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1.
In the past few decades, rapid urbanization has occurred in many regions of the Kingdom of Saudi Arabia due to increasing population and urban development. Additionally, the effects of global warming on rainfall characteristics have been observed. This rapid change in urbanization and climate change has cause significant changes in the nature of land surfaces and rainfall patterns, which affect the runoff process and the amount of surface runoff during floods. This study investigated the effect of urbanization and rainfall intensity for Hafr Al-Batin watershed located in Saudi Arabia. For this purpose, a hydrologic model, HEC-HMS, was adopted to simulate the flow of different rainfall intesities and urbanization levels. Simulated results showed that for a 100-year storm, a 24-h duration, and an urbanization level of 80%, the peak flow was 213% higher than the estimated current peak and the runoff volume was 112% higher than the current runoff volume. These results show a strong linear correlation between the level of urbanization and both peak discharge and runoff volume. Furthermore, the results indicate that for short return periods, the peak flow is more sensitive to the level of urbanization compared to long periods.  相似文献   

2.
Typhoon-induced extreme storm runoffs often cause flood hazards. In this study, a hydrological model (HEC-HMS) was applied to Shihmen watershed located in Taiwan. Three typhoon-induced storm events, with return period ranging from 1 to 90 years, were used in case studies to characterize storm runoff. With a 5-year storm for model calibration, model parameters were carefully calibrated through the comparison between model simulated and observed flows at a stream gage station. The calibrated model was then verified for a 90-year storm and a 1-year storm event. Results indicate that the calibrated and verified HEC-HMS hydrological model is capable of providing satisfactory predictions of the typhoon-induced extreme storm runoff to support reservoir operation and flood hazard mitigation. Based on model simulations, typhoon-induced water table increases for different initial water volumes at Shihmen Reservoir was derived by adding storm-runoff volume to the reservoir’s initial elevation-volume rating curve. Water tables above the top elevation of the dam in the reservoir indicate the need for immediate water releases to avoid the risk of overflow over the dam.  相似文献   

3.
赵求东  赵传成  秦艳  苌亚平  王建 《冰川冻土》2020,42(4):1285-1298
木扎提河是天山南坡冰川面积覆盖率最大(48.2%)的河流, 流域径流过程对气候变化极为敏感, 为了合理管理和规划水资源, 确保水资源的可持续利用, 亟需定量评估气候变化对该流域水文过程的影响。以VIC-CAS分布式水文模型为计算平台, 利用实测的径流和两次冰川编目间的冰川面积变化数据开展了模型的多目标参数化校正和验证, 有效提高了模拟结果的“真实性”, 然后通过数值模拟结果结合观测数据定量解析了流域径流的组成、 变化特征及对气候变化的响应机理。结果表明: 木扎提河总径流集中在暖季(5 - 9月), 占全年总径流量的77.9%, 冰川径流、 融雪径流和降雨径流分别占总径流量的66.6%、 26.4%和7.0%。1971 - 2010年木扎提河流域气温和降水呈显著增加趋势, 由于降水的增加, 降雨和融雪径流均呈增加趋势, 但冰川径流呈现明显减少趋势, 导致总径流呈现下降趋势。在RCP4.5情景下, 未来该流域气温呈现明显升高趋势, 降水表现为微弱下降趋势; 气候变暖后, 更多降水以降雨形式发生, 未来降雨径流将明显增加, 降雪和融雪径流已于20世纪90年代达到峰值, 随后明显减少; 冰川面积将持续萎缩, 冰川径流于21世纪10年代达到拐点, 随后明显减少, 导致河道总径流量也将明显减少。  相似文献   

4.
中国暴雨面雨量极值分布   总被引:2,自引:1,他引:2       下载免费PDF全文
研究了暴雨面积、面平均雨深、暴雨降水总量等有关面暴雨量极值的主要内容;给出了最大时面深记录等各种雨量极值;探讨了面暴雨极值的地域分布规律和影响因素。  相似文献   

