气候变化和都市化双重驱动下流域未来水文响应

近年来,受气候变化和人类活动的共同影响,流域的气候和水文状况发生了显著改变,分析变化环境下未来水资源演化格局成为当前国内外学者关注的重点研究内容之一。以柘溪水库流域为研究区域,利用人文因素和自然因素作为土地利用变化的驱动因子构建土地利用模型,采用MIROC5气候模式多个情景作为未来气候典型代表,利用分布式水文模型分析了气候变化和都市化双重驱动下的流域未来水文响应。结果表明:都市化发展明显增加了流域地表径流,减少了地下径流;而气候变化对水文响应驱动力比都市化对水文响应的驱动作用更强。     

妫水河流域水文模拟及参数不确定性分析

以北京市延庆区妫水河为例,使用SWAT(Soil and Water Assessment Tool)模型对妫水河流域进行月尺度水文模拟,使用SUFI-2(Sequential Uncertainty Fitting)算法分析参数的敏感性,依据SWAT-CUP自动率定得到P因子和R因子分析模型的不确定性,从而完成本流域分布式水文模型的构建。率定结果显示,率定期确定系数R 2为0.65,效率系数NSE为0.61;验证期确定系数R 2为0.89,效率系数NSE为0.88;不确定性分析结果中P-factor均大于0.5,R-factor均小于0.3。通过以上分析可得该模型对妫水河流域的水文模拟有良好的效果。     

妫水河流域生态清洁小流域建设跃上大流域治理新台阶

妫水河流域自1983年开展小流域治理,已经有20多个年头,积累了一定的经验。在北京面临严重缺水的形势下,以水源保护为中心,构筑"生态修复、生态治理、生态保护"三道防线正式启动,妫水河流域形成了自己的"养山保水、进村治水、入川护水"三道水土保持防线。在具体操作上,仍以小流域为单元进行治理,但又不拘泥于小流域,突破小流域的局限性,树立妫水河流域的整体观,充分完整地考虑妫水河大流域的特点,把生态清洁小流域建设与水源保护结合起来,使妫水河流域的生态清洁小流域建设跃上大流域治理的新台阶。     

昕水河流域水文要素变化特征分析

根据有关水文气象台站的观测资料,对近45年来昕水河流域径流、泥沙、降水等水文气象要素变化特征和趋势进行了分析,可为昕水河流域防汛减灾、水资源综合规划和合理开发利用提供可靠的分析依据。     

运城市过去50a和未来气候变化趋势研究

基于运城市1961—2010年的年平均气温和降水量实测数据,运用Mann-Kendall趋势检验和线性回归法对其进行了分析,并结合SDSM模型分析了未来两种气候情景下年平均气温和降水量的变化趋势。结果表明:1运城市50 a来年平均气温呈显著上升趋势,且1990年之后的年平均气温明显高于1990年前的,降水量呈下降趋势,但1991—2010年变化趋势较为平缓;2未来两种气候情景下,年平均气温和降水量基本呈上升(增加)趋势,且累计增长率也呈逐渐增大趋势,与B2情景相比,A2情景下年平均气温的增幅更大。     

东江流域土地覆被变化的水文响应模拟研究

采用近年来快速发展的水文模型模拟手段,应用HSPF模型模拟东江流域不同下垫面条件下的径流影响变化情况,定量地评估了东江流域土地覆被变化对径流深、年内径流分配的影响。结果表明,随着流域内城镇化进程的加快,流域调蓄能力下降,因而产流能力增强;从年内分配的情况来看,汛期影响最为明显,这显然与土地利用变化影响到流域调蓄能力有关。     

汉江流域水文对气候变化的响应

利用两参数月水量平衡模型分析了汉江流域水文变量对气候变化的响应值。     

基于SWAT模型的秦淮河流域气候变化水文响应研究

为了解气候变化对水文水资源的影响机理,以秦淮河流域为研究区构建SWAT模型,使用SWAT-CUP对模型进行参数敏感性分析、率定及验证,并采用任意假设法设计未来气候情景,分析温度及降雨变化对流域径流及实际蒸散发量的影响。结果表明:模型在月径流模拟中具有较高的精度,适用于秦淮河流域气候变化下的水文响应研究;气温降低或降雨量上升都会引起流域径流量增加,反之则减少;实际蒸散发量与降雨量正相关,而实际蒸散发量对气温变化的响应不明显;平水年径流量对降雨量变化的响应较强,枯水年径流量对温度变化的响应较强;枯水年实际蒸散发量对降雨量变化的响应较强。     

