Time filter

Source Type

Urunchi, China

Tao H.,CAS Nanjing Institute of Geography and Limnology | Mao W.,Xinjiang Climate Center | Huang J.,Nanjing University of Information Science and Technology | Zhai J.,National Climate Center
Shuikexue Jinzhan/Advances in Water Science

Drought and wetness indices are important elements since they closely associated with water and energy balance over a geographical area and extending along a certain period of time. Studying of possible cause of drought and wetness variability is of great importance to understand the hydrological cycle and disaster reduction. Based on daily observations of 39 meteorological stations in the Tarim River basin, the spatial and temporal variability of drought and wetness has been analyzed using the standardized precipitation evapotranspiration index (SPEI). The result shows an increasing trend in annual mean SPEI with a significant change point in 1986. Although the frequency of moderate and severe drought decreased after 1986, the frequency of extreme drought events increased slightly. But different categories of wetness show a consistent increase in frequency. Furthermore, we also investigated the corresponding atmospheric circulation anomalies of drought and wetness changes over the Tarim River Basin using NCEP-NCAR reanalysis datasets. Composition analysis of geopotential height and wind field at 500 hPa are performed for typical extreme dry and wetness month as well as for the warm seasons (MJJASO)of the periods 1961 to 1986 and 1987 to 2010, the result shows obvious difference in large scale circulation pattern can be found in typical wet and dry months, the intensified water vapor transportation and unstable atmospheric stratification are the main reasons of the wetter condition in warm seasons after the 1980s. Source

Tao H.,CAS Nanjing Institute of Geography and Limnology | Gemmer M.,National Climate Center | Bai Y.,Xinjiang Academy of Water Resource and Hydropower | Su B.,National Climate Center | Mao W.,Xinjiang Climate Center
Journal of Hydrology

The characteristics of hydro-climatic changes in the Tarim River Basin were analysed based on data collected at 39 weather stations and 29hydrological stations for the period 1961-2008 and 1952-2008, respectively. A non-parametric trend test on basin scale for annual data shows an increasing trend of precipitation, relative humidity, vapour pressure, and the aridity index since 1986. Surface temperature started increasing in 1996. A decreasing trend of sunshine started in 1990. The potential evapotranspiration (ET) is calculated by the Penman-Monteith equation, and points out decreasing trend of potential evapotranspiration since 1985. This negative trend can also be detected for wind speed in both the same time scale and spatial extent. The stations with significant increasing trends in annual streamflow are mainly distributed at the southern slope of Tianshan Mountain, which can only be explained by climatic changes. The detected negative runoff trend of the main stream of the Tarim River can be explained by anthropogenic activities (such as irrigation and domestic water use) and climatic changes. A quantitative assessment reveals that local human activities since the 1970s led to a decrease of the water volume diverted into the main stream of the Tarim River Basin, which has been aggravated in the 2000s. © 2011 Elsevier B.V. Source

Zuo M.,Xinjiang University | Chen H.,Xinjiang University | Chen H.,Xinjiang Climate Center | Wang H.,Xinjiang University | Feng Z.,Xinjiang University
Lecture Notes in Electrical Engineering

By using visual interpretation combined with supervised classification in ENVI 4.5 and with the functions of localization, measurement, and layer overlay of ArcGIS 9.2, the summer season overflowing status in middle and lower reaches of Hotan River had been monitored and analyzed, the results of which shows that: firstly, the overflowing status in middle and lower reaches of Hotan River is fairly serious, at the same time, overflowing status of irrigation areas in oasis area has drawn much attention too. Secondly, compared with other reaches the amount of overflowing water of oasis edge in the middle reach is less, the area of which is below 35 km 2 in monitoring date with the percentage of 94.4%, and the overflowing trace is unavailable in 45% of the monitoring date; From Keshen Mishen on where 2 rivers join together to the crossroad of old river channel and Hotan River, the overflowing areas are all over 35 km 2 in 45% of the monitoring date except 5 August 2004 and 29 July 2008 with the monitoring area being 0; The overflowing status of the reach from the crossroad of the old river channel to Xiaota is heaviest, most of which is over 70km 2 with the maximum of 111km 2. Thirdly, on the whole basin 10 overflowing sites have been observed, among which 4 distribute on the left and right sides of the head reach areas of Hotan River respectively, coupling with a new floodplain on each side, and also a overflowing site on the left of Karakash River has been observed. It can also be found that, on the whole, the overflowing sites mainly distribute on the head reach of Hotan River. © 2012 Springer-Verlag. Source

Li H.J.,Institute of Desert Meteorology | Mao W.Y.,Xinjiang Climate Center | Zhao Y.,Institute of Desert Meteorology | Wang M.Z.,Institute of Desert Meteorology | Huo W.,Institute of Desert Meteorology
Journal of Arid Land

The surface vapor content has a close correlation with the generation of precipitation. Based on the atmospheric circulation data and surface vapor content data from 37 weather stations across the Tarim Basin during 1961-2010, the paper analyzed the vapor variation trend, period, abrupt changes and their causes. The results show that the increase trend of surface vapor content over the Tarim Basin mostly conforms with the average trend coefficient of 0.48. There were 3 centers displaying a trend of high vapor increase and 3 centers displaying a low vapor increase. These centers were distributed in strips and blocks across the basin from northeast to southwest. Notable inter-decadal variations in annual and seasonal vapor contents occurred in the Tarim Basin during the 50 years of the study period, with more vapor after the mid-1980s and less vapor in the 1960s and the 1970s. The significant increase in vapor content in the 50 year period occurred mostly in the 1980s and the 1990s. The increasing trend across the four seasons was strongest in summer, reaching 0.43, and weakest in spring. Great variations existed between the spring trend and the annual, summer, autumn and winter trends. During the 50-year study period, there are distinguishable periods of 4-6 years and 8-10 years in which the annual and seasonal vapor contents varied alternately between low and high concentrations. The annual vapor content and that of the four individual seasons all changed abruptly in about the mid-1980s (α<0.05). The west wind circulation, Tibetan Plateau circulation and the annual mean temperatures of the Tarim Basin are the main factors that influenced the surface vapor content over the study area, of which the Tibetan Plateau circulation may be the most important one. Source

Deng M.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute | Zhang H.,China Meteorological Administration | Mao W.,Xinjiang Climate Center | Wang Y.,Yunnan Provincial Meteorological Bureau
Advances in Climate Change Research

This study focuses on the characters of public perceptions on climate and cryosphere change, which are based on a questionnaire survey in the Ürümqi River Basin. In comparison with scientific observation results of climate and cryosphere change, this paper analyzes the possible impact of the change on water resources and agriculture production in the area. Perceptions of most respondents on climate and cryosphere changes confirm the main objective facts. For the selection of adaptation measures addressing the shortage of water resource, the results are as follows: most people preferred to choose the measures like "policy change" and "basic facility construction" which are mostly implemented by the government and the policy-making department; some people showed more preference to the measures of avoiding unfavorable natural environment, such as finding job in or migrating to other places. The urgency of personal participation in the adaptation measures is still inadequate. Some adaptation measures should be implemented in line with local conditions and require the organic combination of "resource-development" with "water-saving". Source

Discover hidden collaborations