City based on water conservancy rainfall pattern peak value is long lasts design storm pattern method for making
Technical field
The present invention relates to a kind of city based on water conservancy rainfall pattern peak value length and last heavy rain rainfall pattern method for making, belong to Municipal unwatering system, municipal drainage prevention waterlogging system and flood control drainage system technology crossing domain.
Background technology
The prerequisite of municipal drainage prevention waterlogging programming and planning has the rain fall in city and rule to be clearly familiar with and to study, and has the Rainfall Pattern of Urban Design Storm being suitable for this area rainfall rule.And the long heavy rain rainfall pattern that lasts in city is the basic foundation determining city prevention waterlogging facilities design flow, municipal drainage prevention waterlogging systems organization and design.Along with the quickening of Process of Urbanization Construction process, the frequent appearance of extreme catchment, in advance, magnanimity increases rainfall flood peak, and urban waterlogging takes place frequently.The loss brought by urban waterlogging is more serious, brings huge pressure to the planning and design of municipal drainage prevention waterlogging engineering.
At present, the planning and design of China's flood control water drainage and Municipal draining two cover system are constantly perfect, two cover systems are respectively used to defend rivers water system Flood: and the storm runoff within the eliminating Municipal Water drainage system design reoccurrence period, and Each performs its own functions.But the planning and design of marginal municipal drainage prevention waterlogging system remain certain defect.Planning and design and the municipal drainage of municipal drainage prevention waterlogging engineering and the flood control facility that drains flooded fields is closely bound up, and both are respectively the upstream and downstream border of engineering construction of preventing waterlogging.The sampling duration of municipal drainage system is 180min to the maximum, and the sampling duration of urban flood defence drainage system minimum be 1h, owing to lasting the difference chosen, can not machinery rainfall pattern existing in two cover systems is applied in municipal drainage prevention waterlogging system.
According to the correlation experience that domestic and international urban waterlogging is prevented and treated, the length being applied to municipal drainage prevention waterlogging engineering is lasted design storm pattern and should be met below three conditions as far as possible: first, the design storm pattern of municipal drainage prevention waterlogging engineering must be that length lasts raindrop type, according to size and the concentration time of urban waterlogging Engineering Zone scope, it is generally acknowledged 1440min, the design storm pattern growing to 2 days most can meet prevention waterlogging project planning design requirement.Secondly, design storm pattern should embody the real rainfall statistical law in basin as far as possible.Finally, design storm pattern also should take into account with the municipal drainage facility in city and the facility of controlling flood and draining flooded fields of water conservancy adopt and design the effective of rainfall and be connected.
Given this, this patent is from the long demand of lasting heavy rain rainfall pattern of municipal drainage prevention waterlogging system, by the urban meteorological characteristics of rainfall data (.dat file) of standard, adopt mathematical statistics method, add up and sort out actual typical rainfall, then according to the water conservancy rainfall pattern peak value that local hydraulic department provides, thus the peak that moves carrying out typical rainfall is located, and finally makes city length and lasts heavy rain rainfall pattern.Main operational steps is all realized fast by computer program.Feature of the present invention is only to need the typical case by counting to last rainfall to carry out same frequency and move location, peak, the very big refinement rough property of traditional rainfall pattern method for making, the long design storm pattern that lasts in city newly pushed away is made more to meet local real rainfall statistical law, better authenticity.
Summary of the invention
The present invention be mainly solve current city tradition rainfall pattern method for making numerous and diverse, also do not consider whether it has the local problem in science such as representative from Practical Project angle, propose that a kind of city based on water conservancy rainfall pattern peak value is long lasts heavy rain rainfall pattern method for making.
Technical scheme of the present invention is as follows:
City based on water conservancy rainfall pattern peak value is long lasts heavy rain rainfall pattern method for making, and described method comprises following steps successively:
(1) division of catchment;
Under Access database platform, the original rainfall data provided by the meteorological department after digital processing system process, divide rainfall.Rainfall refers to continuous print duration of raining, and the time continuing to stop rain (rainfall amount is 0mm) between the rainfall of front and back is constantly little more than 12, then before and after definition, rainfall is two separate " catchments ".Take year as statistical unit, count catchment annual in the data time limit respectively.
Selecting of (2) 10 typical heavy rains;
Catchment needs all catchments to counting to analyze after having added up, differ greatly because rainfall amount and rainfall intensity change in time, rainfall, raininess are not of uniform size, the catchment little for gross rainfall, raininess is also less is in fact nonsensical to the long rainfall pattern that lasts in research city, is ignored.So-called typical heavy rain generally refers to that the total rainfall amount of selected heavy rain is large, and rainfall intensity is also large, therefore can reflect the rain fall under the regional the most unfavorable processing condition of design really.Up till now, more than 20 years can being reached in the general city of China from note rainfall record, picking out 10 maximum representative rainfalls from city from remembering all catchments in the Rainfall data time limit.
