Precipitation In Flood Season Research Articles

Temporal-spatial distribution of non-point source pollution in a drinking water source reservoir watershed based on SWAT

Abstract. The conservation of drinking water source reservoirs has a close relationship between regional economic development and people’s livelihood. Research on the non-point pollution characteristics in its watershed is crucial for reservoir security. Tang Pu Reservoir watershed was selected as the study area. The non-point pollution model of Tang Pu Reservoir was established based on the SWAT (Soil and Water Assessment Tool) model. The model was adjusted to analyse the temporal-spatial distribution patterns of total nitrogen (TN) and total phosphorus (TP). The results showed that the loss of TN and TP in the reservoir watershed were related to precipitation in flood season. And the annual changes showed an "M" shape. It was found that the contribution of loss of TN and TP accounted for 84.5% and 85.3% in high flow years, and for 70.3% and 69.7% in low flow years, respectively. The contributions in normal flow years were 62.9% and 63.3%, respectively. The TN and TP mainly arise from Wangtan town, Gulai town, and Wangyuan town, etc. In addition, it was found that the source of TN and TP showed consistency in space.

Is the S-shaped curve a general law? An application to evaluate the damage resulting from water-induced disasters

Water-induced disasters are harmful and can cause drastic damage. The response to these disasters is critical, and this task continues to gain global attention. A quick and accurate assessment of the damage is vital to mitigate the effects of the water-induced disasters. This paper begins with exploring the S-shaped curve that is widely observed with many types of damage resulting from the various water-induced disasters. Following that, we propose a conceptual model using the grade of a disaster as the crucial factor and recommend a general function in the form of a hyperbolic tangent function. The damage assessment of the flood and drought events that occurred in the Yangtze River Delta was conducted to explain the processes involved in the function configuration. Flood season precipitation and soil moisture were incorporated into the flood and drought models, respectively, to simulate the functions in agricultural areas hit by drought or flood events. Comparing the calculated result and field survey shows the effectiveness of the proposed damaged estimate function. This proposed methodology can be used to quickly assess the flood and drought damage, and it can also be extended to other types of disasters.

Analysis on the Precipitation in Multiple Scales in Xi’an of China

Based on the data of precipitation from 1951 to 2014 in Xi’an,Shanxi Province,China(hereinafter referred to as Xi’an),after analyzing the characteristics of changes in precipitation over the last 64 years,the multiple scale analysis of annual precipitation and flood season precipitation are analyzed by wavelet analysis in Xi'an.The conclusions are as follows:(1)Flood season precipitation accounts for 79.32% of annual precipitation, and the correlation coefficient is 0.94,so,the contribution of precipitation in flood season to annual precipitation is very great.(2) Annual precipitation and flood season precipitation shows a decreasing trend, with a decreasing rate of -11.3mm/10a and -3.17mm /10a, respectively,which shows 72% of the annual precipitation decreases in the non flood season.(3)Annual precipitation sequence and flood season precipitation sequence have the similar main cycle in Xi'an.Their first main periods are 29 years and 31 years, respectively, and the second, the third,the forth main cycles all are 13 years, 6 years and 3 years.(4)Over any time scale,the annual precipitation and the precipitation in flood season will be into a less period after 2014.Since the oscillation intensities of the first and the second main cycles of annual precipitation is basically same,the possibilities of the less period of annual precipitation continuing to 2020 or 2017 are the same.However,the oscillation intensity of the first main cycle of precipitation in flood season is much greater than that of the second main cycle,so the probability of the less period of precipitation in the flood season is more likely to continue to 2020 than 2017.

