淮河流域历史覆被变化及其对水文过程的影响

以淮河流域蚌埠集水区为研究区域,利用淮河流域1700、1800和2000年3种历史覆被情景,结合陆面水文耦合模型(CLHM)定量评价了流域土地利用/覆被变化的水文效应,并分析了流域径流与主要覆被类型变化方式的定量关系。结果表明:CLHM模型可以较好地模拟淮河流域的流量过程,在研究区具有较好地适用性;三期覆被情景下主要覆被类型变化为林地转变为耕地或草地以及草地转变为耕地,此种变化导致流域总蒸发量减少了6.5%,流域出口研究期平均径流量增加了6.1%;极端覆被情况下,年均蒸发量由多到少依次为林地、草地和耕地;林地对流域径流过程的影响主要体现在洪峰上,相对于耕地,林地具有削减洪峰的作用;通过分析覆被类型变化与流域多年平均径流的相关关系,林地转变为草地以及林地转变为耕地是近400年来影响淮河流域水文过程及水资源分配的主要覆被变化因子。因此,合理规划土地利用格局对流域水资源高效利用具有重要意义。     

基于水文模型与遥感信息的植被变化水文响应分析

针对地表覆被改变带来的流域水文响应存在不确定性这一问题,为了探索我国南方山区植被变化下的水文过程时空演变规律,依据东江流域的土地覆被类型,结合野外调查试验与遥感数据提取典型植被特征信息,利用考虑水文、地形、土壤、植被等多要素综合的分布式水文模型DHSVM,对流域内各种典型覆被情景下的水文过程进行模拟,进而分析植被变化引起的径流、蒸发、土壤水变化的响应关系。结果表明:大面积人工种植桉树林,将会对流域水文过程产生较大影响,地表径流深比现状针叶林增大17.5%,蒸散发量减小18.1%,洪峰流量也有所增加,流域洪水灾害发生概率加大;当流域现有针叶林生态系统退化为草地时,多年平均径流量增加24.4%,蒸散量减少25.3%,不利于自然流域的水源含蓄;针叶林、阔叶林和混交林三类森林植被更替对流域的水文过程影响相比其他植被类型要小。研究成果为分析流域变化环境下的水文过程时空演变规律及其生态环境效应提供参考,对我国南方山区水资源管理规划和生态环境保护具有实际意义。     

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。     

五台山清水河流域植被垂直带水循环过程研究

五台山为华北地区最高峰(海拔3058 m),发源于五台山的清水河流域,海拔梯度大,植被垂直分异显著,目前关于植被垂直带的水循环过程及其相互之间的差异研究尚显不足。为此,利用分布式水文模型WEP-L模拟清水河流域水循环过程,分析不同植被垂直带的水循环过程。结果表明:受气温显著升高影响,高海拔地区的季节性冻土消退、活动层变厚及土壤蓄水容量增加,促进降水入渗。海拔1500 m以下区域蒸散发主要受降水影响,而海拔1600 m以上区域则主要受能量的影响。不同植被垂直带的水循环过程差异显著,径流系数表现为:耕地亚高山草甸荒漠草地常绿针叶灌木林落叶阔叶林。研究结果可为山区流域水资源高效利用和生态建设提供科学依据。     

基于SWAT模型的诺敏河流域径流对土地利用/覆被变化的响应模拟研究

土地利用/覆被变化直接反映了人类活动的影响程度,对于流域水文循环过程影响显著。本文以诺敏河流域为研究区,基于1976和2000年两期土地利用数据,结合SWAT模型定量评价了径流对土地利用/覆被变化的响应。研究结果表明:SWAT模型可以较好地模拟诺敏河流域的月径流变化过程,在研究区具有一定的适用性;相对于1976年的土地利用条件,2000年土地利用变化主要表现为林地和草地面积减小,耕地面积增加。1976-2000年间诺敏河流域土地利用变化导致年均地表径流增加了17.78%,且空间差异显著,尤其是下游的莫力达瓦达斡尔族自治旗和阿荣旗等地地表径流增加趋势更为明显,增加幅度超过20 mm。模拟研究对于诺敏河流域合理规划土地利用格局具有重要意义。     

Approach for Estimating Available Consumable Water for Human Activities in a River Basin

