The effects of climate change on the water resources of the Geumho River Basin,Republic of Korea

Assessments of the variation and vulnerability of water resources due to climate change are essential for future planning in agriculture. In this study, the impacts and uncertainty associated with climate change on water resources in the Geumho River Basin were measured based on the relative change in the mean annual runoff and the aridity index. Statistically adjusted and downscaled multi-ensemble General Circulation Model (GCM) predicted rainfall and temperature data for three representative concentration pathways (RCPs) (RCP2.6, 4.5 and 8.5) were applied to two lumped parameter conceptual rainfall runoff models. The results revealed considerable uncertainty in the projected temperature, rainfall, potential evapotranspiration (PET), runoff and aridity index (AI). Additionally, temperature and rainfall were predicted to increase significantly in the future. The PET was projected to increase by a mean (range) of 9% (7–12%), 18% (9–30%) and 25% (8–49%), while the mean annual runoff was projected to change by a mean (range) of 1% (−33 to 40%), −9% (−47 to 27%) and −4% (−44 to 35%), in the 2030s, 2060s and 2090s, respectively. The AI was projected to decrease in the future, particularly for the RCP8.5. Overall, the results of this study indicate that climate change will most likely lead to lower water resource levels than are currently present in the Geumho River Basin.     

气候变化对海河流域水文特性的影响

本文应用大尺度陆面水文模型——可变下渗能力模型VIC(Variable Infdtration Capacity)与区域气候变化影响研究模型PRECIS(Providing Regional Climatefor Impacts Studies)耦合，对气候变化情景下海河流域水资源的变化趋势进行预测。结果表明：未来气候情景下，即使海河流域降水量增加，年平均径流量仍将可能减少，预示海河流域的水资源将十分短缺；若考虑21世纪人口增长因素，海河流域的水资源形势将更加严峻；未来气候情景下，汛期的径流量增加，说明海河流域发生洪水的可能性将增大。     

情景分析技术在未来太湖水位预见中的应用

为了探讨未来太湖水位对气候变化及人类活动的响应,基于情景分析技术,利用分布式水文模型VIC,水动力学模型ISIS,并结合区域气候模式PRECIS,对太湖水位进行水文-水动力学模拟。结果表明:未来时期(2021—2050年),太湖流域平原区下垫面不透水面积增加显著,水田、旱地和水面的面积均呈减少趋势;太湖汛期最高水位和平均水位较基准期(1961—1990年)均显著升高,未来诱发同量级太湖最高水位的暴雨重现期将显著减小,太湖流域未来大洪水的发生可能更趋频繁。     

大尺度分布式水文模型VIC在嘉陵江流域径流模拟中的应用

大尺度分布式流域水文模型是目前评价流域环境变化的重要工具,以嘉陵江流域为研究对象,构建了嘉陵江流域大尺度分布式VIC模型(Variable Infiltration Capacity,VIC model),利用Maryland大学的全球1 km×1 km土地覆盖数据,同时参考LDAS(Land Data Assimilation System)成果,建立了嘉陵江流域VIC模型的参数库,通过4个水文站以上流域的水文模拟试验,结果表明建立的VIC模型能有效地模拟嘉陵江流域各典型站的日、月径流过程,模拟的水量平衡误差在5%以内,日径流过程模拟的确定性系数均在70%以上,月径流过程模拟的确定性系数超过90%。该模型可以用来分析环境变化对嘉陵江流域水资源及洪水过程的影响。     

气候变化对嘉陵江流域水资源量的影响分析

 嘉陵江是长江的最大支流,流域面积约16万km2。针对2050,2100年不同的气候变化情景,选取较为不利的参数组合,根据降水、气温、湿度、风速、日照等气候要素的变化,建立潜在蒸发量模型计算流域的潜在蒸发量（ET0）,再根据流域内植被的蒸散发系数（Kc）,计算流域的面平均蒸散发量（ETc）。并利用流域面平均降水量减去径流深得到流域的实际蒸散发量,对计算的流域面平均蒸散发量进行验证。对不同的水平年利用降水的预测成果（气候变化情景不同具有不同的降水量预测成果）及计算流域的面平均蒸散发量,根据水量平衡模型分析计算气候变化对嘉陵江流域水量的影响。结果表明：不利条件下2050年年径流将减少23.0%～27.9%;2100将减少28.2%～35.2%;2050,2100年平均年径流分别相当于目前7年一遇和12年一遇的干旱年。由此说明,气候变化对流域内的水资源量影响十分显著。      

