基于GCM模型的塔里木河流域未来降水与气温变化规律研究

为研究塔里木河流域未来降水、气温变化,提出了GCM下RCP2. 6、RCP4. 5、RCP8. 5三种情景与分布式水文模型SWAT相对接的研究方案。采用气候模式输出的降水、气温等资料作为SWAT模型输入数据,分析未来2020-2050年流域降水、气温变化规律,结果表明:在RCP2. 6情景下,各子流域降水大多表现为增加趋势,在RCP4. 5情景下降水表现出减少趋势,在RCP8. 5情景下降水趋势性不明显;在不同RCP情景下,各子流域温度均呈现明显上升趋势,且升温情况随着RCP情景对应辐射强迫的增加而增加。研究结果为流域水资源规划和管理提供了重要参考。     

气候变化下雅鲁藏布江拉孜以上流域径流过程模拟与预测

西部高寒河源区因冰川积雪冻土等特殊的地理环境,其径流过程的模拟与预测一直是水文学研究的难点和热点问题之一,全球气候变暖为这一地区的水文模拟提出了新的挑战。以雅鲁藏布江拉孜以上流域为研究区域,基于可考虑冰川积雪融水的SWAT分布式水文模型对拉孜站径流过程进行模拟,评估SWAT模型在高寒河源区的适用性。基于未来气候变化情景,统计分析了未来研究区降水、气温的变化趋势,预估了气候变化对区域径流过程的影响。结果表明:SWAT模型在拉孜以上流域径流过程模拟中具有较好的适用性,模型在率定期和验证期月尺度NS系数分别达到了0.78和0.84;未来研究区降水、气温均呈现出增加趋势,且随着排放情景的上升,气温、降水增加幅度有变大趋势;未来研究区不同时段径流量也呈现出不同的增加趋势,在2020～2049年的RCP2.6、RCP4.5和RCP8.5情景下,相较于基准期径流分别增加了约11.8%、14.0%、16.5%,为下游水资源可持续开发利用带来了更大的挑战。     

基于气候情景的岩溶断陷盆地2020—2050年植被动态变化模拟预测

岩溶断陷盆地作为我国西南部重要生态脆弱区和生态安全屏障区,生态价值不可估量.其独特的植被生态系统对气候变化十分敏感,探讨在未来全球变暖的必然趋势下断陷盆地植被变化趋势,能为进一步了解岩溶断陷盆地植被变化的气候驱动机制提供了重要依据.本研究基于2001—2016年间气象数据集和NDVI时间序列数据,利用TS非参数趋势分析法对未来2020—2050年两种RCPs(Representative Concen-tration Pathways)未来气候情景下的NDVI值进行预测,开展了不同气候变化背景下断陷盆地未来植被的可能演变趋势分析.结果表明:相对于基准期(2001—2016年),在不同典型浓度路径(RCP4.5和RCP8.5)情景下,断陷盆地气候整体呈持续增温增湿趋势,且植被NDVI也有一定的升高.综合分析两种情景下的NDVI变化共性趋势发现:青藏高原东南缘木里河谷地区温度和降水量升高缓慢,区域性干旱增强,植被出现退化,是未来断陷盆地植被修复的难点地区;而云贵两省边界地区温度和降水涨幅迅速,未来植被改善明显,是植被修复成果的重点保护区.     

近三十年黑河中下游盆地地下水资源变化特征与演变趋势分析

根据1980～2005年地下水观测资料,对黑河流域中游张临高盆地与下游额济纳绿洲地下水资源变化特征及未来演变趋势进行了分析和预测。结果显示,近几十年来黑河流域中下游盆地地下水资源的变化过程主要分两个阶段。2000年黑河实施调水之前,中游盆地地下水资源主要受地表径流和阶段性土地开发利用的影响,出山径流与地下水资源的关系相对稳定,下游盆地地下水资源受中游用水的影响十分明显;从2000年实施调水后,中游盆地地下水资源与出山径流的关系发生了变化,中游盆地地下水平均水位持续下降,地下水资源量呈减少趋势,而下游额济纳旗盆地由于流入地表水数量增加,相应对地下水的补给量也增大,地下水水位则有不同程度的上升。为此,建议在水资源的利用中,应当充分利用地表水、地下水多次转化过程,最大限度地提高水资源的总体利用率。     