Water is vital for economic development and environmental sustainability in arid and semi-arid basins. Management of water resource requires good understanding of available water for human consumption. Evapotranspiration (ET) is an important component of the hydrological cycle and represents the amount of water lost to the atmosphere in a basin. This study proposes a new approach to estimate available consumable water for human activities (ACW) in a basin based on precipitation, natural ET, and uncontrollable outflow, thus capping water use for human consumption in a basin. The ACW is illustrated for the Hai Basin in North China, where the average ACW from 2001 to 2012 for the entire basin is estimated at 31.97?×?10⁹m³ yr.^?1, varying between 18.61?×?10⁹m³yr^?1 in 2002 and 42.60?×?10⁹m³yr^?1 in 2003. A water balance analysis for the basin indicates that the aquifer water depletion in Hai Basin for 2001–2012 is 5.23?×?10⁹m³yr^?1. Compared to existing water resources assessment, ACW provides an easier approach to water management planning as no hydrological data are required, only data on precipitation and ET, supported by landcover data.     

黄土丘陵沟壑区典型流域土地利用覆被变化的径流调节效应

基于动力水文过程测定技术和景观生态学测度方法,分析了黄土丘陵沟壑区罗玉沟流域土地利用/覆被变化的径流调节效应。结果表明：由森林植被增加与坡改梯的耕作措施调整共同引起的土地利用/覆被变化,对径流有显著的调节作用。无论场暴雨、雨季及年尺度,土地利用结构优化及森林植被覆盖增加,均使流域产流能力降低。罗玉沟流域土地利用后期在丰、平和枯水年径流系数比前期分别减少约51％、85％和84％;在剔除降水量的影响,通过相同降水条件径流系数的预测,后期较前期在丰、平、枯水年均减少约63％。土地利用覆被对流域径流的影响表现为季节性,且土地利用结构优化,场暴雨洪峰流量呈减小的规律。相对于森林植被增加和坡改梯耕作措施调整,前者对流域产流能力的影响大于后者,但对于山区土地整理与生态修复政策,二者共同实施才可促进土地资源的可持续利用。     

大通河降雨径流关系演变与水资源衰减初步研究

大通河位于祁连山区,开发利用程度低,实测径流基本为天然径流,1956—2000年平均径流量28.95亿m~3。在全球气候变暖的背景下,降雨-径流关系发生了明显的改变,以水文气象要素明显的分界点1997年进行分时段比较,汛前径流明显衰减,汛后上游径流明显增加,中下游径流有一定减少,年均水资源减少1.72亿m~3。选择受冰川融水和冻土释水影响较小的中下游区间来水分析,得到蒸发增加减少径流深38 mm。基于上中游分阶段径流比较认为,枯季径流的增加来自冻结层下水的稳定释水,春季径流的减少由季节性冻土释水疏干和陆面蒸发增加导致,夏秋季径流的增加主要是冰川融水和冻结层上水转化成冻结层下水减少沼泽消耗所致。综合分析认为,随着气温的继续升高,冰川融水消失,冻结层上水进一步转化,伴随着源头沼泽的消失,冻结层下水的增加对蒸发增加引起的水资源衰减有所缓减。     

海河流域径流变化趋势及其归因分析

在气候变化和人类活动共同影响下,流域径流发生了很大变化。尤其是海河流域,水资源匮乏的现象更为严重,分析水资源变化趋势对实现水资源的可持续开发利用具有重要意义。根据海河流域实际地形地貌特征及水文站分布情况,选取观台、响水堡、张家坟、下会和桃林口等5个水文站所在的区域,采用Mann-Kendall秩次相关检验法及线性回归方法,分析检验各典型区域年径流量的历史变化趋势。基于半分布式流域水文模型——TOPMODEL,采用水文模拟的途径,定量评估了典型区域气候变化和人类活动对径流变化的影响。归因结果表明:除桃林口外的其他4个水文站的年径流量均呈显著减小趋势,海河典型区域年径流减小主要跟人类活动有关,其占比都在65%以上。人类活动对观台、张家坟和响水堡站径流量减小的影响占比为65%~70%,对桃林口站径流量减小的影响占比为75.4%,对下会站径流量减小的影响占比高达81.7%,主要原因是海河流域自20世纪60年代中后期以来进行大规模水利建设所产生的水文效应。     