基于SWAT模型的浏阳河流域径流对土地利用和气候变化的协同响应

气候和土地利用同时作用于流域径流,影响着流域水资源的量和质。以浏阳河流域为例,基于SWAT模型和情景分析方法定量评估未来流域内土地利用和气候变化对径流的作用。首先采用元胞自动机-马尔科夫(CA-Markov)模型模拟浏阳河流域2020和2050年的土地利用空间格局,其次在World Clim数据库中获得未来流域内气候变化数据,最后采用SWAT模型定量评估未来不同情境下土地利用和气候变化对径流的影响。研究结果表明:未来浏阳河流域林地比例下降、城市建设用地和耕地比例增加;气候呈暖干趋势; 2020和2050年,土地利用变化时,浏阳河榔梨站模拟径流将分别减少2. 42和0. 96 m~3/s;气候变化时,榔梨站模拟径流将分别减少3. 02和1. 13 m~3;土地利用和气候变化综合影响下,榔梨站模拟径流将分别减少8. 54和4. 27 m~3/s;说明浏阳河流域径流的变化对气候响应更加敏感,土地利用和气候变化对径流的影响呈非线性协同作用。     

基于冻土水文模拟的松花江流域水资源演变规律

为分析松花江流域水资源的演变规律,基于寒区水-热-氮素循环模型（the?water?and?energy?transfer?processes and?nitrogen?cycle?processes?model?in?cold?regions,WEP-N）和水资源评价方法,对径流发生突变的 1998 年前后（即 1999—2018 年和 1956—1998 年）进行比较,松花江流域年水资源总量减少 217.0 亿 m3,减幅达到 22.2%。其中, 地表水资源量减少是水资源总量减少的主要组分,占水资源总量减少的比例为 96.9%,不重复地下水资源减少量 占 3.1%。基于多因子归因分析方法分析可知,气候变化是松花江流域水资源减少的主要因素,对松花江流域全年 水资源总量、地表水资源量、不重复地下水资源量减少的贡献率分别为 81.6%、74.9%、286.6%,取用水的贡献率 分别为 18.4%、25.1%、－86.6%。从年内不同时期分析可知,非冻融期是全年水资源量减少的主要时期,占全年水 资源总量减少的 82.6%,冻融期占 17.4%。和北方的海河流域、黄河流域相比,水资源减少幅度和主要影响因素各 不相同,主要取决于气候变化和人类活动强度变化幅度的不同。与位于华北和西北的两大流域海河流域和黄河 流域对比,气候变化对松花江流域水资源衰减的影响与海河流域相当,明显大于黄河流域,而人类活动对松花江 流域水资源衰减的影响明显小于两大流域。     

Assessment of Future Climate Change Impacts on Water Resources of Upper Sind River Basin, India Using SWAT Model

A study has been conducted to assess future climate change impacts on water resources of the Upper Sind River Basin using Soil Water Assessment Tool. Sequential uncertainty fitting (SUFI-2) algorithm has been applied for model calibration and uncertainty analysis. Monthly observed stream flows matched well with simulated flows with respect to p-factor, d-factor, Correlation coefficient and Nash-Sutcliffe coefficients with values of 0.73, 0.42, 0.82, 0.80 during calibration (1992–2000) and 0.42, 0.36, 0.96, 0.93 during validation (2001–2005) respectively. PRECIS generated outputs under IPCC A1B Scenarios for Indian conditions corresponding to the baseline (1961–1990), midcentury (2021–2050) and endcentury (2071–2098); extracted by Indian Institute of Tropical Meteorology, Pune (India) have been used for the study. It has been found from the model results that the average annual streamflow could increase by 16.4 % for the midcentury and a significant increase of 93.5 % by the endcentury. The results also indicate that streamflow may rise drastically in monsoon season, but will decrease in non-monsoon season due to the projected future climate change.     

