全球气候变化对中国未来地表径流的影响

本文应用改进的水分平衡模型研究了不同气候变化情景下中国未来地表径流的变化。结果表明:基于不同的气候变化情景模拟所得的地表径流变化在空间上有差异,总体上,中国未来的地表径流将增加;长江上游地区的地表径流春季下降但在夏季增加,而下游地区的则相反,夏季径流下降而春季径流剧增;气溶胶对地表径流变化方面有影响,但在各个气候变化情景下缺乏一致性。     

Characteristics of winter mass balance of Glacier No.1 at the headwaters of the Urumqi River,Tianshan Mountains

This study analyzes the response of glacier to climate change during the past 49 years in Urumqi River source region, the Tianshan Mountains of China. The temporal and spatial variations of winter mass balance (bn-w) at different time scales were analyzed to identify their response to climate change during 1988–2006 (The observation of winter mass balance observation began in 1988) on the Glacier No.1 at the headwaters of the Urumqi River, Tianshan Mountains, China. The winter accumulation shows a significantly decreasing trend. The results show that the cumulative values on Glacier No.1 is 2,202 mm water equivalent during 1988–2006 and the mean values is 116 mm a⁻¹. Furthermore, the trend analysis of the winter mass balance indicates a rapid decrease since 1990, and the mean mass balance is only 79 mm a⁻¹ during 1997–2006. Winter mass balance correlates well negatively with the total evaporation from September to April (r = −0.68, α = 0.01), and positively with the total precipitation from September to April (r = 0.74, α = 0.01). However, winter mass balance shows a weak correlation with mean minimum air temperature during September to April (r = −0.35), and runoff on September (r = −0.13).     

Environmental Forcing of Phytoplankton in a Mediterranean Estuary (Guadiana Estuary,South-western Iberia): A Decadal Study of Anthropogenic and Climatic Influences

Phytoplankton seasonal and interannual variability in the Guadiana upper estuary was analyzed during 1996–2005, a period that encompassed a climatic controlled reduction in river flow that was superimposed on the construction of a dam. Phytoplankton seasonal patterns revealed an alternation between a persistent light limitation and episodic nutrient limitation. Phytoplankton succession, with early spring diatom blooms and summer–early fall cyanobacterial blooms, was apparently driven by changes in nutrients, water temperature, and turbulence, clearly demonstrating the role of river flow and climate variability. Light intensity in the mixed layer was a prevalent driver of phytoplankton interannual variability, and the increased turbidity caused by the Alqueva dam construction was linked to pronounced decreases in chlorophyll a concentration, particularly at the start and end of the phytoplankton growing period. Decreases in annual maximum and average abundances of diatoms, green algae, and cyanobacteria were also detected. Furthermore, chlorophyll a decreases after dam filling and a decrease in turbidity may point to a shift from light limitation towards a more nutrient-limited mode in the near future.     

Climate changing characteristics of Zhangye City in Heihe River basin during 1968–2005

At present, researches on climate change of the Heihe River basin mainly focus on the relationship between basin climate change and regional water resources, regional desertification and dynamic climatic seasons of sandstorm, but less on climate change of oasis region, where there are more intense and frequent human activities. Based on data of precipitation, temperature, strong wind and dust events frequencies obtained from the six meteorological stations of Zhangye region in Heihe River basin, the features of climate change during 1968–2005 were carefully studied. Results show that the regional temperature rise rate exceeded the average level of China. The annual precipitation changed a little, but the precipitation had a slowly increasing trend in spring and winter. Frequencies of strong wind and sandstorm days show obviously descending trends, which had a close correlation with the regional temperature rise and the precipitation increase in spring and winter. Meanwhile, further human economic activities and exploitations to the oasis in the inland valley of arid regions also affected the climate change of this region, which has a sensitive and fragile eco-environment. __________ Translated from Journal of Desert Research, 2007, 27(6): 1048–1054 [译自: 中国沙漠]     

气候变化对玛纳斯河的径流量影响预测模拟分析

山区积雪和冰川融水径流是内陆干旱区的重要水资源, 研究全球变暖情景下温度对融雪径流的影响具有重要意义. 以典型的内陆河玛纳斯流域上游为例, 利用基于度-日因子算法的SRM(Snowmelt Runoff Model)融雪径流模型, 根据当前变化趋势和年内分配模拟出20种假定来模拟未来气候情景(气温上升1 ℃、 2 ℃、 3 ℃、 4 ℃和降水变化率为0、 ±10%、 ±20%的随机组合情况)下的河道径流量, 从而计算出径流量的变化率, 分析了温度和降水变化对径流量的影响. 结果表明: 对于以雪冰融水为主要补给的玛纳斯河, 随着温度和降水的增加, 径流量也会增加, 并会使融雪径流提前. 假定降水量不发生大的变化, 温度增高1 ℃, 径流量增大13%~16%; 在气温一定时, 降雨量增加10%, 径流量增加2%左右, 说明气温和降水都对干旱区内陆河山区径流形成具有重要影响. 该研究对制定气候变化情景下的水资源适应对策具有重要指导意义.     

