川北山丘区地下水补给特征与定量研究          下载免费PDF全文

周志超  李杰彪  苏锐  郭永海  赵宏刚  王彦江  季瑞利  张明 《水文》2015,35(5):54-60

针对川北山丘区地下水资源和污染防护研究中地下水补给难以定量等问题,以川北典型山丘区平溪河北岸的山丘区子流域为研究对象,布设监测孔并对其地下水的水位和水温开展动态监测,并基于大气压监测数据校正地下水监测水位,分析了山丘区地下水水位及水温的年内动态变化特征;采用渗水试验和分段双栓塞水文地质试验获取含水层空间渗透系数;基于达西断面法定量计算了研究区内观测断面的地下水径流补给量,并建立了月降雨量与降水入渗系数的函数关系,结果显示:研究区多年平均大气降水入渗补给量为16.61mm,多年平均降水入渗系数为0.0182;月降雨量与降水入渗系数呈幂函数关系;此成果可为研究区地下水资源、地下水防污性能评价及地下水数值模拟等研究提供重要依据。  相似文献   

北极海冰的年代际转型与中国冻雨年代际变化的关系   总被引：1，自引：0，他引：1  

牛璐  黄菲  周晓 《海洋学报》2015,37(11):105-117

基于1961-2013年HadISST海冰密集度资料,定义了北极海冰的季节性融冰指数,结果显示近几十年来北极季节性融冰范围呈显著的上升趋势,并分别在20世纪70年代末和90年代中期存在显著的年代际转型,相应地,中国冻雨发生频数总体上呈现出显著的减少趋势,但也存在显著的年代际转型。在20世纪70年代末之前,北极季节性融冰范围较小但显著增长,中国冻雨频数年际变化振幅较大,且主要受巴伦支海、喀拉海海冰的影响;20世纪70年代末至90年代中期北极季节性融冰范围维持振荡特征,没有显著的线性趋势,中国冻雨频数变化振幅减小,与北极海冰相关较弱,主要相关因子为北大西洋及北太平洋海表温度变化;而90年代中期以后,北极海冰融化加快,特别是2007年以后,季节性融冰范围大大增加,而中国冻雨频数处于低发时段,其变化与太平洋扇区海冰及堪察加半岛附近海温呈显著负相关,季节性融冰的显著区域也从东西伯利亚海逆时针旋转向波弗特海-加拿大群岛北部扩张,同时向北极中央区扩张。不同年代影响冻雨的海温或海冰关键海区不同,产生特定的大气环流异常响应,进而影响到我国冻雨。  相似文献   

国内水文序列变异点分析方法及在各流域应用研究进展   总被引：10，自引：0，他引：10  

周园园  师长兴  范小黎  杜俊 《地理科学进展》2011,30(11):1361-1369

变异点识别在区分气候变化和人类活动对水文过程的影响中具有十分重要的作用。近几十年来,国内水文序列变异点的研究逐渐发展,从最早的使用单一方法发展到由多种方法组成的水文序列变异点诊断系统和对部分方法的改进。同时,各种方法在中国各主要流域得到广泛应用,但是使用的方法不同,水文序列时间年限不同,得到的变异点的结果也不完全一致。本文将目前普遍采用的方法及在各流域的应用成果进行了系统总结,为今后水文序列变异点的方法改进及其在流域中的应用发展提供参考。  相似文献   

气候变化下极端水文事件的研究进展   总被引：9，自引：2，他引：7  

张利平  杜鸿  夏军  徐霞 《地理科学进展》2011,30(11):1370-1379

气候异常变化导致洪涝灾害、干旱等极端水文事件的发生及其增加的水灾害风险正成为人类生存所面临的重大挑战。近年来,开展气候变化背景下流域极端水文事件的变化趋势、发生机理及其对气候变化的响应与预测研究正逐渐受到国内外众多学者的关注。本文从极端水文事件的定义、研究方法、水文极值分布函数、观测事实及模拟研究等方面分析评述了极端水文事件问题的研究现状和研究成果。在此基础上,讨论了研究现状存在的问题并对该领域未来研究方向进行了展望。  相似文献   

