承德市降雨量时间序列特征分析

以承德市9个气象观测站资料为基础,运用经典统计学、小波分析方法,研究了区域降雨量的倾向趋势、震荡周期与空间分布特征。结果表明,1951～2018年承德市年降雨量呈弱增加趋势,倾向斜率1.1105mm/a,各季节中除了秋季和冬季降雨量呈减少趋势外,春夏季节的降雨量表现出增加趋势,但均不显著。承德市年、季降雨量变化周期以3～5a的短周期为主,另外有13,20a等多个长周期;区域降水受季风与海洋暖湿气流路径影响,呈现自中南部向西和北部减少的地带性特征。     

Analysis of rainfall time series with regard to temporal disaggregation for the use in urban hydrology

The temporal resolution of rain data recorded by national weather services is often lower (10-min resolution) than the data needed for rainfall-runoff simulations (1–5 min resolution). However, the time series are sufficiently long for statistical analysis. The goal of the project presented here is to develop a procedure that disaggregates the 10-min rainfall data of the Swiss Meteorological Institute (SMI) to 1-min time resolution. The aim is to implement the procedure in a computer program which can be used by practitioners for generating high resolution rainfall time series at a specific location. In a first step the 1-min data and the 10-min data of two rainfall time series in Switzerland (Heiden, Lucerne) were compared to find characteristic patterns and correlations. The position of 1-min peak within the 10-min interval, the ratio of 1-min peak to 10-min intensity as well as the distribution of the 1-min values within the 10-min interval were investigated. The analysis showed that the positions of the 1-min peaks within a 10-min interval were not uniformly distributed. The distribution depended on the temporal trend of the 10-min values. The ratio of 1-min peak to 10-min intensity seemed to tend towards a constant ratio for high intensities. The results for the two series (Heiden and Lucerne) were not significantly different. These first findings are encouraging with regard to developing a disaggregation to 1-min values which satisfy the accuracy needed in urban hydrology.     

On the spatial validity of heavy point rainfall measurements

Model simulations rely on rainfall measurements, mostly recorded by point measurement devices, i.e. raingauges. When using data from extreme rainfall events, the model user has to take into account the validity of point measurements in space. The presented study outlines investigations in the field of rainfall variability due to the actual situation of general weather types during several events. The Boye catchment is part of the Emscher system (850 km²), located in north west Germany. Data from seven continuous raingauges (1990 to 1996) were analysed, together with data from synoptic classifications of the general weather type. Various statistical parameters were computed for the 200 most important rain events, both stationwise and for the whole event over the complete catchment area. The investigation results show that for particular synoptic rainfall situations, the raingauge in the centre of the catchment overestimated the areal rainfall calculated by the Thiessen procedure from all seven raingauges. The results also demonstrate the spatial variation of rainfall as well as observed event duration and event volume variation for different synoptic situations. It is pointed out that reduction factors should be applied to the data of the single raingauge in the centre of the 80 km² catchment area used in longterm simulation.     

基于分形插值的城市降雨时间序列精细化估算

基于分形原理对济宁市降雨时间序列进行精细化插值,对降雨数据的分形特征进行分析,通过MATLAB软件计算降雨分形插值,最终将分形插值与传统插值进行对比;所得结果可满足当前中小型城市的城市雨洪建模的降雨数据需求。     

降雨空间分辨率对城市内涝模拟敏感性研究

为研究降雨空间分辨率对城市内涝模拟的影响规律以及一、二维耦合的城市雨洪模型的敏感性降雨空间分辨率,本研究选取西安市小寨片区为研究区,以西安市气象局提供的3场降雨为基础,采用空间插值算法获取5种降雨（0.2、0.5、1.0、2.0和4.0 km）空间分辨率,引入洛伦兹曲线、基尼系数判断不同降雨空间分辨率的不均匀程度,驱动一、二维耦合的城市雨洪模型进行模拟分析。结果表明,3场降雨0.5 km降雨空间分辨率对应的基尼系数分别为0.163、0.201、0.165,评价结果均为均匀分布。随着降雨空间分辨率的降低,基尼系数逐渐减小,峰值积水面积相对误差、内涝积水水量相对变化范围、内涝淹没水深相对变化范围均逐渐增大。对于这3个水力要素评价指标,降雨空间分辨率为0.5 km对应的模拟误差最小,且该降雨空间分辨率为敏感性降雨空间分辨率。     

