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1.
气候变化对汉江上游径流的影响 总被引：5，自引：0，他引：5
根据汉江上游安康以上流域1961-2005年历年逐月气温和降水量资料,统计分析了近45 a流域气候变化的基本特点。同时,通过对各站气温、降水量与安康站径流量的相关计算,建立了天然径流量气候模型,并分析了径流量对气候变化响应的敏感性。结果表明：1) 近45 a来汉江上游安康以上流域的年平均气温呈上升趋势;降水量呈递减趋势,90年代以后减少更为显著。2) 在过去45 a中,汉江上游径流量总体呈下降趋势;1961年以来,汉江上游径流量大体经历了两个丰水段和两个枯水段;1985年发生跃变,以前呈微弱的上升趋势,以后呈下降趋势。3) 径流量与区域年平均气温呈负相关,而与年降水量呈较显著的正相关,年径流量对降水变化的响应较其对气温变化的响应更为敏感。 相似文献
2.
根据汉江上游安康以上流域1961-2005年历年逐月气温和降水量资料,统计分析了近45 a流域气候变化的基本特点。同时,通过对各站气温、降水量与安康站径流量的相关计算,建立了天然径流量气候模型,并分析了径流量对气候变化响应的敏感性。结果表明：1) 近45 a来汉江上游安康以上流域的年平均气温呈上升趋势;降水量呈递减趋势,90年代以后减少更为显著。2) 在过去45 a中,汉江上游径流量总体呈下降趋势;1961年以来,汉江上游径流量大体经历了两个丰水段和两个枯水段;1985年发生跃变,以前呈微弱的上升趋势,以后呈下降趋势。3) 径流量与区域年平均气温呈负相关,而与年降水量呈较显著的正相关,年径流量对降水变化的响应较其对气温变化的响应更为敏感。 相似文献
3.
利用汉江上游流域21个测站1971~2011年汛期(5~10月)逐日降水资料及安康和石泉2000~2011年逐日库流量资料,采用距平分析、Morlet小波分析、Mann-Kendall检验、相关分析及重标极差R/S分形等方法,系统地分析了汉江上游流域汛期面雨量的气候变化特征和未来趋势。结果表明:汉江上游流域汛期降水主要集中在7~9月,月、日面雨量极大值均发生在7月;20世纪80年代为汉江上游流域丰水期,90年代为明显少雨期,进入21世纪以来降水逐渐增长,突变点为2005年,面雨量总体呈不显著增长趋势;强降水主要集中在7月和9月,且日面雨量在50.0 mm及以上的强降水,仅7月就占了一半以上;7月和9月发生3 d以上集中强降水过程的频次显著偏高,20世纪80年代为集中强降水过程的频发期,90年代频次明显下降,21世纪以来频次明显增多,这与汉江流域汛期面雨量的年代际变化趋势相一致。另外,Hurst分形指数为0.690,表明未来汉江上游流域汛期面雨量具有持久性和长效记忆效应,未来雨量虽仍存在着增加趋势,但其变化具有较大的不确定性。 相似文献
4.
Impacts of climate variability and human activities on decrease in streamflow in the Qinhe River,China 总被引：1，自引：0，他引：1
Under the impacts of climate variability and human activities, there are statistically significant decreasing trends for streamflow in the Yellow River basin, China. Therefore, it is crucial to separate the impacts of climate variability and human activities on streamflow decrease for better water resources planning and management. In this study, the Qinhe River basin (QRB), a typical sub-basin in the middle reach of the Yellow River, was chosen as the study area to assess the impacts of climate variability and human activities on streamflow decrease. The trend and breakpoint of observed annual streamflow from 1956 to 2010 were identified by the nonparametric Mann–Kendall test. The results showed that the observed annual streamflow decreased significantly (P?<?0.05) and a breakpoint around 1973 was detected. Therefore, the time series was divided into two periods: “natural period” (before the breakpoint) and “impacted period” (after the breakpoint). The observed annual streamflow decreased by 68.1 mm from 102.3 to 34.2 mm in the two periods. The climate elasticity method and hydrological model were employed to separate the impacts of climate variability and human activities on streamflow decrease. The results indicated that climate variability was responsible for 54.1 % of the streamflow decrease estimated by the climate elasticity method and 59.3 % estimated by the hydrological modeling method. Therefore, the climate variability was the main driving factor for streamflow decrease in the QRB. Among these driving factors of natural and anthropogenic, decrease in precipitation and increase in water diversion were the two major contributions of streamflow reduction. The finding in this study can serve as a reference for regional water resources management and planning. 相似文献
5.
