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反映流域整体降水情势的面雨量一直是水文模型的重要输入参数之一,在泰森多边形雨量法的基础上考虑地理空间要素对降雨空间分布的影响,采用面向对象的遥感信息聚类方法提取出雅砻江流域2项形状因子(周长、面积)和5项地形因子(平均高程、平均坡度、平均坡向、高程差周长比和高程差面积比)。降雨—径流相关性分析结果表明:地形因子雨量法在月尺度上的降雨估算精度高于年尺度,且在月尺度上能更好地反映流域不同区段的降雨空间分布特征;在月、年际降雨变化趋势分析方面,年尺度上的降雨与径流一阶差分后平均相关系数为0. 903,高于月尺度的0. 629,主要由于水电站调蓄过程对流域径流异质性的影响,且影响度随着时间尺度缩小而放大。 相似文献
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为研究中国不同区域的降雨特征对径流总量控制效果的影响,利用186个气象站近30年的日降雨量资料,通过空间分析与统计计算,得到不同年径流总量控制率所对应的设计降雨量以及年均控制降雨量;结合年径流总量控制率与年均控制降雨量的关系将中国区域分为9种类型。结果表明:中国设计降雨量地域变化明显,广东、四川、广西、河北和河南等省的标准差为全国平均水平的1.5~3倍,且随年径流总量控制率的提升而增加,源头径流控制效果差异明显;南部地区径流控制效果多为"高量低率";"低量低率"区位于甘肃、宁夏等地,面积占比为9.44%,其降雨特征不适合发挥源头控制设施的效果;而最适宜发挥源头控制作用的"高量高率"区位于西南部分地区,面积占比为3.80%。 相似文献
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利用呼和浩特市1961-2010年6个国家气象观测站逐小时降水量资料,应用数理统计、滑动平均和M-K突变检验分析了呼和浩特市短时强降水时空分布特。结果表明：呼和浩特市短时强降水频次的空间分布不均匀,主要分布在呼和浩特市南部及山脉迎风坡;呼和浩特市短时强降水具有明显的季节变化和日变化特征,短时强降水频次最高在7月下旬和8月上旬,最容易发生在午后至傍晚,年代和年变化显示20世纪90年代为正距平,1993年之后,呼和浩特市短时强降水次数呈上升趋势,1997年通过显著性检验水平临界线,即呈明显上升趋势,1998年达到峰值。 相似文献
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Analysis of a Long Record of Annual Maximum Rainfall in Athens,Greece, and Design Rainfall Inferences 总被引：2，自引：0，他引：2
An annual series of maximum dailyrainfall extending through 1860–1995, i.e., 136 years,was extracted from the archives of a meteorologicalstation in Athens. This is the longest rainfall recordavailable in Greece and its analysis is required forthe prediction of intense rainfall in Athens, wherecurrently major flood protection works are under way.Moreover, the statistical analysis of this long recordcan be useful for investigating more generalisedissues regarding the adequacy of extreme valuedistributions for extreme rainfall analysis and theeffect of sample size on design rainfall inferences.Statistical exploration and tests based on this longrecord indicate no statistically significant climaticchanges in extreme rainfall during the last 136 years.Furthermore, statistical analysis shows that theconventionally employed Extreme Value Type I (EV1 orGumbel) distribution is inappropriate for the examinedrecord (especially in its upper tail), whereas thisdistribution would seem as an appropriate model iffewer years of measurements were available (i.e., partof this sample were used). On the contrary, theGeneral Extreme Value (GEV) distribution appears to besuitable for the examined series and its predictionsfor large return periods agree with the probablemaximum precipitation estimated by the statistical(Hershfield's) method, when the latter is consideredfrom a probabilistic point of view. Thus, the resultsof the analysis of this record agree with a recently(and internationally) expressed scepticism about theEV1 distribution which tends to underestimate thelargest extreme rainfall amounts. It is demonstratedthat the underestimation is quite substantial (e.g.,1 : 2) for large return periods and this fact must beconsidered as a warning against the widespread use ofthe EV1 distribution for rainfall extremes. 相似文献
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降雨与滑坡灾害相关性分析及预警预报阀值之探讨 总被引：34，自引：3，他引：31
详细研究了深圳市降雨与滑坡的历史资料,对区域性滑坡与降雨量进行偏相关分析,与降雨强度进行相关分析以及与降雨时间进行了系统地统计分析。研究结果表明,（1）滑坡的活动1～4日的降雨量及一次降雨过程的降雨量偏相关系数较大,表明一次性降雨量达到或超过某一数值时区域性滑坡就可以出现;（2）暴雨尤其是大暴雨及特大暴雨与滑坡的关系非常密切,相关系数达0.8以上,大暴雨或特大暴雨具有直接触发滑坡的作用;（3）滑坡活动时间与季节性降雨相对应,季节雨量越多,滑坡亦越多;另外滑坡活动时间与暴雨、大暴雨相吻合或略滞后,滞后时间一般不超过4 d,暴雨的当天及次日发生滑坡的可能性最大。在此基础上,探讨了区域性滑坡发生的临界降雨量和降雨强度阀值。最后将滑坡灾害的地质模型与降雨模型耦合建立了滑坡灾害的空间预警预报区划指标和等级系统,为区域滑坡灾害发生的时间与空间预报预警提供了科学依据。 相似文献
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地质灾害与不同尺度降雨时空分布关系 总被引：2，自引：0，他引：2
