长江源区高寒生态与气候变化对河流径流过程的影响分析

近40 a来长江源区气候变化剧烈,是青藏高原增温最为显著的地区之一,高寒生态系统与冻土环境不断退化.采用多因素逐次甄别方法与半经验理论方法相结合,基于多年冻土的不同植被覆盖降水-径流观测场观测试验结果,分析了长江源区气候-植被-冻土耦合系统中各要素变化对河川径流的不同影响.结果表明:近40 a来长江源区河川径流呈持续递减趋势,年均径流量减少了15.2%,频率>20%的径流量均显著减少,而>550 m³·s^-1的稀遇洪水流量发生频率增加;气候变化与高寒草甸覆盖变化对源区径流变化的影响较大,分别占5.8%和5.5%;气候与植被覆盖变化对径流的显著影响是与冻土耦合作用的结果,但冻土环境与冰川变化对径流的贡献尚不能准确评价.高寒沼泽湿地和高寒草甸生态系统对于源区河川径流的形成与稳定起到关键作用,这两类生态系统的显著退化是驱动河川径流过程中变差增大、降水-径流系数减少以及洪水频率增加的主要原因.保护源区高寒草甸与独特的高寒湿地生态,对于维护源区水涵养功能和流域水安全意义重大.     

Regional climate change and its effects on the runoff of Manas River,Xinjiang, China

The effects of climate change on annual runoff were analyzed on the basis of hydrologic and meteorological data for the past 50 years recorded by six meteorological stations and the Kenswatt Hydrological Station in the headstream of the Manas River watershed. The long-term trends of climate change and hydrological variations were determined in a nonparametric test, and the periodicities were determined employing the extrapolation method of periodic variance analysis. Subsequently, a periodicity-trend superposition model was used to predict future change. The results show that both the climate factors (temperature and precipitation) and runoff have increased considerably and have significant relations; the relation between temperature and runoff is the more significant. There is periodicity of 18 years in the change in annual runoff, and the primary periodicity of changes in temperature and precipitation is, respectively, 3 and 15 years. The runoff variations are affected by climate change in the headstream, but do not shift simultaneously with abrupt changes in temperature and precipitation in the headstream. There is a significant positive relationship in winter between the North Atlantic Oscillation (NAO) and runoff, while there are negative correlations annually and in summer for the runoff lagging the NAO by 1 year. The NAO has certain effects on climate change that are mainly due to atmospheric circulation in the Manas River Basin, and thus, the NAO affects the runoff.     

Modeling and assessing land-use and hydrological processes to future land-use and climate change scenarios in watershed land-use planning

Effective information regarding environmental responses to future land-use and climate change scenarios provides useful support for decision making in land use planning, management and policies. This study developed an approach for modeling and examining the impacts of future land-use and climate change scenarios on streamflow, surface runoff and groundwater discharge using an empirical land-use change model, a watershed hydrological model based on various land use policies and climate change scenarios in an urbanizing watershed in Taiwan. The results of the study indicated that various demand and conversion policies had different levels of impact on hydrological components in all land-use scenarios in the study watershed. Climate changes were projected to have a greater impact in increasing surface runoff and reducing groundwater discharge than are land use changes. Additionally, the spatial distributions of land-use changes also influenced hydrological processes in both downstream and upstream areas, particularly in the downstream watershed. The impacts on hydrological components when considering both land use and climate changes exceeded those when only considering land use changes or climate changes, particularly on surface runoff and groundwater discharge. However, the proposed approach provided a useful source of information for assessing the responses of land use and hydrological processes to future land use and climate changes.     