若尔盖湿地流域径流变化及其对气候变化的响应

为探索未来气候变化情景下若尔盖高寒湿地水文过程和水循环演变规律,利用分布式水文模型,研究2020—2050年不同气候变化情景下若尔盖湿地流域径流变化趋势以及气候变化对湿地径流的影响。结果表明:在未来气候变化情景下,若尔盖湿地流域径流呈减少趋势,玛曲站径流减少比率最大,其次为若尔盖站,最后为唐克站;非汛期径流量减少幅度明显高于汛期,若尔盖湿地2020—2050年非汛期径流在未来气候变化情景下径流减少比率大部分在25%以上。非汛期径流的锐减可能会进一步加剧若尔盖湿地的退化和萎缩,导致黄河中下游区域的可利用水资源量减少。     

Quantifying the Relative Contribution of Climate and Human Impacts on Runoff Change Based on the Budyko Hypothesis and SVM Model

The Wei River Basin (WRB), the largest tributary of the Yellow River in China, has experienced a noticeable decrease in annual runoff during the last 50 years. Quantifying the relative contributions of climate change and human activities on runoff changes is thus important for local water resources management and sustainable water resources utilizations. In this study, the heuristic segmentation method was first adopted to detect the change points of annual runoff at Linjiacun and Huaxian stations which lies in the middle and lower reaches of the basin, respectively. Then, the Budyko hypothesis and SVM-based model were applied to attribute the detected runoff changes to climate change and human activities. Results showed that: (1) two change points were detected for the annual runoff at the Linjiacun station (1971 and 1993), and Huaxian station (1969 and 1993); (2) based on the Budyko hypothesis, the relative contributions of climate change and human activities to runoff changes at Linjiacun and Huaxian stations are 42.2 %, 57.8 % and 30.5 %, 69.8 %, respectively, whilst those based on the SVM-based model are 45.3 %, 54.7 % and 34.7 %, 65.3 %, respectively. The high consistence between the two approaches indicates that human activities are the dominate factor on historical runoff changes in the WRB.     

Hydrological Responses to Climate Change in Nenjiang River Basin,Northeastern China

Under the background of global climate change, hydrological responses to climate change were investigated in Northeastern China. This study analyses the trends of annual and seasonal temperature, precipitation and streamflow series in Nenjiang River Basin. Correlations between streamflow and meteorological variables were investigated, while parametric method and nonparametric tests were applied to determine the trends and correlations. Data collected from a series of monitoring stations showed significant increasing trends of annual and seasonal mean temperature versus time, whereas during the whole period the annual and seasonal precipitation in the basin did not exhibit similar trends although temporal and spatial variations were detected. Affected by the precipitation and temperature changes, significant trends of decreasing annual, spring and autumn streamflow were demonstrated; the decrease concentrating mainly on the mainstream and tributaries of the left bank. Correlation analyses revealed strong relationships between the streamflow and meteorological variables in Nenjiang River Basin, and the impacts of climate change on streamflow were complicated. Results from this study will help water resource managers for decision makings that address the consequences of climate change.     

气候变化对北江流域径流影响的模拟研究

通过构建北江流域SWAT分布式水文模型,以北江流域13个雨量站10年逐月降水量及北江流域干流石角水文站同步逐月流量数据为输入条件进行水文模型参数率定,应用气候情景设置方法研究了北江流域在降水和气温等不同气候变化条件下径流量的变化规律。研究表明:气温变化1℃对年径流量及其年内分配的影响变化均在1%以内。降水量变化对年径流量影响十分显著,降水量变化10%对年径流量的影响变化可达到15%,而对径流年内分配的影响变化在1%以内,影响较小。随着气温下降和降水量的增加,枯季径流量占年内分配比例均有所上升,枯水期来水量提高,有利于流域城乡供水安全和生态用水安全。     

Assessing the Impacts of Climate Change on Hydrology of the Upper Reach of the Spree River: Germany

The aim of this study was to assess the potential impacts of future climate change on the hydrological response in the upper reach of the Spree River catchment using the Soil and Water Assessment Tool (SWAT). The model was calibrated for ten years (1997–2006) and validated with the data from four years (2007–2010) using average monthly stream flow. The impact of future climate change on precipitation, temperature, evapotranspiration and stream flow was then investigated from two different downscaled climate models (CLM and WETTREG2010) under SRES A1B scenarios for two future periods (2021–2030 and 2041–2050). Besides that, sensitivity analysis was carried out with and without observations, to test robustness of the sensitivity algorithm used in the model. Results of the determination coefficient R² and Nasch-Sutcliff efficiency E_NC were 0.81 and 0.80, respectively, during the calibration; 0.71 and 0.70, respectively, during the validation. Although some parameters were changed their sensitiveness ranking when the model run with observations, the SWAT model was, however, able to predict the top influential parameters without observations. According to 12 realizations from the two downscaled climate models, annual stream flow from 2021–2030 (2041–2050) is predicted to decrease by 39 % (43 %). This corresponds to an increase in annual evapotranspiration from 2021–2030 (2041–2050) of 36 % (38 %). The upper reach of the Spree River catchment will likely experience a significant decrease in stream flow due to the increasing in the evapotranspiration rates. This study could be of use for providing insight into the availability of future stream flow, and to provide a planning tool for this area.     