Impact of SST in Northern Pacific Ocean on Flood Season Precipitation in Guizhou

Based on the precipitation of summer at 83 stations in Guizhou from 1979 to 2011 and the mean monthly reanalysis SST data,the relationship between summer precipitation and the SST in the Pacific Ocean are investigated in terms of SVD. The results are as follows:( 1) The key SST region which influencing precipitation in Guizhou from California cold current to Kuroshio from previous summer to spring,the relationship between SST in spring and precipitation in Guizou is not close,the relationship between the previous SST and precipitation in the middle-east of Guizhou is closer.( 2) Composite analysis results are as follows: In flood year,the distribution of Northern Pacific Ocean SST from west-north to east-south is‘+- + ',but in drought year the distribution of Northern Pacific Ocean SST from west-north to east-south is ‘- +- ',the relationship between rainfall rich and El Nino events isn' t close,but the relationship between rainfall deficit and La Nina event is close.( 3) The possible mechanism that the influence of previous Northern Pacific Ocean SST on precipitation in Guizhou: Northern Pacific Ocean SST rising can cause wave train spreading to the middle Western Pacific Ocean,which making the Western Pacific subtropical high moving to west,benefiting to rainfall; the influence of Northern Pacific Ocean SST dropping was not as good as those caused by SST rising,it can cause Western Pacific subtropical high moving to east,not benefiting to rainfall.

Changes in persistent and non-persistent flood season precipitation over South China during 1961–2010

The characteristics and possible causes of changes in persistent precipitation (PP) and non-persistent precipitation (NPP) over South China during flood season are investigated using daily precipitation data from 63 stations in South China and NCEP/NCAR reanalysis data from 1961 to 2010. This investigation is performed using the Kendall’s tau linear trend analysis, correlation analysis, abrupt climate change analysis, wavelet analysis, and composite analysis techniques. The results indicate that PP dominates total precipitation over South China throughout the year. The amounts of PP and NPP during flood season vary primarily on a 2-5-yr oscillation. This oscillation is more prominent during the early flood season (EFS; April-June). NPP has increased significantly over the past 50 years while PP has increased slightly during the whole flood season. These trends are mainly due to a significant increase in NPP during the EFS and a weak increase in PP during the late flood season (LFS; July-September). The contribution of EFS NPP to total flood season precipitation has increased significantly while the contribution of EFS PP has declined. The relative contributions of both types of precipitation during LFS have not changed significantly. The increase in EFS NPP over South China is likely related to the combined effects of a stronger supply of cold air from the north and a weaker supply of warm, moist air from the south. The increase in NPP amount may also be partially attributable to a reduction in the stability of the atmosphere over South China.

Impacts of Urbanization on Precipitation in Taihu Lake Basin, China

AbstractTaking Suxichang and Hangjiahu urban agglomerations in Taihu Lake Basin as study areas, the authors explore differences in annual precipitation, flood season precipitation, annual maximum daily precipitation, and rainfall days of different types between cities and suburbs from 1961 to 2006. The authors also investigate the trends of precipitation change by means of Mann-Kendall test and rescaled range analysis. The results show that the amount of precipitation increased with the level of urbanization at spatial and temporal scales. The maximum daily precipitation and the number of rainstorms in urban areas also increased. With further development of urbanization, the increase would continue in the future. The two urban agglomerations with similar level of urbanization and climatic conditions are consistent in terms of all research indicators applied in this paper. The results are basically consistent with many previous studies, while the study area has its own characteristics in that the maximum r...

Analysis on Variation Characteristics of Precipitation Time Series in Weihe River Basin during the Past 55 Years

By using linear regression, moving average, Mann-Kendall test and Morlet wavelet analysis method, the annual, flood seasonal and dry seasonal precipitation series during 1954~2008 in Weihe River basin are analyzed. The results indicate that: ①Annual precipitation and precipitation in flood season and dry season present decreasing trends during the past 55 years, and the variation trends are not significant. ②There is an irregular spatial distribution of mean annual precipitation, which shows a decreasing trend from southeast to northwest. ③Annual precipitation exists principal periods of about 2, 10, 17 and 50 years, and the phase changes of 2 and 50 years period are most obvious. Time scales of phase change of precipitation series in flood season and dry season are roughly consistent with those in annual. The research results will provide reference for climate analysis and future weather forecasting in Weihe River basin.

Effect of Urbanization on Precipitation in Yangtze River Delta

Taking Yangtze River delta(YRD) as the typical region, on basis of daily rainfall data from 1961 to 2006, this paper made contrastive analysis of annual and flood season precipitation between cities and suburbs in the study area with the method of statistical analysis，linear regression and R/S method. The results showed that 1) on the scale of region, for the area with relatively rapid development of urbanization, increasing trend of rainfall in urban areas was more than that of suburban areas, while for the areas with relatively slow development of urbanization, the gap was not obvious; 2) on the scale of city, for the city with relatively rapid development of urbanization, the increase amplitude of rainfall and urban-suburban gap were both obvious, for which with relatively slow development of urbanization, both were not obvious. This study can provide a reference for the analysis of urbanization.

