TY - JOUR AU - Van, Nguyen Khanh AU - Tuan, Tong Phuc AU - Vu, Vuong Van AU - Ha, Nguye Manh PY - 2014/06/13 Y2 - 2024/03/29 TI - The heavy rain differences based on topo-geographical analyse at Coastal Central Region, from Thanh Hoa to Khanh Hoa JF - Vietnam Journal of Earth Sciences JA - Vietnam J. Earth Sci. VL - 35 IS - 4 SE - Articles DO - 10.15625/0866-7187/35/4/4113 UR - https://vjs.ac.vn/index.php/jse/article/view/4113 SP - 301-309 AB - Following the article “The Role of topo-geographical conditions of Northern Central Region Vietnam and the difference of heavy rains between North and South Ngang Pass” [Journal of Sciences of the Earth T.34, N°1/2012], this paper present the reseach results of the resonant influences of topo-geographic conditions in heavy rains patterns in<br />Coastal Central Region of Vietnam, those divided into some areas along N-S direction by E-W orientation mountain ranges (Ngang, Hai Van, Ca passes).<br />Base on the weather situation maps, daily rainfall data (1987-2006) over Coastal Central territory (from Thanh Hoa to Khanh Hoa), the count and frequencies of heavy rains occurrence (during this timeline) corresponding to 7 types of 309<br />Synoptic Weather Situation (SWS) - major factor leading to heavy rain - have been analised and evaluated. The results of analysing simultaneously topo-geographic conditions of 4 areas: Northern Ngang Pass (KV1), Ngang Pass to Hai Van Pass (KV2), Hai Van Pass to Ca Pass (KV3) and Southern Ca Pass (KV4) together with SWS show that:<br />- For the heavy rain caused purely by cold air mass (CAM): in KV1: there are only 7 waves equivalent 10,4% of total number of SWS, while in KV2 there are 41 waves - accupeid 36,9%, in KV3: 11 weves ∼ 19,3%, and in KV4 there are 13 waves ∼ 38,2%.<br />- For the heavy rain caused by CAM and combination of CAM with other SWS: in KV1 there are 8 waves (11,9% of total number of SWS), in KV2: 51 waves (accounts for 45,9%), in KV3: 37 weves (64,9%) and in KV4 there are 24 weves (70,6%). It meens the sounthern areas have higher havy rain frequence.<br />- The differences in topo-geographic condition of 4 areas, especially the directions of mountain ranges, characteristics of major mountain ranges, the directions of coast line and the presence of some mountain passes<br />(Ngang, Hai Van, Ca), are the main reason leading to the increasing convergence and as the consequently the noticeable increase of heavy rains frequence those relative to CAM.<br />- The study on the heavy rain differences based on topo-geographical analyse will be a source of valuable information, contributing to more precisely forecast of heavy rains in different areas of Coastal Central Region of Vietnam.<br />The above approach of geographic climatology to examine the topo-geographical conditions and heavy rains is a new and reasoable approach, it allows to solve the natural disaster problem more effective and more useful at difference areas in Coastal Central Region of Vietnam.<br />The study was supported by 2 projects of Vietnam Academy of Science and Technology [7, 8], Science brench "Preventing Disaster Reduction", performed in the years 2008-2009 and 2012-2013. ER -