玛纳斯河流域地表径流过程时空分异特征研究

新疆内陆河流域干旱缺水。在全球气候变化影响下,流域水资源不确定性增加。以玛纳斯河流域为研究典型,依据流域内塔西河、玛纳斯河、金沟河以及八音沟河出山口水文站1957-2012年径流量资料,统计分析了56年来玛纳斯河流域各河流年径流量的多年变化规律以及空间变异特征。研究结果表明,玛纳斯河流域内各河流年径流过程大致存在4~5个时间尺度的周期性规律,其中8~10 a和16~20 a左右的周期性变化起作用主导。通过泊松相关分析,基本可以认定,流域4条河流年径流过程存在着正相关性,也即存在着同步变化规律。     

气候变化和人类活动对白河流域径流变化影响的定量研究

分析气候变化和人类活动对白河流域径流变化的贡献率,可为流域水资源规划与管理提供依据。以白河流域作为研究对象,首先采用线性趋势法、滑动平均法分析水文气象要素的年际变化趋势,其次采用Mann-Kendall检验、有序聚类检验和滑动t检验探究年径流量的突变年份,最后采用基于Budyko假设的水量平衡法评估气候变化和人类活动对径流变化的影响。结果表明:白河流域年径流量呈下降趋势,2008-2017年平均径流量仅为1960-1969年平均径流量的36.5%;年径流量在1979年发生突变,在1986年以后呈显著下降趋势;与基准期相比,变化期流域的干旱指数在增加,2001-2017年流域的干旱更为明显;人类活动是白河流域径流变化的主要原因,1980-2000年、2001-2017年人类活动对径流变化的平均贡献率分别为85.6%、73.6%,说明2000年以后气候变化对径流变化的影响呈上升趋势。     

Optimal water allocation at different levels of climate change to minimize water shortage in arid regions (Case Study: Zayandeh-Rud River Basin,Iran)

Climate change is one of the most important factors influencing the future of the world's environment. The most important impacts of climate change are changes in water supply and demand in different regions of the world. In this study, different climate change patterns in two RCP4.5 and RCP8.5 emission scenarios (RCP: Representative Concentration Pathway), were adopted for the Zayandeh-Rud River Basin, Iran, through weighting of GCMs (General Circulation Models). These climate change patterns are including ideal, medium, and critical patterns. Using the LARS-WG model (Long Ashton Research Station Weather Generator), the outputs of the GCMs were downscaled statistically and the daily temperature and precipitation time series were generated from 2020 to 2044. Then, based on this information, the inflow volume into the Zayandeh-Rud Reservoir was predicted by the IHACRES model (Identification of unit Hydrograph and Component flows from Rainfall, Evaporation and Streamflow) and the agricultural water demand was also estimated based on future evapotranspiration. Finally, using GAMS (General Algebraic Modeling System) software, water resources in this basin were allocated based on the basic management scenario (B) and the water demand management scenario (D). The results showed that the average monthly temperature will increase by 0.6 to 1.3 °C under different climate change patterns. On the other hand, on the annual basis, precipitation will decrease by 6.5 to 31% and inflow volume to the Zayandeh-Rud Reservoir will decrease by 21 to 38%. The results also showed that the water shortages based on the baseline management scenario (B) will be between 334 and 805 MCM (Million Cubic Meters). These range of values varies between 252 and 787 MCM in the water demand management scenario (D). In general, the water shortage can be reduced in the Zayandeh-Rud River Basin with water demand control, but complete resolution of this problem in this region requires more integrated strategies based on a sustainable development, such as a fundamental change in the cropping pattern, prevention of population growth and industrial development.     

未来气候变化影响下的流域面源污染负荷特征响应评估

针对流域面源污染负荷在未来气候变化影响下的变化特征,以我国新安江上游率水流域为例,使用通用流域污染负荷模型(GWLF),对其2000-2013年的水量及总氮、总磷面源污染负荷通量进行了模拟,并解析了其负荷来源分配。在此基础上,基于政府间气候变化专业委员会(IPCC)的气候变化评估报告结果,利用GWLF模型分析了到21世纪20年代、50年代、80年代在A1FI(最高排放)和B1(最低排放)情景下,率水流域的水文及总氮、总磷面源污染负荷特征变化。结果表明:未来气候变化对流域水文及面源污染负荷特征均有一定影响。年水资源量先减少后增加,地表径流量和蒸发量逐渐上升而地下水量逐渐下降。到2080s,A1FI情景比B1情景有更多的水资源量。年总氮通量先增加后减少,在2050s最高,而年总磷通量则逐渐增加,且两种污染物均在A1FI排放情景下有更高的污染负荷量,表明人类温室气体的排放会潜在地增加流域水体面源污染负荷。     

