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Climate change over the Yarlung Zangbo River Basin during 1961-2005
雅鲁藏布江流域1961-2005年气候变化趋势

YOU Qinglong,KANG Shichang,WU Yanhong,YAN Yuping,
游庆龙
,康世昌,吴艳红,闫宇平

地理学报(英文版) , 2007,
Abstract: The Yarlung Zangbo River (YR) is the highest great river in the world, and its basin is one of the centers of human economic activity in Tibet. Using 10 meteorological stations over the YR basin in 1961-2005, the spatial and temporal characteristics of temperature and precipitation as well as potential evapotranspiration are analyzed. The results are as follows. (1) The annual and four seasonal mean air temperature shows statistically significant increasing trend, the tendency is more significant in winter and fall. The warming in Lhasa river basin is most significant. (2) The precipitation is decreasing from the 1960s to the 1980s and increasing since the 1980s. From 1961 to 2005, the annual and four seasonal mean precipitation is increasing but not statistically significant, especially in fall and spring. The increasing precipitation rates are more pronounced in Niyangqu and Palong Zangbo river basins, the closer to the upper YR is, the less precipitation increasing rate would be. (3) The annual and four seasonal mean potential evapotranspiration has decreased, especially after the 1980s, and most of it happens in winter and spring. The decreasing trend is most significant in the middle YR and Nianchu river basin. (4) Compared with the Mt. Qomolangma region, Tibetan Plateau, China and global average, the magnitudes of warming trend over the YR basin since the 1970s exceed those areas in the same period, and compared with the Tibetan Plateau, the magnitudes of precipitation increasing and potential evapotranspiration decreasing are larger, suggesting that the YR basin is one of the most sensitive areas to global warming.
Evolution Trend and Causation Analysis of the Runoff Evolution in the Yarlung Zangbo River Basin
雅鲁藏布江径流变化趋势及原因分析

LIU Jian,YAO Zhi-jun,CHEN Chuan-you,
刘剑
,姚治君,陈传友

自然资源学报 , 2007,
Abstract: This paper makes use of the monthly natural runoff data from1956 to 2000, the monthly air temperature data and precipitation data from 1956 to 2004 to analyze the evolution characteristics of the runoff in the Yarlung Zangbo River basin in the later half of the 20th century and the relation between runoff evolution and climatic change.The results show that the interannual evolution of the runoff in the Yarlung Zangbo River basin is stable,but the intraannual distribution of the runoff is extremely uneven, the maximum monthly runoff accounts for 30.1%, while the minimum runoff only accounts for 2.1%, and indication of the great difference in the runoff between low water season and flood water season.The climate in the Yarlung Zangbo River basin is calefactive, and the increasing trend of the precipitation is obvious, having the same evolution periods with runoff.After elementary analysis of the decadal runoff in the Yarlung Zangbo River basin,we found that the increase of the water supply is mainly controlled by climate change,but is also affected by the changes of the earth surface conditions in the basin and maybe a representation of the long period of variation of high and low stream flow. Relevant data are required to validate and analyze this kind of periodic variations.
Temporal and spatial variations of δ18O in precipitation of the Yarlung Zangbo River Basin

LIU Zhongfang,TIAN Lide,YAO Tandong,GONG Tongliang,YIN Changliang,YU Wusheng,

地理学报 , 2007,
Abstract: This paper reveals the temporal and spatial variations of stable isotope in precipita-tion of the Yarlung Zangbo River Basin based on the variations of δ18O in precipitation at four stations (Lhaze, Nugesha, Yangcun and Nuxia) in 2005. The results show that δ18O of pre-cipitation has distinct seasonal changes in the Yarlung Zangbo River Basin. The higher value of δ18O occurs in spring prior to monsoon precipitation, and the lower value occurs during monsoon precipitation. From the spatial variations, with the altitude-effect and rainout process during moisture transport along the Yarlung Zangbo River Valley, 18O of precipitation is gradually depleted. Thus, δ18O of precipitation decreases gradually from the downstream to the upstream, and the lapse rate of δ18O in precipitation is approximately 0.34‰/100m and 0.7‰/100km for the two reasons. During monsoon precipitation, spatial variation of δ18O in precipitation is dominated by the amount effect in the large scale synoptic condition.
Changes of NDVI and their relations with principal climatic factors in the Yarlung Zangbo River Basin
雅鲁藏布江流域NDVI变化与主要气候因子的关系