Biophysical impacts of climate change on some terrestrial ecosystems in Estonia

Climate warming due to the enhanced greenhouse effect is expected to have a significant impact on the natural environment and human activity in high latitudes. Because of its geography, wide coastal areas, water resources, forests, and wetlands, the environment of Estonia is sensitive to climate change and sea level rise. Climate change scenarios for Estonia were generated using a Model for the Assessment of Greenhouse-gas Induced Climate Change (MAGICC) and a regional climate change database, Scenario Generator (SCENGEN). Three alternative emission scenarios were combined with data from 14 general circulation model experiments. The assessment results of forest resources using RipFor, a forest-soil-atmosphere model, show that climate warming would enhance forest growth in Estonia resulting in increased productivity (2–9%) of harvestable timber on highly productive sites. Nutrient mobility increases greatly and in highly permeable soils with stable vegetation, increased mobility may result in nutrient losses through leaching. The assessment results of water resources using the simple water balance model, WatBal, show that the runoff regime of Estonian rivers would equilibrate and the groundwater table would rise. Climate warming would not cause any particular problems with water supply but the groundwater quality may suffer from increased leaching. Due to milder winters and increased storminess, the destruction of coastal areas, inundation of wetlands and disappearance of rare plant communities in coastal areas would be the most damaging results of climate change. Most sandy beaches high in recreational value would disappear. However, isostatic uplift and settlements inland from the present coastline reduce the risk of socio-economic decline. This revised version was published online in July 2006 with corrections to the Cover Date.     

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.     

An analysis of water column distributions in Florida Bay

Florida Bay is a shallow, semi-enclosed lagoon that has recently experienced significant changes to its ecosystem. These include increased turbidity and the occurrence of cyanobacteria blooms in the central region of the bay. To accurately understand these changes we need to understand the spatial and temporal patterns in observed water quality parameters. To this end, we have used empirical orthogonal functions (EOFs) to analyze both the spatial and temporal variability in an 8-yr record of water quality variables. We have used the EOFs in two ways, one highlighting local changes occurring in the bay, the other emphasizing changes occurring on a bay-wide scale. The local analysis shows that the central region of the bay has the greatest variability in water quality parameters, especially with respect to chlorophyll and nutrient concentrations. The bay-wide analysis shows a different picture. The chlorophyll blooms in the central bay are not apparent bay-wide indicating that they are a local manifestation of processes occurring on a bay-wide scale. The spatial and temporal patterns for nitrate are dissimilar from the other nutrients raising the possibility that the mechanisms controlling nitrate differ from those controlling other nutrients. On a bay-wide scale, spatial patterns are similar to distributions of sediment type and show the significance of interactions between the water column and benthos. Time-series analysis of the EOFs shows that the dominant variation of many water quality parameters is seasonal, even though a system-wide shift occurred between 1994–1995 corresponding to an increase in rainfall and runoff from the Everglades.     

长江流域水储量变化的时间变化特征及归因分析

为开展长江流域水储量变化（Terrestrial Water Storage Change,T_WSC）的时间变化特征及归因分析研究,结合GRACE（Gravity Recovery and Climate Experiment）卫星观测及水文模拟,重建并分析了长江流域1988—2012年逐月T_WSC;基于13个实验情景的模拟结果,定量区分了气候波动及关键人类活动（土地利用变化、水库调蓄）对T_WSC的相对贡献。结果表明:①流域平均T_WSC、降水、蒸散发、径流深分别以0.1 mm/a、-3.5 mm/a、0.6 mm/a、-4.2 mm/a的线性速率增减;②逐月非季节性T_WSC与南方涛动指数（Southern Oscillation Index,I_SO）呈现显著负相关性（α < 0.01）;③气候波动对T_WSC影响占主导地位,水库调蓄与气候波动对月平均T_WSC的相对贡献率存在负相关性;④三峡水库运行后,水库调蓄对月平均T_WSC的影响显著增强,且呈现季节性规律,即1—5月削减T_WSC,7—12月增加T_WSC。本研究提供了一种T_WSC归因分析研究框架,研究结果可为长江流域水资源规划管理提供决策支持。     