未来气候情景下天山西部山区融雪径流变化研究

基于三种不同模式的CMIP5气象数据,采用互信息法挑选预报因子结合RBF神经网络模型,预测不同排放情景(RCP2.6、RCP4.5、RCP8.5)下未来气候变化下天山西部山区融雪径流的变化情况。对三种模式下不同排放情景预测出的未来径流量进行分析发现:(1)未来径流量在2020～2030年将持续上升,在2060年趋于稳定;未来径流量在非汛期有大幅度的增加而在汛期径流量减少;(2)通过灰色相关性分析找到未来不同模式不同情景下影响径流的主要相关因子,对各相关因子未来变化情况进行分析,发现径流在非汛期有大幅度的增加而在汛期径流量减少的主要原因是:非汛期的降水增加而蒸发减少或增加幅度不大;汛期降水减少而蒸发随气温升高导致汛期的径流量减少。     

基于RCP情景的黄河流域未来气候变化趋势

根据国家气候中心提供的7个气候模式的情景资料和黄河流域108个站点的实测气候要素资料,评估了不同气候模式对黄河流域历史(基准期1961~1990年)气候要素的模拟能力,在此基础上,采用较为适合黄河流域的气候模式资料,分析了不同RCP排放情景下黄河流域未来的气候变化趋势。结果表明,MPI-ESM模式能够较好地模拟黄河流域气温降水的历史变化。黄河流域未来气温将持续升高,线性升率约为0.28~0.45℃/10a,未来降水变化具有较大的不确定性,与基准期相比,未来黄河流域降水与基准期基本持平或偏少。气温降水变化的季节分配和空间分布差异明显,2、8、9月份升温幅度较大,5月份升温幅度较小;2、5、12月份降水普遍增多,6~8月份降水减少;黄河源头及宁夏内蒙河段升温幅度较大;黄河源头降水以增多或减少幅度较小为主,中游下段及下游地区降水以减少为主。     

CMIP5多模式对中国及各分区气温和降水时空特征的预估

利用7个参加耦合模式比较计划第五阶段(CMIP5)的全球气候模式模拟数据,在RCP4.5、RCP8.5两种排放情景下,从年、季、月尺度上对中国以及中国的7个区域的气温和降水进行未来情景预估分析。分析结果表明:2010~2099年,两种情景下中国的气温增加明显,并呈现出春弱秋冬(尤其是一、八、九、十一、十二月)强的特征,北部(N)、西北东部(ENW)、西北西部(WNW)、西藏(Tibet)的升温趋势高于其他地区。RCP8.5情景下的气温线性趋势值大部分都高于RCP4.5情景下的值。在RCP4.5情景下,2060~2099年东北部(NE)呈现降温。两种情景下,全国降水量也呈增加趋势,呈现由东南向西北递减的地理分布,并表现出冬弱春夏强的季节变化特征。西北西部(WNW)在全年降水偏少,春夏季黄河以北降水趋势较小,降水大值中心在长江以南地区,尤其是在五、六、七、八月份。秋季,在RCP4.5、RCP8.5情景下SE降水线性趋势分别低于或等于全国平均水平,东北部(NE)、北部(N)、西北东部(ENW)的降水线性趋势略高。在2010~2039年,在RCP8.5情景下西南(SW)的降水减少。     

基于不同排放情景的浑河流域水资源演化研究

人类活动与气候变化是影响流域水资源演化、水文循环规律的两大关键性因素。以浑河流域为例,通过分析CMIP5公布的气候模式相关性和相似性,选取5种典型模式并分别计算不同排放情景下的降水和气温,建立产汇流特性水文模型分析模拟浑河流域水资源及其演化规律。结果显示:在未来30年浑河流域水资源量呈现出逐渐增大的趋势,并增加了汛期水量的提升概率;枯季水资源量在高排放情景下呈现出降低的变化趋势,浑河流域水资源时程分配在未来更加不均衡,温室气体的排放将进一步加剧这种不均匀态势。     

黑河中游盆地水资源转化规律研究

基于近二十多年黑河中游盆地的地表水和地下水观测资料,通过对盆地水资源转化规律的认识,利用水文系统分析法分析了该区域地表水、地下水相互转化规律,建立了盆地出口断面水资源量转化模型和盆地平均地下水水位变幅变化模型,经模型计算值与实测值比较吻合的较好,故可运用模型预测该盆地出口断面的水资源量和地下水水位的变化幅度。根据黑河出山径流不同频率的来水量,预测了现状条件下中游绿洲区平均地下水水位的变化幅度。得出了应该充分利用地表水和地下水的相互转化提高水资源的总体利用率,单方面考虑提高地表水利用率的做法有可能破坏地下水资源、降低水资源的总体利用率和造成生态与环境恶化的结论。     