FU Xin-feng,YANG Sheng-tian,LIU Chang-ming,
付新峰
,杨胜天,刘昌明

地理研究 , 2007,
Abstract: As an index denoting vegetation cover, NDVI is influenced by many climatic factors such as precipitation and average air temperature.In this paper,NDVI is calculated on the basis of waveband characteristic of NOAA/AVHRR data(National Oceanic Atmospheric Administration/Advanced Very High Resolution Radiometer) for the Yarlung Zangbo River Basin.Then,the spatio-temporal change of NDVI is analyzed.The basin's NDVI is in consistency with season from 2001 to 2003.High value zone of NDVI is mainly distributed in the lower reaches and part of the middle reaches.Meanwhile,point data of principal climatic factors(precipitation and average air temperature) are interpolated to spatial grid data with Kriging method consistent with NDVI based on DEM of the Yarlung Zangbo River Basin.Then,the relation of NDVI and precipitation or average air temperature is analyzed with F checking and two-sample variance test in the basin.The result is P=0,which shows that correlation analysis has higher confidence.The linear and logarithmic correlation of NDVI and precipitation or average air temperature is analyzed at confidence level of 0.05. The conclusion is that NDVI and precipitation and average air temperature in the basin vary with seasons and are closely correlated.The linear correlation coefficient of NDVI and precipitation is 0.8,and that of NDVI and average air temperature is about 0.77.And the logarithmic correlation coefficient of NDVI and precipitation is 0.71,and that of NDVI and average air temperature is 0.7.
Variations of δ18O in Pr ecipitation of the Yar lung Zangbo River Basin
雅鲁藏布江流域降水中δ18O 的时空变化

LIU Zhongfang,TIAN Lide,YAO Tandong,GONG Tongliang,YIN Changliang,YU Wusheng,
刘忠方
,田立德,姚檀栋,巩同梁,尹常亮,余武生

地理学报 , 2007,
Abstract: The paper reveals the temporal and spatial variations of stable isotope in precipitation of the Yarlung Zangbo River Basin based on the variations of precipitation δ18O at four stations (Lazi, Nugesha, Yangcun and Nuxia) in 2005. The results show that the δ18O of precipitation has distinct seasonal variations in the Yarlung Zangbo River Basin. The maximum value of δ18O occurs in spring prior to monsoon precipitation, and the minimum value occurs during monsoon precipitation. From the spatial variations, with the "altitude effect" and rainout process during moisture transport along the Yarlung Zangbo River valley, δ18O of precipitation is gradually depleted. Thus δ18O of precipitation reduced gradually from the downstream to the upstream, and the lapse rate of δ18O in precipitation is approximately 0.34‰/100m and 0.7‰/100km due to the two reasons. During monsoon precipitation, spatial variations of δ18O in precipitation is dominated by "amount effect" in the large scale synoptic condition.
基于EOF的雅鲁藏布江流域干湿季降水变化的时空分异研究
Analyzing Spatial and Temporal Distribution of Precipitation at Wet or Dry Season in Yarlung Zangbo River Basin Using Empirical Orthogonal Function
 [PDF]

王熊飞, 陈思思, 张嘉琪
Open Journal of Soil and Water Conservation (OJSWC) , 2014, DOI: 10.12677/OJSWC.2014.24004
Abstract:
根据2000年~2010年雅鲁藏布江流域的15个气象站点的月值降水数据,采用经验正交函数分解法(EOF),分别计算出雅鲁藏布江流域干湿季降水的时空分布特征和时间系数序列。结果表明:应用EOF方法可以很好地揭示降水场的时空分布特征,且对雅鲁藏布江流域而言前4种模态揭示了四种分布场,干季降水的累计贡献率达99.84%,湿季降水的累计贡献率达89.81%。雅鲁藏布江流域干湿季降水的主要空间分布特征是“东–西差异分布”,即表现出西部偏少东部偏多的特点,尤其是在喜马拉雅山脉最东端的米林宽谷地带降水最为丰富,分析其原因是季风气候和印度洋的暖湿气流对东部影响较大,西部由于海拔高,水汽很难到达,因此西部降水较东部少。
According to the monthly precipitation data of 15 meteorological stations in the Yarlung Zangbo river basin during the period from 2000 to 2010, and using the method of empirical orthogonal function (EOF), we respectively calculated the spatial and temporal distribution characteristics of precipitation in wet and dry season and the time-coefficient series. The results showed that the EOF method was capable of revealing the spatial and temporal distributions of precipitation field for the Yarlung Zangbo river basin, with the first four EOFs reflecting the four vector distribution fields; furthermore, we can know that the cumulative contribution rate of precipitation is 99.84% at dry season and 89.81% at wet season. The main space distribution characteristic of dry or wet season precipitation is different distribution from west to east in Yarlung Zangbo river valley. It shows that the precipitation in western district is more than that in eastern district, such as Milin wide valley in the eastern end of Himalayas, which is one of most abundant precipitation areas, because it is influenced by the monsoon climate and the warm moist air flow from the eastern Indian Ocean. However, due to the high altitude, the water vapor is hard to reach the west area. So the precipitation of west area is relatively less compared to the east.
Trend of Surface Humid Index in the Middle Reaches of the Yarlung Zangbo River over Tibet in Recent 40 Years
雅鲁藏布江中游地表湿润状况的趋势分析