5.
Despite continuing efforts to upgrade the urban storm sewer system since the late 1950s, the City of Shanghai is still vulnerable to persistent rainstorm waterlogging due to excess surface runoff and sewer surcharge, which frequently cause significant damage to buildings and disruption to traffic. Rapid urbanization and associated land cover changes are the major factors contributing to waterlogging. However, it is unclear to what extent changes in rainfall variability over the past few decades are also involved. This paper investigates the combined impacts of land use and land cover change, storm sewer development, and long-term variations in precipitation. Evidence of persistent waterlogging is presented first. We then give an account of land surface modifications during the process of urbanization and the development of the city??s urban storm sewer system. Statistical analysis suggests that the increase in runoff coefficient due to conversion of lands from agricultural to industrial, commercial, and residential uses is a major factor driving greater waterlogging risk. In particular, historical analysis of aerial photographs reveals the rate and extent of modification to river networks in the past few decades. The natural drainage network has shrunk by 270?km, significantly reducing the city??s capacity to transport excess surface flow. In line with other studies, we find no significant overall trends in annual rainfall totals (at Baoshan and Xujiahui). However, seasonal and monthly rainfall intensities have increased. At the daily scale, we find that compared to pre-1980s: (i) there has been an increase in the number of wet days with precipitation exceeding 25?mm (Heavy Rainfall) and decrease in those below 25?mm and (ii) the number of consecutive wet days with precipitation maximum and average exceeding the threshold known to cause waterlogging shows an increasing trend. Since rainfall intensity is expected to increase under climate change, this could further compound the impacts of land use changes and place even greater pressure on the existing storm sewer system.  相似文献   

6.
基于HEC-HMS模型,选择SCS及Kinematic wave理论为基础构建了曾达沟泥石流的流域模型,并设置不同类型的12种降雨模型进行了流量计算以探讨不同降雨类型下泥石流清水流量的特征。结果显示泥石流沟口清水流量同降雨峰值到来时间、降雨集中程度(降雨模型幂次数)分别线性正相关;流量峰值延时(沟口峰值流量到来时间相较峰值雨强时间的延后值)同降雨峰值到来时间、降雨集中程度分别呈二次相关,相关关系主要为负相关,但随着第三变量的增加,相关关系不再单调;对前后两组各3个变量进行了二元多次方程拟合,拟合效果良好;将计算结果同生产中常用的推理公式法的计算结果进行对比,并分析了两者的区别及优缺点。  相似文献   

7.
黄维东 《水文》2019,39(6):27-33
选取甘肃省境内11个典型小流域的水文站实测资料,在分析资料可靠性、一致性、代表性及暴雨洪水特性的基础上,综合利用水文学、数理统计学等理论和方法,建立了小流域最大暴雨量-暴雨历时关系模型、最大洪峰流量-流域特征关系模型。结果表明:各时段最大暴雨量较大值主要分布在泾河流域和嘉陵江流域东南部,较小值主要分布在渭河流域、洮河流域、嘉陵江流域的北峪河;绘制了各代表站最大暴雨量-暴雨历时关系曲线,嘉陵江流域以90min为转折点,其他流域均以180min为转折点,小于转折点时,暴雨量随暴雨历时增长而急剧增加,大于转折点后,变化趋于平缓稳定。重点选取危害较大、难以防范的330场次短历时暴雨洪水,建立各小流域暴雨洪水概化模型,短历时洪水发生时间很短,洪水起涨时间约2~5h,洪峰出现时间约5~7h。研究典型小流域水文要素变化规律,分析局地短历时暴雨洪水特性,并模拟其变化过程,对区域抗旱防汛减灾、水资源管理、小流域治理及生态环境保护具有重要意义。  相似文献   

8.
极端降水条件下北京西山黑龙关泉响应研究   总被引:3,自引:0,他引:3       下载免费PDF全文
2012年7月21日,北京房山区发生特大暴雨,暴雨从21日10时开始到22日2时结束。总降雨量达228mm,是北京60年一遇暴雨。暴雨后,黑龙关泉域岩溶水系统内的各种水资源要素都对其形成积极响应。依据岩溶地下水位统测、区域地质构造以及地貌条件综合分析黑龙关泉地下水系统补、径、排。研究黑龙关泉地下水系统对7.21洪水响应。从地下水位、地表河流、泉水水量、岩溶地下水化学分析7.21洪水前后变化情况。降水后,大石河流量最大达221m~3/s,水化学类型中带硫酸根离子的样品数显著增加。7月15日,实测黑龙关泉水流量为0.31m~3/s,7月21日上午实测为0.30m~3/s,25日分别对大石河的黑龙关泉口上、下游进行实测,获得泉水流量为3.47m~3/s,到29日降至2.34m~3/s,流量变化较为剧烈,与大石河水对岩溶水的补给密切相关。为进一步研究北京黑龙关泉域岩溶水的变化规律和岩溶水资源评价及合理开发利用提供了科学依据。  相似文献   