降雨是地质灾害最重要的诱发因素之一,开展地质灾害与不同尺度降雨的时空分布研究,分析降雨诱发地质灾害的特点规律,对于提升地质灾害区域预警水平和防灾减灾实践具有重要意义。本文以2006～2007年汛期地质灾害的实际发生情况为例,通过统计分析方法,对区域地质灾害与年降雨量、月降雨量、月暴雨日数、典型降雨过程之间的时空分布关系开展系统分析,研究表明:降雨是群发型地质灾害发生的重要诱发因素,地质灾害的发育密度与年均雨量成正比,地质灾害发育密度最大的区域,其年均雨量最大;地质灾害分布与月降雨量、月暴雨日数的分布总体上具备一定的对应关系,但并不是完全对应的,主要受到典型强降雨过程的落区控制;在地质灾害多发区出现典型强降雨过程时,地质灾害群发。 相似文献
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Identification of homogeneous rainfall regimes in parts of Western Ghats region of Karnataka 总被引：1，自引：0，他引：1
In view of the ongoing environmental and ecological changes in the Western Ghats, it is important to understand the environmental
parameters pertaining to the sustenance of the region. Rainfall is one such parameter governing the hydrological processes
crucial to agriculture planning, afforestation and eco-system management. Therefore, it is essential to understand rainfall
distribution and its variation in relevance to such activities. The present study is an attempt to gain in-depth understanding
in this direction. The study area comprises of one coastal district and its adjoining areas in Karnataka State. Mean annual
rainfall data of 93 rain gauge stations distributed over the study area for a period of 10–50 years are used for the study.
In order to assess the variation of rainfall across the ghats, several bands were constructed parallel to the latitudes to
facilitate the analysis. The statistical analyses conducted included cluster analysis and analysis of variance. The study
revealed that there exist three distinct zones of rainfall regimes in the study area, namely, Coastal zone, Transition zone
and Malanad zone. It is observed that, the maximum rainfall occurs on the windward side ahead of the geographical peak. Further,
mean monthly rainfall distribution over the zones has been depicted to enable agricultural planning in the study area. 相似文献
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《Atmósfera》2014,27(4):411-427
Daily extreme precipitation values are among environmental events with the most disastrous consequences for human society. Information on the magnitudes and frequencies of extreme precipitations is essential for sustainable water resources management, planning for weather-related emergencies, and design of hydraulic structures. In the present study, regional frequency analysis of maximum daily rainfalls was investigated for Golestan province located in the northeastern Iran. This study aimed to find appropriate regional frequency distributions for maximum daily rainfalls and predict the return values of extreme rainfall events (design rainfall depths) for the future. L-moment regionalization procedures coupled with an index rainfall method were applied to maximum rainfall records of 47 stations across the study area. Due to complex geographic and hydro-climatological characteristics of the region, an important research issue focused on breaking down the large area into homogeneous and coherent sub-regions. The study area was divided into five homogeneous regions, based on the cluster analysis of site characteristics and tests for the regional homogeneity. The goodness-of-fit results indicated that the best fitting distribution is different for individual homogeneous regions. The difference may be a result of the distinctive climatic and geographic conditions. The estimated regional quantiles and their accuracy measures produced by Monte Carlo simulations demonstrate that the estimation uncertainty as measured by the RMSE values and 90% error bounds is relatively low when return periods are less than 100 years. But, for higher return periods, rainfall estimates should be treated with caution. More station years, either from longer records or more stations in the regions, would be required for rainfall estimates above T=100 years. It was