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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.


Zhang K.,Institute of Arid Meteorology | Zhang K.,Chinese Academy of Sciences | Wang R.,Institute of Arid Meteorology | Wang H.,Institute of Arid Meteorology | And 4 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2016

In order to predict effects of future climate change on spring wheat production, and to understand the response characteristics of dry matter production in different growing period of spring wheat and the distribution characteristics of photosynthetic products in different organs, we conducted a field infrared temperature-increasing simulation experiment with the applications of free air temperature increased system (FATI) to investigate the effects of air temperature increases (non-warming, warming 1℃ and warming 2℃) on dry matter production and distribution of rainfed spring wheat at the Dingxi Arid Meteorology and Ecological Environment Experimental Station of the Institute of Arid Meteorology of China Meteorological Administration (35°35'N, 104°37'E). The results showed that with the increase of temperature, growth and development of spring wheat accelerated, the growth duration was shortened significantly, Warming of 1.0 and 2.0℃ shortened the growth duration by 7 days and 11 days, respectively. Appropriate temperature increases can promote the growth of crops. However when temperature increased more than the optimal temperature for wheat growth, the temperature could become a factor limiting the growth. Based on the dry matter accumulation in various organs of spring wheat, warming of 1.0 and 2.0℃ increased leaf dry matter weight by 11.23% and 27.49%, respectively at trefoil stage. In comparison, during and after jointing stage, warming of 1.0 and 2.0℃ decreased leaf dry matter weight by 20.12% and 30.83%, respectively. During and before jointing stage, warming of 1.0 and 2.0℃ increased stem dry matter weight by 17.30% and 30.30%, respectively. In contrast, after jointing stage, warming of 1.0 and 2.0℃ decreased stem dry matter weight by 13.19% and 22.09%, respectively. During and before booting stage, warming of 1.0 and 2.0℃ increased root dry weight by 10.26% and 23.30%, respectively. But, after booting stage, warming of 1.0 and 2.0℃ decreased root dry weight by 15.79% and 26.05%, respectively. Warming of 1.0 and 2.0℃ decreased panicle dry weight by 16.43% and 29.00%, respectively. During and before jointing stage, warming of 1.0 and 2.0℃ increased aboveground dry weight and total dry weight by 11.19%, 20.61% and 11.46%, 21.79%, respectively. However, after jointing stage, warming of 1.0 and 2.0℃ decreased aboveground dry weight and total dry weight by 16.43%, 27.15% and 15.96%, 26.26%, respectively. The time response curves of dry matter production to temperature at different growth stages of spring wheat were basically consistent with the time response curves of NAR and LAI, which all increased first then decreased. The response pattern of the matter production of spring wheat under different warming treatments was mainly caused by the change of NAR. From the dry matter distribution of various organs of spring wheat, at trefoil, jointing, booting, heading, flowering, grain filling and milk ripe stage, warming of 1.0℃ decreased the ratio of dry matter of leaf to total dry weight by 0.24%, 14.28%, 4.63%, 11.23%, 12.66%, 6.83%, and 8.39%, respectively. However, with warming of 2.0℃ the decrease for each growth stage was 1.35%, 19.46%, 8.08%, 11.82%, 18.23%, 12.56%, and 12.58%, respectively, The warming of 1.0℃ increased the ratio of dry matter of stem to total dry weight by 0.94%, 9.55%, 0.20%, 5.37%, 4.62%, 2.67%, and 4.07% for different growth stages, respectively. In comparison, the warming of 2.0℃ for the ratio was 2.55%, 12.01%, 2.19%, 6.86%, 8.33%, 5.37%, and 6.46% for each growth stage, respectively. Warming of 1.0℃ increased the ratio of dry matter of root to total dry weight by 0.43%, 3.11%, 10.45%, 1.59%, 5.25%, 2.96%, and 3.21% each for different growth stage. But warming of 2.0℃, the ratio for different growth stages was 3.73%, 8.96%, 23.54%, 2.75%, 10.49%, 5.33%, and 6.17%, respectively. At booting, heading, flowering, grain filling and milk ripe stage, warming of 1.0℃ decreased the ratio of dry matter of panicle to total dry weight by 0.46%, 0.69%, 0.90%, 0.37%, and 0.39%, and 9.21%, 2.44%, 3.32%, 0.97%, and 1.07% for 2.0℃, respectively. For spring wheat, decrease of dry matter distribution in leaf and the increase of dry matter distribution in root may be due to improving water uptake ability. The research results can give the theoretical references for the sensitivity and adaptability of spring wheat in semi-arid area of China under global climate change. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.

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