未来气候变化对黄河和长江流域极端径流影响的预估研究 总被引：4，自引：0，他引：4
使用NASA-NCAR全球环流模式FvGCM结果驱动高分辨率区域气候模式RegCM3 (20 km),进行1961～1990年当代气候模拟(控制试验)和2071～2100年IPCC A2排放情景下未来气候情景模拟(A2情景模拟试验)。将RegCM3同高分辨率大尺度汇流模型LRM(分辨率0.25°×0.25°)连接,分析水文极端事件在A2情景下相对于当代气候的变化,预估未来气候变化对我国黄河和长江流域水文极端事件的影响。结果表明:(1)未来黄河流域径流年变率增大,月变率减小,日变率在头道拐站以上流域减小,以下流域增大。未来兰州以上半湿润地区,流域东南部湿润区出现径流量峰值的可能性增大,而流域西北部干旱半干旱区出现径流量百分位极值的可能性减小。未来黄河流域中游地区发生流域洪水的风险在夏季月份减少,其余月份均增大。(2)未来长江干流径流年际变率增大,上中游地区径流日和月变率减小,下游地区略有增大;未来汉江流域径流量的年、月和日变率均增大。未来长江干流发生流域洪水的风险在夏季明显降低,而汉江流域各月发生流域洪水的可能性均增大。 相似文献
6.
秦岭山区近50 年降水差异及可能局地成因探讨 总被引：2，自引：1，他引：1
利用秦岭山区54个气象站50年以上日降水资料,分析了复杂地形下小区域降水变化差异,探讨了可能的局地成因,结果表明:(1)年均降水量总体为南高北低、西高东低,反映出秦岭阻挡作用和山谷东风回流影响;(2)近50年来区域年降水以减为主,9个增加站位于东部,夏季降水以增加为主,减少站集中在秦岭山上和区域西部,降水向夏季集中倾向明显;(3)日雨量小于5 mm的年雨量和雨日数减少趋势明显,雨量≥50 mm的年雨量和雨日数增加趋势明显,即小雨减少大雨增多;(4)降水变化的多个方面及其与海拔高度和经度对应关系的分析结果,反映出气溶胶抑制地形降水以及成冰作用恢复被抑制降水的作用,说明局地成因中气溶胶起了不可忽视作用;(5)地形作用和区域能量平衡也是重要局地成因. 相似文献
7.
基于ASD（automated statistical downscaling）统计降尺度模型提供的多元线性回归和岭回归两种统计降尺度方法,采用RCP4.5（representative concentration pathways 4.5）和RCP8.5情景下全球气候模式MPI-ESM-LR输出的预报因子数据、NCEP/NCAR再分析数据和秦岭山地周边10个气象站观测数据,评估两种统计降尺度方法在秦岭山地的适用性及预估秦岭山地未来3个时期（2006-2040年、2041-2070年和2071-2100年）的平均气温和降水。结果表明:率定期和验证期内,两种统计降尺度方法均可以较好地模拟研究区域的平均气温和降水的变化特征,且多元线性回归的模拟效果优于岭回归。在未来气候情景下,两种统计降尺度方法预估的研究区域平均气温均呈明显上升趋势,气温增幅随辐射强迫增加而增大。降水方面,21世纪未来3个时期降水均呈不明显减少趋势,但季节分配发生变化。综合考虑两种统计降尺度方法在秦岭山地对平均气温和降水的模拟效果和情景预估结果,认为多元线性回归降尺度方法更适用于秦岭山地气候变化的降尺度预估研究。 相似文献
8.
