Probable Maximum Precipitation probable maximum precipitation Under modern climatic conditions, the maximum rainfall within a certain period. English abbreviations pmp. This precipitation for a given geographic area on a given storm, certain times of the year are physically possible. China also called probable maximum storm. Precipitation may be large and the temporal and spatial distribution (see design storm), and through the confluence basin runoff calculations, calculate the appropriate flood, called the probable maximum flood (probable maximum flood, pmf). Hydrological calculations, when the basin or nearby areas have more information when heavy rain is usually the following steps Deriving Probable Maximum Precipitation: ① to be analyzed each time heavy rain occurs within the design basin and adjacent areas before. Analysis includes two aspects: First, the weather causes storm analysis to clarify the formation of a local storm weather systems and major physical conditions (such as dynamic conditions, water vapor); Second, analysis of spatial and temporal characteristics storm, each time when heavy rains come face deep curve. ② The main physical factors each time heavy rain (as reflected in the condition of the air force convergence rate of increase, reflecting the conditions of moisture vapor inflow rate, etc.) reasonable adjustments to its maximum, the various sub-storm enlarge. ③ The second big storm draw amplified surface darker when outsourcing data lines, drawn face possible maximum rainfall depth curve. Thus the maximum precipitation curve may have read various design time period. Then comply with both temporal and spatial distribution of heavy rainfall in the region, but also to meet the requirements of various design engineering typical storm lasted for distribution, launched probable maximum flood. When designing a watershed or adjacent areas without heavy rainfall information can be relocated rainstorm climate agreement in the region as a basis for estimating pmp. This method is called storm displaced. Displacement should consider two factors affect the rainstorm, different as latitude, elevation, water vapor source and terrain obstacles, etc., with the necessary corrections. Because of the topography of the storm's no exact method of calculation is generally not as heavy rains displace mountainous region. For a large area of long duration pmp, combination method can be used to estimate storm. In case of heavy rain weather conditions and the development of more in-depth study of dynamic conditions, can be used to model probable maximum precipitation storm. For example, to reflect the convergence of moisture and upward motion as a parameter to model, and heavy rain on the measured parameters can be tested, then the maximum parameters into the model used to estimate the probable maximum precipitation. Probable Maximum Precipitation also used statistical methods to estimate. The basic formula is: pm = Lu n + kσn Where pm is probable maximum precipitation (point rainfall); mean Lu n mid n is the maximum rainfall; σn is the standard deviation of n years series; k is the coefficient, and the mean duration and size, climate conditions, using empirical methods have out. After point by point and area rainfall relations obtained are translated into surface rainfall. In order to facilitate the planning and design can be made pmp contour map, China and its possible maximum 24 hours contour plot point storm provinces have been made. Modern scientific knowledge about meteorology storm physical mechanism is not enough accurate calculation of heavy rainfall maxima, therefore, to estimate probable maximum precipitation must be multifaceted reasonable analysis. Its accuracy depends on the quantity and quality of data.
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可能最大降水 百科大全
keneng zuida jiangshui Probable Maximum Precipitation probable maximum precipitation Under modern climatic conditions, the maximum rainfall within a certain period. English abbreviations PMP. This precipitation for a given geographic area on a given storm, certain times of the year are physically possible. China also called probable maximum storm. Precipitation may be large and the temporal and spatial distribution (see design storm), and through the confluence basin runoff calculations, calculate the appropriate flood, called the probable maximum flood (probable maximum flood, PMF). Hydrological calculations, when the basin or nearby areas have more information when heavy rain is usually the following steps Deriving Probable Maximum Precipitation: ① to be analyzed each time heavy rain occurs within the design basin and adjacent areas before. Analysis includes two aspects: First, the weather causes storm analysis to clarify the formation of a local storm weather systems and major physical conditions (such as dynamic conditions, water vapor); Second, analysis of spatial and temporal characteristics storm, each time when heavy rains come face deep curve. ② The main physical factors each time heavy rain (as reflected in the condition of the air force convergence rate of increase, reflecting the conditions of moisture vapor inflow rate, etc.) reasonable adjustments to its maximum, the various sub-storm enlarge. ③ The second big storm draw amplified surface darker when outsourcing data lines, drawn face possible maximum rainfall depth curve. Thus the maximum precipitation curve may have read various design time period. Then comply with both temporal and spatial distribution of heavy rainfall in the region, but also to meet the requirements of various design engineering typical storm lasted for distribution, launched probable maximum flood. When designing a watershed or adjacent areas without heavy rainfall information can be relocated rainstorm climate agreement in the region as a basis for estimating PMP. This method is called storm displaced. Displacement should consider two factors affect the rainstorm, different as latitude, elevation, water vapor source and terrain obstacles, etc., with the necessary corrections. Because of the topography of the storm's no exact method of calculation is generally not as heavy rains displace mountainous region. For a large area of long duration PMP, combination method can be used to estimate storm. In case of heavy rain weather conditions and the development of more in-depth study of dynamic conditions, can be used to model probable maximum precipitation storm. For example, to reflect the convergence of moisture and upward motion as a parameter to model, and heavy rain on the measured parameters can be tested, then the maximum parameters into the model used to estimate the probable maximum precipitation. Probable Maximum Precipitation also used statistical methods to estimate. The basic formula is: P □ = □ □ + K □ □ P □ formula for the probable maximum precipitation (point rainfall); □ □ □ every year for the average maximum rainfall; □ □ □ in the series is the standard deviation; K is a factor, and the duration and Mean size, climate conditions, derived by empirical methods. After point by point and area rainfall relations obtained are translated into surface rainfall. In order to facilitate the planning and design can be made PMP contour map, China and its possible maximum 24 hours contour plot point storm provinces have been made. Modern scientific knowledge about meteorology storm physical mechanism is not enough accurate calculation of heavy rainfall maxima, therefore, to estimate probable maximum precipitation must be multifaceted reasonable analysis. Its accuracy depends on the quantity and quality of data. Bibliography River Road, the Zou Jin: "probable maximum storm and flood," Water Power Press, Beijing, 1983. O, Manual for Estimation of Probable MaximumPrecipitation, WMO-No.332, 1973. J.Wiesner, Hydrometeorolo □ y, Champman% 26 Hall, London, 1970. (Zhandao Jiang)