Changes in streamflow regime following vegetation changes from paired catchments     

Fangfang Zhao  Zongxue Xu  Lu Zhang 《水文研究》2012,26(10):1561-1573

Vegetation changes can significantly affect catchment water balance. It is important to evaluate the effects of vegetation cover change on streamflow as changes in streamflow relate to water security. This study focuses on the use of statistical methods to determine responses in streamflow at seven paired catchments in Australia, New Zealand, and South Africa to vegetation change. The non‐parametric Mann–Kendall test and Pettitt's test were used to identify trends and change points in the annual streamflow records. Statistically significant trends in annual streamflow were detected for most of the treated catchments. It took between 3 and 10 years for a change in vegetation cover to result in significant change in annual streamflow. Presence of the change points in streamflow was associated with changes in the mean, variance, and distribution of annual streamflow. The streamflow in the deforestation catchments increased after the change points, whereas reduction in streamflow was observed in the afforestation catchments. The streamflow response is mainly affected by the climate and underlying vegetation change. Daily flow duration curves (FDCs) for the whole period and pre‐change and post‐change point periods also were analysed to investigate the changes in flow regime. Three types of vegetation change effects on the flow regime have been identified. The relative reductions in most percentile flows are constant in the afforestation catchments. The comparison of trend, change point, and FDC in the annual streamflow from the paired experiments reflects the important role of the vegetation change. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Spatial–temporal variability and hydrologic connectivity of runoff generation areas in a North Alabama pasture—implications for phosphorus transport     

Sumit Sen  Puneet Srivastava  Jacob H. Dane  Kyung H. Yoo  Joey N. Shaw 《水文研究》2010,24(3):342-356

This study delineated spatially and temporally variable runoff generation areas in the Sand Mountain region pasture of North Alabama under natural rainfall conditions, and demonstrated that hydrologic connectivity is important for generating hillslope response when infiltration‐excess (IE) runoff mechanism dominates. Data from six rainfall events (13·7–32·3 mm) on an intensively instrumented pasture hillslope (0·12 ha) were analysed. Analysis of data from surface runoff sensors, tipping bucket rain gauge and HS‐flume demonstrated spatial and temporal variability in runoff generation areas. Results showed that the maximum runoff generation area, which contributed to runoff at the outlet of the hillslope, varied between 67 and 100%. Furthermore, because IE was the main runoff generation mechanism on the hillslope, the data showed that as the rainfall intensity changed during a rainfall event, the runoff generation areas expanded or contracted. During rainfall events with high‐intensity short‐ to medium‐duration, 4–8% of total rainfall was converted to runoff at the outlet. Rainfall events with medium‐ to low‐intensity, medium‐duration were found less likely to generate runoff at the outlet. In situ soil hydraulic conductivity (k) was measured across the hillslope, which confirmed its effect on hydrologic connectivity of runoff generation areas. Combined surface runoff sensor and k‐interpolated data clearly showed that during a rainfall event, lower k areas generate runoff first, and then, depending on rainfall intensity, runoff at the outlet is generated by hydrologically connected areas. It was concluded that in IE‐runoff‐dominated areas, rainfall intensity and k can explain hydrologic response. The study demonstrated that only connected areas of low k values generate surface runoff during high‐intensity rainfall events. Identification of these areas would serve as an important foundation for controlling nonpoint source pollutant transport, especially phosphorus. The best management practices can be developed and implemented to reduce transport of phosphorus from these hydrologically connected areas. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

A comparison of stream water temperature regimes from open and afforested moorland,Yorkshire Dales,northern England     

L. E. Brown  L. Cooper  J. Holden  S. J. Ramchunder 《水文研究》2010,24(22):3206-3218

Despite the known importance of water temperature for river ecosystems, the thermal regime of streams and rivers can be heavily modified by afforestation. Although the nature of the heat budget affecting streams in forested catchments shows high variability in space and time, most of the studies of stream temperature response to afforestation have lacked replication among streams. This study examined the impacts of coniferous forest plantations on stream water temperature at six sites (three forested and three open moorland) in the Yorkshire Dales, northern England. Our aim was to test the hypothesis that afforestation would alter the thermal regime of streams, leading to reduced year‐round thermal variability, and cooler summer/warmer winter water temperatures, relative to streams flowing across open moorland. Data collected from April 2007 to March 2009 showed similar thermal dynamics among all six streams over the study period, although variability in forested streams was markedly lower as expected. Mean and maximum daily water temperatures were significantly higher in open moorland streams for much of the year but while some forested streams were warmer than individual moorland streams during winter months (November to February), there was considerable overlap in water temperature between moorland and forest streams. Most stream temperature records showed evidence of low/no winter flow and freezing. These results contrast with many previous studies that have reported warmer temperatures in forested versus open moorland streams during winter, a finding that most likely reflects site‐specific hydrological, geomorphological and climatological influences on water temperature in addition to afforestation. This study demonstrates the need for replication of hydrological monitoring when examining the effects of basin‐scale management practices and provides further evidence for changes in stream thermal regime following afforestation, a practice that is likely to increase in future due to growing demands for increased forest cover in the UK uplands. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Hydrologic simulation of clay‐settling areas in the phosphate mining district,Florida     