In order to investigate the physical structure characteristics of the clouds and precipitation over the Tianshan Mountains in summer, the Urumqi Institute of Desert Meteorology of China Meteorological Administration (CMA) carried out an atmospheric detection experiment in Bayanbulak from 1st to 31st August 2012 by means of a wind-profiling radar and a Doppler weather radar. Using the radar observation data, this paper analyzes the dynamic, thermodynamic, radar echo intensity and macro-micro structure characteristics of the 2–3 August precipitation process. The results show that: (1) The radar echo intensity of this rainfall process changes within 5–38 dBZ, and the precipitation cloud system is under the height of 6500 m, with notable 0 °C level echo bright band between 1200 m and 2000 m height. NCEP analysis data shows that the cloud top temperature ranges from ?25 °C to ?32 °C. These indicate the features of typical stratiform cold cloud precipitation. (2) Atmospheric motion during the precipitation process presents the multi-layer structure with wind velocity varying within the range of 3.0–8.0 m/s. The temperature advection is presented with the vertical structure distribution of “cold-warm-cold”, which indicates relative stability of the atmospheric stratification. (3) By retrieving and analyzing the raindrop size distributions below 0 °C level bright band within 600–1200 m height, when the precipitation evolve from early stage to its peak stage, the concentration of the tiny particle zone (D?≤?2.5 mm) changes a little while the concentration of the medium particle zone (2.5?<?D?≤?4 mm) and the concentration of the large particle(D?>?4 mm) increase considerably; but after peak stage the concentration in the medium particle zone and the concentration in the large particle zone decline first, then the concentration in the tiny particle zone reduces. (4) Raindrop size distribution data is used to calculate the precipitation intensity and the liquid water content, whose spatial-temporal variation characteristics are the same. During peak stage of the precipitation, the instantaneous precipitation intensity reaches 5.0 mm/h, and the liquid water content reaches 0.35 g/m3. This study would help deepen the understanding on the physical structure of the clouds and precipitation over the Tianshan Mountains in summer, and also provide some scientific basis for cloud seeding operation over this area. 相似文献
9.
Haibo Du Zhengfang Wu Yinghua Jin Shengwei Zong Xiangjun Meng 《Theoretical and Applied Climatology》2013,113(3-4):659-670
This paper investigates monthly and seasonal precipitation–temperature relationships (PTRs) over Northeast China using a method proposed in this study. The PTRs are influenced by clouds, latent and sensible heat conversion, precipitation type, etc. In summer, the influences of these factors on temperature decrease are different for various altitudes, latitudes, longitudes, and climate types. Stronger negative PTRs ranging from ?0.049 to ?0.075 °C/mm mostly occur in the semi-arid region, where the cold frontal-type precipitation dominates. In contrast, weaker negative PTRs ranging from ?0.004 to ?0.014 °C/mm mainly distribute in Liaoning Province, where rain is mainly orographic rain controlled by the warm and humid air of East Asian summer monsoon. In winter, surface temperature increases owing to the release of latent heat and sensible heat when precipitation occurs. The stronger positive PTRs ranging from 0.963 to 3.786 °C/mm mostly occur at high altitudes and latitudes due to more release of sensible heat. The enhanced atmospheric counter radiation by clouds is the major factor affecting increases of surface temperature in winter and decreases of surface temperature in summer when precipitation occurs. 相似文献
10.
11.
