Forecasting of Damage Length of Maritime Structures Caused by Typhoons Based on Improved CP Method

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Forecasting of Damage Length of Maritime Structures Caused by Typhoons Based on Improved CP Method

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Forecasting of Damage Length of Maritime Structures Caused by Typhoons Based on Improved CP Method

  1. 1. International Disaster and Risk Conference IDRC Davos 2010 Davos, Switzerland May 30 – June 3, 2010 Ryusuke Hashimura Department of EcoDesign, Sojo University, Japan Forecasting of Damage Length of Maritime Structures Caused by Typhoons Based on Improved CP METHOD
  2. 2. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>INTRODUCTION </li></ul><ul><li>This paper deals with the damage length of the maritime structures by the typhoons in the harbors and coastal areas along the coasts in Kumamoto Prefecture in the Kyushu Island of Japan (Figure 1 and Figure 2). </li></ul>
  3. 3. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>Fig. Location of the Kyushu Island of Japan </li></ul>
  4. 4. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD Fig.1 The 4 coastal regions locate in the Kumamoto Prefecture In Kumamoto Prefecture, the coasts face open and closed seas. The open sea is East China Sea. The closed seas are Ariake and Yatsushhiro seas.
  5. 5. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD Fig.1 The 4 coastal regions locate in the Kumamoto Prefecture In this paper, we divided the coastline into 4 coastal regions . Each coast has different topographical characteristics.
  6. 6. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD Fig. 3 Surrounded area including Kyushu Island All typhoons had passed through an area delineated by a latitude of 30 ° and 35°N and a longitude of 127˚ and 132°E in the past 25 years from 1980 to 2004. The number of typhoons passing through the delineated area is 74 .
  7. 7. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>A statistical analysis is done on the damage length of the maritime structures in harbors and coastal areas, the path and scale of the typhoons. </li></ul><ul><li>Based on the analysis, a forecasting method is proposed for the damage in each coast caused by typhoon. </li></ul><ul><li>In this paper, the author proposes the improved CP method which is calculated based on 74 typhoons during 25 years from 1980 until 2004 is proposed for forecasting the damage length of structures caused by a coming typhoon in each coast. </li></ul>
  8. 8. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>Considering the effect of waves with storm surge on the maritime structure damage, the central pressure of typhoon is important parameter. </li></ul><ul><li>The central pressure is closely relation with the maximum wind speed of typhoon. </li></ul>
  9. 9. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>A relation between the central pressure of typhoon and the damage length of maritime structures is examined. </li></ul><ul><li>The vulnerability and the damage length at each coast for each path of typhoon are estimated. </li></ul>
  10. 10. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>The delineated area was determined judging from the possibility of damage of the maritime structures along the coasts in Kumamoto Prefecture. </li></ul>Fig. 2 13 courses of typhoons
  11. 11. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>The 74 typhoons are divided into 13 groups based on their paths (Fig. 2). </li></ul><ul><li>The direction of the strong wind is from ENE and SE. </li></ul><ul><li>Therefore, the coast facing the sea rightwards in the right area near the center of the typhoon is affected by high waves coming from SE . </li></ul>Fig. 2 13 courses of typhoons
  12. 12. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>In this paper, it is tried to estimate the damage of maritime structures at the coasts from the central pressure of typhoon. </li></ul><ul><li>The central pressure of typhoon is obtained from the data observed periodically near at a latitude of 30˚ N by Japan Meteorological Agency (JMA). </li></ul><ul><li>The reasons why a latitude of 30˚ N is selected is that the direction of movement of typhoon is roughly fixed and the scale becomes stable there. </li></ul>
  13. 13. <ul><li>3. SMOOTHED LENGTH OF DAMAGE AT EACH COAST </li></ul><ul><li>Smoothed length of damage is defined as in Equation (1): </li></ul><ul><li>Y = (P/T) ×100 (1) </li></ul><ul><li>Y is the smoothed length of damage, </li></ul><ul><li>P is the total length of damage caused by each typhoon for each coast, </li></ul><ul><li>T is the total length of damage by all typhoons for this particular coast. </li></ul><ul><li>The smoothed length of damage indicates the contribution to the total damage length by each typhoon. </li></ul>IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD
  14. 14. <ul><li>Table: Smoothed length of damage </li></ul><ul><li>On the whole, Typhoon 9918 in path No. 4 induced enormous damage at the coast in Kumamoto Prefecture. </li></ul>
  15. 15. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>In any case, large damage occurs at the coasts near the center of typhoon in the right side in the direction of typhoon movement. </li></ul><ul><li>This result suggests a close relation between the damage length and the distribution of wind speed in the typhoon. </li></ul>
  16. 16. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>4. THE RELATION BETWEEN THE CETRAL PRESSURE OF TYPHOON AND THE SMOOTHED LENGTH OF DAMAGE </li></ul><ul><li>The smoothed length of damage is expressed by Equation (2): </li></ul><ul><li>Y = exp [{(– 2.932 ×10 -3 P 2 + 5.209518 P </li></ul><ul><li>– 2262.334518 – m) ln8}/10] (2) </li></ul><ul><li>where Y is the smoothed length of damage, and P is the central pressure of 74 typhoons at a latitude of 30˚ N. </li></ul>
  17. 17. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>Fig. 3 Central pressure and smoothed length of damage </li></ul><ul><li>Y = exp [{(– 2.932 ×10-3 P 2 + 5.209518 P </li></ul><ul><li>– 2262.334518 – m) ln8}/10] (2) </li></ul>
  18. 18. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>Y = exp [{(– 2.932 ×10-3 P2 + 5.209518 P </li></ul><ul><li>– 2262.334518 – m) ln8}/10] (2) </li></ul><ul><li>The values of m are selected to equal to the smallest maximum wind speed in the first 7 ranks of typhoon classified by JMA before, the values of m for first 7 ranks are 44, 41, 37, 33, 29, 25 and 17 m/s respectively for the lines a, b, c, d, e, f and g (Fig. 3). </li></ul>