9.
Flash floods are one of the most significant natural hazards of today. Due to the complexity of flash flood triggering factors, to prevent or mitigate flood triggered losses, numeric model based flood forecasting models are capable tools to predict stream water levels. The main goal of the current research was to reproduce two flow peaks with the HEC-HMS rainfall-runoff model and test the model sensitivity for various input parameters. To obtain sufficient input data, we monitored soil depth, maximum infiltration rate, soil moisture content, rainfall, time of concentration and flow. To obtain input data, parameters were calculated, measured in the Sás Valley experimental watershed (SW Hungary) or optimized with the built in function of the HEC-HMS. Soil moisture was monitored in the 1.7 km2 pilot catchment over the period between September 2008 and September 2009. HEC-HMS had a good performance reproducing the two events, however simulated flow time series are highly influenced by the antecedent soil moisture, infiltration rate and canopy storage. Outflow modeled data were verified for two flood events (June 4, 2008 and July 9, 2009). The HEC-HMS was over-sensitive for input soil moisture and with increasing input rainfall and increasing outflow, larger simulation errors were observed.  相似文献   

10.
黄土高原暴雨空间分布的不均匀性及点面关系   总被引:14,自引:0,他引:14       下载免费PDF全文
根据黄土高原13个中小流域的448场暴雨的统计分析,对这一地区不同类型暴雨空间分布的不均匀性进行了系统研究,内容包括流域面雨量离差系数、降雨不均匀系数、最大点与最小点的比值系数、点面关系以及降雨量的空间相关特性等。  相似文献   

11.
Runoff peak and volume in flood studies are estimated relying on temporal rainfall distribution from various storm patterns. Usually, SCS distributions types (I, II, III, IA) are commonly used. Using these distributions in runoff calculations assume that the in situ temporal rainfall pattern typically behaves as the one described by the SCS-type distribution, which is due to cyclonic frontal storms and actually developed in temperate environment. To what extent such assumption is valid in the arid environment? How much the impacts of rainfall temporal patterns are reflected in runoff volumes and peaks? The aim objectives of the current study are to answer the above two questions and clarify the validity of aforementioned assumption and exemplify such effect. Real rainfall data collected from rain gauges of Makkah Al-Mukkramah region over a period of more than 20 years are utilized. Temporal rainfall patterns and their parameters are deduced. Many hydrological simulations are performed and comparisons, in terms of runoff volume and peak flows, are made to show the effects of the common rainfall storm patterns and the developed rainfall storm patterns in the region based on the current study. Results indicate that major bursts of the design rainfall storm pattern are located in the first time of the storm period in the two quartiles which is mainly due to convective rainfall type in thunderstorms unlike the commonly used by SCS types relying on frontal cyclonic storms. Makkah Al-Mukkramah temporal rainfall pattern does not behave as the “typical pattern” assumed by SCS distributions that are deduced from different environments. The impacts of the temporal pattern reflected as an overestimate in the runoff peak reached to 68 %. The developed hyetographs and tables presented in the current study are recommended to enhance economical and rational design practice in watersheds of Makkah Al-Mukkramah region.  相似文献   

12.
利用鲁东南地区18个代表站1961-2015年的逐日降水量、逐日天气现象、积雪深度资料,对近55 a来降雪的气候特征进行了统计分析。结果表明:鲁东南地区年均降雪日数、强降雪日数、降雪量、强降雪量及年均雪深、年最大积雪深度的空间分布总体上山区多于平原和沿海,区域差异明显。21世纪00年代以前为多雪时期,以后为少雪时期。近55 a的年均降雪日数、强降雪日数、降雪量、强降雪量及年均雪深、年最大积雪深度皆呈减少趋势,降雪由多转少的转折年份均在1993年,年均雪深、年最大积雪深度的减少分别出现在1987年、1986年。鲁东南地区降雪主要集中在1-2月份,3月份强降雪量最大,平均雪深、最大积雪深度的最大月份分别出现在11月份、3月份。降雪时段为10月23日-次年4月28日,降雪的初终日西北部山区皆为最早。降雪日数、强降雪日数、降雪量、强降雪量、雪深均存在3 a的周期,最大积雪深度存在4~5 a的周期。  相似文献   

