对长江宜昌站月平均径流量突变的分析     

江剑民  谷湘潜  游性恬 《湖泊科学》2003,15(Z1):131-137

本文简要叙述了一阶矩突变扫描式t检验和二阶矩突变扫描式F检验算法,并应用于长江宜昌水文站1882-2002年间历年月平均径流量的实测序列,划分出24个年际至十年际时间尺度的相对5级旱、涝时段及其变率特征,与有关长江上游洪水、干旱灾害的历史记载相吻合.  相似文献   

Spatio‐temporal tracer variability in the glacier melt end‐member — How does it affect hydrograph separation results?          下载免费PDF全文

Jan Schmieder  Jakob Garvelmann  Thomas Marke  Ulrich Strasser 《水文研究》2018,32(12):1828-1843

Geochemical and isotopic tracers were often used in mixing models to estimate glacier melt contributions to streamflow, whereas the spatio‐temporal variability in the glacier melt tracer signature and its influence on tracer‐based hydrograph separation results received less attention. We present novel tracer data from a high‐elevation catchment (17 km², glacierized area: 34%) in the Oetztal Alps (Austria) and investigated the spatial, as well as the subdaily to monthly tracer variability of supraglacial meltwater and the temporal tracer variability of winter baseflow to infer groundwater dynamics. The streamflow tracer variability during winter baseflow conditions was small, and the glacier melt tracer variation was higher, especially at the end of the ablation period. We applied a three‐component mixing model with electrical conductivity and oxygen‐18. Hydrograph separation (groundwater, glacier melt, and rain) was performed for 6 single glacier melt‐induced days (i.e., 6 events) during the ablation period 2016 (July to September). Median fractions (±uncertainty) of groundwater, glacier melt, and rain for the events were estimated at 49±2%, 35±11%, and 16±11%, respectively. Minimum and maximum glacier melt fractions at the subdaily scale ranged between 2±5% and 76±11%, respectively. A sensitivity analysis showed that the intraseasonal glacier melt tracer variability had a marked effect on the estimated glacier melt contribution during events with large glacier melt fractions of streamflow. Intra‐daily and spatial variation of the glacier melt tracer signature played a negligible role in applying the mixing model. The results of this study (a) show the necessity to apply a multiple sampling approach in order to characterize the glacier melt end‐member and (b) reveal the importance of groundwater and rainfall–runoff dynamics in catchments with a glacial flow regime.  相似文献   

Quantitative evaluation of the rainfall influence on streamflow in an inland mountainous river basin within Central Asia     

Congjian Sun  Yaning Chen  Wei Chen  Weibo Liu  Yongqing Zhang 《水文科学杂志》2018,63(1):17-30

Stable isotopes of water have been widely used in understanding the hydrological functions of alpine inland catchments. This study identifies dominant runoff generation mechanisms based on isotopic data (δ¹⁸O and δ²H) of 487 rainwater and river-water samples from three tributaries in the Tarim River Basin in China for the period May–September 2013. The isotope hydrograph separation results provide a comprehensive overview of the rainfall influence on hydrological processes. Stream water and groundwater have varied responses to different intensities of rainfall events. Only a small proportion of rainfall is directly transported to the stream during such events. An inconsistent temporal trend of event water contribution is observed in the three catchments. The average fractional contributions of rainfall for the Tizinafu, Kumalak and Huangshuigou rivers are 10.3% (±1.1%), 9.7% (±2.9%) and 8.7% (±2.4%), respectively.  相似文献   

On the importance of soil moisture in calibration of rainfall–runoff models: two case studies     

Mahshid Shahrban  Jeffrey P. Walker  Q. J. Wang  David E. Robertson 《水文科学杂志》2018,63(9):1292-1312

Streamflow modelling results from the GR4H and PDM hydrological models were evaluated in two Australian sub-catchments, using (1) calibration to streamflow and (2) joint-calibration to streamflow and soil moisture. Soil moisture storage in the models was evaluated against soil moisture observations from field measurements. The PDM had the best performance in terms of both streamflow and soil moisture estimations during the calibration period, but was outperformed by GR4H during validation. It was also shown that the soil moisture estimation was improved significantly by joint-calibration for the case where streamflow and soil moisture estimations were poor. In other cases, addition of the soil moisture constraint did not degrade the results. Consequently, it is recommended that GR4H be used, in preference to the PDM, in the foothills of the Murrumbidgee catchment or other Australian catchments with semi-arid to sub-humid climate, and that soil moisture data be used in the calibration process.  相似文献   