新疆阿尔泰山区克兰河上游水文过程对气候变暖的响应

额尔齐斯河支流克兰河上游发源于西风带水汽影响的阿尔泰山南坡,主要由融雪径流补给,年内积雪融水可占年径流量的45%.年最大月径流一般出现在6月份,融雪季节4~6月径流量占65%.流域自20世纪60年代开始明显升温,年平均温度从50年代的1.4℃上升到90年代的5.2℃;年降水总量也呈增加趋势,尤其是冬季和初春增加最多.随着气候变暖,河流年内水文过程发生了很大的变化,主要表现在最大月径流由6月提前到5月,月径流总量增加约15%,4~6月融雪径流量也由占年流量的60%增加到近70%.在多年变化趋势上,气温上升主要发生在冬季,降水也以冬季增加明显,而夏季降水呈下降趋势;水文过程主要表现在5月径流呈增加趋势,而6月径流为下降趋势;夏季径流减少而春季径流增加明显.冬春季积雪增加和气温上升,导致融雪洪水增多且洪峰流量增大,使洪水灾害破坏性加大.近些年来气候变暖引起的年内水文过程变化,已经对河流下游的城市供水和农牧业生产产生了影响.     

中国不同气候区河川径流对气候变化的敏感性

利用一个简单的月水量平衡模型,模拟了位于中国不同气候区的21个典型流域的径流量过程,采用假定的气候情景,分析了河川径流量对不同气候变化的敏感性。结果表明,所采用的月水量平衡模型能够较好地模拟不同气候区的月流量过程,21个典型流域的Nash-Sutcliffe模型效率系数大多超过65%,水量平衡误差也均控制在1%以内。黄河以北干旱半干旱地区的典型流域径流量对气温和降水变化的响应敏感,其次为华中、华南半湿润区和湿润区,西部高寒山区径流对气候变化的响应最弱。因此,中国适应气候变化的重点应集中在干旱半干旱地区。     

Dynamic downscaling of global climate projections for Eastern Europe with a horizontal resolution of 7 km

Climate change is one of the key factors influencing the quantity and quality of water resources in hydrologically sensitive regions. In order to downscale global climate simulations from horizontal resolutions of about 125–200 km to about 7 km, a double nesting strategy was chosen. The modelling approach was implemented with the Regional Climate Model CCLM (COSMO-Climate Local Model) with a first nesting covering a central part of Europe and with a second nesting covering parts of Poland, Belarus, and the Ukraine. A control run—driven by global reanalysis data—was evaluated by comparing the model results with corresponding reference data. Long-term yearly and monthly mean differences of temperature and precipitation were statistically assessed. As reference data for the first nesting, the gridded CRU data set with a horizontal resolution of about 55 km was used. Station data of the NOAA and ECA databases were interpolated to provide an appropriate reference data set for the second nesting. Both nestings overestimated long-term yearly precipitation means. Seasonal evaluation of the first nesting showed positive precipitation biases for spring and winter months and negative biases in summer. Furthermore, differences in the spatial precipitation patterns occured, especially in the high mountain area of the Carpathians. The second nesting overestimated precipitation in spring and summer with smaller biases than in the first nesting. Long-term area means of temperature were properly reproduced. The first nesting showed an overestimation for all months with maximal deviations in summer and spring. In contrast, the second nesting was slightly too warm for summer and autumn and too cold for winter and spring.     

气候自然变异在气候变化对水资源影响 评价中的贡献分析——Ⅱ.未来期应用分析

基于模型率定期(基准期)气候自然变异的模拟方法及气候自然变异引起的径流变化的可能情况分析,此部分研究未来期(2021~2051年,2061~2091年)气候变化下径流变化情况及气候自然变异的影响。基于CSIRO、NCAR、MPI三种气候模式及A1B、A2、B1三种排放方式共7种未来气候情景,应用和基准期相同的水文模型和研究流域,引入基准期模型率定出的参数,考虑气候自然变异的影响,对未来气候变化对水资源的影响进行分析。为消除气候模式本身的系统误差,采用δ差值方法得到各模式各排放情景下的未来气候情景。该项研究主要说明如何在气候变化的影响评价中将气候自然变异的贡献分离出来,从而实现更客观的气候变化的影响评价。研究结果表明,气候变异的影响在整个气候变化进程中的贡献随时间的推移将有所不同。未来2021~2051年期间,气候自然变异的影响相对较大;未来2061~2091年期间,由温室气体引起的气候变化的影响占主导。     

Review on snowmelt runoff simulation in mountain regions,Northwest China北大核心CSCD

Snowmelt runoff is a valuable water resource in Northwest China. In the past few decades, progress has been achieved in snowmelt runoff simulation in mountainous areas, including observation and simulation of snow melt process, improvement and development of distributed snow melt runoff model, and ability for application of snow melt runoff model with temporal and spatial distribution driving data. The development of interpolation algorithm, remote sensing and data assimilation technology provides data support for the widespread application of distributed snowmelt runoff model in northwest mountainous regions of China. Climate warming and economic and social development will further aggravate the contradiction between supply and demand of water resources in the arid regions of Northwest China, which requires higher precision and detail spatial and temporal resolution of snowmelt runoff simulation. Based on the progress and challenges on snowmelt runoff simulation in mountainous regions of Northwest China, following studies need more attention：the mechanism of snow accumulation and ablation, snow cover spatial and temporal distribution monitoring and high precision of snow distribution data acquisition, quantitative climate change impact on river basin snowmelt runoff. © 2022 The authors.     