found from the analyses that, the index rainfall (at-site average maximum rainfall) can be estimated reasonably well as a function of mean annual precipitation in Golestan province. Index rainfalls combined with the regional growth curves, can be used to estimate design rainfalls at ungauged sites. Overall, it was found that cluster analysis together with the L-moments based regional frequency analysis technique could be applied successfully in deriving design rainfall estimates for northeastern Iran. The approach utilized in this study and the findings are of great scientific and practical merit, particularly for the purpose of planning for weather-related emergencies and design of hydraulic engineering structures. 相似文献
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广东省1960～2007年降雨侵蚀力变化趋势分析 总被引：3，自引：0，他引：3
降雨侵蚀力反映由降雨引起的土壤侵蚀的潜在能力.本文利用广东省25个站点48年(1960～2007)的日雨量资料计算了各站的降雨侵蚀力,并用Mann-Kendall(M-K)非参数检验和克里格空间插值法分析了降雨侵蚀力的时空变化规律.结果表明:广东省降雨侵蚀力的空间分布呈沿海向内陆逐渐递减的趋势.全省大部分地区的年降雨侵蚀力呈现不明显上升趋势,且存在较明显的年代际和年际变化.降雨侵蚀力的年内分布特征和降雨量分布类似,呈"双峰型",主要集中在4～9月的雨季.对于季节序列,冬季、春季和夏季大部分地区的降雨侵蚀力有不同程度的上升,秋季全省几乎所有地区呈下降趋势.汛期的降雨侵蚀力变化特征与年降雨侵蚀力相似. 相似文献
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研究了柑桔林下穿透雨的分布特征,结果表明:在测定期间,穿透雨量占总降雨量的68.3%,5月的穿透雨量最大(245.1 mm),而穿透雨率最大值(73.3%)出现在8月。穿透雨量与降雨量具有显著相关性(p<0.01),而穿透雨率与降雨量和降雨强度的相关性均达到显著水平(p<0.05)。柑桔林下穿透雨显示出明显的空间变化,各观测点间穿透雨率具有显著性的差异,而且穿透雨的空间异质性(穿透雨率的变异系数CV)随着降雨量或降雨强度的增加而降低,聚类分析也显示出穿透雨在不同观测点间具有差异性。柑桔林下穿透雨呈现明显的聚集效应。 相似文献
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Ali M. Subyani 《Arabian Journal of Geosciences》2011,4(5-6):817-824
In arid regions, flash floods often occur as a consequence of excessive rainfall. Occasionally causing major loss of property and life, floods are large events of relatively short duration. Makkah area in western Saudi Arabia is characterized by high rainfall intensity that leads to flash floods. This study quantifies the hydrological characteristics and flood probability of some major wadis in western Saudi Arabia, including Na’man, Fatimah, and Usfan. Flood responses in these wadis vary due to the nature and rainfall distribution within these wadis. Rainfall frequency analysis was performed using selected annual maximums of 24-h rainfall from eight stations located in the area. Two of the most applied methods of statistical distribution, Gumbel’s extreme value distribution and log Pearson type III distribution, were applied to maximum daily rainfall data over 26 to 40 years. The Gumbel’s model was found to be the best fitting model for identifying and predicting future rainfall occurrence. Rainfall estimations from different return periods were identified. Probable maximum floods of the major wadis studied were also estimated for different return periods, which were extrapolated from the probable maximum precipitation. 相似文献
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以长江上游金沙江流域典型高山峡谷地区为研究对象,用该区域地面观测降雨量数据对TRMM PR 3B42 V6产品进行了3 h、日、月3个时间尺度的有效性评估,旨在为开展区域卫星与地面降水数据融合的流域水文模拟及预报奠定数据基础。分别采用了线性回归方法分析降雨量相关性、经验正交函数-奇异值分解方法(EOF-SVD)分析降雨量主要模态空间分布特征、相对偏差Bias、错报率RFA和探测率PD指标对该卫星产品进行了精度评定。研究结果表明:研究区该卫星产品与地面观测数据在3个时间尺度存在显著的线性时间和空间相关性,但相关程度随时间尺度的减小而减弱;二者在空间分布上总体具有一致性特征,但在高海拔、大坡度区域表现出较为显著的差异;相对偏差指标显示2008-2010年降雨量均值相对偏差在±10%的概率密度百分数为36.08%;随高程的增加,卫星数据RFA呈逐渐增加趋势变化,PD呈逐渐减小趋势变化;总体上小雨对误差的贡献最大,大雨峰值误差贡献次之,时段降雨量偏差随时间尺度的增加逐渐减小,而随高程的增加卫星数据的探测精度下降。因此,对于类似的高山峡谷流域,要应用该卫星产品进行日、3 h尺度水文模拟及预报,有必要对流域卫星数据和地面观测数据进行融合,充分发挥两种数据的优势。 相似文献
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Homa Razmkhah Ali Mohammad AkhoundAli Fereydoun Radmanesh Bahram Saghafian 《Arabian Journal of Geosciences》2016,9(4):323