(3) long lasting designs the selected of the main rain peak position of rainfall pattern;
First, according to the main rain peak-to-peak value recommending rainfall pattern to determine water conservancy rainfall pattern in local hydrologic manual, due to hydraulic department usually adopt be by hour in units of 24 hours design storm patterns of period, so the rain peak position determined by water conservancy rainfall pattern can only be accurate to the maximum little period; City length is lasted to the determination of the rain peak position in design storm pattern in maximum hours, then according to the defining method of municipal drainage short duration rainfall pattern rain peak position, namely in 10 the typical heavy rains picked out, in units of 5min, the rain peak position of the maximum hour rainfall of period is determined, combines the rain peak position determined and be long main rain peak position of lasting design storm pattern, city both final.
(4) that under excel system platform, carries out typical rainfall moves location, peak;
Namely catchment combinatorial compound Heavy Rainfall Process is picked out 10 maximum typical heavy rains by actual rainfall and is analyzed, and controls the same frequency design rainfall under different lasting, uses for reference the method for flood risk analysis, carry out same frequency time-division transfer convergent-divergent.Concrete steps: according to the principle of main rain peak alignment, the rain peak position of 10 selected typical heavy rains is moved to respectively the long main rain peak place lasting design rainfall pattern, the city determined in (3), the rainfall of the 1440min typical case rain after intercepting rain peak position is consistent, take 5min as statistical unit, the rainfall amount series of 288 5min of 10 typical heavy rains can be drawn.
(5) under excel system platform, carry out according to the following steps growing and last design storm pattern distribution:
(5.1) for every that intercepts out typical heavy rain, add up the ratio of every 5 minutes rainfall shared by its whole rainfall respectively, the allocation proportion of every typical heavy rain can be obtained.No matter then play, get the mean value of allocation proportion in each position, altogether can obtain 288 averages.
(5.2) find continuously in 288 averages 144 maximum numbers and, the series of 144 numbers now picked out is period corresponding to the rainfall of maximum 720min, the series of remaining 144 numbers is re-started each section of proportional distribution as unit 1, thus obtains the final proportional distribution of H1440 – H720 section in rainfall pattern.In like manner the like, the final proportional distribution of H720 – H240, H240 – H180, H180 – H120, H120 – H90, H90 – H60, H60 – H45, H45 – H30, H30 – H15, H15 – H5, H5 can be obtained respectively.
(6) the long generation lasting design storm pattern
By long for city last rainfall value that Rain Intensity Formula Based tries to achieve respectively correspondence bring final allocation proportion into, can obtain that city is long lasts design storm time distribution and length lasts rainfall pattern.
Beneficial effect is mainly reflected in:
1. adopt method for making of the present invention, only need the peak that moves carrying out water conservancy rainfall pattern peak value by lasting rainfall to the typical case counted to locate, the length that just can realize meeting municipal drainage prevention waterlogging system simple and easy, accurately last design storm pattern.
2. this patent is with Drainage Design specification for constraint condition, carries out growing the distribution lasting rainfall pattern from the angle of engineering connecting.By real typical rainfall data in conjunction with water conservancy rainfall pattern peak, make the long design storm pattern that lasts in the city that newly pushes away not only more meet local real rainfall statistical law, better authenticity, and based on the length of water conservancy rainfall pattern peak value last design storm pattern can also take into account with the municipal drainage facility in city and the facility of controlling flood and draining flooded fields of water conservancy adopt and design the effective of rainfall and be connected.
3. this patent considers the operability of each step, only needs the ease of Use under the platforms such as computer Excel to complete, without the need to the programming software by complexity, ensure that the exploitativeness of this patent.
Accompanying drawing explanation
Fig. 1 is the schematic flow sheet that the present invention's " city based on water conservancy rainfall pattern peak value is long lasts design storm pattern method for making " works.
Fig. 2 is typical heavy rain rainfall process schematic diagram.
Design storm graph under 50 year reoccurrence period that Fig. 3 is the period in units of 1 hour.
Fig. 4 is the principle according to the alignment of main rain peak, the rain peak position of 10 selected typical heavy rains is moved to the schematic diagram behind the long d=566min place, main rain peak lasting design rainfall pattern, the city determined.
Fig. 5 calculates period figure corresponding to rainfall.
Fig. 6 embodiment result figure.
Embodiment
Below by L city embody rule example, and 1 detailed production method of the present invention done further illustrate by reference to the accompanying drawings.
Specific embodiment of the invention flow process as shown in Figure 1, comprises the following steps:
(1) the local meteorological department in city is obtained by the original rainfall data after digital processing system process, under Access database platform, according to working as the rainfall standard of duration more than 12 hours stopping rain, carry out the division of a catchment, and count the annual field catchment in the city pluviograph record data time limit.
