1957-2017年泾河流域降雨量及降雨侵蚀力时空变化分析

泾河流域受土壤侵蚀的影响,水土流失较为严重,为对流域水土流失风险评估和防治等提供参考依据,根据1957-2017年泾河流域5个气象站点的日降水资料,运用ArcGIS空间插值、小波分析、R/S分析等方法,分析了该时段降雨量及降雨侵蚀力时空变化规律。结果表明:泾河流域及各气象站点的降雨量与降雨侵蚀力均呈显著正相关关系;泾河流域降雨量与降雨侵蚀力年内分布不均,主要集中在夏季,分别占全年的67.80%和52.86%;泾河流域年均降雨量和降雨侵蚀力分别为496.83 mm和1 481.24 (MJ·mm)/(hm~2·h),年际总体呈波动上升趋势且未来降雨侵蚀力将延续增加趋势,两者均在1996和2009年出现突变点且第一主周期分别为27和17 a;泾河流域降雨量和降雨侵蚀力在空间上均呈从西北到东南递增的趋势。     

巴江流域R值时空分布特征

以巴江流域5个气象站的降雨资料为基础,运用DPS软件结合日、月降雨侵蚀模型分析了巴江流域降雨侵蚀力及其时空分布变化规律。结果表明：巴江流域降雨侵蚀力年际变化明显。最大年降雨侵蚀力是最小年降雨侵蚀力的3．6倍;降雨侵蚀力的年内变化与降雨量的年内变化情况基本一致,主要集中在5—10月,占全年降雨侵蚀力的91．53％;空间上呈北低南高分布,变化幅度西大东小。     

泰森多边形法在小流域面雨量计算中的应用

为探究泰森多边形法在小流域面雨量计算中的适用性,以地处江淮丘陵区适宜进行产汇流机制等水文基础理论研究的典型闭合小流域花山流域为例,结合流域现状站点分布和地形特点,选取流域多年面雨量、典型场次与典型日面雨量三种不同降雨量级实例,分别采用算术平均法、泰森多边形法和等值线法计算面雨量进行对比。年面雨量和场次面雨量计算中泰森多边法对比等值线法计算值相对误差小于 1.00%,日面雨量计算值相对误差小于 2.00%;算术平均法在典型场次面雨量样本中有 40.0%的计算值相对误差大于 1.00%,最大相对误差为 -2.47%,在典型日面雨量样本中有36.8%的计算值相对误差大于 2.00%,最大相对误差为 9.38%。结果表明：不同降雨量级使用泰森多边形法计算面雨量比算术平均法更接近于等值线法计算值;算术平均法在降雨量较小时受局部降雨影响计算误差较大,在年面雨量计算时可以和泰森多边形法互换使用。     

Spatial Pattern Characterization and Multivariate Hydrological Frequency Analysis of Extreme Precipitation in the Pearl River Basin, China

Consecutive extreme rainfall events, especially those having unfavourable spatio-temporal patterns, always trigger large floods. This paper aims to examine, through the multivariate hydrological frequency analysis, the probability of the synchronous occurrence of rainfall extremes in the Pearl River basin. The copula method together with the stationarity and independence tests, which are crucial to the valid use of statistical methods in regional frequency analyses, were applied in the study. The obtained results indicate that: (1) major precipitation events of the annual maximum 1-, 3-, 5- and 7-day rainfall recorded at 42 stations are the flat looking series and variables are independent, (2) the marginal distribution of all extreme rainfall variables in four homogeneous hydrologic regions fits the log-normal probability distribution and most of their joint distribution fits the Gumbel-Hougaard distribution, (3) on that basis the contour maps of the joint distribution of annual maximum 1-, 3-, 5- and 7-day rainfall between different regions are drawn and the probability of the synchronous occurrence of the extreme rainfalls in different regions are estimated. These findings have great practical value for the regional water resources and flood risk management and are important in exploration of the spatial patterns of rainfall extremes in the Pearl River basin in order to reveal the underlying linkages between precipitation and floods from a broader geographical perspective.     

基于地理因子的福建省年降水空间估算模型研究

为研究福建省多年平均降水量的空间分布格局,为工农业生产、自然灾害预测、生态环境建设提供科学依据,利用福建省及周边区域35个气象站点1951—2011年降水资料,分析年均降水量与海拔、纬度、距海岸距离、坡向的相关性;同时,结合多元回归方程和克里金插值构建降水空间估算模型,反映出年均降水量空间分布的总体趋势,突出局部地区降水的差异,估算福建省1951—2011年年均降水量空间分布。结果表明:已知气象站点年均降水量估算的平均相对误差为3.4%,绝对误差为56 mm,验证站点的平均相对误差为3.6%;福建省年均降水量从东南沿海向西北山区呈现波动式上升的特点。     

