Variability of water levels and impacts of streamflow changes and human activity within the Pearl River Delta,China     

Qiang Zhang  Chong-Yu Xu  Yongqin David Chen 《水文科学杂志》2013,58(4):512-525

Abstract

The Pearl River Delta (PRD) is a complicated criss-cross river network. The booming economy and intensifying human activity have greatly altered the natural water levels, which threatens regional sustainable development. The Mann-Kendall trend test and the kriging interpolation method were used to detect the spatial and temporal patterns in the trends of extreme high/low water levels related to different magnitudes of streamflow, in order to explore the impacts of hydrological processes on the water-level changes throughout the PRD. The results indicate that: (a) streamflow changes at the Sanshui and Makou stations exhibit different characteristics. No significant trend can be identified in the streamflow changes at Makou station; however, the streamflow at Sanshui station shows a significant increasing trend, especially in low-flow periods. The decreasing Makou/Sanshui streamflow ratio exerts tremendous impacts on the water-level changes in the hinterland of the PRD region. (b) Extreme high/low water levels exhibit similar changing patterns. The extreme high/low water levels in the high/normal flow periods are decreasing in both the upper PRD and the hinterland of the PRD region. Increasing extreme high/low water levels in low-flow periods can be identified in the hinterland of the PRD region. The coastal regions are characterized by increasing extreme high/low water levels. (c) Extreme high/low water levels for high/normal flow periods in the hinterland of the PRD are heavily impacted by topographic changes due to in-channel dredging. Increasing extreme high/low water levels along the coastal regions are mainly backwater effects caused by serious siltation and rising sea level. This study has scientific and practical merits in regional fluvial management and mitigation of natural hazards.

Citation Zhang, Q., Xu, C.-Y. & Chen, Y. D. (2010) Variability of water levels and impacts from streamflow changes and human activity within the Pearl River Delta, China. Hydrol. Sci. J. 55(4), 512–525.  相似文献   

The Amazon River headstream area in the Cordillera Chila,Peru: hydrographic,hydrological and glaciological conditions     

Bohumír Janský  Zbyněk Engel  Jan Kocum  Luděk Šefrna  Julius Česák 《水文科学杂志》2013,58(1):138-151

Abstract

The source of the world's largest river has fascinated scientists and adventurers for a long time. Extensive studies have been undertaken in the unexplored Llogueta River valley, Cordillera Chila, to identify the main stream of the Amazon River. Analysis of the Lloqueta River network and measurements of its hydrographic and hydrometric characteristics are presented in this study. On the basis of the acquired data, the northern hillside of the Cordillera Chila massif, concretely the basins of four mountainous courses—the Carhuasanta, Apacheta, Ccaccansa and Sillanque rivers—should be regarded as the headwaters territory of the Amazon River. Factors influencing the river system—glaciers and soils—were examined for each catchment. Glacier retreat in the last 50 years has left perennial snowfields only in the highest part of the study area, resulting in modification of the headwater runoff regimes. Preliminary results are afforded by the continual automatic water-level monitoring of the Lloqueta River since June 2008. Our investigations have determined that all types of soil in the area could be classified into two main categories: hydromorphic soils or poorly developed cryic soils.

Citation Janský, B., Engel, Z., Kocum, J., ?efrna, L. & ?esák, J. (2011) The Amazon River headstream area in the Cordillera Chila, Peru: hydrographical, hydrological and glaciological conditions. Hydrol. Sci. J. 56(1), 138–151.  相似文献   

Tidal Reduction Method Based on Temporal Tidal Time-Difference Variations     

Ju Liu  Jingyang Bao  Wei Zhou  Jun Xu  Xianghong Zhao 《Marine Geodesy》2013,36(5):407-421

Abstract

Technical developments in the positioning and depth detection fields have allowed for vast improvements in sounding results, but the effects of tidal reduction (TR) yet merit improvement; today, TR is the main factor that limits bathymetry precision. It is crucial to determine tidal time difference (TTD) between tidal gauges to conduct effective TTD-based TR. The influence of temporal TTD variations is usually ignored, and the temporal observation window to determine TTD is generally freely selected. In this study, temporal TTD variations were analyzed under the tidal constituent merging theory. Daily and hourly TTDs were compared and utilized to reduce the TR error during time difference method operation. At-sea experiments were conducted to contrast the effects of daily versus hourly TTDs on TR; the results indicate that hourly TTD is more precise and thus better suited to TR.  相似文献   