(2) according to the above-mentioned annual field catchment counted, carry out choosing of 10 maximum representative heavy rains, the typical heavy rain chosen possesses and lasts the total rainfall amount of heavy rain (1440min) in greatly, rainfall intensity is also large regulation is long.According to the 1961-2012 city pluviograph record that L city provides, adopt rainfall intensity method that continuous print precipitation time series is divided into 7833 catchments.From 7833 actual measurement catchments, the wherein raininess that selects and maximum 10 the representative heavy rains of rainfall are respectively: 3-4 day in September, 2010,4-6 day in September, 1964,22-24 day in August, 1999, on May 7th, 2010,25-26 day in June, 2008,16-17 day in May, 1989,16-19 day June nineteen eighty-three, 14-15 day in May, 2010,26-27 day in May, 1975,25-27 day in September, 1993, typical heavy rain rainfall process schematic diagram as shown in Figure 2.
(3) based on the long determination lasting design storm pattern peak value in city of water conservancy rainfall pattern peak value:
(3.1) determination of design storm pattern peak value in water conservancy, can inquire about design storm pattern in the local hydrologic manual in city, obtain peak, determine main rain peak is in which hours according to list in hydrologic manual or rainstorm duration figure.The storm runoff that certain hydrology master station of province of example provides is looked into nomogram table service manual subordinate list 3 ~ 1 and is checked in location, the L city hydraulic engineering design rainfall pattern of maximum 24 hours.With reference to 24 hours rainfall line rainfall patterns that this province hydraulic department uses, rain peak position the 10th slot position, the namely period of 9:01 to 10:00, in units of 1 hour the period 50 year reoccurrence period under design storm graph as shown in Figure 3.
(3.2) determination of maximum hour rain peak position, lower rainfall peak value statistics is lasted according to the maximum 60min in 10 the typical rainfalls picked out in units of 5min, obtain the rain peak position in maximum hour, thus determine the peak-peak position in the period.L city is by the rain peak to average r=0.42 of 5min period in maximum 1 hour of 10 typical heavy rains.
(3.3) above-mentioned both combine the rain peak position determined and be long main rain peak position of lasting design storm pattern, city.Because of original from note rainfall data be by minute in units of carry out rainfall statistics, therefore main rain peak-to-peak value position calculation formula is: d=9*60min+0.42*60min=566min, therefore, this city fixes on based on long design storm pattern main rain peak position of lasting, the city of water conservancy rainfall pattern peak value the basis that 566min distributes as following rainfall pattern.
(4) peak that moves of typical rainfall is located, and uses for reference the method for flood risk analysis, carries out the same frequency time-division transfer convergent-divergent of typical rain.In Execl table procedure, scatter chart (as shown in Figure 2) is claimed when making rainfall according to the data of 10 typical rainfalls respectively, according to the principle of main rain peak alignment, the rain peak position of 10 selected typical heavy rains is moved to the long d=566min place, main rain peak lasting design rainfall pattern, the city determined in (3), as shown in Fig. 4 schematic diagram.Intercept every rain peak position consistent after the rainfall lasting 1440min typical case rain, take 5min as statistical unit, the rainfall amount of 5min under 288 periods that can draw 10 typical heavy rains respectively in Excel table procedure.
(5) under Excel system platform, for 10 that intercept out (being lasted for 288 sections of 1440min) typical heavy rains, add up the ratio of every 5 minutes rainfall shared by its corresponding whole rainfall respectively, the allocation proportion of every typical heavy rain can be obtained.No matter then play, get the mean value of allocation proportion in 10 each position, finally can obtain serial 288 averages.
(6) as shown in Figure 5, find in 288 averages continuously 144 maximum numbers and, the series of 144 numbers now picked out is period (720min location) corresponding to the rainfall of maximum 720min, the series of remaining 144 numbers is re-started each section of proportional distribution as unit 1, thus obtains the final proportional distribution of H1440 – H720 section in rainfall pattern.
(7) in like manner, according to the rainfall of maximum 144 sections (the 720min location) picked out, the final proportional distribution of H720 – H240, H240 – H180, H180 – H120, H120 – H90, H90 – H60, H60 – H45, H45 – H30, H30 – H15, H15 – H5, H5 can be obtained respectively.
(8) the long generation lasting design storm pattern, mayor L lasts Rain Intensity Formula Based and is:
wherein P is Designed recurrence period, and t is rainfall duration.
Rain Intensity Formula Based (various places provincial standard can check in) is lasted by city is long, the rainfall value (q=i*t) under specifying the reoccurrence period to last can be tried to achieve, and the final apportioning cost of rainfall=rainfall value * allocation proportion, according to the final Partition of rain value generated, can obtain L city and last design storm pattern based on the city length of water conservancy rainfall pattern peak value, example results as shown in Figure 6.