Lack of accuracy of rainfall-runoff simulation (RRS) remains critical for some applications. Among various sources of uncertainty, precipitation plays a particular role. Rainfall rates as the main input data of RRS are of the first factors controlling the accuracy. In addition to the depth, spatial and temporal distributions of rainfall impact the flood discharge. Most of the previous studies on RRS uncertainty have ignored rainfall spatial distribution, where in large catchments, it is necessary to be modeled explicitly. Karoon III is one most important basin of the Iran because of the Karoon III dam in the outlet. In the present work, effect of spatial correlation of rainfall on HEC-HMS (SMA) continuous RRS uncertainty is evaluated using 2variate copula (2copula). Monte Carlo simulation (MCS) approach was used to consider the rainfall spatial dependence. To reduce the computational expense, sampling efficiency and convergence for MCS, Latin hypercube sampling (LHS) was used. Copula functions consider wide range of marginal probability distribution functions (PDFs), eliminating limits of regular join PDFs. For this aim, two scenarios were investigated. In the first scenario, sub-basin rainfall was considered independent, and in the second scenario, 2copula was adopted to model spatial correlation of rainfall. Dimensionless rainfall depths were calculated for each sub-basin, and the PDFs were determined. The generated random dimensionless rainfalls were reweighted and multiplied by watershed’s mean rainfall value. Stochastic Climate Library was used to generate continuous daily rainfalls. Sampling from dimensionless rainfalls using LHS algorithm, 100 runs of calibrated model-simulated 100 flows for each day following MCS, and 80 % certainty bound was calculated. Results showed that considering dependence decreased 18 % of the maximum uncertainty bound width, so the methodology could be recommended for decreasing predicted runoff error. 相似文献
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Harianto Rahardjo Mărgărit-Mircea Nistor Nurly Gofar Alfrendo Satyanaga Qin Xiaosheng Sabrina Ip Chui Yee 《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2020,14(3):177-191
ABSTRACT This paper presents the spatial distribution, variation and trend of 5-day antecedent rainfall in Singapore based on rainfall data from 22 meteorological stations. The effect of climate was analyzed by dividing the study period into three decades i.e. Decade 1: 1982–1991, Decade 2: 1992–2001 and Decade 3: 2002–2011. Kriging interpolation was used for rainfall mapping. The results show that spatial distribution of 5-day antecedent rainfall does not coincide with that of the annual rainfall. The maximum annual rainfall occurred in the northwestern side of Singapore. On the other hand, the maximum 5-day antecedent rainfall occurred in the north and northeastern sides. The results of this study suggest that the climate change has increased the amount of 5-day antecedent rainfall quite significantly, i.e. from 420.5 (1987) to 592.9 mm (2006), thus affecting the vulnerability of the area with respect to rainfall-induced slope failure. The analyses also showed that most of slope failures were located in the north and northeast of Singapore between December and earlier March. More slope failures were observed in Decade 3 as compared to Decades 1 and 2. In other words, the analysis confirmed that 5-day antecedent rainfall had affected the slope stability in Singapore. 相似文献
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在经验性降雨阈值和边坡稳定性数值分析两大类研究的基础上,考虑了降雨入渗和非饱和土性质,使用岩土有限元软件Plaxis高级模式对滑坡预警降雨阈值进行研究分析。算例表明,将降雨量在降雨时间范围内分成2段后,得到的边坡稳定性变化与实际情况更接近,重新定义前期降雨为在给定初始条件下引起边坡最危险滑裂面到坡面之间土体吸力分布发生变化的降雨。前期降雨时长与潜在滑裂面最大深度成正比,与饱和渗透系数成反比。将前期降雨量引入到降雨强度—持时曲线中作为第三个空间坐标轴,将该曲线拓展为前期降雨量-降雨强度-持时曲面。通过一基岩型边坡算例展示了阈值曲面的建立方法,并通过与模型试验数据的对比验证了其可靠性。 相似文献