利用中尺度数值模式MM5V3.5对2002年6月8～9日陕西特大暴雨过程进行了数值模拟, 在模拟结果和实况较吻合的情况下, 通过敏感性试验, 研究了秦岭山脉在这次暴雨过程中所起的作用。结果表明, 秦岭山脉在这次暴雨过程中对降水的强度有很大的影响, 即秦岭山脉使陕甘宁边界的长城沿线、 秦岭山脉、 汉江河谷一带降水量增加, 使关中盆地、 陕北南部、 大巴山东南坡降水量减少。进一步研究表明, 秦岭山脉主要是通过形成局地环流, 使气流产生辐合, 大量的水汽和位势不稳定能量在迎风坡堆积, 上升运动加强, 从而使位势不稳定能量得以释放, 触发了对流降水。 相似文献
12.
Xiaomang Liu Xiangqian Dai Yidan Zhong Jinjing Li Peng Wang 《Theoretical and Applied Climatology》2013,114(1-2):183-191
The Yiluo River is the largest tributary of the middle and lower Yellow River below the Sanmenxia Dam. Hydro-climatic variables have changed in the Yiluo River during the last half century. In this study, the trends in the annual precipitation and streamflow were analyzed in the Yiluo River during 1960–2006. The results indicated that both the annual precipitation and streamflow decreased significantly (P?<?0.05) from 1960 to 2006. Pettitt’s test shows that there was a change point for annual streamflow series around the year 1986 (P?<?0.05), while there was no change point identified for the annual precipitation series from 1960 to 2006. Annual streamflow decreased more significantly than annual precipitation since 1986. The relationship between the annual precipitation and streamflow presented a non-stationary state since 1986. This non-stationary relationship was mainly influenced by human activities. The average annual amount of water diversion from the Yiluo River increased significantly since the mid-1980s, accounting for 31.3 % of the total streamflow decrease from 1986 to 2006. In addition, land use/cover change (LUCC) contributed to 27.1–29.8 % of the decrease in streamflow. Human activities, including water diversion and LUCC, together contributed to 58.4–61.1 % of the decrease in streamflow and led to the non-stationary relationship between the annual precipitation and streamflow from 1986 to 2006. This study detected the changes in the precipitation–streamflow relationship and investigated the possible causes in the Yiluo River, which will be helpful for the understanding of the changes in streamflow in the Yellow River Basin. 相似文献
13.
利用1951—2010年中国160站气温、降水资料,分析中国代表性台站冬季和夏季气温、降水的气候值及气候变率在前后30 a的差异,并对结果使用不同方法进行显著性检验。结果表明,季气温气候平均值的变化总体与全球增暖一致,以升温为主,但夏季在秦岭以南及长江中游地区出现显著局部变冷现象;季气温气候变率的变化相对较小,冬季总体不显著,夏季仅有少数台站显著。降水的气候变化总体不明显,季降水气候值变化的空间分布复杂,冬季南方地区、夏季东部地区总体增加,冬、夏季降水气候变率的变化均不显著。理论检验方法（t检验、F检验）与随机模拟方法（EMC法）的显著性检验结果,对气温的差别较小、对降水的差别较大,这与样本距平序列是否服从正态分布有关。EMC法可在确保样本统计特征不变的情况下,通过多次随机模拟,无需考虑其理论统计分布特征,使检验结果更为可靠。 相似文献
14.
M. Gonçalves A. Barrera-Escoda D. Guerreiro J. M. Baldasano J. Cunillera 《Climatic change》2014,122(1-2):243-256
The complex topography and high climatic variability of the North Western Mediterranean Basin (NWMB) require a detailed assessment of climate change projections at high resolution. ECHAM5/MPIOM global climate projections for mid-21st century and three different emission scenarios are downscaled at 10 km resolution over the NWMB, using the WRF-ARW regional model. High resolution improves the spatial distribution of temperature and precipitation climatologies, with Pearson's correlation against observation being higher for WRF-ARW (0.98 for temperature and 0.81 for precipitation) when compared to the ERA40 reanalysis (0.69 and 0.53, respectively). However, downscaled results slightly underestimate mean temperature (≈1.3 K) and overestimate the precipitation field (≈400 mm/year). Temperature is expected to raise in the NWMB in all considered scenarios (up to 1.4 K for the annual mean), and particularly during summertime and at high altitude areas. Annual mean precipitation is likely to decrease (around ?5 % to ?13 % for the most extreme scenarios). The climate signal for seasonal precipitation is not so clear, as it is highly influenced by the driving GCM simulation. All scenarios suggest statistically significant decreases of precipitation for mountain ranges in winter and autumn. High resolution simulations of regional climate are potentially useful to decision makers. Nevertheless, uncertainties related to seasonal precipitation projections still persist and have to be addressed. 相似文献
15.
