Identification of Streamflow Response to Climate Change and Human Activities in the Wei River Basin,China

In this study, the calibration and validation period with stable underlying surface conditions was determined by using a statistically significant change point of the annual streamflow in several catchments of the Wei River basin (WRB). The effects of climate changes and human activities on streamflow were estimated by using the sensitivity-based method and the dynamic water balance model, respectively. The contributions of climate effects and human activities effects on streamflow were also investigated. The results showed that almost all the catchments exhibited significant decreasing trend of streamflow in the early 1990s. The streamflow was more sensitive to changes in precipitation than changes in potential evapotranspiration (PET). Effects of climate due to changes in precipitation and PET are weak in Linjiacun, Weijiabao and Xianyang catchments, while it is strong in the catchments controlled by other hydrological stations, accounting for more than 40 % of streamflow reduction. Effects of human activities on streamflow in Linjiacun, Weijiabao, Xianyang and Zhangjiashan catchments accounted for more than 50 % of the streamflow reduction. The study provides scientific foundation to understand the causes of water resources scarcity and useful information for the planning and management of water resources in the ecological fragile arid area.     

The Impacts of Climate Variability and Future Climate Change in the Nile Basin on Water Resources in Egypt

This paper describes the application of hydrologic models of the Blue Nile and Lake Victoria sub-basins to assess the magnitude of potential impacts of climate change on Main Nile discharge. The models are calibrated to simulate historical observed runoff and then driven with the temperature and precipitation changes from three general circulation model (GCM) climate scenarios. The differences in the resulting magnitude and direction of changes in runoff highlight the inter-model differences in future climate change scenarios. A 'wet' case, 'dry' case and composite case produced +15 (+12), -9 (-9) and + 1(+7) per cent changes in mean annual Blue Nile (Lake Victoria) runoff for 2025, respectively. These figures are used to estimate changes in the availability of Nile water in Egypt by making assumptions about the runoff response in the other Nile sub-basins and the continued use of the Nile Waters Agreement. Comparison of these availability scenarios with demand projections for Egypt show a slight surplus of water in 2025 with and without climate change. If, however, water demand for desert reclamation is taken into account then water deficits occur for the present-day situation and also 2025 with ('dry' case GCM only) and without climate change. A revision of Egypt's allocation of Nile water based on the recent low-flow decade-mean flows of the Nile (1981-90) shows that during this period Egypt's water use actually exceeded availability. The magnitude of 'natural' fluctuations in discharge therefore has very important consequences for water resource management regardless of future climate change.     

Extreme value analysis of streamflow time series in Poyang Lake Basin, China

Extreme meteorological and hydrological events may cause major disasters and heavy social and economic losses.Therefore,more and more studies have focused on extreme hydro-meteorological events in various climates and geographic regions.Based on nearly 50 years of observed records of the Poyang Lake Basin,the occurrence and changing trends of extreme streamflow indices,including the annual maximum flow,annual peak-over-threshold flows,and low flows,were analyzed for ten hydrological stations.The results indicate that most annual maximum flows occurred from April to July,highly attributed to the Southeast Asian summer monsoons,whereas the annual minimum flows were concentrated between January and February.As for the low flow indices (the annual minimum flow,annual minimum 7-d flow,and annual minimum 30-d flow),a significant increasing trend was detected in most parts of the Poyang Lake Basin.The trends illustrate the potential effects of climate change and human activities on the hydrological cycle over the Poyang Lake Basin.     

Streamflow Response to Climate Change in the Brahmani River Basin,India

Climate change can significantly affect the water resources availability by resulting changes in hydrological cycle. Hydrologic models are usually used to predict the impacts of landuse and climate changes and to evaluate the management strategies. In this study, impacts of climate change on streamflow of the Brahmani River basin were assessed using Precipitation Runoff Modeling System (PRMS) run under the platform of Modular Modeling System (MMS). The plausible hypothetical scenarios of rainfall and temperature changes were used to assess the sensitivity of streamflow to changed climatic condition. The PRMS model was calibrated and validated for the study area. Model performance was evaluated by using joint plots of daily and monthly observed and simulated runoff hydrographs and different statistical indicators. Daily observed and simulated hydrographs showed a reasonable agreement for calibration as well as validation periods. The modeling efficiency (E) varied in the range of 0.69 to 0.93 and 0.85 to 0.95 for the calibration and validation periods, respectively. Simulation studies with temperature rise of 2 and 4°C indicated 6 and 11% decrease in annual streamflow, respectively. However, there is about 62% increase in annual streamflow under the combined effect of 4°C temperature rise and 30% rainfall increase (T4P30). The results of the scenario analysis showed that the basin is more sensitive to changes in rainfall as compared to changes in temperature.     