Development and application of a spatially‐distributed Arctic hydrological and thermal process model (ARHYTHM)     

Ziya Zhang  Douglas L. Kane  Larry D. Hinzman 《水文研究》2000,14(6):1017-1044

A process‐based, spatially distributed hydrological model was developed to quantitatively simulate the energy and mass transfer processes and their interactions within arctic regions (arctic hydrological and thermal model, ARHYTHM). The model first determines the flow direction in each element, the channel drainage network and the drainage area based upon the digital elevation data. Then it simulates various physical processes: including snow ablation, subsurface flow, overland flow and channel flow routing, soil thawing and evapotranspiration. The kinematic wave method is used for conducting overland flow and channel flow routing. The subsurface flow is simulated using the Darcian approach. The energy balance scheme was the primary approach used in energy‐related process simulations (snowmelt and evapotranspiration), although there are options to model snowmelt by the degree‐day method and evapotranspiration by the Priestley–Taylor equation. This hydrological model simulates the dynamic interactions of each of these processes and can predict spatially distributed snowmelt, soil moisture and evapotranspiration over a watershed at each time step as well as discharge in any specified channel(s). The model was applied to Imnavait watershed (about 2·2 km²) and the Upper Kuparuk River basin (about 146 km²) in northern Alaska. Simulated results of spatially distributed soil moisture content, discharge at gauging stations, snowpack ablations curves and other results yield reasonable agreement, both spatially and temporally, with available data sets such as SAR imagery‐generated soil moisture data and field measurements of snowpack ablation, and discharge data at selected points. The initial timing of simulated discharge does not compare well with the measured data during snowmelt periods mainly because the effect of snow damming on runoff was not considered in the model. Results from the application of this model demonstrate that spatially distributed models have the potential for improving our understanding of hydrology for certain settings. Finally, a critical component that led to the performance of this modelling is the coupling of the mass and energy processes. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

Streamflow elasticity,in a context of climate change,in arid Andean watersheds of north-central Chile     

Cristián Barrera  Jorge Núñez Cobo  Maxime Souvignet  Jorge Oyarzún 《水文科学杂志》2020,65(10):1707-1719

ABSTRACT

Based on a future temperature increase of 0.5°C and precipitation decrease of 25%, the climate elasticity of streamflow to precipitation and temperature changes in 12 Andean watersheds of the Coquimbo Region, north-central Chile, was assessed. Also, the possible relationships between this elasticity and specific physiographic characteristics of the watersheds (area, average elevation, slope distribution, terrain roughness, slope orientation, vegetation cover) were studied. Climate elasticity of streamflow ranged between 0 and 2.8. Watersheds presenting higher elevations, with a fairly well-balanced distribution of slope exposure tend to exhibit lower elasticity, which could be explained by the contribution of snowfall to the hydrological regime, more significant in those watersheds. Results should be considered when downscaling climate model projections at the basin scale in mountain settings. Finally, uncertainties in the approach, given by factors such as streamflow seasonality, data availability and representativeness and watershed characteristics, and therefore the scope of the results, are discussed.  相似文献   

气温对太湖蓝藻复苏和休眠进程的影响   总被引：6，自引：4，他引：2  

谢小萍  李亚春  杭鑫  黄珊 《湖泊科学》2016,28(4):818-824

利用2005 2014年每日的卫星数据、气象站和浮标站观测资料研究复苏期和休眠期的平均气温、稳定通过界限温度初终日、周有效积温与太湖蓝藻休眠和复苏时间的关系,探讨气温是否是影响蓝藻休眠和复苏时间进程的关键因子.分析结果显示:太湖蓝藻复苏早晚与春季(3 5月)气温密切相关,春季气温越高,蓝藻复苏时间越早;太湖蓝藻休眠时间与秋、冬季(11次年1月)气温密切相关,秋、冬季气温越高,蓝藻休眠时间越晚.此外根据分析结果发现,太湖首次出现蓝藻水华的时间一般是气温稳定通过9℃初日之后的1个月左右,但上一周期的休眠与下一周期的复苏之间气温异常偏高会导致蓝藻水华首次出现时间早于稳定通过9℃初日;最后一次蓝藻水华出现时间与气温稳定通过4℃的终日相近;在复苏期,湖水中的叶绿素a浓度随周有效积温变化而变化,二者相关系数为0.9.  相似文献   