13.
邹全  王国亚  贺斌  沈永平 《冰川冻土》2013,35(3):733-740
利用玛纳斯河流域肯斯瓦特站1957-2010年的气温、 降水和洪水径流等资料, 分析了该流域自1957年以来的气候变化以及夏季洪水径流过程对极端气候的响应. 结果表明: 玛纳斯河流域自1957年以来平均气温呈明显的上升趋势, 1979年是年均温由下降趋势转为上升的转折点, 并且1978年之后极端高温天气增多, 主要出现在7月份.玛纳斯河年降水量总的变化趋势是波动减少的, 1986年以后降水有所增加, 但只是恢复到多年平均降水量水平的上下波动.降水主要集中在4-8月, 约占年降水量的70%.气温高的月份与降水量多的月份并不完全对应, 如5月份气温较低, 但降水较大; 7月气温最高, 但6月降水量最大; 8月气温较高, 但降水量较少.玛纳斯河年径流主要集中在6-9月, 4个月的总径流量约占全年总径流量的80%, 7月份径流量最大, 约占全年总径流量的28.8%.历年最大洪峰流量呈显著增加趋势, 1993年是最大洪峰流量由下降变为增多的转折点, 而1994-2010年最大洪峰流量基本保持在高位上下波动.最大15日洪量占年径流量的比例较大, 说明洪水过程持续时间较长, 汛期水量较为集中.最大洪峰流量出现时间基本都在7月和8月上旬.玛纳斯河夏季月径流与夏季月气温和降水的关系并不密切, 低度相关, 说明玛纳斯河流域自1993年以来夏季洪水频繁发生, 尤其超标准洪水次数增多、 量级增大主要是由于夏季极端高温和极端降水天气增多引起的.  相似文献   

14.
目前,中国城区大多缺乏实测管道流量数据,给城市水文模型构建及精细化模拟带来了挑战。在北京亦庄经济开发核心区下垫面精细数字化的基础上,以典型点的最大径流深为验证要素,以实地踏勘为主、经验率定为辅,分别选取2012年"7·21"和2011年"6·23"两场典型大暴雨径流过程,完成了区域SWMM(Storm Water Management Model)模型的参数率定和验证;并就不同重现期设计暴雨下,不同典型用地子汇水区的产汇流响应特征及内涝交通拥堵风险进行了分析及评估。结果表明:随着重现期的增加,道路与交通设施用地对暴雨增幅的响应速率远高于公园绿地的响应速率,前者的内涝交通拥堵风险亦远高于后者;间接反映了不同下垫面条件造成产汇流响应的差异程度。相关成果可为区域城市洪涝管理与预警提供决策参考。  相似文献   

15.
由实测暴雨推求设计洪水方法的探讨   总被引:1,自引:0,他引:1  
曹世惠  柏绍光 《水文》2002,22(1):38-40
基于南方湿润地区洪水由暴雨形成的特点,可根据实测暴雨资料分析流域代表性产、汇流参数,将历年最大面暴雨系列转换为对应的洪水系列,并由该洪水系列作为样本来计算洪水统计参数。实例分析结果表明,与实测洪水计算结果相近,该方法不但克服了山区河流雨洪同频率的假定,而且还为研究暴雨形成洪水的产、汇流机制,创造了一定的条件。  相似文献   

16.
Rainfall intensity–duration (ID) thresholds are commonly used to predict the temporal occurrence of debris flows and shallow landslides. Typically, thresholds are subjectively defined as the upper limit of peak rainstorm intensities that do not produce debris flows and landslides, or as the lower limit of peak rainstorm intensities that initiate debris flows and landslides. In addition, peak rainstorm intensities are often used to define thresholds, as data regarding the precise timing of debris flows and associated rainfall intensities are usually not available, and rainfall characteristics are often estimated from distant gauging locations. Here, we attempt to improve the performance of existing threshold-based predictions of post-fire debris-flow occurrence by utilizing data on the precise timing of debris flows relative to rainfall intensity, and develop an objective method to define the threshold intensities. We objectively defined the thresholds by maximizing the number of correct predictions of debris flow occurrence while minimizing the rate of both Type I (false positive) and Type II (false negative) errors. We identified that (1) there were statistically significant differences between peak storm and triggering intensities, (2) the objectively defined threshold model presents a better balance between predictive success, false alarms and failed alarms than previous subjectively defined thresholds, (3) thresholds based on measurements of rainfall intensity over shorter duration (≤60 min) are better predictors of post-fire debris-flow initiation than longer duration thresholds, and (4) the objectively defined thresholds were exceeded prior to the recorded time of debris flow at frequencies similar to or better than subjective thresholds. Our findings highlight the need to better constrain the timing and processes of initiation of landslides and debris flows for future threshold studies. In addition, the methods used to define rainfall thresholds in this study represent a computationally simple means of deriving critical values for other studies of nonlinear phenomena characterized by thresholds.  相似文献   