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。     

人工降雨试验中风速对落地雨强空间分布的影响研究

气候变化和城镇化发展使得极端暴雨发生频率增加,实验室降雨试验可为极端暴雨灾害的研究提供数据支撑。通过开展不同情景下的实验室降雨试验与数值模拟,研究了风对落地雨强分布的影响,分析了风导致试验区域平均落地雨强减小的原因。结果表明：（1）风会使试验区域的实际平均落地雨强减小,主要原因是降雨中不同粒径雨滴在风场作用下漂移距离的不同,导致了地面受雨面积扩张。（2）受雨范围内落地雨强的均匀性受风速影响,落地雨强均匀性随风速增加而下降。为提高试验数据的准确性,在进行降雨模拟试验时需要考虑风速的影响,结合实验室实际条件合理确定试验范围。     

自然状态下流域洪峰对降雨时空异质性的响应规律

针对自然状态下降雨时空异质性如何影响流域洪峰的难题,提出了基于RainyDay模型和SWAT模型的洪水频率分析方法。以东江流域为例,利用RainyDay模型构建不同重现期下的设计降雨,并将其重构为6种不同降雨时空异质性的降雨情景,将上述情景作为SWAT模型前端输入,定量模拟自然状态下流域洪峰对降雨时空异质性的响应。结果表明：当情景间的时间异质性差值趋于0时,随着情景间的空间异质性差值的增加,洪峰差值随之增大,最大洪峰差值超过700 m³/s,平均洪峰差值超过300 m³/s;当情景间的空间异质性差值趋于0时,随着情景间的时间异质性差值的增加,洪峰差值随之增大,最大洪峰差值接近700 m³/s,平均洪峰差值超过200 m³/s;在同一重现期下,降雨时空异质性均较高的情景所产生的洪峰高于其他情景,最大洪峰差值超过1 000 m³/s;降雨空间异质性对洪峰的影响较时间异质性更为显著。     

城市流域径流峰值对降雨时空异质性的响应

基于高时空分辨率的降雨产品,采用RainyDay暴雨生成器生成具有不同时空分布情景和降雨历时的设计降雨,通过分布式水文模型GSSHA模拟分析径流峰值对降雨时空异质性的响应规律,结合协方差分析方法和所构建的降雨时空异质性指标体系,定量研究不同降雨时空异质性指标对径流峰值的影响。结果表明:耦合短时序(2008—2016年)栅格降雨数据和RainyDay暴雨发生器,可以生成与实际降雨时空分布相似的流域设计降雨;降雨时空异质性对径流峰值具有显著的影响,其影响比降雨历时和降水量对径流峰值的影响大;雨峰系数、降雨集中度、1 h最大降水量对径流峰值的影响较大,其中雨峰系数的影响随着降雨历时或降雨重现期增大而减小,而降雨集中度则相反。     

R/S method for evaluation of pollutant time series in environmental quality assessment

The significance of the fluctuation and randomness of the time series of each pollutant in environmental quality assessment is described for the first time in this paper. A comparative study was made of three different computing methods： the same starting point method, the striding averaging method, and the stagger phase averaging method. All of them can be used to calculate the Hurst index, which quantifies fluctuation and randomness. This study used real water quality data from Shazhu monitoring station on Taihu Lake in Wuxi, Jiangsu Province. The results show that, of the three methods, the stagger phase averaging method is best for calculating the Hurst index of a pollutant time series from the perspective of statistical regularity.     

Identification of sewer pipes to be cleaned for reduction of CSO pollutant load.

