 1961 to 2008. The temporal-spatial distribution, anomaly distribution and sub-regional temporal variations of the terrestrial surface dry and wet conditions were analyzed as well. The results showed a decreasing trend in the annual average surface humidity from the southeast to the northwest in the research area. Over the period of 1961-2008, an aridification tendency appeared sharply in the central interior region of the Loess Plateau, and less sharply in the middle part of the region. The border region showed the weakest tendency of aridification. It is clear that aridification diffused in all directions from the interior region. The spatial anomaly distribution of the terrestrial surface dry and wet conditions on the Loess Plateau can be divided into three key areas: the southern, western and eastern regions. The terrestrial annual humidity index displayed a significantly descending trend and showed remarkable abrupt changes from wet to dry in the years 1967, 1977 and 1979. In the above mentioned three key areas for dry and wet conditions, the terrestrial annual humidity index exhibited a fluctuation period of 3-4 years, while in the southern region, a fluctuation period of 7-8 years existed at the same time. © 2013 Science Press, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences and Springer-Verlag Berlin Heidelberg.
Yao Y.-B.,Lanzhou Institute of Arid Meteorology China Meteorological Administration |
Zhang Q.,Lanzhou Institute of Arid Meteorology China Meteorological Administration |
Wang J.-S.,Lanzhou Institute of Arid Meteorology China Meteorological Administration |
Shang J.-L.,Meteorological Bureau of Dingxi City |
And 3 more authors.
Journal of Animal and Plant Sciences | Year: 2015
A drought index analytical method based on a relative moisture index was used to evaluate meteorological data between 1958 and 2012 and study the temporal variation, spatial distribution, and sub-regional evolution characteristics of spring drought in Southwest China. The results showed a decreasing frequency of spring drought in the West Sichuan Plateau, Southwest Sichuan Upland, and Yunnan Plateau and an increasing frequency in the East Sichuan Basin and Guizhou Plateau from 1958 to 2012. In the first EOF model for spring drought intensity, the load vector fluctuated in equal phases of different areas. The main abnormal areas were the North Yunnan Plateau and Southwest Sichuan Upland. The second EOF model, distributed in opposite phases of the east and west, showed the characteristics of variances influenced by the atmospheric system. Four subregional abnormalities including the Yunnan Plateau, Guizhou Plateau, West Sichuan Plateau, and East Sichuan Basin were divided according to the load vector abnormality in REOF. The intensity of spring drought had a significantly increasing frequency in Jiangcheng and Ganzi, which had its mutation point from weak to strong appear in 1970a and 1975a, respectively. It also showed an increasing but not significant frequency in Anshun and Suining. The temporal fluctuating period was mainly 4 to 6a in the southwest during the recent 55a. © 2015, Pakistan Agricultural Scientists Forum. All rights reserved.