Jing Zhang  Mark Ross 《水文研究》2012,26(24):3770-3778

Clay‐settling areas (CSAs) are one of the most conspicuous and development‐limiting landforms remaining after phosphate mining. Many questions are asked by the mining and regulatory communities with regard to the correct modelling (predictive) methods and assumptions that should be used to yield viable hydrologic post‐reclamation landforms within CSAs. Questions as to the correct methodology to use in modelling/predicting long‐term CSA hydrologic performance have historically been difficult to answer because the data and analysis to support popular hypotheses did not exist. The goal of this paper was to substantially improve the data, analysis and predictive methodology necessary to return CSAs to viable hydrologic units, and moreover, to develop better understanding of the hydrology of CSAs and their ability to support wetlands. The study site is located at the Fort Meade Mine in Polk County, Florida. In this paper, continuous model simulation and calibration of study site were conducted for the hydrologic model, Hydrological Simulation Program – FORTRAN, which was generally selected on the basis of its popularity in predicting the hydrologic behaviour of CSAs. The objective of this study was to simulate streamflow discharges and stage to estimate runoff response from these areas on the basis of the observed rainfall within the CSA. A set of global hydrologic parameters was selected and tested during the calibration by the parameter estimation software PEST. A comparison of the simulated and observed flow data indicates that the model calibration adequately reproduces the hydrologic response of the CSAs. The estimated parameters can be used as references for future application of the model. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Thermal regime of the northwest Indian rifted margin – Comparison with predictions     

Gérôme Calvès  Anne M. Schwab  Mads Huuse  Peter D. Clift  Asif Inam 《Marine and Petroleum Geology》2010

We use a simple approach to estimate the present-day thermal regime along the northwestern part of the Western Indian Passive Margin, offshore Pakistan. A compilation of bottom borehole temperatures and geothermal gradients derived from new observations of bottom-simulating reflections (BSRs) allows us to constrain the relationship between the thermal regime and the known tectonic and sedimentary framework along this margin. Effects of basin and crustal structure on the estimation of thermal gradients and heat flow are discussed. A hydrate system is located within the sedimentary deep marine setting and compared to other provinces on other continental margins. We calculate the potential radiogenic contribution to the surface heat flow along a profile across the margin. Measurements across the continental shelf show intermediate thermal gradients of 38–44 °C/km. The onshore Indus Basin shows a lower range of values spanning 18–31 °C/km. The Indus Fan slope and continental rise show an increasing gradient from 37 to 55 °C/km, with higher values associated with the thick depocenter. The gradient drops to 33 °C/km along the Somnath Ridge, which is a syn-rift volcanic construct located in a landward position relative to the latest spreading center around the Cretaceous–Paleogene transition.  相似文献   

Distinguishing streamflow trends caused by changes in climate,forest cover,and permafrost in a large watershed in northeastern China          下载免费PDF全文

Liangliang Duan  Xiuling Man  Barret L. Kurylyk  Tijiu Cai  Qiang Li 《水文研究》2017,31(10):1938-1951

Understanding how rivers respond to changes in land cover, climate, and subsurface conditions is critical for sustainably managing water resources and ecosystems. In this study, long‐term hydrologic, climate, and satellite data (1973–2012) from the Upper Tahe River watershed (2359 km²) in the Da Hinggan Mountains of northeast China were analysed to quantify the relative hydrologic effects of climate variability (system input) and the combined influences of forest cover change and permafrost thaw (system characteristics) on average annual streamflow (system response) using 2 methods: the sensitivity‐based method and the Kendall–Theil robust line method. The study period was subdivided into a forest harvesting period (1973–1987), a forest stability period (1988–2001), and a forest recovery period (2002–2012). The results indicated that the combined effects of forest harvesting and permafrost thaw on streamflow (+ 47.0 mm) from the forest harvesting period to the forest stability period was approximately twice as large as the effect associated with climate variability (+20.2 mm). Similarly, from the forest stability period to the forest recovery period, the decrease in average annual streamflow attributed to the combined effects of forest recovery and permafrost thaw (?38.0 mm) was much greater than the decrease due to climate variability (?22.2 mm). A simple method was used to separate the distinct impacts of forest cover change and permafrost thaw, but distinguishing these influences is difficult due to changes in surface and subsurface hydrologic connectivity associated with permafrost thaw. The results highlight the need to consider multiple streamflow drivers in future watershed and aquatic ecosystem management. Due to the ecological and hydrological susceptibility to disturbances in the Da Hinggan Mountains, forest harvesting will likely negatively impact ecohydrological processes in this region, and the effects of forest species transition in the forest recovery process should be further investigated.  相似文献