矿井最大涌水量计算和参数确定──试论南方岩溶矿井的水均衡预测方法     

董兴文 《四川地质学报》1995,(1)

我国南方岩溶管道流矿井涌水量计算问题较复杂。本文通过地下水动态过程曲线的均衡分析，以暗河排泄流量反求补给水量，并借河渠洪流估算理论预计矿井最大涌水量。由于对确定的数学模型，采用了集中参数系统和宏观求取参数的方法，使计算简便新颖。文中附有计算涌水量实例和矿井涌水量预测验证资料，表明方法的可靠性。  相似文献   

Groundwater monitoring for earthquake prediction by an amateur network in Japan   总被引：1，自引：0，他引：1  

Yasue Oki  Shiro Hiraga 《Pure and Applied Geophysics》1988,126(2-4):211-240

Since 1976 groundwater-levels and the temperature of thermal water have been monitored in 100 wells distributed mostly in the southern Kanto and Tokai districts of Japan in order to predict earthquakes. Good examples of groundwater precursors were recognized prior to the following destructive earthquakes: the 1978 West Off Izu-Oshima Earthquake (M 7.0), the 1978 Off Miyagi Earthquakes (M 7.4), and the 1980 East Off Izu Peninsula Earthquake (M 6.7). In the 1978 West Off Izu-Oshima Earthquake, groundwater levels and the Japan Meteorological Agency (JMA) volume strainmeters, installed in the Izu peninsula, showed precursory changes at about the same time. In the other cases, however, precursory behavior was observed only in water level and temperature monitoring. Empirical relations are given between earthquake magnitude and the epicentral distance of the farthest groundwater anomaly, and between earthquake magnitude and the precursor time of groundwater.  相似文献   

Tank模型在模拟滑坡地下水位中的应用     

洪勇  日浦启全  栾茂田 《吉林大学学报(地球科学版)》2006,(Z1)

季节性的降雨及其所引起的地下水状态的变化是促使日本大型结晶片岩滑坡活动和诱发灾害发生的重要原因。基于对一典型结晶片岩滑坡、降雨和地下水位的长期观测,利用Tank模型建立了一种模拟滑坡地下水位变化的方法。通过对滑体内不同观测点地下水位实际观测数据与模拟结果的对比分析,证明所采用的模拟方法能够很好地再现地下水位随降雨的变化形态,从而为预测和评价降雨型滑坡的地下水状态变化提供了依据。  相似文献   

Observing water-level variations from space-borne high-resolution Synthetic Aperture Radar (SAR) image correlation     

Daniel Raucoules  Gonéri Le Cozannet  Marcello de Michele  Sylvain Capo 《国际地球制图》2018,33(9):977-987

The potential of correlating high-resolution Synthetic Aperture Radar images to estimate local water-level variations is analysed based on observing the motions of floating structures. By computing range and azimuth offsets on a COSMO-SkyMed multi-temporal data-set in an area of the French Atlantic Coast, displacement signatures were detected in several harbours of the region. They can be associated with specific floating structures, whose vertical motion is mostly driven by tides. Although the image resolution is not the best achievable for the COSMO-SkyMed sensor, comparison with ground-based tide information revealed that the obtained space-borne measurements are consistent with the tide gauges to a decimetric accuracy. Even if the requirements for traditional users of tidal data are not met by the current revisit time of the COSMO-SkyMed constellation, the method proposed here provides complementary measures, which are already well aligned to requirements of users concerned with long-term sea-level variation and river or lake water stocks.  相似文献   