Combined Impacts of Climate Variability Modes on Seasonal Precipitation Extremes Over China

Water Resources Management - The joint effects of natural climate variability on the variations in seasonal precipitation extremes across China during 1961–2017 were studied based on a...     

鄱阳湖流域未来降水变化预测分析

利用鄱阳湖流域的 13 个国家气象站 1961-2001 年的实测降水数据和 NCEP 再分析数据,建立了鄱阳湖流域降水的统计降尺度模型;在 IPCC 2000 年排放情景特别报告（ SRES ）中的A2和B2 排放情景下,应用 HadCM3 的输出数据,预测鄱阳湖流域未来3个时段（2010-2039 年、 2040-2069 年、 2070-2099 年）的降水变化情况。结果表明：鄱阳湖流域大部分区域的降水量有所增加,在本世纪末最大可能增加 11.15% 。     

鄱阳湖流域气候变化及其对入湖径流量的影响

为分析鄱阳湖流域气候变化特征及评估其对流域径流的影响,研究利用1961-2010年间鄱阳湖流域29个气象站和入湖"五河"水文控制站观测数据,分析该时段内流域气候和径流量变化趋势,建立统计模型分析其对流域径流量的影响。研究结果表明:鄱阳湖流域年气温呈显著性(99%置信度检验)波动上升趋势,流域降水总体呈略上升趋势,降水天数呈下降趋势。受气候变化的影响,鄱阳湖流域径流量呈上升趋势。统计模型计算结果表明,径流量与降雨变化呈非线性关系,径流量对降雨变化有着较强的敏感性,相同的气温变化情景下,降水增加比降水减少对径流量的影响更加显著,表明降水变化对径流量有着不同程度和方向的影响作用。气温对径流的影响呈线性,但其影响不明显。未来气候变化情景下,2050年前鄱阳湖流域在高排放A2和RCP8.5情景下呈现明显增长趋势,但其径流量低于其他排放情景。     

鄱阳湖流域饶河水资源分配探讨

饶河是鄱阳湖流域5大河流之一,水资源较为丰富,但区域用水量与资源分布不均。通过对饶河区域水资源分布进行分析,采用用水定额预测法、分类权重法、层次分析决策法等多种方法,探讨区域水资源分配比例,为界定初始水权、进行初始水量分配、逐步实现水权管理制度的建立提供保证。     

Impacts of Climate Change and Seasonal Variability on Economic Treatment Costs: A Case Study of the Nitra River Basin,Slovakia

Analysis of climate change impacts upon water resources has focused prim arily on water quantity issues. The impacts upon water qu ality and water quality management have had little attention. This paper presents a framework for assessing climate change impacts upon stream water quality and the management costs associated with adaptation to the new hydroclim atic conditions resulting in changes in streamflow and stream temperature. W ater quality indicators as well as chemical and biological processes important to water quality are a fu nction of stream temperature. This paper reports not on ly on how water quality indices will be im pacted by alternative climate change scenarios, but on the econom ic cost of maintaining water quality stan dards. The costs of maintaining water quality standards result from increased treatm ent of waste loads due to decreased waste assimilation capacity of warmer streams. A case study based on regionally developed climate change scenarios shows that water quality levels are greatly impacted in the low flow periods (by as m uch as 14 times), while average annual conditions are n ot impacted significantly.     

鄱阳湖流域典型稻田水量平衡分析

为探索稻田田间水量平衡要素之间关系及其影响因素,通过在鄱阳湖流域赣抚平原灌区选取典型田块,结合江西省灌溉试验中心站系列灌溉试验资料,开展了稻田田埂渗流试验和田间水量平衡试验。田埂渗流试验表明,田埂侧向渗流速度为3.97 mm/d,侧向渗流占稻田蒸渗量49.2%,这一部分水将在下田块或下游区域得以重复利用;上框和双套环水位呈直线下降趋势,在田面低水层情况下(田面覆水30 mm),田面覆水深度对田间渗漏影响较小,田间渗漏(垂直入渗和侧向渗流)保持一个相对平稳状态。田间水量平衡试验表明,典型地块的灌水量和排水量明显小于有底测坑;在一季稻全生育期内,典型田块的侧向渗流在当地稻田渗漏量中占相当大比例,占全生育期耗水量的10.9%。     