气候变化对江河流量变化趋势影响研究进展

气候变化对基于自然稳定气候假定的流量变化趋势的检测和水资源评价方法提出了挑战。在流量变化趋势的检测中分离出气候变化的影响,不仅对水资源管理和水利工程设计有重要的应用价值,而且有助于了解气候变化以何种方式、在何时、何地、已经或尚未对水文循环产生影响,对改进气候模型的模拟与预测有重要的科学价值。 统计方法是检验流量变化趋势显著性的有效工具。直接用气候模型模拟和预测未来径流变化的可靠性取决于模型对当代降水模拟的可信度。多个气候模型集合分析有可能在一定程度上减少模型对降水、径流模拟的不确定性。近年发展起来的多个气候模型集合分析与统计显著性检验技术结合的方法,有可能模拟并预测出气候强迫导致大尺度径流空间分布的变化。随着气候模型尤其是陆—气耦合的区域气候模型对降水模拟的改进,可以预见径流变化的检测、归因和预测的趋同化模拟已为期不远。将温室气体外强迫导致的水文气候变化作为一个因子引入到水资源评价中,对于水资源管理经济与生态评估,以及未来的发展规划将是一件十分重要的变革。      

山东鲁北平原地下水资源与可持续利用

鲁北平原目前区内供水水源以黄河客水和地下水为主。最新均衡计算结果为:浅层地下水开采资源量37 03×108m3 a,深层地下水开采资源量2 62×108m3 a。据山东省水资源可持续利用总体规划报告,现状年需水量约74×108m3 a,2010年需水量为93×108m3 a,2030年需水量为109×108m3 a,现状年供需基本平衡,远景供水不足。浅层地下水易采易补,更新能力强,应以合理调控水位为中心,优先开采浅层地下水,充分发挥浅层地下水资源的供水功能,尤其是东阿—齐河—商河—利津沿黄地区更应加强开发浅层水的力度。浅层水为可持续利用的地下水资源量。深层地下水更新能力弱,应严格限制其开发利用。在德州、滨州漏斗中心区,建议实施部分封井,调减开采量。实行地表水与地下水联合调度,优化水资源开发结构,适当增加地表水引用量,实施含水层的恢复工程,遏制地面沉降等环境问题的继续发展,走全面、协调、可持续发展的路子。     

Pumping dry: an increasing groundwater budget deficit induced by urbanization,industrialization, and climate change in an over-exploited volcanic aquifer

A methodology is proposed to improve the groundwater budget model by determining the past, present, and future recharge and discharge rates. The model is applied to an increasingly urbanized and industrialized region with drying tendencies: the Toluca Valley, Mexico. This study includes spatially variable recharge determined from the historical climate data, the climate change predictions, and the multiple parameters used in the Hydrologic Evaluation of Landfill Performance (HELP3) model. Using HELP3 a spatial discretization for the average recharge is obtained and estimated at 376 million cubic meters per year (Mm³/year). When considering climate change predictions, by 2050 the average scenario projects recharge to decrease by 15 Mm³/year (from 376 to 361 Mm³/year), and in a worst case scenario up to a maximum decrease of 88 Mm³/year (from 376 to 288 Mm³/year). Groundwater pumping has increased steadily since 1970 and is estimated at 495 Mm³/year for 2010. The current average deficit estimated for 2010 is 172 Mm³/year with average projections increasing to over 292 Mm³/year by 2050. This study of two of the most important components of the water cycle (recharge and discharge) clearly shows that the decreasing water availability in the Toluca basin is due mainly to groundwater pumping and that the current pumping rates are not sustainable. The current deficit can be considered problematic and projections based on expected water consumption and climate change reinforce the need for management of the water resources to be addressed.     

气候变化影响下水资源脆弱性评估方法及其应用

气候变化和人类活动影响下的水资源脆弱性评价,是将气候变化影响纳入水资源规划管理、提出缓解气候变化不利影响的适应性对策的重要科学依据。针对与气候变化影响的水资源系统的敏感性和抗压性相联系的脆弱性与适应性问题,提出变化环境下水资源脆弱性评估理论体系和一般性公式。进一步,以水资源供需安全为出发点,采用温度、降雨双参数弹性系数和有水资源基础,直观、简单的水资源关键性指标体系方法,提出气候变化和人类活动背景下水资源脆弱性评估模型。将模型应用于缺水最严重的海河流域,评价了现状和未来情境下流域水资源的脆弱性情况。结果表明:整体上海河流域水资源脆弱性偏高,且平原区较山区更脆弱;气候因素对流域水资源的脆弱性影响明显,未来如不采取措施,海河流域的水资源脆弱性将进一步加重。     

Hierarchy evaluation of water resources vulnerability under climate change in Beijing,China