雅鲁藏布江流域气候和下垫面变化对径流的影响研究

典型高原寒区雅鲁藏布江流域径流变化是反映该区域气候和下垫面变化的重要指标。在全球升温背景下,由于观测资料稀缺,导致缺乏针对整个流域的气候和下垫面变化对径流影响的研究。因此,本研究基于1986—2010年的气象数据和奴下水文站月尺度、动态土地利用数据等,利用改进的水文模型并结合不同的模拟策略厘清了流域1991—2010年不同时段间气候和下垫面变化对径流的影响。结果表明：在1991—2010年期间,不同时段间气候和下垫面变化对径流变化的贡献率差异较大,气候变化对径流变化的贡献率高于下垫面变化,且使径流量增加。从空间上看,气候变化对流域产流的贡献率在上游和中游都较大,在下游东北部的贡献率较小,而在该区域下垫面变化的贡献率较大。雪冰融水径流呈增加的趋势,对年径流的平均贡献率在21.1%~48.6%范围内,多年平均贡献率为33.6%;雪冰融水径流一般从4月开始增大,8月达到最大,10月达到消融末期。本研究的开展和发现既是雅鲁藏布江流域水文、水资源基础性研究的需要,具有重要的理论研究意义,同时也可为该流域的水资源保护、规划与管理提供科学理论和决策依据,具有重要的现实意义。     

洮儿河上游径流时序变化特征分析

干旱、半干旱地区河流径流对全球气候变化具有更高敏感性.主要位于内蒙古东北部半干旱、半湿润地区的洮儿河是本区域为数不多的河流,分析其径流的时序变化特征对研究本区域的全球气候变化响应具有重要意义.本文主要利用洮儿河上游索伦和察尔森两个代表性站点的近40年时间序列的逐日径流量资料,分别利用Kendall秩次检验,洪水频率和洪水滞时分析方法来分析洮儿河上游河流径流变化趋势、洪水频率和洪水滞时变化特征.结果如下:在过去40年内洮儿河上游径流量经历了下降-上升-下降的变化趋势,呈现平躺的S型,即可将其划分为1957～1972年的下降段、1972～1988年的上升段和1988～1997年的下降段.而通过Kendall秩次检验发现在相应的时段内两站的径流呈现显著性变化趋势.洪水频率分析表明,40年来洮儿河洪水发生频率有增加趋势,滞时分析结果则显示流域滞时时间呈减小变化.     

气候变化下东北中等流域冬季径流模拟和预测

为了预测未来气候变化下冬季径流，利用寒区水文模型CRHM（Cold Region Hydrological Model platform）模拟2000—2012年和预测2025—2060年松花江二级支流依吉密河上游冬季径流流量。研究结果表明:①根据2025—2060年际冬季径流深和径流系数变化，发现典型排放浓度增加，冬季径流序列不稳定性增大。②根据识别突变点位置，发现典型排放浓度越高，累积冬季径流拐点增多。③通过相关性分析发现，同时期气候为影响冬季月径流的主要因素，冬季降水是影响冬季月径流变化的主要因素。④利用累积量斜率变化率比较方法发现，相对于2025—2042年，2043—2056年和2057—2060年冬季降水增长对冬季径流增长贡献率分别为39.8%和62.6%；相对于2043—2056年，2057—2060年冬季降水减少对冬季径流减少的贡献率为27.0%。     

Evaluation of drought and flood risks in a multipurpose dam under climate change: a case study of Chungju Dam in Korea

The purpose of this study was to evaluate the effects of climate change on the drought and flood risks of a multipurpose dam. To achieve this, A2 climate change scenarios of RegCM3 were collected about Chungju Dam in Korea. To analyze drought risks, weather data obtained by the statistical downscaling method were entered to produce runoff series by runoff modeling and water balance was analyzed based on water use scenarios to review changes in the storage volume under climate change. To analyze flood risks, changes in water levels of the dam in future flood seasons were reviewed based on the current dam operation method. The results of the review indicated that both the drought and the flood risks of the dam would increase in the future. The reason was considered to be the movement of the flood season’s runoff characteristics from July and August to August and September because of climate change. Therefore, for climate change adaptation planning, not only quantitative changes in hydrologic values but also changes in temporal characteristics should be considered and given importance.     

1960—2010年中国主要流域径流量减小原因探讨分析

针对1960—2010年径流量显著减少的中国主要流域,包括松花江、辽河、海河、黄河和汉江等,选择其上游地区受人类直接取用水影响较少的山区小流域,分析径流变化及其原因.采用基于Budyko假设的流域水热耦合平衡方程,估计了流域年径流量变化的气候弹性系数和下垫面弹性系数,并对各流域径流变化进行了归因分析.结果表明,在气候较为湿润的地区,径流对气候和下垫面变化均不敏感;在气候较为干燥的地区,径流对气候和下垫面变化都更为敏感,且区域差异性明显.潜在蒸散发的变化对径流减少的影响微弱,降水减少和下垫面变化是径流减少的主导因素,其中人类活动导致的下垫面变化对径流减少的影响尤为显著.对比两个阶段的径流变化归因分析结果,近10年间流域下垫面变化对年径流量的影响程度较前20年有显著增加.通过分析近30年的归一化植被指数(NDVI)数据发现,植被覆盖改善是下垫面变化的重要原因,说明中国水土保持工程发挥了显著生态效益的同时也导致了流域径流减小.     