To reduce the CSO (Combined Sewer Overflow) pollutant discharge, one of the effective options is cleaning of sewer pipes before rainfall events. To maximize the efficiency, identification of pipes to be cleaned is necessary. In this study, we discussed the location of pipe deposit in dry weather in a combined sewer system using a distributed model and investigated the effect of pipe cleaning to reduce the pollutant load from the CSO. First we simulated the dry weather flow in a combined sewer system. The pipe deposit distribution in the network was estimated after 3 days of dry weather period. Several specific pipes with structural defect and upper end pipes tend to have an accumulation of deposit. Wet weather simulations were conducted with and without pipe cleaning in rainfall events with different patterns. The SS loads in CSO with and without the pipe cleaning were compared. The difference in the estimated loads was interpreted as the contribution of wash-off in the cleaned pipe. The effect of pipe cleaning on reduction of the CSO pollutant load was quantitatively evaluated (e.g. the cleaning of one specific pipe could reduce 22% of total CSO load). The CSO simulations containing pipe cleaning options revealed that identification of pipes with accumulated deposit using the distributed model is very useful and informative to evaluate the applicability of pipe cleaning option for CSO pollutant reduction.     

Symbiotic algal bacterial wastewater treatment: effect of food to microorganism ratio and hydraulic retention time on the process performance.

Algal incorporation into the biomass is important in an innovative wastewater treatment that exploits the symbiosis between bacterial activated sludge and microalgae (Chlorella vulgaris sp. Hamburg). It allows a good and easy algae separation by means of clarification. The effect of process parameters food to microorganisms ratio (F/M) and hydraulic retention time (HRT) on the process performance, evaluated by settleability, microalgae incorporation to biomass and nutrient removal, was studied. HRT hinted at a significant influence in the growth rate of algae, while F/M turned out to be important for stability when algae are incorporated into the biomass. This parameter also affects the total nitrogen removal of the treatment. Stable flocs with incorporated algae and supernatants with low free swimming algae concentrations were obtained at high HRT and low F/M values.     

时间序列模型在吉林西部地下水动态变化预测中的应用

运用时间序列分析理论对吉林西部地下水位动态变化进行了分析和预报。首先采用多项式拟合提取水位动态的趋势分量,而后运用频谱分析方法中的谐波分析提取其中的周期成分,利用自回归（AR）模型模拟随机分量,最后将三者线性叠加建立预报模型,并给出了模型精度检验方法。通过模型分析,可知该区地下水位变化存在两个主要周期（1年和7～9年）,揭示了地下水位的季节性变化和多年变化规律。2002年以后的预报结果表明部分地区的地下水位将持续下降,应及时加以控制。     

基于数据同化的降雨数值空间分布模拟研究

降雨数值模拟是延长水文预报预见期的重要方法,但由于降雨数值模拟中驱动数据所提供的初始场和边界场条件和大气的实际状态并不是完全吻合,导致模拟结果存在误差。减小降雨数值模拟的误差是提高水文预报精度的关键问题,特别是在大气数值模式和分布式水文模型耦合模拟过程中,高精度的降雨信息是准确模拟的关键。本文基于WRF模式和三维变分数据同化方法,选取雷达反射率和GTS(Global Telecommunication System)数据作为同化资料,开展基于数据同化的降雨数值空间分布模拟研究,从降雨的空间展布和指标评价两方面对同化前后的模拟结果进行对比。结果表明:同化后的模拟数据在CSI指标和RMSE指标上都优于同化前的模拟数据,说明同化后模拟数据的误差小于同化前的误差;将同化前后的数据展布在网格图中,发现同化后的数据可以更加准确地刻画降雨的空间分布规律,说明通过数据同化方法提高了模拟降雨和实际降雨空间分布的一致性,改善了WRF模式模拟降雨空间分布的能力。     

基于网格划分的自然邻点法在降雨空间 分布研究中的应用

基于地理信息系统的网格划分,在泰森多边形法的基础上利用自然部点法内插出相关研究区每个网格上的雨量值,进一步做出降雨空间分布曲线,得出不同量级降雨量在研究区域的覆盖范围,为面雨量和降雨空间分布计算提供了新方法。     