17.
开展不同海绵设施在中国长三角气候模式下的水文效益研究, 对增强城市应对内涝能力从而提高城市对变化环境的适应性具有重要科学意义。选择国家首批海绵试点城市镇江海绵基地4种典型海绵设施作为研究案例, 采用径流系数、削减率、削峰率及洪峰流量等指标, 评估场次降雨与海绵设施出流相关性, 分析海绵设施在不同降水量级和降雨雨型下的水文性能, 以及运行时间对海绵设施水文效益的影响。结果表明: ①透水铺装类海绵设施的降雨—径流关系呈单一式; 而绿植类则表现为分段式, 即在场次降水量超过一定临界暴雨量之后关系线发生转折, 其中平均径流系数增加了8.4~38.5倍, 平均削峰率和削减率分别减少了50.4%和44.6%。②暴雨条件下不同海绵设施的产流能力和洪峰流量最大, 对径流总量消减能力及洪峰流量削减能力最弱, 且从暴雨到大雨变化规律比大雨到中雨变化规律更显著。③海绵设施的水文性能受到降雨雨型、平均降雨强度和最大单位降雨强度等因子多重复合影响。除雨水花园外, 其他海绵设施的径流系数对上述影响因子变化最为敏感, 洪峰流量次之, 削减率第3, 削峰率的敏感性显著低于前面三者。④车行透水砖运行1 a后, 其产流能力与洪峰流量分别显著增加1.7~2.1倍和1.9~2.5倍; 径流控制能力显著减弱, 其中消减能力降低了16%。  相似文献   

18.
 Temporal distributions of the isotopic composition in arid rain storms and in the associated runoff were investigated in a small arid rocky basin in Israel. Customized rain and runoff samplers provided sequential water samples hermetically sealed in high-density PVC bags. In several storms where the runoff was isotopically depleted, compared with the rainfall, the difference could not be explained by fractionation effects occurring during overland flow. A water-balance study relating the runoff discharge to rainfall over a rocky watershed showed that the entire discharge is produced by a very small segment (1–2 mm) of the rain storm. The major objective, therefore, was to provide quantitative relations between segments of rainfall (rain showers and rain spells) and runoff. The time distribution of the composition of stable isotopes (oxygen and hydrogen) was used to quantify the correlation between the rain spell's amount and the consequent runoff. The aim of this work was to (a) utilize the dynamic variations in the isotopic composition in rainfall and runoff and model the magnitude of surface-storage capacity associated with runoff processes of overland flow, and (b) characterize the isotopic composition of the percolating water with respect to the isotopic distribution in rainfall and runoff events. The conceptual model postulates an isotopic mixing of overland flow with water within the depression storage. A transport model was then formulated in order to estimate the physical watershed parameters that control the development of overland flow from a certain rainfall period. Part I (this paper) presents the results and the assessment of the relative depression storage obtained from oxygen-18 and deuterium analyses that lead to the physical and mathematical formulation of a double-component model of kinematic-wave flow and transport, which is presented in Part II (accompanying paper). Received, February 1997 · Revised, September 1997 · Accepted, September 1997  相似文献   

19.
七大流域水文特性分析   总被引:2,自引:0,他引:2  
刘伟  翟媛  杨丽英 《水文》2018,38(5):79-84
我国东西和南北方向地理跨度大,水文特性差异明显。从气候特征、降雨和径流、暴雨和洪水等方面,分析七大流域的水文特性,总结降雨和径流在上下游、干支流等空间上以及年内和年际等时间上的分布规律,并分析暴雨和洪水在成因、发生时间、空间分布、过程等方面的规律,为径流和洪水成果计算提供了基础,也为水文成果的合理性检验提供了参考。  相似文献   

20.
考虑地表径流与地下渗流耦合的斜坡降雨入渗研究   总被引:10,自引:0,他引:10  
汤有光  郭轶锋  吴宏伟  张华 《岩土力学》2004,25(9):1347-1352
为简化分析,在模拟斜坡降雨入渗暂态渗流时,通常没有考虑入渗和产流的耦合过程。笔者提出了一种新的考虑地表径流与地下渗流耦合的斜坡降雨入渗分析方法,它较好地模拟了入渗和产流的过程,并通过算例,研究了考虑与不考虑该耦合作用对斜坡孔隙水压力分布的影响。  相似文献   

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