气候变化下东北中等流域冬季径流模拟和预测

为了预测未来气候变化下冬季径流，利用寒区水文模型CRHM（Cold Region Hydrological Model platform）模拟2000—2012年和预测2025—2060年松花江二级支流依吉密河上游冬季径流流量。研究结果表明：① 根据2025—2060年际冬季径流深和径流系数变化，发现典型排放浓度增加，冬季径流序列不稳定性增大。② 根据识别突变点位置，发现典型排放浓度越高，累积冬季径流拐点增多。③ 通过相关性分析发现，同时期气候为影响冬季月径流的主要因素，冬季降水是影响冬季月径流变化的主要因素。④ 利用累积量斜率变化率比较方法发现，相对于2025—2042年，2043—2056年和2057—2060年冬季降水增长对冬季径流增长贡献率分别为39.8%和62.6%；相对于2043—2056年，2057—2060年冬季降水减少对冬季径流减少的贡献率为27.0%。     

涪江流域径流变化趋势及其对气候变化的响应

采用Mann-Kendall非参数检验方法分析了涪江流域实测径流量的变化趋势,根据假定的气候变化情景和HADCM3预估的气候情景,利用考虑融雪的水量平衡模型(SWBM模型)分析了径流对气候变化的响应。结果表明:涪江流域径流量总体呈现递减趋势,但非汛期的个别月份有增加趋势,实测年径流变化主要是由于气候要素变化引起的,流域内的水电开发对径流量的季节分配存在一定的影响。SWBM模型对涪江流域月流量过程具有较好的模拟效果,实测与模拟径流量总体较为吻合,只有个别年份峰值模拟误差相对较大。气温变化固定的情况下,降水变化与径流变化之间的关系接近线性;在降水变化相同的情况下,单位气温变幅引起的径流量变化幅度也基本相当。尽管不同排放情景下涪江流域径流量的变化有一定差异,但总体来看,未来水资源可能以偏少为主,特别是2030年以后,多年平均偏少量将可能超过5%。     

Water resource impacts of climate change in southwestern Bulgaria

This study assesses the regional impact of climate change on runoff in a mountainous region of southwestern Bulgaria. A GIS-based distributed hydrologic model and two climate change scenarios – HadCM2 and CCC – were employed for years around 2025 and 2085. Results from both scenarios demonstrate the basin's sensitivity of runoff to climate change, which produce significant spatial and temporal changes in the basin's water yield with maximum runoff shift into early spring and further decreases in summer runoff. There could be no reduction in mean annual runoff, except under the Hadley scenario by 2085. Changes in the magnitude of mean monthly and peak flow are associated with early snowmelt and a reduction in snow cover in spring. Increases in spatial variability of runoff reflect the basin's complex physiographic characteristics. The increase of spatial and temporal variability in runoff points to different strategies for future water resource management. This revised version was published online in July 2006 with corrections to the Cover Date.     

中国主要江河径流变化成因定量分析

变化环境下中国主要江河实测径流量发生了较为明显的变化,科学理清径流变化原因是流域水资源评价和管理的重要基础工作。基于中国七大江河代表性水文站1956-2018年的实测径流量资料,诊断了变化环境下水文序列的变异性特征;采用水文模拟途径,定量评估了不同驱动要素对径流变化的影响。结果表明:①淮河、长江和珠江实测径流量变异性特征不明显,相比而言,北方主要江河实测年径流量系列存在较为明显的突变性,但最显著的变异点发生时间存在差异,变异前后降水径流关系发生较大变化。②RCCC-WBM模型能够较好模拟中国南方湿润区和北方干旱区江河天然径流量过程,该模型可以用来还原人类活动影响期间的天然径流量。③总体来看,人类活动对中国北方江河径流量的影响大于气候变化的影响,气候变化是中国淮河及其以南江河径流变化的主要原因。     