基于SWAT模型的北江流域生态径流调节服务评估

为评估北江流域生态径流调节效果并分析径流调节量的时空变化,基于SWAT模型,考虑气象、水文、下垫面等因素,模拟北江流域水文过程,分别计算1980、2000、2015年的植被生态系统对径流的调节量及其经济价值。结果表明:2015年土地利用情况下,生态系统对北江流域的多年平均年调节径流深为-141.2 mm,调节比例为-12.2%,调节价值量为396.2亿元;丰水期的调节径流深为枯水期1.8倍,调节比例小于枯水期,而且丰水期的调节量主要集中在前汛期。流域上游的调节径流深比下游大,2000年与2015年北江流域调节径流深空间分布基本一致,但由于植被覆盖减少、建设用地扩张,北江流域径流调节量减少0.82亿m³,调节价值量降低5.85亿元。     

基于数字平台的黄河多沙粗沙区分布式水文模型研究

本文以黄河无定河水系岔巴沟流域为例，针对其气候、植被以及下垫面条件等时空变化特征，在全流域1∶1万DEM基础上，建立了具有物理基础的分布式流域水文模型，模型由网格单元的超渗产流模型和汇流模型组成，提出了考虑流域水保措施的流域汇流计算。使用该模型对1970～1989年大中场次洪水进行模拟计算，结果表明：计算值与实测值基本吻合。     

于桥水库流域水源供给服务的空间分布格局

空间定量评估流域生态系统水源供给服务功能对水源区可持续发展及生态补偿机制的建立具有重要意义。基于研究区土地利用数据、气象数据和土壤数据,应用In VEST模型评估了于桥水库流域生态系统的水源供给量,并定量分析了流域水源供给能力的空间分布格局特征。结果表明:当Zhang系数为3.2时,流域的年径流深为161 mm,流域内年总产水量为3.14亿m~3。从空间分布格局来看,流域水源供给量存在显著的空间异质性;南部和中东部平原区单位面积水源供给量较高,水库南岸水源供给能力高于北岸;遵化市和蓟县对水源供给总量的贡献率达到85%;流域内不同景观类型的水源供给能力由大到小的排序为:耕地林地人工表面裸地灌草地,耕地、林地和人造表面对水源供给总量的贡献率达到82%。流域南部和中东部平原区是水源供给功能保护的重点区域,但同时也是防控城镇面源污染的关键地区。     

湟水干流近60年径流变化特征分析

研究流域径流演变特征,对流域水资源可持续开发利用及优化配置具有重要意义。本文基于湟水干流1956-2015年海晏、西宁及民和水文站长系列天然径流资料,采用累计距平、滑动平均、M-K检验和小波分析等方法,分析了湟水干流径流年内年际变化、趋势性、突变特征及其周期性。结果表明:湟水干流径流年内分配不均匀,径流年际变化波动明显,经历了"丰—枯—丰—枯—丰"5个循环交替,目前处于丰水期。湟水干流径流量总体呈上升趋势,3站分别以0.0011×10~8、0.0247×10~8、0.0120×10~8m~3/a的幅度增加,变化趋势不明显。小波分析表明湟水干流存在3a、9a及25a左右的振荡周期,其中25 a左右的周期振荡最强,为径流量序列第一主周期。     

黄河流域天然径流量评价探讨

针对现有径流系列一致性处理方法不够具体的问题,提出了一种黄河流域天然径流量还原、还现算法。根据黄河流域入海口利津站的实测径流、利津断面以上流域地表水消耗量、地下水开采引起的地表径流减少量、人工水库和淤地坝水面蒸发增加量、水库蓄变量等数据,对利津站的天然地表径流量进行还原分析,并以2001—2016年下垫面作为参照下垫面估算下垫面还现后的天然径流量。结果表明:1956—2016年长系列的黄河利津站地表水天然径流量为577.72亿m³,下垫面还现后的天然径流量为551.72亿m³,还现天然径流量比流域机构给出的第三次水资源评价结果多61.72亿m³。     