  19. 19. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>The horizontal axis in this Figure shows the central pressure of typhoon at a latitude of 30˚ N. </li></ul><ul><li>The vertical axis shows the smoothed length of damage. </li></ul><ul><li>The symbols represent the different coasts. </li></ul>
  20. 20. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>The lines a to g in Fig. 3 show the relations given by using by Eq. (2), with the values of m varying from 44 to 17. </li></ul><ul><li>The numerical values, 1 to 6, shown outside of Fig. 3, denote the six areas delineated by the lines b to f. </li></ul>
  21. 21. <ul><li>5. SENSITIVITY AT 4 COASTS AND ESTIMATION OF LENGTH OF DAMAGE </li></ul><ul><li>Table 1: Sensitivity values of smoothed length of damage for central pressure </li></ul>
  22. 22. <ul><li>Table shows the number of areas in which the plotted point is located. </li></ul><ul><li>When no damage occurs, the No. is not shown. </li></ul><ul><li>The number given in Table is termed the “ sensitivity value ” for central pressure of typhoon based on the damage length. </li></ul>
  23. 23. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>The sensitivity value indicates </li></ul><ul><li>the vulnerability of the coast to the individual typhoon. </li></ul><ul><li>It should be noticed that a typhoon with the largest smoothed length of damage at the coast does not always has the largest sensitivity value. </li></ul><ul><li>If the numbers 5 and 6 mean to be easily damaged, the following facts are clear: </li></ul>
  24. 24. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>(1) Ariake east coast is easily damaged by the typhoons in paths No. 3, 8 and 11, but is not weak for the typhoons in paths No. 9, 12 and 13. </li></ul><ul><li>(2) Yatsushiro east coast is easily damaged by the typhoons in paths No. 4, 6 and 11, but is not weak for the typhoons in paths No. 1, 7, 9, 12, and 13. </li></ul>
  25. 25. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>(3) Yatsushiro west coast is easily damaged by the typhoons in paths No. 4 and 8, but is not weak for the typhoons in paths No. 7, 12 and 13. </li></ul><ul><li>(4) Amakusa west coast, which faces the open sea, is also easily damaged by the typhoons in paths No. 2, 8 and 11, but is not weak for the typhoons in paths No. 9, 12 and 13. </li></ul>
  26. 26. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>The coasts facing the closed seas areas are easily damaged by the typhoons in paths No. 4 , 8 and 11. </li></ul><ul><li>The coasts facing the open sea are easily damaged by the typhoons in paths No. 2 , 8 and 11. </li></ul>
  27. 27. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>Table 2. Maximum sensitivity values for each course in each coast </li></ul><ul><li>Table 2 shows the maximum sensitivity value for each path at the individual coasts. </li></ul><ul><li>This table indicates the vulnerability index for an individual typhoon path at each coast. </li></ul>
  28. 28. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>(1)   The path is determined based on this Figure from the track of typhoon, which is forecasted by JMA, near at a latitude of 30˚ N. </li></ul>The total length of damage induced by a coming typhoon for a coast can be estimated as follows:
  29. 29. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>(2)   The central pressure at a latitude of 30˚ N is calculated based on the data which is obtained from JMA. </li></ul>
  30. 30. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>Table 2. Maximum sensitivity values for each course in each coast </li></ul>(3) Then the maximum sensitivity value of central pressure is determined from the path and the coast based on this table 2.
  31. 31. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>(4) The maximum and minimum values of the smoothed length of damage is determined in this Fig. 3 by giving the central pressure and the maximum sensitivity value. </li></ul>
  32. 32. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>(5)   The total length of damage by a typhoon for a coast is forecasted by submitting the value of smoothed length and the total length of damage by all 74 typhoons for the same coast in Equation (1). </li></ul><ul><li>   Y = ( P/T ) ×100 (1) </li></ul><ul><li>where Y is the smoothed length of damage, P is the total length of damage caused by each typhoon for each coast, and T is the total length of damage by all typhoons for this particular coast </li></ul>
  33. 33. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>CONCLUSIONS </li></ul><ul><li>Vulnerability and damage of maritime structures along 4 coasts facing the open and closed seas in the west of Kyushu Island of Japan are discussed for 13 courses of typhoon. </li></ul><ul><li>The following conclusions can be drawn: </li></ul>
  34. 34. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>(1) The large damage occurs at the coasts near the center of typhoon in the right side in the direction of typhoon movement. </li></ul><ul><li>(2) The vulnerability of 4 coasts facing the open and closed seas for each path of typhoon is numerically shown by using a concept of sensitivity of central pressure. </li></ul><ul><li>(3) The vulnerability index for an individual typhoon path at each coast is closely related to typhoon passage. </li></ul>
  35. 35. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>(4) The improved CP Method can estimate the damage length of maritime structures that will occur along the coast before a typhoon strikes. </li></ul><ul><li>(5)This paper shows possibility of the estimation of degree of the risk and influence of typhoon on the coasts by central pressure method. </li></ul><ul><li>(6) This forecasting method will be used for the purpose of coastal zone management in disasters prevention works. </li></ul>
  36. 36. IDRC 2010, Forecasting of Damage Length of MS by Improved CP METHOD <ul><li>(7) It is useful for information of storm warning and evacuation for residents along the coastlines. </li></ul><ul><li>Further study including other factors of typhoon is needed for higher quality forecasting. </li></ul>

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