Effect of Urbanization on Regional Precipitation in the Qinhuai River Area, East China

The Qinhuai River, one of the most economically developed areas in China, is also one of the largest urban agglomerations in the world. Recently, rapid urbanization has caused great changes in the regional natural environment and processes of precipitation. Taking 6 precipitation stations for daily rainfall data from 1961-2006 and using statistical analysis, linear regression, R/S method, concentration ratio and concentration period, focusing on the effects of urbanization on the long term precipitation, comparing the annual precipitation, flood season precipitation, winter precipitation, storm rainfall days and precipitation days, rainfall concentration ratio and concentration period in urban and suburban gauges, this paper probes into the effect of urbanization on local precipitation. The results show that with the development of urbanization, the increasing trend of annual precipitation, flood season precipitation and storm rainfall days in urban areas is more than the suburban areas; the increasing speed of annual precipitation and flood season precipitation in urban area are 25.16 mm/10 a and 12.0 mm/10 a, while the suburb’s are 20.28 mm/10 a and 7.3 mm/10 a respectively. The difference of urban and suburban areas is increasing and the urban rain island effect is evident. The annual precipitation is usually concentrated in June and July, the precipitation concentration ratio is on the decline in urban and suburban areas, and the rate of decrease in suburban areas is slightly more than urban areas, the difference of urban and suburban areas is little.

沁河流域汛期降水变化规律研究

利用沁河流域18个雨量站1971~2008年共38a汛期逐日降水资料，分别采用滑动平均法、累计距平、信噪比及小波分析等方法，研究了降水的趋势性及周期性变化。结果表明，38a来汛期降水量以7.89 mm/10a速率呈小幅的下降趋势；汛期降水不存在突变现象；年降水存在着27a、22a、6a及9a的主周期变化，27a周期振荡最为强烈。经预测，沁河流域在2008年后的一段时期内可能处于一个降水偏少期。 Based on daily precipitation in flood season dataset of 18 stations in the Qinhe River basin during 1971-2008, the trend and periodicity variation of precipitation in flood season were analyzed by using meth- ods of moving average, accumulative anomaly, ratio of signal to noise and wavelet analysis. The main results are as follows: the precipitation in flood season declined at a speed of 7.89 mm/10ain recent 38 years, but changes in amplitude are not significant; the precipitation in flood season doesn’t exist mutation phenomenon; the annual precipitation has 27, 22, 6 and 9 years periods, and the oscillation in 27 years were the most in- tense. The study forecast that the annual average precipitation in the Qinhe River basin maybe in the dry pe- riod after 2008.

沁河流域汛期降水变化规律研究<br>Study on Variation Law of Precipitation in Flood Season in the Qinhe River Basin

沁河流域汛期降水变化规律研究<br>Study on Variation Law of Precipitation in Flood Season in the Qinhe River Basin

Analysis on Characteristic of Precipitation in Poyang Lake Basin from 1959 to 2008

