Dynamic storage: a potential metric of inter‐basin differences in storage properties          下载免费PDF全文

James M. Buttle 《水文研究》2016,30(24):4644-4653

The potential for dynamic storage to serve as a metric of basin behaviour was assessed using data from five drainage basins with headwaters on the thick sand and gravel deposits of the Oak Ridges Moraine in southern Ontario, Canada. Dynamic storage was directly correlated with the ratio of variability of δ²H in streamflow relative to that in precipitation. This ratio has previously been shown to be inversely related to basin mean transit time (MTT), suggesting an inverse relationship between dynamic storage and MTT for the study basins. Dynamic storage was also directly correlated with interannual variability in stream runoff, baseflow and baseflow:runoff ratio, implying that basins with smaller dynamic storage have less interannual variability in their streamflow regimes. These preliminary results suggest that dynamic storage may serve as a readily derived and useful metric of basin behaviour for inter‐basin comparisons. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Alteration of hydrological processes and streamflow with juniper (Juniperus virginiana) encroachment in a mesic grassland catchment          下载免费PDF全文

Chris B. Zou  Donald J. Turton  Rodney E. Will  David M. Engle  Sam D. Fuhlendorf 《水文研究》2014,28(26):6173-6182

To understand the effect of woody plant encroachment on hydrological processes of mesic grasslands, we quantified infiltration capacity in situ, the temporal changes in soil water storage, and streamflow of a grassland catchment and a catchment heavily encroached by juniper (Juniperus virginiana, eastern redcedar) in previously cultivated, non‐karst substrate grasslands in north‐central Oklahoma for 3 years. The initial and steady‐state infiltration rates under the juniper canopy were nearly triple to that of the grassland catchment and were intermediate in the intercanopy spaces within the encroached catchment. Soil water content and soil water storage on the encroached catchment were generally lower than on the grassland catchment, especially when preceding the seasons of peak rainfall in spring and fall. Frequency and magnitude of streamflow events were reduced in the encroached catchment. Annual runoff coefficients for the encroached catchment averaged 2.1%, in contrast to 10.6% for the grassland catchment. Annual streamflow duration ranged from 80 to 250 h for the encroached catchment compared with 600 to 800 h for the grassland catchment. Our results showed that the encroachment of juniper into previously cultivated mesic grasslands fundamentally alters catchment hydrological function. Rapid transformation of mesic grassland to a woodland state with juniper encroachment, if not confined, has the potential to drastically reduce soil water, streamflow and flow duration of ephemeral streams in the Southern Great Plains. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Dynamic river–groundwater exchange in the presence of a saline,semi‐confined aquifer          下载免费PDF全文

N. P. Unland  I. Cartwright  E. Daly  B. S. Gilfedder  A. P. Atkinson 《水文研究》2015,29(23):4817-4829

Understanding groundwater–surface water exchange in river banks is crucial for effective water management and a range of scientific disciplines. While there has been much research on bank storage, many studies assume idealized aquifer systems. This paper presents a field‐based study of the Tambo Catchment (southeast Australia) where the Tambo River interacts with both an unconfined aquifer containing relatively young and fresh groundwater (<500 μS/cm and <100 years old) and a semi‐confined artesian aquifer containing old and saline groundwater (electrical conductivity > 2500 μS/cm and >10 000 years old). Continuous groundwater elevation and electrical conductivity monitoring within the different aquifers and the river suggest that the degree of mixing between the two aquifers and the river varies significantly in response to changing hydrological conditions. Numerical modelling using MODFLOW and the solute transport package MT3DMS indicates that saline water in the river bank moves away from the river during flooding as hydraulic gradients reverse. This water then returns during flood recession as baseflow hydraulic gradients are re‐established. Modelling also indicates that the concentration of a simulated conservative groundwater solute can increase for up to ~34 days at distances of 20 and 40 m from the river in response to flood events approximately 10 m in height. For the same flood event, simulated solute concentrations within 10 m of the river increase for only ~15 days as the infiltrating low‐salinity river water drives groundwater dilution. Average groundwater fluxes to the river stretch estimated using Darcy's law were 7 m³/m/day compared with 26 and 3 m³/m/day for the same periods via mass balance using Radon (²²²Rn) and chloride (Cl), respectively. The study shows that by coupling numerical modelling with continuous groundwater–surface water monitoring, the transient nature of bank storage can be evaluated, leading to a better understanding of the hydrological system and better interpretation of hydrochemical data. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Inverse modelling using PS‐InSAR data for improved land subsidence simulation in Las Vegas Valley,Nevada          下载免费PDF全文

Meijing Zhang  Thomas J. Burbey 《水文研究》2016,30(24):4494-4516

Las Vegas Valley has had a long history of groundwater development and subsequent surface deformation. InSAR interferograms have revealed detailed and complex spatial patterns of subsidence in the Las Vegas Valley area that do not coincide with major pumping regions. This research represents the first effort to use high spatial and temporal resolution subsidence observations from InSAR and hydraulic head data to inversely calibrate transmissivities (T), elastic and inelastic skeletal storage coefficients (S_ke and S_kv) of the developed‐zone aquifer and conductance (CR) of the basin‐fill faults for the entire Las Vegas basin. The results indicate that the subsidence observations from InSAR are extremely beneficial for accurately quantifying hydraulic parameters, and the model calibration results are far more accurate than when using only groundwater levels as observations, and just a limited number of subsidence observations. The discrepancy between distributions of pumping and greatest levels of subsidence is found to be attributed to spatial variations in clay thickness. The Eglington fault separates thicker interbeds to the northwest from thinner interbeds to the southeast and the fault may act as a groundwater‐flow barrier and/or subsidence boundary, although the influence of the groundwater barrier to this area is found to be insignificant. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Scales and magnitude of hyporheic,river–aquifer and bank storage exchange fluxes          下载免费PDF全文