DU Jun,HU Jun,CHEN Hu,Sonam Ngotrupd,
杜军
,胡军,陈华,索朗欧珠

自然资源学报 , 2006,
Abstract: Humidity index can be expressed by two factors which indicate input and output of atmospheric moist under natural conditions:Precipitation and potential evaporation,represent the change of water and energy balance.In order to clarify the present situation of the environment and regional variations,research has been done on surface wetness in Tibet.The result provides scientific basis for exploring reasons of environmental change over the past 30 years in Tibet and further research on future climatic change.Based on data of monthly maximum temperature,minimum temperature,precipitation,wind speed,relative humidity and sunshine duration from four meteorological stations in the middle reaches of the Yarlung Zangbo River(Brahmaputra)over Tibet from 1961 to 2000,data of the maximum potential evaporation was computed by Penman,Monteith Model,and the surface humid index was obtained.The linear trend,inter,decadal variation and the seasonal difference of the surface humid index were analyzed,and the its relationship with precipitation and temperature was discussed.The results indicated that an obvious linear trend of the warming of annual and seasonal mean temperature existed during the last 40 years,especially the warming was more obvious in winter.Annual precipitation presented a decreasing trend in the first 20 years(1961-1980) and an obvious increasing trend in the last 20 years(1981-2000).Since 1981,precipitation has increased significantly in the flood season(from May to September),with a mean increase of 8.6mm/a.For potential evaporation in the 1960s and the 1970s,the increasing trend was more significant,but the most significant decrease occurred in the 1980s and the 1990s.Also,the rate of pan evaporation over the Yarlung Zangbo River had,on average,steadily decreased,it is particularly so from 1983 to 2000,with a decreasing rate of 22.1mm/a.From the 1960s to the early 1980s,the ground surface showed a drying trend.While from the mid to the late 1980s and the 1990s,the ground surface presented a wetting trend due to precipitation increase and the maximum potential evaporation decrease.The results showed that the cold wet occurred in the 1960s and the warm wett in the 1990s.
Characteristics of the Seed Bank of Sophora moorcroftiana Population in the Middle Reach of Yarlung Zangbo River, Tibet
西藏雅鲁藏布江中游河谷砂生槐种群种子库特征

LIU Zhi-Min,
刘志民

生态学报 , 2002,
Abstract: Sophora moorcroftiana, an endemic shrub in Tibet, colonizes the terraces, lower slopes and sand dunes in the middle reach of the Yarlung Zangbo River. The soil seed bank characteristics of Sophora moorcroftiana in the middle reach of the Yarlung Zangbo River were discussed in this paper. The objectives are (1) to reveal the variations of soil seed banks among different regions, different plots and different sub-plots; (2) to determine the influences of wind force,floodwater, gravity and cutting on seed...
Mercury speciation and spatial distribution in surface waters of the Yarlung Zangbo River, Tibet
Wei Zheng,ShiChang Kang,XinBin Feng,QiangGong Zhang,ChaoLiu Li
Chinese Science Bulletin , 2010, DOI: 10.1007/s11434-010-4001-y
Abstract: The Yarlung Zangbo River is the highest river in the world. It flows from west to east through the southern part of Tibet. The mercury (Hg) speciation and distribution in surface waters and soils near the bank of the Yarlung Zangbo River and its two tributaries, the Lhasa and Niyang Rivers, were investigated in June 2007. Simultaneously, major water quality parameters were also measured at the same stations. Total Hg (THg) and total methylmercury (TMeHg) concentrations in surface waters of the Yarlung Zangbo River ranged from 1.46 to 4.99 ng/L and from 0.06 to 0.29 ng/L, respectively, representing the background levels in river systems of the Tibetan Plateau. Particulate Hg (PHg) accounted for 69% of the THg, and the two Hg species had a significant relationship (r=0.990, P<0.01). Approximately 61% of the spatial distribution of THg was controlled by the concentrations of total suspended particles (TSP). Reactive Hg (RHg) concentrations ranged from 0.10 to 0.36 ng/L, and this fraction may play a weak role in terms of the transport and fate of Hg in surface waters. Dissolved methylmercury (DMeHg) constituted 71% of the TMeHg and was significantly correlated with TMeHg (r=0.746, P<0.01). The spatial distribution of TMeHg is not strongly affected by environmental factors such as THg, RHg, temperature, pH, dissolved organic carbon (DOC), and TSP. In addition, the inflow of both the Lhasa and Niyang Rivers probably influences the concentrations of THg in surface waters of the mainstream, but such an effect is not obvious for TMeHg.
Glacial distribution and mass balance in the Yarlung Zangbo River and its influence on lakes
TanDong Yao,ZhiGuo Li,Wei Yang,XueJun Guo,LiPing Zhu,ShiChang Kang,YanHong Wu,WuSheng Yu
Chinese Science Bulletin , 2010, DOI: 10.1007/s11434-010-3213-5
Abstract: Glaciers in the Yarlung Zangbo River witness severe glacial retreat nowadays, which gives important influence on lake processes in the region. We have studied glacial distribution, glacial mass balance and found large deficit in glacial mass and its impact in the region. Our study also integrated the variation in glacial-fed lakes of the Nam Co and Ranwu Lake, and presented an initial assessment of the impact of glacial mass balance on lakes. The study has shown a significant contribution of glacial melting to recent lake expansion and lake level rising.
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