鄱阳湖流域水资源开发利用的时空特征

流域水资源开发利用时空特征进行分析是提高未来水资源开发利用合理性、高效性的前提,可为流域未来水资源规划、开发、利用提供有力支撑。基于2010-2019年鄱阳湖流域用水和经济社会数据,采用变异系数、洛伦兹曲线与基尼系数、空间分级分类、信息熵与均衡度分别从水资源的开发利用量、开发利用效率、开发利用结构3方面研究流域近10年水资源开发利用的时空特征。结果表明：鄱阳湖流域各行业中第二产业的用水空间布局均衡性最差,变异系数为0.8～0.9,用水空间布局与水资源空间禀赋的匹配性最差,基尼系数为0.30～0.35;流域内各地市2010-2019年用水结构均衡度在0.40～0.75之间,其中,抚州市均衡度最小,均值约为0.40,南昌市均衡度最大,均值在0.75左右。流域内第二产业的用水空间布局有逐年改善的趋势,其发展布局已逐渐重视水资源因素;各行业用水效率有明显的空间差异性,且各行业的用水效率不具有空间一致性,其中第二产业用水效率有逐年提高的趋势;影响鄱阳湖流域内用水结构均衡性的主要因素是农业用水量占比较大。     

鄱阳湖流域日尺度降水集中度指数的时空分布规律

基于鄱阳湖流域1957—2019年14个气象站点的逐日降水数据,采用降水集中度指数CI（Precipitation Concentration Index）表征鄱阳湖流域日尺度下降水的集中程度。在分析出该流域多年平均降水集中度(A_CI)的空间分布特征的基础上,进一步采用Mann-Kendall和Sen′s方法检测出CI的趋势,利用Pettitt方法检验出CI突变的年份。结果表明:（1）鄱阳湖流域多年平均降水集中度(A_CI)由南至北上升,反映出流域北部降水更为集中,其降水极值的发生概率相对更高;（2）东部地区大部分站点的CI呈显著上升的趋势,反映出东部地区的降水程度愈发集中;（3）东北部景德镇站、南城站,降水集中指数CI分别于2006、2009年发生显著突变。并且,CI突变后的均值较突变前有所增加,表明近些年景德镇站、南城站日尺度下降水在年内显著集中。     

鄱阳湖流域河水、湖水及地下水同位素特征分析

利用鄱阳湖流域同位素按月份呈周期性变化的特征,将氘氧同位素关系作为示踪剂,研究降水入渗及地下水、河水与湖水之间的转化关系。结果表明:4月中旬湖水、河水、井水的δD、δ18O的均值分别为(-2.32%,-0.42%)、(-2.86%,-0.48%)和(-3.18%,-0.55%),δ18O~δD关系点都落在全球雨水线GMWL上;湖水最为富集,湖水的补给除河水之外,湖区及周边的降水也占一定比例。7月下旬湖水、河水与井水的δD、δ18O值明显比4月中旬的值贫化,与降水同位素变化趋势相一致,经历干旱高温天气后,湖水、河水与井水的δ18O~δD关系点落在蒸发线(EL2)上。同位素数据表明,井水与河水之间的转化性强,大量降水入渗地下成为潜水,通过地下径流补给河流,降水转化为河水的周期大约经历了1个月。3—6月为雨季,鄱阳湖对长江水的补给较大,影响到长江水中的同位素。     

鄱阳湖流域降雨量及降雨侵蚀力时空分布特征

水土流失是鄱阳湖流域严重的生态环境问题之一,为了给鄱阳湖流域土壤侵蚀的监测、评估、预测与控制等提供技术支撑,基于流域内均匀分布的15个气象站1961—2014年逐日降雨量数据,分析鄱阳湖流域降雨侵蚀力时空分布与演变特征。结果表明:鄱阳湖流域多年平均降雨侵蚀力为9 537.9 MJ·mm/(hm~2·h),其时空分布不均,时间上主要集中在夏季,空间分布呈现从西南向东北递增的趋势;降雨侵蚀力和降雨量年内分配均呈单峰型,峰值均出现在6月,汛期(4—9月)降雨量、降雨侵蚀力占全年的比例分别为62.4%、71.7%,降雨侵蚀力年内分配较降雨量更加不均匀。     