Roger H. Cranswick  Peter G. Cook 《水文研究》2015,29(14):3084-3097

Many studies have investigated the exchange processes that occur between rivers and groundwater systems and have successfully quantified the water fluxes involved. Specifically, these exchange processes include hyporheic exchange, river–aquifer exchange (groundwater discharge and river loss) and bank storage exchange. Remarkably, there are relatively few examples of field studies where more than one exchange process is quantified, and as a consequence, the relationships between them are not well understood. To compare the relative magnitudes of these common exchange processes, we have collected data from 54 studies that have quantified one or more of these exchange flux types. Each flux value is plotted against river discharge at the time of measurement to allow the different exchange flux types to be compared. We show that there are positive relationships between the magnitude of each exchange flux type and increasing river discharge across the different studies. For every one order of magnitude increase in river discharge, the hyporheic, river–aquifer and bank storage exchange fluxes increase by factors of 2.7, 2.9 and 2.5, respectively. On average, hyporheic exchange fluxes are almost an order of magnitude greater than river–aquifer exchange fluxes, which are, in turn, approximately four times greater than bank storage exchange fluxes for the same river discharge. Unless measurement approaches that can distinguish between different types of exchange flux are used, there is potential for hyporheic exchange fluxes to be misinterpreted as river–aquifer exchange fluxes, with possible implications for water resource management decisions. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

On the relationship between historical land‐use change and water availability: the case of the lower Tarim River region in northwestern China     

T. Liu  H. Fang  P. Willems  A. M. Bao  X. Chen  F. Veroustraete  Q. H. Dong 《水文研究》2013,27(2):251-261

Natural ecosystems in the region of the lower Tarim River in northwestern China strongly deteriorated since the 1950s due to an expanding desertification. As a result, the downstream Tarim River reaches became permanently dry land. This historical evolution in land‐use change is typically the result of the anthropogenic impact on natural ecosystems. On the basis of a spatially distributed hydrological catchment model bidirectionally linked with a fully hydrodynamic MIKE11 river model, land‐use changes characterized by historical changes in leaf area index (LAI) of vegetation, as well as the evolution of irrigated surface areas, can be causally related to changes in water resources (groundwater storage and surface water resources). An increased surface area of irrigated (agricultural) land, together with a majority of inefficient irrigation methods, did lead to a strong increase of water resources consumption of the farmlands located in the upper Tarim River area. Evidently, this evolution influenced available water resources downstream in the Tarim basin. As a result, farmland has been gradually relocated to the upstream regions. This has led to reduced flows from the upper Tarim stream, which subsequently accelerated the dropping of the groundwater level downstream in the basin. This study moreover demonstrates that land surface biomass changes (cumulative LAI) along the lower Tarim River are strongly related to the changes in groundwater storage. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

利用3S技术及三维激光扫描仪进行耕地损毁勘测     

林学艺 《测绘与空间地理信息》2016,(2):88-90

利用RS技术发现耕地损毁,网络RTK测量耕地损毁范围及面积,GIS提取耕地被损毁前的分类面积和等别,以及利用网络RTK配合Maptek I-Site8810三维激光扫描仪重构损毁耕地三维模型。  相似文献   

点云中混合像元的探测与剔除算法     

王春林  郑德华  孟敏  许烨璋 《测绘与空间地理信息》2016,(1):102-105

针对地面三维激光扫描仪扫描过程中产生混合像元的问题,通过对混合像元产生原理和相关特性的分析,提出了一种用于探测和剔除混合像元的算法,并且编制相应的计算机程序予以实现。同时以球体作为实验扫描对象,用混合像元剔除算法对扫描过程中产生的混合像元予以剔除,并比较了混合像元剔除前后点云拟合模型与实际物体在尺寸上及拟合精度的差异,从而验证了该算法的有效性和实用性。混合像元探测与剔除算法可以为后期进行的点云配准、特征提取和曲面建模等工作提供更精确的点云。  相似文献   

基于CIPS软件探讨高山地DOM数据的生产方式     

刘涛  王明宇  于洪雨 《测绘与空间地理信息》2016,(4):186-188

在DOM数据生产中,山地、高山地数据一直以来都是重点和难点。本文分析了高山地影像数据的特点,提出一种与山地、高山地数据相适应的处理方式。最后基于CIPS软件,按需求设计对应的软件处理流程,并使用满足实验要求的高山地影像数据,对这种方式加以实现和验证。  相似文献   

车载移动测量系统应用于城市大比例尺地形图更新     

田茂义  俞家勇  谢欣鹏  李鹏飞  周茂伦 《测绘与空间地理信息》2016,(6):5-7

将车载移动测量系统与城市大比例尺数字地形图测图相结合,成功地将车载移动测量系统运用于城市大比例尺测图更新应用中。通过在测区内布设靶标控制点,对比靶标的点云量算坐标与全站仪实测实际坐标,统计分析车载移动测量系统的测图精度。实验结果表明,车载移动测量系统能够满足城市大比例尺地形图测图要求。  相似文献