Rapid population growth and increased economic activity impose an urgent challenge on the sustainability of water resources in Beijing. Water resources system is a complex uncertain system under climate change which is of vulnerability. But water resources system vulnerability research is relatively weak. In this study, we present a multifunctional hierarchy indicator system for the performance evaluation of water resources vulnerability (WRV) under climate change. We established an evaluation model, i.e., analytic hierarchy process combining set pair analysis (AHPSPA) model, for assessing WRV, in which weight is determined by the analytic hierarchy process (AHP) method and the evaluation degrees are determined by the set pair analysis (SPA) theory. According to the principle of scientificalness, representative, completeness and operability, the index systems and standard of water resources vulnerability evaluation are established based on the analysis of sensibility and adaptability which include five subsystems: climate change, water resources change, social and economic infrastructure, water use level and water security capability. The AHPSPA model is used to assess water resource vulnerability in Beijing with 26 indexes under eight kinds of future climate change scenarios. Certain and uncertain information quantity of the WRV is calculated by connection numbers in the AHPSPA model. Results show that the WRV of Beijing is in the middle vulnerability (3 or III) under above-mentioned different climate change scenarios. The uncertain information is between 37.77 and 39.99 % in the WRV evaluation system in Beijing. Compared with present situation, the WRV will become better under scenario I and III and will become worse under scenario II, scenario IV, scenario representative concentration pathways (RCP)2.6, scenario RCP4.5, scenario RCP6.0 and scenario RCP8.5. In addition, we find that water resources change and water use level factors play more important role in the evaluation system of water resource vulnerability in Beijing. Finally, we make some suggestions for water resources management of Beijing.

     

Loss caused by earthquakes: rapid estimates

Rapid population growth and increased economic activity impose an urgent challenge on the sustainability of water resources in Beijing. Water resources system is a complex uncertain system under climate change which is of vulnerability. But water resources system vulnerability research is relatively weak. In this study, we present a multifunctional hierarchy indicator system for the performance evaluation of water resources vulnerability (WRV) under climate change. We established an evaluation model, i.e., analytic hierarchy process combining set pair analysis (AHPSPA) model, for assessing WRV, in which weight is determined by the analytic hierarchy process (AHP) method and the evaluation degrees are determined by the set pair analysis (SPA) theory. According to the principle of scientificalness, representative, completeness and operability, the index systems and standard of water resources vulnerability evaluation are established based on the analysis of sensibility and adaptability which include five subsystems: climate change, water resources change, social and economic infrastructure, water use level and water security capability. The AHPSPA model is used to assess water resource vulnerability in Beijing with 26 indexes under eight kinds of future climate change scenarios. Certain and uncertain information quantity of the WRV is calculated by connection numbers in the AHPSPA model. Results show that the WRV of Beijing is in the middle vulnerability (3 or III) under above-mentioned different climate change scenarios. The uncertain information is between 37.77 and 39.99 % in the WRV evaluation system in Beijing. Compared with present situation, the WRV will become better under scenario I and III and will become worse under scenario II, scenario IV, scenario representative concentration pathways (RCP)2.6, scenario RCP4.5, scenario RCP6.0 and scenario RCP8.5. In addition, we find that water resources change and water use level factors play more important role in the evaluation system of water resource vulnerability in Beijing. Finally, we make some suggestions for water resources management of Beijing.     

浅水湖泊洪水资源适度开发规模优选模型

在保障防洪与河湖生态安全的前提下,将汛期洪水尽可能多地蓄存起来以满足当前及未来一段时间的河道外用水需求,是浅水湖泊洪水资源利用所追求的目标。为综合考虑区域来水和需水不确定性、潜在储水空间和利用方式,合理确定洪水资源开发规模,采用模拟与优化相结合的方法,建立了浅水湖泊洪水资源适度开发规模优选模型,并将该模型应用于南四湖。研究结果表明:以滨湖反向调节利用方式为主的浅水湖泊洪水资源开发规模,受制于泵站启动水位、抽水能力和河道外蓄水空间的共同作用,但并不呈现线性关系,存在明显的阈值效应;南四湖洪水资源开发的适度规模为多年平均全年3.63亿m3、汛期1.56亿m3,开发条件是泵站启动水位为33.75 m、泵站抽水能力为48 m3/s、区域蓄水体容积为4.80亿m3。研究可为确定南四湖洪水资源利用规模提供依据,为类似流域提供借鉴和参考。     