Steven P. Hamburg Matthew A. Vadeboncoeur Andrew D. Richardson Amey S. Bailey 《Climatic change》2013,116(3-4):457-477
Observing the full range of climate change impacts at the local scale is difficult. Predicted rates of change are often small relative to interannual variability, and few locations have sufficiently comprehensive long-term records of environmental variables to enable researchers to observe the fine-scale patterns that may be important to understanding the influence of climate change on biological systems at the taxon, community, and ecosystem levels. We examined a 50-year meteorological and hydrological record from the Hubbard Brook Experimental Forest (HBEF) in New Hampshire, an intensively monitored Long-Term Ecological Research site. Of the examined climate metrics, trends in temperature were the most significant (ranging from 0.7 to 1.3 °C increase over 40–50 year records at 4 temperature stations), while analysis of precipitation and hydrologic data yielded mixed results. Regional records show generally similar trends over the same time period, though longer-term (70–102 year) trends are less dramatic. Taken together, the results from HBEF and the regional records indicate that the climate has warmed detectably over 50 years, with important consequences for hydrological processes. Understanding effects on ecosystems will require a diversity of metrics and concurrent ecological observations at a range of sites, as well as a recognition that ecosystems have existed in a directionally changing climate for decades, and are not necessarily in equilibrium with the current climate. 相似文献
16.
The three-dimensional structures and ingredients leading to extremely heavy precipitation associated with the passage of Typhoon Morakot (2009) over the Central Mountain Range (CMR) of Taiwan are investigated. Using a numerical model, the track, track deflection, characteristic rainbands, and precipitation patterns and maxima are successfully reproduced after verification against observational data. The high-level outward flow of the secondary circulation around the eyewall is not very clear even during Morakot’s strongest stage. In the control case, the eyewall collapses within 5 h after landfall that is closely associated with limited precipitation along the track after landfall. During the early stage of landfall, the deep convection on the windward (west) side of the CMR helps strengthening the secondary circulation. A quantitative comparison of total precipitable water, translation speed, and orographic lifting among 12 typhoons in recent years causing large accumulated rainfall in Taiwan shows that the abundant water vapor around Taiwan outweighs translation speed and orographic lifting in resulting in the record-breaking precipitation. It is found that the major processes leading to strong upward motion in the extremely heavy precipitation during 0000 UTC 8 August–0000 UTC 9 August are initiated by orographic lifting by CMR. 相似文献
17.
宜昌处在我国地形第二、第三级阶梯的过渡地带,又位于我国南北过渡带秦巴山地南麓的中低纬度过渡带,长江中上游结合部,山地河谷平原并存,地形复杂,垂直高差大。气候资料分析和文献调研表明,宜昌天气气候因特殊地理环境具有过渡性和特异性：（1）年平均气温主要随地形高度递减,年总降水量主要随纬度升高减小。（2）年暴雨日数、连阴雨天数,在中西部随纬度升高而递减,等值线近似纬向排列;东部随地形升高而递增,等值线近似经向排列。（3）山地平原过渡带地形的阻挡滞留、辐合抬升等对极端短时强降水有明显加强作用,这种作用在秦岭与黄淮过渡带、太行山与华北平原过渡带有相似的天气气候效应。（4）宜昌位于江淮梅雨的西界、华西秋雨的东界,具有天气气候“分水岭”特征。（5）宜昌是暴雨雨团、西南涡移动的主要通道之一。 相似文献
18.