新安江流域气候变化及径流响应研究

针对新安江流域新安江水库控制区域,构建新安江月水文模型,利用1979-2005年实测水文资料对模型进行率定和验证,并以CMIP5大气环流模式输出驱动水文模型,生成2006-2099年该流域在RCP2.6、RCP4.5和RCP8.5情景下的逐月径流过程。在此基础上,研究气候变化背景下流域气温、降雨、蒸发和径流的变化趋势,并对其不确定性进行分析。结果表明:2006-2099年该流域年均气温与年蒸发深度均呈上升趋势,且对于辐射强度变化较敏感,呈显著正相关关系。流域年降雨量与径流深呈波动上升趋势,对于辐射强度变化敏感性并不显著。年径流深在丰水年和平水年相对基准期有所减少,而在枯水年和特枯水年则呈增加趋势。月径流深在秋、冬季呈上升趋势,在春、夏季则呈下降趋势。     

晋江西溪流域气候变化下的水文响应研究

气候变化的水文响应研究主要集中在气温和降水的变化对流域各水文要素的影响,选用分布式水文模型SWAT模型,采取直接设定气候情景的方法,定量的评估晋江西溪流域在不同气温和降水条件下产流量、产沙量及蒸发量的变化情况.模拟结果表明气温升高或降水减少都会使产流量减少,气温升高4℃,降水减少20 %,产流量减幅最大,为33.34 %,气温升高或降水增加会使产沙量及蒸发量增加,气温升高4℃,降水增加20 %,产沙量及蒸发量增幅最大,分别为106.73 %和25.12 %,且降水对产流、产沙的敏感性要大于气温.     

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.     

花园口年平均流量对不同气候条件的响应

基于花园口水文站以上区域的71个气象站1961—2005年逐日降水量、气温和花园口水文站1961—2005年逐日实测流量,利用人工神经网络模型建立月平均流量与降水、气温之间的关系,并设定不同气候变化条件,研究了花园口水文站年平均流量对不同气候条件的响应。结果表明:花园口水文站年平均流量在降水增加10%和20%、气温变化-2～2℃时均为增加趋势,在降水减小10%和20%、气温变化-2～2℃时均为减小趋势,且增大幅度大于减小的幅度。     

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.     

Diagnosing Climate Change and Hydrological Responses in the Past Decades for a Minimally-disturbed Headwater Basin in South China

Identifying the trends of climate and hydrological changes is important for developing adaptive strategies for effective water resources management. Many studies focused on the prediction of future climate at a regional/global scale using General Circulation Models (GCM) or these models’ downscaled outcomes. However, diagnosing historical trends is regarded valuable for local areas, especially considering the spatial heterogeneity (both occurrence and magnitude) of climate change and uncertainty of climate projection. In this study, we selected the headwater area of the East River Basin in South China, which has minimal human-induced disturbance, to detect climate change and its hydrological changes over a past 50-year (1955–2004) time period. Although the climate warming agreed with the global situation, its magnitude was small and no sign of intensified rainfall or change of annual rainfall was found. Nevertheless, no-rain days increased and light-rain days decreased, indicating a longer dry interval between rainfall events. There was a significant downtrend of wind speed with a substantial reduction in magnitude, resulting in a decrease in the estimated potential evapotranspiration and a slight increase in the soil water content. Risks of flooding may not be a big concern, but water availability may be affected marginally in May and June due to the decreased rainfall and increased no-rain days. Overall, our results can improve the understanding of climate change and help watershed managers take precautions when facing climate change. This study also implies the necessity of investigating climate change at a local scale and at different time scales.     