中国主要江河径流变化成因定量分析

变化环境下中国主要江河实测径流量发生了较为明显的变化，科学理清径流变化原因是流域水资源评价和管理的重要基础工作。基于中国七大江河代表性水文站1956—2018年的实测径流量资料，诊断了变化环境下水文序列的变异性特征；采用水文模拟途径，定量评估了不同驱动要素对径流变化的影响。结果表明：①淮河、长江和珠江实测径流量变异性特征不明显，相比而言，北方主要江河实测年径流量系列存在较为明显的突变性，但最显著的变异点发生时间存在差异，变异前后降水径流关系发生较大变化。② RCCC-WBM模型能够较好模拟中国南方湿润区和北方干旱区江河天然径流量过程，该模型可以用来还原人类活动影响期间的天然径流量。③总体来看，人类活动对中国北方江河径流量的影响大于气候变化的影响，气候变化是中国淮河及其以南江河径流变化的主要原因。     

Study on runoff simulation of the upstream of Minjiang River under future climate change scenarios

Climate change is one of the main factors that affect runoff changes. In the upstream of Minjiang River, the temperature increased significantly in the last 50 years, while the precipitation decreased on the contrary. In order to analyze the effect of climate change on site runoff, watershed runoff depth and evaporation, nine climate scenarios are assumed based on rainfall and temperature indicators. A SWAT model of Minjiang River is constructed, and runoff simulation is carried out with the nine scenarios. The results show that if precipitation increases or decreases 20 %, the change rate of runoff depth will increase or decrease 28–32 %; if temperature increases or decreases 2 °C, the change rate of runoff depth will decrease or increase 1–6 %; if temperature increases or decreases 2 °C, the change rate of the potential evaporation will increase or decrease 5–16 %, and the actual evaporation rate of variation will increase or decrease 1–6 %. Overall, precipitation variation has greater effect on simulated runoff than temperature variation dose. In addition, temperature variation has more obvious effect on the runoff simulation results in dry years than in wet years. The actual evaporation of watershed depends on evaporation capacity and precipitation and increases with the increasing of the potential evaporation and precipitation. The study also shows that the climate change scenarios analysis technology, combined with SWAT hydrological model, can effectively simulate the effect of climate change on runoff.     

土地利用与气候变化对密云水库来水量变化的影响研究

综合应用多种方法,评估了土地利用与气候变化对密云水库来水量变化的影响.应用Mann-Kendall全时段趋势检验方法检验不同时段降水与径流的变化趋势;结合水量平衡方法分析气候与土地利用变化对流域径流的影响;利用双累积曲线方法检测了流域降水-径流关系的突变点,并探讨其原因.结果表明,1960～2016年,密云水库来水量整...     

Study on runoff simulation of the upstream of Minjiang River under future climate change scenarios

Climate change is one of the main factors that affect runoff changes. In the upstream of Minjiang River, the temperature increased significantly in the last 50 years, while the precipitation decreased on the contrary. In order to analyze the effect of climate change on site runoff, watershed runoff depth and evaporation, nine climate scenarios are assumed based on rainfall and temperature indicators. A SWAT model of Minjiang River is constructed, and runoff simulation is carried out with the nine scenarios. The results show that if precipitation increases or decreases 20 %, the change rate of runoff depth will increase or decrease 28–32 %; if temperature increases or decreases 2 °C, the change rate of runoff depth will decrease or increase 1–6 %; if temperature increases or decreases 2 °C, the change rate of the potential evaporation will increase or decrease 5–16 %, and the actual evaporation rate of variation will increase or decrease 1–6 %. Overall, precipitation variation has greater effect on simulated runoff than temperature variation dose. In addition, temperature variation has more obvious effect on the runoff simulation results in dry years than in wet years. The actual evaporation of watershed depends on evaporation capacity and precipitation and increases with the increasing of the potential evaporation and precipitation. The study also shows that the climate change scenarios analysis technology, combined with SWAT hydrological model, can effectively simulate the effect of climate change on runoff.