贵州省喀斯特流域赋水遥感定量研究

喀斯特流域具有特殊的双重含水介质和地表-地下水系结构,与常态流域相比,其水资源影响因素复杂多样,除气候、地貌、岩性等因素外,流域植被覆盖率起到了重要作用。在贵州省内选择20个典型流域作为研究样区,根据植被光谱特征、流域赋水光谱特征,利用遥感技术,对TM影像进行光谱辐射亮度及表观反射率计算,得到各类植被指数。根据多元回归分析原理,借助Spss、MATLAB软件,利用比值植被指数、差值植被指数、归一化植被指数、转换型植被指数、重归一化植被指数、增强型植被指数构建了喀斯特流域赋水动态变化监测、预测模型,通过方差分析和样区检验,表明该模型监测、预测效果好,精度较高。     

Assessing Impacts of Conservation Measures on Watershed Hydrology Using MIKE SHE Model in the Face of Climate Change

Climate change triggers changes in temperature, precipitation, evapotranspiration, etc. and has a significant impact on water resources in many regions. Considering the increasing scarcity of water as a result of climate change, conservation of water and groundwater recharge have become crucial factors for water resources planning and management. In this paper, an attempt is made to study the detailed hydrological behaviour of a treated watershed using physically based distributed hydrological modelling system MIKE SHE to assess the impact of conservation measures on watershed hydrology considering future climate change. Three hypothetical management scenarios are simulated for the period 2010–2040. RegCM4 regional climate model is used in the study for RCP 4.5 and RCP 8.5 scenarios. Detailed hydrological water balance is extracted for individual years from 1979 to 2009 to compare relevant components. The evaluation for base period shows 10.06% reduction in surface runoff and 11.33% enhancement in groundwater recharge. Further simulation with RCP 4.5 and RCP 8.5 scenarios show notable reduction in surface runoff and increase in groundwater recharge. The structures in the micro-watershed influence the surface runoff and increase infiltration into the soil, resulting in higher groundwater recharge. MIKE SHE simulations for various structures management scenarios establish the role of conservation measures in reducing surface runoff and enhancing groundwater recharge under substantial effect of climate change. The results will assist in decision-making on watershed development plans in quantitative terms, including planning for water conservation measures in the face of climate change.

     

流域非闭合特性对岩溶地区水文过程模拟的影响

岩溶地区通常发育有大量岩溶裂隙、管道和洞穴,构成错综复杂的地下输水网络,形成了独特的流域水循环模式。地下岩溶构造的存在会造成地下分水岭与地表分水岭的不重合,流域趋于非闭合状态。为了弄清岩溶流域非闭合特性对水文过程模拟的影响,本文以桂林岩溶地区潮田河(漓江支流)流域为研究区域,采用三水源新安江模型模拟该地区多年降雨径流过程。通过比较几组给定流域面积的模拟结果,分析了流域计算面积选取对潮田河流域水文模拟结果精度的影响,并探讨了流域非闭合特性影响下该地区的水体流动模式。研究结果表明:模型率定时,当流域计算面积由340 km~2变化至460 km~2时,NSE先增大后减小,RE值持续增大,两者在380~390 km~2时可同时达到最优;结合不同时间尺度下径流模拟精度的分析结果,给出了合理的流域计算面积,比基于地表分水岭提取的流域面积约小8.9%~11.2%,故部分水量可能通过地下岩溶构造流向邻近流域。合理的流域计算面积对潮田河流域径流模拟精度提高显著,尤其是提升了枯季径流的模拟。     

Optimizing the Runoff Estimation with HEC-HMS Model Using Spatial Evapotranspiration by the SEBS Model

Most of the commonly used hydrological models do not account for the actual evapotranspiration (ETa) as a key contributor to water loss in semi-arid/arid regions. In this study, the HEC-HMS (Hydrologic Engineering Center Hydrologic Modeling System) model was calibrated, modified, and its performance in simulating runoff resulting from short-duration rainfall events was evaluated. The model modifications included integrating spatially distributed ETa, calculated using the surface energy balance system (SEBS), into the model. Evaluating the model’s performance in simulating runoff showed that the default HEC-HMS model underestimated the runoff with root mean squared error (RMSE) of 0.14 m³/s (R²?=?0.92) while incorporating SEBS ETa into the model reduced RMSE to 0.01 m³/s (R²?=?0.99). The integration of HECHMS and SEBS resulted in smaller and more realistic latent heat flux estimates translated into a lower water loss rate and a higher magnitude of runoff simulated by the HECHMS model. The difference between runoff simulations using the default and modified model translated into an average of 95,000 m³ runoff per rainfall event (equal to seasonal water requirement of ten-hectare winter wheat) that could be planned and triggered for agricultural purposes, flood harvesting, and groundwater recharge in the region. The effect of ETa on the simulated runoff volume is expected to be more pronounced during high evaporative demand periods, longer rainfall events, and larger catchments. The outcome of this study signifies the importance of implementing accurate estimates of evapotranspiration into a hydrological model.