基于HIMS的渭河中游黑峪口子流域径流模拟及其对气候变化的响应研究

水文模型是认识水循环机理、模拟水文系统及其对气候变化响应的重要工具和方法。基于国内自主研发的水文综合模拟系统(Hydro-Informatic Modeling System,HIMS),选择渭河中游的黑峪口子流域(面积1 476 km2)作为研究对象,构建黑峪口子流域的集总式水文模型,模拟黑峪口子流域1991—2000年的日径流过程,并在此基础上模拟8种气候变化情景(降水增加10%、不变、减少10%;蒸发增加10%、不变、减少10%)下的径流响应。研究取得了以下几点认识:①模型的整体模拟效果评价:在模型率定期(1991—1996年)Nash-Suttcliffe系数为0.64,相关系数为0.65,体积误差为5%;在模型验证期(1997—2000年)Nash-Suttcliffe效率系数为0.63,相关系数为0.66,体积误差为10%;②降雨的空间差异性较大,并且降雨是径流的直接来源,而在整个黑峪口子流域内只用到了3个气象站的连续观测资料,导致在整个子流域内降雨站点分布较少的情况对于径流模拟效果并不理想(Nash-Suttcliffe系数未大于0.7);③模型的体积误差在验证期偏大,约为10%,引起体积误差偏大的原因是模型在对最大洪峰的模拟上效果不理想,模型还需要在洪峰模拟上改进;④径流对于降雨与蒸发的响应均很敏感,并且径流对于降雨量的敏感性高于对于潜在蒸发的敏感性,在降水量不变的情况下蒸发每增加10%,年径流量减少0.2亿m3,在降水增加10%和减少10%时,年径流量的变化率分别为17.1%和-16.0———而在蒸发不变的情况下,降水每增加10%,年径流量增加0.6亿m3,在蒸发增加10%和减少10%时,年径流量的变化率分别为-4.6%和5.0%,降水引起的径流变化率为蒸发引起的径流变化率的3～4倍;⑤径流与降雨量的变化呈现正相关关系,而径流与潜在蒸发量的变化呈现负相关关系,并且径流对于降雨量和潜在蒸发量的响应均呈现非线性关系。     

呼图壁河径流对气候变化的敏感性分析

为了预测干旱地区径流对气候变化的敏感性,选取天山北坡中段的呼图壁河流域,根据1978—2011年的气象数据和径流数据,建立了径流与气温、降水的多变量时间序列模型,并设置不同的情景方案对径流对气候的敏感性进行了分析。结果表明:呼图壁河径流主要受降水和气温的影响,径流对降水的敏感性比对气温的高。     

Evidence of Climate Change in the Senegal River Basin

International development policy makers are recognizing climate change and desertification as fundamental obstacles to the social and economic development of the Third World. Sub-Saharan Africa, particularly the Sahel region, has been severely impacted by the compounding effects of drought, deforestation and desertification. The Senegal River Basin in the West Africa is a prime example of a region where development objectives are seriously undermined by the drought-induced desertification process. The basic hydrologic constraint on development is revealed in a time series decompositionof Senegal River annual flow volumes, which strongly suggests that water resources availability has been substantially curtailed since 1960. Two alternative time series mechanisms are hypothesized to account for the decreased flow volumes in recent decades. The first time series model suggests the presence of a long-term periodicity, while the second model hypothesizes an ARMA(1,1,) process. The second hypothesis provides a superior model fit. The stationary ARMA(1,1) model can be fitted successfully, however, only after explicitly removing a non-stationary component by linearly detrending after 1960. The implication of non-stationarity in Senegal River hydrology provides additional analytic evidence that the landscape degradation and desertification processes observed in Sahelian Africa can be in part attributed to climate change effects. Efforts to redress desertification should be at once conscious of complex socioeconomic forces exacerbating the desertification process and fundamental hydrologic constraints to river basin development.     

气候变化下湟水河西宁段区域水文变化研究

采用线性回归法、滑动平均法、Mann-Kendall趋势检验法和滑动t检验法对湟水河流域气候变化趋势进行了分析,在此基础上构建气候变化情景,利用SWAT模型进行了湟水河西宁段水文变化模拟。结果表明:1955—2010年气温与降水量均呈明显上升趋势,降水量、年均气温的线性变化率分别为20.01 mm/10 a、0.12℃/10 a;径流随降水量的增加而增加,随气温的升高而减少,且降水量变化对径流的影响更明显。     

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.