Impact of Spatial Data Availability on Climate Change Prediction in the Weyib River Basin in Ethiopia

Impact of spatial data availability on the temperature and precipitation prediction characteristics of Weyib River basin in Ethiopia has been investigated using CMIP5-CanESM2 model for the RCP8.5, RCP4.5 and RCP2.6 scenarios. The objective of the present study is to characterize how future temperatures and precipitation prediction under CMIP5-CanESM2 model output varies against diverse averaged arbitrary spatial weather stations found in the basin. The statistical downscaling model tested and verified using the observed daily data for twelve, six and three averaged arbitrary spatial weather stations as well as for a single weather station was used to predict the future climate scenarios. The results revealed that the mean annual daily maximum and minimum temperature and precipitation for twelve, six and three arbitrary spatial stations have revealed an increasing trend in the upcoming periods until the end of the century. In single station analysis, the trend itself has changed from increasing trend to decreasing trend in case of maximum and minimum temperature. In case of precipitation, no visible trend has been observed in case of single station analysis. Therefore, the variation in amount and distribution of precipitation and temperature among the four averaged spatial stations in the same study area might affect the water resources and agriculture of the basin and also instead of using a single weather station to predict future climate variables for a particular study basin, it is more reliable using averages of numerous spatial weather stations data.     

金沙江流域降水特征分析

为了分析金沙江流域的降水特征,采用金沙江流域17个代表站的逐日降水量资料,对其多年降水量的时间分布、空间分布、多年时段特征和多年1,3,5,7 d连续最大降水量等进行了初步分析.结果表明:金沙江流域降水量年际变化不大,但年内分配极不均匀,雨季降水量大而集中,约占全年总量的90%;旱季降水量少而不稳定,约占全年总量的10...     

广东北江流域降水集中度和集中期的时空变化特征

基于广东北江流域分布较均匀的18雨量站1965年-2009年日降水资料,统计出各站各年份降水集中度(PCD)和集中期(PCP)指标,然后基于该指标分析流域降水集中度和集中期多年均值、变化趋势、与年降水量相关性、丰水年枯水年合成分析的空间分布情况,以期研究流域降水年内非均匀分布的时空变化特征。结果表明:(1)降水集中度总体表现为从南向北递减;降水集中期主要表现为中北部的大部分区域较为提前,南部区域较为滞后。(2)大部分区域表现为年降水量随着降水集中度的下降而增加;南部区域年降水量随着降水集中期的滞后而减少,北部区域反之。(3)MK趋势检验表明,流域降水集中度、集中期均主要表现为上升,但不显著。(4)降水集中度空间分布上,丰水年与枯水年比较一致,但枯水年降水集中度更高;丰水年降水集中期差别较大,从流域平均来看,丰水年集中期较枯水年约滞后20天。     

河南省主要河川径流变化归因

为相对全面客观地分析气候变化和人类活动对河南省主要河川径流变化的影响,基于河南省内卫河、伊洛河、洪汝河和唐河流域1961—2022年径流和降水资料,以及国家气候中心根据Penman-Monteith公式计算的年潜在蒸散发资料,比较4个蒸发对比站年潜在蒸散发和蒸发皿年蒸发值,运用Mann-Kendall突变检验法和累积双曲线法分析4个研究流域控制水文站年径流序列的变化趋势和突变年份,以及4个流域年降水和潜在蒸散发的变化趋势。采用基于Budyko假设的弹性系数法对径流变化开展归因分析。结果表明：4个蒸发对比站年潜在蒸散发与蒸发皿年蒸发变化趋势基本一致,4个水文站年径流深及4个流域年降水和年潜在蒸散发均呈下降趋势。4个水文站年径流深分别在1977年、1985年、2008年和2010年发生了突变。气候变化对径流减少的贡献率在卫河和伊洛河流域为7%以下,在洪汝河和唐河流域约为12%～18%,降水减少不显著和潜在蒸散发呈下降趋势是贡献率小的原因,可见人类活动是影响4个流域径流变化的主要驱动因素。     

降雨空间尺度对径流模拟的影响研究

通过分析不同分辨率的雷达降雨数据所产生的降雨空间分布的变化对径流模拟的影响发现:本文所用的基于DEM的蓄满产流分布式水文模型对降雨时间和空间的变化是比较敏感的;由于降雨空间分辨率的变化计算的径流总量、洪峰都有不同程度的变化,但是这种变化的大小又与降雨场的特征、流域面积的大小以及土壤含水量的变化有很大的关系:随着面平均降雨量(P BAS)的增减,洪量也随着增减,P BAS与洪量有很好的相关性;降雨CV值的增加导致洪峰和洪量都相应的增加;流域的面积越小洪峰和洪量对降雨空间变化就越敏感;在前期干旱的条件下降雨空间变化导致的洪峰和洪量的变化要比在湿润的条件下产生的洪峰和洪量的变化大。     