基于大湖视野的鄱阳湖流域水生态文明内涵及特性分析

水生态文明建设是当前经济社会可持续发展的现实需求。基于水生态文明发生的过程和要素,从自然环境、水利活动和社会经济文化层面及其相互关系,对鄱阳湖流域水生态文明内涵进行解析,提出水生态文明的具体性、整体性和发展性特点。从鄱阳湖流域特点、历史发展等角度分析了流域水生态文明特征,提出应从自然、水利、社会三个层面构建水生态文明建设评价指标体系,建立生态环境—水利行为—社会经济三方面的动态平衡。     

2020年鄱阳湖流域超标准大洪水分析与思考

2020年,鄱阳湖流域发生超标准大洪水.江西省深入贯彻落实习近平总书记关于防汛救灾工作的重要指示精神,始终坚持以人民为中心发展思想,众志成城,顽强奋战,取得防汛救灾工作全面胜利.阐述了2020年超标准洪水特点,以及防御手段的变化,分析了防范工作中存在的薄弱环节,研究提出了下一步做好超标准洪水防御工作的对策建议.     

Climate Variability Influences on Hydrological Responses of a Large Himalayan Basin

The hydrological cycle, a fundamental component of climate is likely to be altered in important ways due to climate change. In this study, the historical daily runoff has been simulated for the Chenab River basin up to Salal gauging site using a simple conceptual snowmelt model (SNOWMOD). The model has been used to study the impact of plausible hypothetical scenarios of temperature and rainfall on the melt characteristics and daily runoff of the Chenab River basin. The average value of increase in snowmelt runoff for T + 1°C, T + 2°C and T + 3°C scenarios are obtained to be 10, 28 and 43%, respectively. Whereas, the average value of increase in total streamflow runoff for T + 1°C, T + 2°C and T + 3°C are obtained to be 7, 19 and 28%, respectively. Changes in rainfall by −10 and + 10% vary the average annual snowmelt runoff over the T + 2°C scenario by −1% and + 1% only. The result shows that melt is much more sensitive to increase in temperature than to rainfall.     

鄱阳湖流域1961—2010年极端降水变化分析

基于鄱阳湖流域14个国家气象站1961—2010年的日降水量数据,采用百分位法定义阈值,识别极端降水事件;采用线性回归方法进行趋势检验,进而对鄱阳湖流域1961—2010年极端降水的时空变化特征进行分析。结果表明,相比年降水,流域极端降水的变化趋势更为明显;1961—2010年鄱阳湖流域极端强降水强度呈显著增大趋势而极端强降水天数显著减小;极端降水强度增大的区域主要分布在赣江流域和抚河流域。1961—2010年鄱阳湖流域大部分站点极端降水不存在突变,降水在时间上有分布更加集中的趋势。鄱阳湖流域极端降水的上述变化,对流域水资源管理提出了更加严峻的挑战。     

鄱阳湖流域主要旱作物需水规律研究

应用大田试验和小型旱作物需水测坑相结合的方法,采用喷/滴灌、沟灌、不灌三种不同灌溉方式,针对鄱阳湖流域主要旱作物需水量变化规律进行研究,找出其缺水敏感期,为灌好关键水提供理论依据,同时分析其作物需水系数,提出不同灌溉方式下作物水分利用率.     

Assessments of Impacts of Climate Change and Human Activities on Runoff with SWAT for the Huifa River Basin,Northeast China

The impacts of climate change and human activates on the runoff for Huifa River Basin, Northeast China, have been investigated with the soil and water assessment tool (SWAT), which is calibrated and verified for the baseline period 1956–1964, and then used to reconstruct the natural runoff from 1965 to 2005. The results indicate that both climate change and human activities are responsible for the decrease of observed runoff in Huifa River. The climate change could result in a decrease or increase of runoff depending on precipitation, temperature, radiation variation, as well as land cover changes. Its impacts on annual runoff are -36.7, -59.5, +36.9 and -45.2 mm/a for 1965–1975, 1976–1985, 1986–1995 and 1996–2005, respectively, compared with the baseline period 1956–1964. Human activities, on the other hand, generally lead to a decrease of runoff and a relatively larger magnitude than climate change after 1985. It has decreased the annual runoff by -32.9, -46.8, -67.8 and -54.9 mm/a for 1965–1975, 1976–1985, 1986–1995 and 1996–2005, respectively. Human activities contributed more to runoff decrease in wet years due to regulation and storage of the water projects. The results of this study could be a reference for regional water resources management since there are quite a number of reservoirs in the Huifa River basin.