Objective-Based Method for Environmental Flow Assessment in Estuaries and Its Application to the Yellow River Estuary,China

We developed an objective-based method for assessing environmental flows in estuaries; this method consists of two steps: identifying ecological objectives with temporal–spatial variability and establishing a relationship between variations in environmental factors and the alteration of freshwater inflows. Critical salinity and water depth requirements for different species in special seasons in addition to temporal variation in natural river discharge were combined as objectives with spatial and temporal variability. In a case study of the Yellow River Estuary, we determined that 15% and 101% of the natural river discharge should be provided to ensure the minimum and maximum levels of environmental flows, respectively, for successful integration of various objectives. Periods in early April, the end of June, August, and early October were identified as critical for fulfilling reasonable water requirements. Although the recommended environmental flows may not be ideal for certain types of species, they offer a boundary of environmental flows for preserving habitats and biodiversity in estuaries.     

中亚干旱区陆地水资源对气候变化的响应

气候变化对中亚干旱区高山融雪、蒸散发以及径流等水循环过程产生影响,从而引起区域水资源在空间和时间上的重新分配.在归纳总结降水、土壤水、地表水、陆地水储量等不同水体类型在气候变化下改变情况的基础上,综述了中亚干旱区陆地水资源变化对气候变化响应的现状及进展.由于使用的数据和评估方法不同,水资源变化研究结果具有一致性及不确定...     

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.     

基于WEP-L模型的寒区流域径流演变模拟及归因分析

寒区在我国分布广泛,且多为我国主要江河的源头区,其水循环演变会对地区乃至全国的水资源情势产生重要影响。针对寒区冻土作用下特殊的水文特性,研究选择松花江、黄河、黑河、长江、雅鲁藏布江流域内5个典型寒区流域,采用改进的WEP-L模型模拟分析了寒区径流在1960—2010年的时空变化规律。同时,基于水文模拟法,设计不同气候变化与土地利用情景对各寒区流域径流变化进行了归因分析。研究表明：WEP-L针对不同的寒区流域逐月径流过程,取得了较好的模拟效果,NSE（纳什效率系数）基本在0.7以上,相对误差控制在±15%内。5个流域的径流量变化趋势表现为弱显著性,但是黄河流域（唐乃亥以上）和黑河流域（莺落峡以上）的基流指数显著增加,说明这两个流域的河川基流占比不断增加,主要原因可能在于冰川融雪的增加。除了松花江流域（阿彦浅以上）外的四个寒区流域的气候变化对径流的影响较高,贡献率达到78%以上,是径流演变的主导作用。研究结果有助于增强对寒区水循环和水资源演变的认识,为应对未来变化环境下寒区水问题提供参考。     

气候变化对京津唐地区水资源及供需平衡的影响

根据大气环流模型(GCMs)输出的未来气候变化情景,结合历史资料的诊断分析,应用建立的流域水文模型及水资源利用综合评价模型,研究了气候变化对京津唐地区水资源数量和时空变化的影响。在地区未来经济发展及部门用水量预测的基础上,分析了气候变化对供水、需水和部门缺水的影响以及经济损失。     

气候与土地利用变化对涟水流域径流的影响

以涟水流域为研究对象,选用1990年、2000年、2010年三期土地利用数据资料,将1985-2014年30 a气象条件相应划分为1985-1994年、1995-2004年、2005-2014年三段气象背景时期,并组合细分为7种模拟情景,应用SWAT分布式水文模型模拟不同情景下的径流量,探讨气候和土地利用变化对流域径流的影响。利用PSO粒子群优化算法,以克林效率系数KGE为目标函数,通过湘乡站实测径流数据校准模型参数。运用p-factor、r-factor评价模拟的不确定性,采用相关系数R²、纳什效率系数NS和偏差百分比PBIAS评价模型模拟效果,评价结果表明不同土地利用情景下,校准期和验证期的模拟效果均达到可信程度,模拟的不确定性较小。组合情景间模拟分析结果表明,1985-2014年30 a间,气候变化使涟水流域径流不断减少,土地利用变化使径流有所增加,年径流深总体呈现下降趋势。气候变化对涟水流域径流变化的影响贡献率在逐渐上升,从71.4%上升到了86.3%。土地利用变化对径流变化的影响贡献率则相应下降,从28.6%降低至13.7%。因此,在气候变化背景下,科学管理流域水资源还需要充分考虑流域土地资源空间配置结构和利用方式。