TRMM卫星降雨数据在湖南省的精度和可靠性评定

卫星降雨数据的高时空分辨率使其在洪涝灾害监测、流域水文模型模拟等方面得以广泛应用,而对卫星降雨数据的精度评定和可靠性分析仍然是当前重要的研究课题。采用中低纬度旱涝灾害频发的湖南省23个国家基准气象站的降雨数据作为地面验证数据,对最新一代TRMM卫星降雨产品(3B42V7)的精度和误差特征进行了全面评估。从日、月、年和季节的不同时间尺度以及空间分布和高程等不同的空间要素方面对比分析了1999-2012年该卫星降雨产品在湖南地区的适应情况。研究表明:TRMM卫星反演降雨数据在日尺度上与地面气象站数据的匹配情况较差,相关系数仅为0.31;而在月尺度上有显著提高,相关系数为0.88。在干旱季节(11、12、1、2月)的表现要优于湿润季节(5、6、7、8月)。3B42卫星反演降雨数据存在比较明显的空间变异性,空间要素如高程、位置分布等对卫星降雨数据可靠性的影响强于降雨量的影响。     

金沙江流域降水量变化特征分析

为了分析金沙江流域降水量变化特征,根据该流域28个雨量站1971~2011年月降水量资料,应用基于ArcGIS平台的泰森多边形法,计算了流域年和四季的平均降水量;使用基于ArcGIS平台的反距离权重空间插值法,分析了降水量及其变化趋势的空间变化情况;运用线性回归分析、滑动平均法、Kendall秩次相关法以及降水集度法,分析了年和四季降水量的变化趋势以及年内分配情况;通过Mann-Kendall检验法分析了降水量的突变性;采用小波分析法对年和四季降水量进行了周期分析。结果显示:金沙江流域降水量空间分布不均;年、春季、夏季和冬季降水量呈增加趋势,秋季降水量呈减少趋势,降水量年内分配呈季节性变化;春季、夏季和秋季降水量突变开始的时间分别为1999,1979年和2001年;年及四季降水量变化周期为5~22 a。     

Evaluation of latest TMPA and CMORPH satellite precipitation products for Yellow River Basin

The main objective of this study was to evaluate four latest global high-resolution satellite precipitation products (TMPA 3B42RT, CMORPH, TMPA 3B42V7, and CMORPH_adj) against gauge observations of the Yellow River Basin from March 2000 to December 2012. The assessment was conducted with several commonly used statistical indices at daily and monthly scales. Results indicate that 3B42V7 and CMORPH_adj perform better than the near real-time products (3B42RT and CMORPH), particularly the 3B42V7 product. The adjustment by gauge data significantly reduces the systematic biases in the research products. Regarding the near real-time datasets, 3B42RT overestimates rainfall over the whole basin, while CMORPH presents a mixed pattern with negative and positive values of relative bias in low- and high-latitude regions, respectively, and CMORPH performs better than 3B42RT on the whole. According to the spatial distribution of statistical indices, these values are optimized in the southeast and decrease toward the northwest, and the trend is similar for the spatial distribution of the mean annual precipitation during the period from 2000 to 2012. This study also reveals that all the four products can effectively detect rainfall events. This study provides useful information about four mainstream satellite products in the Yellow River Basin, and the findings can facilitate the use of global precipitation measurement (GPM) data in the future.     

Evaluation of latest TMPA and CMORPH satellite precipitation products over Yellow River Basin

The main objective of this study was to evaluate four latest global high-resolution satellite precipitation products(TMPA 3B42 RT, CMORPH,TMPA 3B42V7, and CMORPH_adj) against gauge observations of the Yellow River Basin from March 2000 to December 2012. The assessment was conducted with several commonly used statistical indices at daily and monthly scales. Results indicate that 3B42V7 and CMORPH_adj perform better than the near real-time products(3B42RT and CMORPH), particularly the 3B42V7 product. The adjustment by gauge data significantly reduces the systematic biases in the research products. Regarding the near real-time datasets, 3B42 RT overestimates rainfall over the whole basin, while CMORPH presents a mixed pattern with negative and positive values of relative bias in low- and high-latitude regions,respectively, and CMORPH performs better than 3B42 RT on the whole. According to the spatial distribution of statistical indices, these values are optimized in the southeast and decrease toward the northwest, and the trend is similar for the spatial distribution of the mean annual precipitation during the period from 2000 to 2012. This study also reveals that all the four products can effectively detect rainfall events. This study provides useful information about four mainstream satellite products in the Yellow River Basin, and the findings can facilitate the use of global precipitation measurement(GPM) data in the future.     