浅水湖泊洪水资源适度开发规模优选模型

在保障防洪与河湖生态安全的前提下,将汛期洪水尽可能多地蓄存起来以满足当前及未来一段时间的河道外用水需求,是浅水湖泊洪水资源利用所追求的目标。为综合考虑区域来水和需水不确定性、潜在储水空间和利用方式,合理确定洪水资源开发规模,采用模拟与优化相结合的方法,建立了浅水湖泊洪水资源适度开发规模优选模型,并将该模型应用于南四湖。研究结果表明：以滨湖反向调节利用方式为主的浅水湖泊洪水资源开发规模,受制于泵站启动水位、抽水能力和河道外蓄水空间的共同作用,但并不呈现线性关系,存在明显的阈值效应;南四湖洪水资源开发的适度规模为多年平均全年3.63亿m³、汛期1.56亿m³,开发条件是泵站启动水位为33.75 m、泵站抽水能力为48 m³/s、区域蓄水体容积为4.80亿m³。研究可为确定南四湖洪水资源利用规模提供依据,为类似流域提供借鉴和参考。     

Assessing the impacts of climate and land use change on streamflow,water quality and suspended sediment in the Kor River Basin,Southwest of Iran

This research addressed the separate and combined impacts of climate and land use change on streamflow, suspended sediment and water quality in the Kor River Basin, Southwest of Iran, using (BASINS–WinHSPF) model. The model was calibrated and validated for hydrology, sediment and water quality for the period 2003–2012. The model was run under two climate changes, two land use changes and four combined change scenarios for near-future period (2020–2049). The results revealed that projected climate change impacts include an increase in streamflow (maximum increases of 52% under RCP 2.6 in December and 170% under RCP 8.5). Projected sediment concentrations under climate change scenarios showed a monthly average decrease of 10%. For land use change scenarios, agricultural development scenario indicated an opposite direction of changes in orthophosphate (increases in all months with an average increase of 6% under agricultural development scenario), leading to the conclusion that land use change is the dominant factor in nutrient concentration changes. Combined impacts results indicated that streamflows in late fall and winter months increased while in summer and early fall decreased. Suspended sediment and orthophosphate concentrations were decreased in all months except for increases in suspended sediment concentrations in September and October and orthophosphate concentrations in late winter and early spring due to the impact of land use change scenarios.     

Water resources assessment in the Minqin Basin: an arid inland river basin under intensive irrigation in northwest China

The Minqin Basin is at the lower reach of the Shiyang River of Gansu province in northwest China. Dramatic decline in groundwater level has resulted from over-abstraction of groundwater since the late 1950s to satisfy increasing irrigation and other demands. Severe water shortage led to environmental degradation. To better understand the spatial–temporal variation of groundwater levels and to evaluate the groundwater resources in the region, a three-dimensional regional groundwater flow model was built and calibrated under transient condition. The MODFLOW program was used and the research area was discretized as a square network with cell size of 400 × 400 m. The model showed that the aquifer was under destructive stress, with a groundwater resource deficit of 260 million cubic meters per year (Mm³/year) on average. Since the inflow of surface water from the upstream basin has declined to about 100–150 Mm³/year in recent decades, the irrigation return flow had become the main recharge and accounted for 60.6% of total recharge; meanwhile, abstraction by pumping wells took 99.2% from the total groundwater discharge.     

Assessing anthropogenic impacts on limited water resources under semi-arid conditions: three-dimensional transient regional modelling in Jordan

Both increasing aridity and population growth strongly stress freshwater resources in semi-arid areas such as Jordan. The country’s second largest governorate, Irbid, with over 1 million inhabitants, is already suffering from an annual water deficit of 25 million cubic meters (MCM). The population is expected to double within the next 20 years. Even without the large number of refugees from Syria, the deficit will likely increase to more then 50 MCM per year by 2035 The Governorate’s exclusive resource is groundwater, abstracted by the extensive Al Arab and Kufr Asad well fields. This study presents the first three-dimensional transient regional groundwater flow model of the entire Wadi al Arab to answer important questions regarding the dynamic quality and availability of water within the catchment. Emphasis is given to the calculation and validation of the dynamic groundwater recharge, derived from a multi-proxy approach, including (1) a hydrological model covering a 30-years dataset, (2) groundwater level measurements and (3) information about springs. The model enables evaluation of the impact of abstraction on the flow regime and the groundwater budget of the resource. Sensitivity analyses of controlling parameters indicate that intense abstraction in the southern part of the Wadi al Arab system can result in critical water-level drops of 10 m at a distance of 16 km from the production wells. Moreover, modelling results suggest that observed head fluctuations are strongly controlled by anthropogenic abstraction rather than variable recharge rates due to climate changes.