青海湖流域50年来(1956-2007年)河川径流量变化趋势——以布哈河和沙柳河为例   总被引：1，自引：0，他引：1  

李岳坦  李小雁  崔步礼  彭海英  伊万娟 《湖泊科学》2010,22(5):757-766

通过对青海湖流域布哈河和沙柳河50年来的河川径流量分析发现,布哈河和沙柳河年径流量50年来没有显著的变化趋势,这两条河流的河川径流量对青海湖水位下降所起的作用不明显;布哈河月平均流量的年际变化在1月、2月和3月有减少的趋势,沙柳河月平均流量的年际变化在1月、2月、4月和5月亦有减少的趋势;布哈河的径流量大于沙柳河的径流量,在55%-91%频率范围内,布哈河的径流量小于沙柳河的径流量,在其它频率范围内,布哈河的径流量显著大于沙柳河的径流量,在一年中,布哈河和沙柳河的月径流量具有显著的差异;布哈河来水丰沛期是20世纪60年代,贫乏期是90年代,70和80年代为平水期;沙柳河月径流量从20世纪60年代到90年代一直比较稳定,没有发生显著的变化.  相似文献   

长江三角洲地区TZK3孔碎屑锆石U-Pb年龄及其物源意义   总被引：2，自引：2，他引：0  

程瑜  李向前  赵增玉  张祥云  郭刚 《地质力学学报》2018,24(5):635-644

以TZK3孔的磁性地层学为基础,结合沉积物的岩性、结构构造及锆石年龄谱系特征,探讨沉积物的物质来源及长江贯通的时限。古地磁结果表明:96.7 m、263.3 m、603.75 m分别对应B/M界线、M/G界线、晚上新世/早上新世的界线（3.58 Ma）。锆石年龄谱系数据显示,TZK3孔的U-Pb锆石年龄主要分为5组:100~300 Ma,400~500 Ma,700~850 Ma,1800~2000 Ma,2400~2600 Ma。其中3.7 Ma的锆石年龄谱相对简单,以白垩纪（100~150 Ma）为主,物质主要来自于长江中下游的火山盆地,为近源沉积。TZK3孔3.04 Ma以来,锆石年龄谱变得复杂且主峰相对较多,表明物源区更广且加入了远源的成分。3.04 Ma的锆石年龄谱中开始出现峨眉山玄武岩年龄段（251~260 Ma）的锆石,表明在此时期长江上游的物质就已到达了长江三角洲地区,即长江贯通的时限为3.04~3.7 Ma。   相似文献   

Riparian responses to reduced flood flows: comparing and contrasting narrowleaf and broadleaf cottonwoods     

Thomas K. Wilding  David M. Merritt  Stewart B. Rood  N. LeRoy Poff 《水文科学杂志》2014,59(3-4):605-617

Abstract

To enable assessment of risks of water management to riparian ecosystems at a regional scale, we developed a quantile-regression model of abundance of broadleaf cottonwoods (Populus deltoides and P. fremontii) as a function of flood flow attenuation. To test whether this model was transferrable to narrowleaf cottonwood (Populus angustifolia), we measured narrowleaf abundance along 39 river reaches in northwestern Colorado, USA. The model performed well for narrowleaf in all 32 reaches where reservoir storage was <75% of mean annual flow. Field data did not fit the model at four of seven reaches where reservoir storage was >90% of mean annual flow. In these four reaches, narrowleaf was abundant despite peak flow attenuation of 45–61%. Poor model performance in these four reaches may be explained in part by a pulse of narrowleaf cottonwood expansion as a response to channel narrowing and in part by differences between narrowleaf and broadleaf cottonwood response to floods and drought.