基于TRMM卫星产品的长江流域降水精度评估

卫星降水产品在降水空间格局分析中扮演着重要角色。为分析卫星降水产品在长江流域的应用精度,利用2003~2010年长江流域175个雨量站实测降水资料检验了同期TRMM(Tropical Rainfall Measurement Mission)降水产品3B42 RTV7及V7的精度。结果显示:(1)长江流域年平均降水总量从东南向西北呈现明显的梯度变化,年降水量从2 000 mm/a减少到400 mm/a,降水空间差异极大,时间分布也不均。(2)RTV7和V7降水产品能够捕捉到长江流域降水空间分布格局,尤其是V7在长江流域有较高的精度,对59.85%流域面积的估算偏差在-10%~10%之间;实时产品RTV7在长江上游存在明显的高估现象,偏差大于50%的流域面积高达33.51%。(3)长江中下游RTV7和V7日降水数据与对应的实测数据相关系数都大于长江上游地区,偏差更小。(4)RTV7和V7降水产品在丰水期的估算精度整体优于枯水期。     

平原区小流域降水量变化特征分析

利用平原区朱家河流域降水量实际观测资料,对流域内降水变化特征进行分析。阐明朱家河流域降水空间分布较均匀,降水量自东向西略有减小;降水量年际变化差异较大,最大年降水量接近最小年降水量的3倍;降水有明显的3～5a小周期变化;降水量丰、枯年份出现次数相当且次数多,占序列的81.8%;降水量年内分布极不均匀,主要集中在汛期6～9月;流域多年总体降水量并无增减,汛期降水量有减小趋势,非汛期降水量呈增长之势,年内降水差异逐步在缩小。     

长江上游面雨量低频特征分析

目前,对长江上游降雨的研究多以过程和影响分析为主,对其低频特征研究较少。基于1961～2017年长江上游276站逐日降水资料,利用泰森多边形法得到长江上游7大流域逐日面雨量,分析了长江上游面雨量低频特征。结果表明:①长江上游面雨量存在着显著的低频振荡,但各流域周期不同,金沙江石鼓以上和金沙江石鼓以下2个流域具有10～40 d周期,而其他流域具有10～25 d周期。②长江上游夏季低频强降水事件在频次、持续天数、降水强度和最大面雨量特征量上排首位,秋季次之,春季最小,但各流域之间特征量存在着较大的差异。③低频强降水过程次数年际差异大,在15～25次之间,随持续时间、流域数量增加,过程次数呈减少趋势。     

Precipitation Trends and Variability in River Basins in Urban Expansion Areas

River basins are important territorial units for geographical analysis, and are crucial for environmental planning, especially in metropolitan settings. The aim of this article was to evaluate rainfall trends and variability in the Guapimirim-Macacu basin, located in an urban development area in the Rio de Janeiro Metropolitan Region. Annual, monthly and daily records were collected from twenty rain gauge stations, for the period of 1967 to 2015. Analyses conducted using the RClimDex software revealed an increase in rainfall volume and number of wet days. The remaining indicators and patterns observed across stations also suggested that changes in precipitation trends occurred mostly on the day scale, and were likely attributable to global climate change. After controlling for seasonality and normalizing the series, a linear tendency between the mean monthly precipitation in the Guapimirim-Macau basin and sea surface temperature (SST), obtained from the National Centers for Environmental Prediction, revealed that rainfall in the region is strongly correlated with Pacific and Atlantic SST, revealing the importance of the South Atlantic Convergence Zone for rainfall variability in the area of study, especially in summer. These data are important for development planning and the management of water resources and supply in the Rio de Janeiro Metropolitan Region.

     

考虑降雨空间异质性的动态临界雨量预警指标推求

降雨空间分布的不均匀性对中小河流洪水预警的临界雨量有较大影响,而降雨的空间分布难以准确量化,成为制约洪水预警精度的重要难题。结合泰森多边形和等流时面,提出一种既能反映降雨空间分布不均匀程度,又能反映降雨中心位置的降雨空间异质性指数SHIP,进一步基于支持向量机的分类原理,将SHIP用于中小河流洪水动态临界雨量预警指标的推求。以汉江旬河上游为例,分析了降雨空间异质性对临界雨量及预警精度的影响。结果表明,降雨中心越靠近下游,临界雨量越小,若不考虑降雨空间分布的差异性,则可能会出现漏报的风险。由于间接考虑了流域的调蓄作用,引入SHIP推求的临界雨量指标可以显著提高洪水预警的精度。     

周期波均值叠加法在年降水量预报中的应用

介绍了周期波均值叠加法的计算原理及方法,并根据韩江流域梅县雨量站、潮安雨量站1952-2006年雨量资料,利用周期波均值叠加法分析雨量变化规律,将得到的周期分别外延,然后进行线性叠加预报2007-2009年梅县雨量站、潮安雨量站的年降雨量,其中2007-2008年的预报成果满足精度要求。