     

Land‐use effects on water quality of a first‐order stream in the Ozark Highlands,mid‐southern United States

Urban and agricultural land uses can alter the natural hydrologic conditions of streams and rivers and often degrade water quality. In the Ozark Highlands of the mid‐southern United States, the climate, topography, soil properties, karst limestone geology, agricultural practices and rapid urbanization make water quality of particular concern due to the increased potential for water quality degradation by contaminant leaching to groundwater and runoff to surface waters. The objective of this study was to evaluate the effects of season (i.e. dry/cool and wet/warm) and riparian land use (i.e. urban, grazed pasture, ungrazed pasture, wetland, cultivated agriculture and grassland) on surface water quality in a first‐order stream within a diverse agricultural watershed in the Ozark Highlands. Water samples were collected twice a month within each land use during base‐flow conditions from October 2006 through October 2007. Samples were also collected periodically during storm‐flow conditions from October 2006 through December 2007. The greatest in‐stream pH was adjacent to the grazed pasture. In‐stream NO₃‐N concentrations were greatest adjacent to the cultivated agriculture and grassland during the dry/cool season (i.e. October 2006 to March 2007) and averaged 2.67 mg L^?1. In‐stream soluble reactive P (SRP) concentrations were greatest adjacent to the grassland during the wet/warm season (i.e. April 2007 to October 2007) and averaged 0.81 mg L^?1. Concentrations of SRP, K, Mg and Zn were greater during storm‐ than base‐flow conditions and in‐stream As concentrations frequently exceeded 0.01 mg L^?1. Discharge and in‐stream NH₄‐N concentrations were unaffected by land use or season and averaged 0.003 m³ s^?1 and 0.10 mg L^?1, respectively, across all land uses and seasons. Results of this study clearly demonstrate the significant effect of adjacent land use on in‐stream water quality of a first‐order stream in a diverse agricultural watershed and highlight the importance of managing upstream land use in order to regulate downstream water quality. Copyright © 2010 John Wiley & Sons, Ltd.     

The calculation of riverine ecological instream flows and runoff profit‐loss analysis in a coal mining area of northern China

The northern Shaanxi province of China has severe water shortages, especially in coal mining areas, and it is very important to calculate the riverine ecological instream flows (EIFs) and analyse the runoff profit‐loss situation. Using the Kuye River as a case study, the EIF was calculated for different years and seasons using the instream flows rate (IFR) method and compared with the Tennant and the minimum monthly average flow (MAF) methods. The recommended value of the Kuye River EIF was obtained by an analysis of the results of these three methods. The river runoff profit‐loss situation associated with the EIF was also calculated and the main reason for the loss explained. The Kuye River EIF was calculated to be 1.69 to 11.14 m³/s by the IFR method, 1.94 to 8.50 m³/s by the Tennant method, and 3.81 to 10.87 m³/s by the MAF method. Based on these results, the EIF annual recommended value of the Kuye River was 4.00 m³/s for the 1961–2010 period. The wet season (July–October), average season (March–June), and dry season (November–following Feb) EIFs were 6.50, 3.50, and 2.00 m³/s, respectively. The Kuye River had a large surplus runoff within the EIF prior to1999, but from 1999 to 2010, the runoff and EIF were very close and the April to June average runoff did not meet the EIF. The main factors that affected the river runoff were rainfall, temperature, water and soil conservation, coal mining, and water consumption for industry and domestic use, with coal mining becoming a more important factor since 1999. This case study provides important technical support and guidance for the ecological restoration of the Kuye River basin, and the concept can be applied to other similar coal mining areas.