降雨信息空间插值研究评述与展望

降雨空间分布对于区域水文模拟、水资源规划与管理、旱涝灾害评估以及生态环境治理等均具有基础性的科学研究意义,是水文水资源学科中的热点研究课题之一。本文主要从方法论的角度评述了微观层面的降雨信息空间插值研究进展,首先探讨了确定性方法与空间统计学方法各自的优势与局限性,最后着重论述了利用信息熵的理论与方法研究降雨信息插值的科学基础,以及对其可行性、合理性和技术特征予以了展望。     

On the issue of trend and noise in the estimation of extreme rainfall properties.

Up until today extreme rainfall properties are frequently applied in sewer design guidelines. Uncertainty in the estimation of such properties will hence directly influence the dimensions of sewers, structures and pumps. In this paper the issue of potential trend and noise in the estimation is investigated for 6 rain series ranging from 19 to 55 years in duration. Different to recent research that predicts a climate induced-increase in heavy precipitation no clear indication for such trend was found in the investigated historical rain series. Another important aspect is the length of the rain series that is required for the estimation of extreme rainfall properties and the associated uncertainty. The analysis indicates that at least a period of 10 years should be used for the estimation. But even so the possible deviation expressed in terms of the 90 percentile is in the order of 5 to 10% of the 'true value', defined as the value derived when the whole given series is used for the estimation.     

西咸新区降雨空间非一致性对内涝过程影响模拟研究

为分析降雨空间分布非一致性对城市内涝的影响,应用耦合了水文和水动力过程的数值模型,以陕西省西咸新区海绵城市部分核心试点区为研究区域,对不同重现期设计暴雨及离差系数Cv条件下的内涝过程进行模拟,并对内涝积水总量峰值、重度内涝积水总量峰值及其与均匀降雨情况下的内涝积水削减进行对比分析。结果表明:相比于空间均匀降雨,各重现期下空间分布不均匀的内涝积水量均会减少。各重现期下,Cv值越大,即降雨越不均匀,相比于均匀情况内涝积水削减量越大。当Cv值为0.07、0.11、0.15及0.2时,积水总量削减率分别为1.94%～2.05%,3.00%～3.17%,4.08%～4.23%,4.86%～5.15%。重度内涝情况下,同一Cv值,相比于均匀情况内涝积水削减量随设计降雨重现期变长而增多,当Cv=0.07、Cv=0.11、Cv=0.15、Cv=0.20时,削减率的范围分别为2.00%～2.51%、2.60%～3.82%、3.66%～4.98%、3.80%～5.83%。研究结果揭示了降雨空间分布非一致性对内涝的影响规律,为城市内涝防治工作提供了理论依据。     

考虑降雨空间变化的流域产流模型

本文从确定性与随机性相结合的途径出发，将超渗产流模型与降雨空间变化的频率特性有机结合，引入流域降雨产流计算中，经在黄土地区四个流域的初步应用，表明模型具有模型具有物理概念明确，弹性大的特点，对不同面积大小的流域均具有良好的适用性。     

东江流域汛期降雨序列的小波分析

为了揭示流域汛期降雨变化的多时间尺度的复杂结构,采用Morlet小波函数,对东江流域1956~2005年汛期降雨时间序列进行了小波分析,找出了不同时间尺度下降雨序列变化的周期和突变点,并根据降雨主周期对未来汛期降雨变化进行了预测。研究结果表明,汛期降雨序列呈现微弱的减少趋势,倾向率为每10 a12.08 mm,近50 a汛期降雨量减少了约60.4 mm;汛期降雨量变化的特征时间尺度为2、4、7、12 a与19 a,其中4、7 a左右的周期振荡最强,为汛期降雨量变化主周期;依据主周期的变化趋势,预测2006年前后东江流域汛期降雨将偏少,在2008~2010年汛期降雨将偏多。