利用第五次国际耦合模式比较计划(CMIP5)中5个气候模式在3种典型浓度路径(RCPs)下的预估结果驱动SWAT水文模型,预估了21世纪气候变化对长江上游年径流量、季节分配以及极端径流的影响。结果表明：预估的长江上游平均气温呈显著上升趋势,21世纪末较当前(1986—2005年)升高1.5~5.5℃,降水总体呈增加趋势,在21世纪30年代后高于当前气候平均值,21世纪末相对于当前增加5%~15%。流域内气候变化存在明显空间差异,金沙江和岷沱江流域气温升高和降水增加幅度均大于流域平均值。预估的长江上游年径流量及各月平均径流均有增加趋势,在21世纪30年代后高于当前多年平均值,21世纪中期增加4%~8%,21世纪末增加10%~15%。预估的径流年内分布的均匀性有所增加,但年际变化明显增大,极端旱涝事件的频率和强度明显增加。预估的各子流域径流变化对气候变化的响应也存在差异,金沙江和岷沱江流域年径流量、年际变化和年内分布变化小,对气候变化的响应表现为低敏感;嘉陵江流域、乌江流域和长江上游干流径流增加幅度大,同时极端丰枯出现的频率和程度增加显著,是气候变化响应的敏感区域。 相似文献
19.
Sajjad Saeed Nicole Van Lipzig Wolfgang A. Müller Fahad Saeed Davide Zanchettin 《Climate Dynamics》2014,43(1-2):503-515
We investigate European summer (July–August) precipitation variability and its global teleconnections using the NCEP/NCAR reanalysis data (1950–2010) and a historical Coupled Model Intercomparison Project climate simulation (1901–2005) carried out using the ECHAM6/MPIOM climate model. A wavelike pattern is found in the upper tropospheric levels (200 hPa) similar to the summer circumglobal wave train (CGT) extending from the North Pacific to the Eurasian region. The positive phase of the CGT is associated with upper level anomalous low (high) pressure over western (eastern) Europe. It is further associated with a dipole-like precipitation pattern over Europe entailing significantly enhanced (reduced) precipitation over the western (eastern) region. The anomalous circulation features and associated summer precipitation pattern over Europe inverts for the negative CGT phase. Accordingly, the global teleconnection pattern of a precipitation index summarizing summer precipitation over Western Europe entails an upper level signature which consists of a CGT-like wave pattern extending from the North Pacific to Eurasia. The imprint of the CGT on European summer precipitation is distinct from that of the summer North Atlantic Oscillation, despite the two modes of variability bear strong similarities in their upper level atmospheric pattern over Western Europe. The analysis of simulated CGT features and of its climatic implications for the European region substantiates the existence of the CGT-European summer precipitation connection. The summer CGT in the mid-latitude therefore adds to the list of the modes of large-scale atmospheric variability significantly influencing European summer precipitation variability. 相似文献
20.
利用博斯腾湖流域开都河、黄水沟和清水河的出山口水文站月径流量和气象站月平均数据，开展变化特征分析和径流变化对气候因子的响应研究。结果表明，博斯腾湖流域年际气候变化以气温上升为主，降水量增加趋势不显著；域内主要河流径流量持续上升。突变检验发现，三条入湖河流90年代之前径流量增加主要是域内降水量增加的结果，随后受气温上升导致冰雪消融加快也对径流量的增加有贡献。相关分析结果显示，博斯腾湖三条入湖河流年径流量变化主要受4月和7月降水因子影响。此外，开都河的径流变化还表现出对8月气温和降水的显著响应，同时开都河流域集水区冰川的面积和占比均大于黄水沟和清水河流域，这表明冰川融水补给对开都河径流的影响大于黄水沟和清水河。所建立的气候因子-径流量多元线性回归模型，能够很好的模拟开都河、黄水沟和清水河的径流变化过程，证明了博斯腾湖流域水文变化受气候因子的显著影响。 相似文献