Abstract Based on the daily precipitation observational data in 78 counties and municipalities in Jiangxi province in Poyang Lake Basin from 1959 to 2008, day-to-day observation data of the past 50 year are firstly completed with inverse distance weighting (IDW) and complete day-to-day precipitation observation data on PoYang Lake Basin has been established; Secondly, Mexican Hat wavelet analysis is used on periodic law of annual rainfall and precipitation in flood season in this basin. Spatial distribution of annual rainfall and precipitation in flood season in this basin is technically analyzed with GIS geo-statistics; variation tendency of total annual rainfall, sprinkle, downfall, rainstorm days and successive no-rain days are studied respectively with linear regression and credit analysis is also made on these variation tendencies. Results show that: (1) No significant changes have taken place on annual rainfall and precipitation in flood season in this basin in the past 50 years and periodic fluctuation is presented. Wavelet analysis reveals that annual rainfall has a quasi-period of 20 years and precipitation in flood season has a quasi-period of 6 years. (2) Annual rainfall and precipitation in flood season are featured by basically similar spatial distribution. Areas with heavy precipitation are concentrated in Raohe basin and Xinjiang basin in the northeast of Jiangxi province. (3) Total rainfall days and days of sprinkle in this basin are in a descending tendency; on the contrary, accumulated longest time of no rainfall in all observation station are in an ascending tendency; which indicates that risks of draught and flood occurrence in this basin are in an ascending tendency. (4) Spatial distribution of total rainfall days and mean annual precipitation differs a lot; Total rainfall days in west Jinggangshan area and central and east part of the basin are the most; spatial distribution of rainstorm days and mean annual precipitation are similar. Areas with the most rainstorm days are also concentrated in Raohe basin and Xinjiang basin in the northeast of Jiangxi province. It can be seen from this that spatial distribution of mean annual precipitation, storm rainfall and rainstorm days are closely linked with each other.

Impacts of urbanization on hydrology in the Yangtze River Delta, China

The Yangtze River Delta is one of the most developed regions in China and the rapid development of urbanization have greatly influenced regional hydrology and water resources. Taking several typical urbanizing areas in the Yangtze River Delta as examples, this paper probes into the impacts of urbanization on hydrologic cycle and hydrological process with the support of RS, GIS and hydrological model. The research centers on the impacts of urbanization on precipitation, hydrological process, river networks, and water environment in some typical cities. The results show that: (1) Urban rain island effect is not evident when the process of urbanization is slow, while the differences of annual precipitation and flood season precipitation between urban and suburban areas increased to a certain extent in the booming stage of urbanization. (2) The annual runoff depth and the runoff coefficient increased with the development of urbanization, and the effect will be more notable when the urban areas expand to a certain size; (3) River network systems, especially low-grade rivers have been greatly destroyed in the process of urbanization, which increases the risk of flood and water degradation, so it is very important to protect natural river systems. Based on the results, some proposals of sustainable utilization and protection of water resources is also addressed.

Climate change and its effects on runoff of Kaidu River, Xinjiang, China: A multiple time-scale analysis

This paper applied an integrated method combining grey relation analysis, wavelet analysis and statistical analysis to study climate change and its effects on runoff of the Kaidu River at multi-time scales. Major findings are as follows: 1) Climatic factors were ranked in the order of importance to annual runoff as average annual temperature, average temperature in autumn, average temperature in winter, annual precipitation, precipitation in flood season, average temperature in summer, and average temperature in spring. The average annual temperature and annual precipitation were selected as the two representative factors that impact the annual runoff. 2) From the 32-year time scale, the annual runoff and the average annual temperature presented a significantly rising trend, whereas the annual precipitation showed little increase over the period of 1957–2002. By changing the time scale from 32-year to 4-year, we observed nonlinear trends with increasingly obvious oscillations for annual runoff, average annual temperature, and annual precipitation. 3) The changes of the runoff and the regional climate are closely related, indicating that the runoff change is the result of the regional climate changes. With time scales ranging from 32-year, 16-year, 8-year and to 4-year, there are highly significant linear correlations between the annual runoff and the average annual temperature and the annual precipitation.

Analysis of the Influence of Great Earthquakes (Ms ≥ 7.8) in Northwest Pacific Ocean on the Monthly‐Seasonal Rainfall Processes in China

AbstractThe relationship between earthquake and climatic change has become a hotspot in geosciences with the upgrading of our understanding of the earth system. Based on the long wave theory in Geophysical Fluid Dynamics, we studied the long wave features of Geothermal Vortexes accompanied by strong earthquakes, and analyzed the corresponding patterns of strong earthquakes (Ms ≥ 7.8) in northwest Pacific ocean and the monthly precipitation fields in China. The result shows that when the scale of Geothermal Vortex accompanied by strong earthquake is larger than 850 km, the Geothermal Vortex will move westward, as a result, it will have impact on the evolution of monthly‐seasonal precipitation field in China. From the result above, we predicted the flood season's precipitation in 2007 in China, the observed precipitation proved our prediction well.