報告書番号

N15012

タイトル（和文）

台風配電設備被害推定システムRAMPTにおける風速の予測精度の把握

タイトル（英文）

Validation of wind speed prediction in damage estimation system of power distribution due to typhoon, RAMPT

概要 （図表や脚注は「報告書全文」に掲載しております）

風速予測精度向上への基礎的な理解の取得を目指し，台風配電設備被害推定システムRAMPTによる風速予測性能を検討した．近年の台風のうち，中心気圧や強風域半径の異なる4つの台風（T1204,T1217，T1318，T1411）を取り上げた．観測値と予測値との比較からRAMPTが有する3つの誤差要因を明らかにした．一つは傾度風を算定する過程に用いる台風モデルに関連し，もう一つは地上風を算定する過程に用いる地上風モデルに関連する．RAMPTは，傾度風の算定において，気圧との関係に理想状態を仮定しており，台風の減衰過程に対して過大評価を与える．また，RAMPTが用いている地上風モデルは，のぼり斜面での増速のみを考慮しており，下り斜面において過大評価を与える．これらの結果から，RAMPTの風速予測精度向上において，台風の減衰過程における傾度風の再現性を有する数値気象モデル（例えばNuWFAS）や下り斜面における減速の再現性を有する数値気流モデル（例えばNuWiCC）の活用が有効であることを明らかにした．

概要 （英文）

We examined the performance of strong wind speed prediction due to typhoon by the damage estimation system of power distribution "RAMPT", and obtain basic understanding for the development of wind speed prediction. We tested 4 different types of typhoon in recent years (T1204, T1217, T1318, T1411), which have various values of the minimum pressure and radius of maximum wind speed. The comparison between observations and predictions revealed two kinds of causes of error through the comparison between observations and prediction, i.e., one is related to the prediction of gradient wind at upper atmosphere by using typhoon model, and the other is related to the prediction of surface wind near the ground by using surface wind model. The RAMPT used the typhoon model with an assumption based on the ideal relationship between pressure and gradient wind, and thus yielded the overestimation of wind speed during the decay period of typhoon. Also, the RAMPT used the surface wind model which has a capability to evaluate the increase in wind speed at upslope, and thus yielded the overestimation of wind speed at downslope. These results suggests that the aiding of numerical weather models and wind model, such as NuWFAS and NuWiCC, which have reproducibility of the relationship also during decay period of typhoon and numerical wind model, and decreases in wind speed at downslope must be an approach for developing wind speed prediction.

報告者

キーワード