     

Characteristics and causes of changes in annual runoff of the Wuding River in 1956–2009

The Yellow River is the second largest river in China. Its runoff experienced rapid changes in the past decades. The trend and driving forces of change of the river’s runoff has been a hot topic in some academic fields in China in recent years, due to its importance in solving the contradiction between supply and demand of water resources, reasonable exploitation and utilization of water resources and its significance in promoting the social, economic and ecologically sustainable development. The Wuding River is one of the large tributaries in the Middle Yellow River and soil and water conservation measures have been implemented in the tributary much earlier. It can be a good example for investigating the trend and causes of changes of runoff of the Yellow River. In this paper, the variation trend and abrupt change are determined in the time series of annual runoff of the Wuding River recorded at a hydrological station near its outlet during the period from 1956 to 2009 using several time series analysis methods. Secondly, the influences of climate change and human activities are estimated through calculating the amount of runoff reduction due to climate change in different periods. Results show that the annual runoff was continually decreasing, the drought trend was aggravating, and abrupt change in runoff series appeared in 1971 and 1997 as a result of large scale water and soil conservation measure after 1971 and ecosystem restoration program since 1997. It is also found that human activities were the main influence factor for runoff reduction during the period from 1972 to 2009. The contributions from climate change increased from about 23 to 30 %, and those from human activities decreased from 77 to 70 % from the period of 1972–1996 to the period of 1997–2009. Finally, a formula is built to reveal the relation of runoff with both climate factors and each main kind of human activities.     

祁连山老虎沟流域强消融期径流对气候变化的响应

为定量研究老虎沟流域径流对气候变化的响应,利用老虎沟流域1959年和2014年强消融期（7月）的气象、径流数据,分析了强消融期气温、降水、蒸发、冰川消融量、径流（流域的径流深）等的变化,进而探讨了老虎沟流域强消融期气温分布和降水形态、流域蒸发和冰川消融对径流的影响。结果表明：老虎沟流域2014年强消融期径流比1959年多159 mm,增加了49.67%。2014年7月平均气温较1959年升高0.38℃,最低气温升高1.34℃。1959年和2014年7月降水量相差较小;老虎沟流域强消融期日降水和日径流之间呈负相关,蒸发量的变化较小,流域内祁连山站的混合态降水比例减少23.01%,导致降水转化为径流的比例增大;起决定性作用的是正积温, 2014年7月较1959年的正积温高11.71℃·d,主要由于2~4℃的气温日数增多导致正积温增加,从而加剧冰川消融对径流的补给。     

雅鲁藏布江流域径流演变规律与归因分析

气候变化驱动下的水循环与水资源演变规律研究是重要的科学问题, 也是国际社会普遍关注的全球性问题。以雅鲁藏布江流域为研究区, 利用线性倾向估计、多元线性回归等方法检验气象要素变化特征, 揭示下垫面演变规律;基于Budyko假设的弹性系数法, 揭示径流演变规律, 并进行归因分析。结果表明: 1961—2014年, 雅鲁藏布江流域气温呈升高趋势, 降水整体呈增加趋势, 气候向暖湿化方向发展;植被整体改善, 上游西北部和下游植被存在退化现象;年径流序列具有3~4 a、12 a、20 a和32 a左右的周期;降水变化、潜在蒸散发量变化、下垫面变化和冰川变化对径流量增加的贡献率分别为39.62%、-2.74%、32.32%和30.94%。相关结果对理解气候变化和下垫面变化下雅鲁藏布江径流演变规律, 具有重要的参考价值。     

叶尔羌河源流区近50年来年径流变化及其对气候变化的响应

  基于新疆卡群水文站和塔什库尔干气象站1959～2005年的观测资料,运用小波分析和统计分析相结合的方法,从多时间尺度研究叶尔羌河源流区近50年来年径流的非线性变化趋势,以及径流对气候变化的响应。结果表明: 1）年径流、气温和降水的主要变化周期几乎一致,年径流和年降水量都存在24年的主要变化周期,而年平均气温则是23年。2）年径流量表现出具有时间尺度依赖性的非线性变化趋势,与区域气候变化密切相关。3）年径流变化是区域气候变化响应的结果,从8（2³）年、4（2²）年和2（2¹）年时间尺度上来看,年径流量与年平均气温和年降水量之间存在显著的线性相关关系。