Investigation of the Behavior of an Agricultural-Operated Dam Reservoir Under RCP Scenarios of AR5-IPCC

In regions where the Mediterranean climate prevails, the agricultural sector and agricultural-operated dam reservoirs are threatened by climate change. In this respect, the prediction of hydro-meteorological changes that may occur in surface water resources under climate change scenarios is essential to examine the sustainability of reservoirs. In this paper, Demirköprü reservoir in the Gediz Basin/Turkey, a reservoir operated for irrigation purposes, was analyzed against the RCP4.5 and RCP 8.5 scenarios specified in the AR5 report of the IPCC. Projection period was evaluated as 2016-2050 water year period. First, statistical downscaling, Bayesian model averaging and quantile delta mapping bias correction techniques were respectively applied to monthly total precipitation and monthly average temperatures of meteorological stations in the region using 12 GCMs. According to RCP4.5 and RCP8.5, negligible reductions in precipitation are foreseen, while significant increases of 1.3 and 1.8 °C, respectively, are projected for temperatures under the same scenarios. Following the calibration of rainfall-runoff models for the sub-basins feeding the reservoir, streamflow simulations were also performed with projected precipitation and temperatures. In particular, according to the RCP 8.5 scenario, reservoir inflows during the period 2016-2050 could be reduced by 21% compared to the reference scenario results. Finally, the projected crop water demands and hydro-meteorological changes are evaluated together and the reservoir performances are examined using various indices. Assuming that the performance of the past irrigation yields will not change in the future, it is foreseen that reservoir’s sustainability will decrease by 16% under the RCP8.5 scenario. Even if the irrigation efficiency is increased by 40%, the reservoir cannot reach past sustainability characteristics.     

基于HBV的黑河流域径流对气候变化的响应

黑河流域是我国西北干旱区内陆河研究的代表性流域,研究未来气候变化对黑河流域山区径流的定量影响,对干旱区水资源规划设计、开发利用和保护管理具有重要意义。采用HBV-light模型,首先根据实测径流数据验证了该模型在黑河流域上游的适用性,然后拟定25种气候变化情景模式,模拟气温与降水变化对径流的定量影响。结果表明:(1)当气温保持不变时,降水增加会造成年径流增加;而当降水维持不变时,气温升高将导致年径流减少。(2)关于径流年内分布,气温变化与6~9月份的径流呈负相关关系,而与4月份的径流呈显著正相关关系;降水变化与径流呈明显的正相关关系;年径流与年内分配均表现为对于降水变化的敏感性高于气温变化。(3)未来气候变化有助于缓解黑河流域水资源短缺的现状。     

Assessment of future climate change impacts on hydrological behavior of Richmond River Catchment

This study evaluated the impacts of future climate change on the hydrological response of the Richmond River Catchment in New South Wales (NSW), Australia, using the conceptual rainfall-runoff modeling approach (the Hydrologiska Byrans Vattenbalansavdelning (HBV) model). Daily observations of rainfall, temperature, and streamflow and long-term monthly mean potential evapotranspiration from the meteorological and hydrological stations within the catchment for the period of 1972–2014 were used to run, calibrate, and validate the HBV model prior to the streamflow prediction. Future climate signals of rainfall and temperature were extracted from a multi-model ensemble of seven global climate models (GCMs) of the Coupled Model Intercomparison Project Phase 3 (CMIP3) with three regional climate scenarios, A2, A1B, and B1. The calibrated HBV model was then forced with the ensemble mean of the downscaled daily rainfall and temperature to simulate daily future runoff at the catchment outlet for the early part (2016–2043), middle part (2044–2071), and late part (2072–2099) of the 21st century. All scenarios during the future periods present decreasing tendencies in the annual mean streamflow ranging between 1% and 24.3% as compared with the observed period. For the maximum and minimum flows, all scenarios during the early, middle, and late parts of the century revealed significant declining tendencies in the annual mean maximum and minimum streamflows, ranging between 30% and 44.4% relative to the observed period. These findings can assist the water managers and the community of the Richmond River Catchment in managing the usage of future water resources in a more sustainable way.