Nonlinear multivariate rainfall–stage model for large wetland systems     

Alaa Ali   《Journal of Hydrology》2009,374(3-4):338-350

Wetland restoration is often measured by how close the spatial and temporal water level (stage) patterns are to the pre-drainage conditions. Driven by rainfall, such multivariate conditions are governed by nonstationary, nonlinear, and nonGaussian processes and are often simulated by physically based distributed models which are difficult to run in real time due to extensive data requirements. The objective of this study is to provide the wetland restorationists with a real time rainfall–stage modeling tool of simpler input structure and capability to recognize the wetland system complexity. A dynamic multivariate Nonlinear AutoRegressive network with eXogenous inputs (NARX) combined with Principal Component Analysis (PCA) was developed. An implementation procedure was proposed and an application to Florida Everglade’s wetland systems was presented. Inputs to the model are time lagged rainfall, evapotranspiration and previously simulated stages. Data locations, preliminary time lag selection, spatial and temporal nonstationarity are identified through exploratory data analysis. PCA was used to eliminate input variable interdependence and to reduce the problem dimensions by more than 90% while retaining more than 80% of the process variance. A structured approach to select optimal time lags and network parameters was provided. NARX model results were compared to those of the linear Multivariate AutoRegressive model with eXogenous inputs. While one step ahead prediction shows comparable results, recursive prediction by NARX is far more superior to that of the linear model. Also, NARX testing under drastically different climatic conditions from those used in the development demonstrates a very good and robust performance. Driven by net rainfall, NARX exhibited robust stage prediction with an overall Efficiency Coefficient of 88%, Mean Square Error less than 0.004 m², a standard error less than 0.06 m, a bias close to zero and normal probability plots show that the errors are close to normal distributions.  相似文献   

高水位隧道堵水限排围岩与支护相互作用分析   总被引：2，自引：1，他引：1  

王秀英  谭忠盛  王梦恕  张弥 《岩土力学》2008,29(6):1623-1628

为了保护环境并尽可能降低衬砌结构所受的水压力,提出高水位山岭隧道应采取“以堵为主,限量排放”,即“堵水限排”的防排水设计原则。但对于堵水限排情况下衬砌结构的设计,目前尚没有规范可依,这是目前隧道设计施工亟待解决的问题。在隧道力学和渗流力学的基础上进行理论分析,研究渗流应力耦合作用下围岩的力学特性,利用特征曲线法分析了不同排放量下围岩与支护的相互作用,并与数值方法计算结果进行对比。计算结果表明：不同排水量下围岩特性曲线不同,支护阻力也不同,不同排水条件下围岩有效切向应力和有效径向应力的变化很明显,排水对围岩应力以及支护体系受力的影响是不容忽视的。另外,传统隧道设计方法在全排水时完全不考虑水的作用是不安全的。所得结论可为堵水限排衬砌结构设计提供理论依据。  相似文献   

三峡水库消落带适生树种落羽杉(Taxodium distichum)叶片-细根碳/氮/磷生态化学计量特征     

刘明辉  谢婷婷  袁中勋  李丽娟  李昌晓 《湖泊科学》2020,32(6):1806-1816

为探究三峡库区消落带落羽杉（Taxodium distichum（L.） Rich.）叶片与细根C、N、P生态化学计量特征,于2018年7月对忠县三峡库区消落带植被修复示范基地3个水淹处理组（深度水淹组,DS;中度水淹组,MS;浅淹对照组,SS）的落羽杉进行叶片与细根采集,并调查其生长特征,测定分析落羽杉叶片与细根C、N、P生态化学计量特征及相关性.结果表明：（1）各水淹处理组落羽杉叶片C含量表现为SS组 > DS组 > MS组,且SS组显著高于MS组;细根C含量在不同水淹处理组之间均无显著性差异.（2）细根N、P含量表现为DS组 < MS组 < SS组的协同增长趋势;叶片N、P含量则表现为DS组 > MS组 > SS组的协同降低趋势,且叶片N、P含量分别约为细根N、P含量的3倍和2倍.（3）各水淹处理组的叶片C/N、C/P比值均显著或极显著低于细根;叶片N/P比值均高于细根,且其比值相对恒定,均表现为SS组 > DS组 > MS组的趋势.（4）相关性分析表明,叶片P含量与细根N含量呈显著负相关关系,叶片N/P比值与细根N/P比值呈显著正相关关系.研究表明,落羽杉叶片与细根在生长和代谢过程中具有整体性,养分和光合产物在地上与地下部分之间分配权衡,以维持营养的动态平衡,使落羽杉具有内稳性,从而更好地适应和响应三峡消落带水位变化.  相似文献