Large river-bed areas of Kaoping river has been exposed due to Typhoon Morakot in 2009 leading to severe fugitive dust events at the river region. In order to investigate the effect of fugitive dust on the communities, basic hydrological and meteorological background information was collected and evaluated to justify the possible pollution sources and affected areas. A river fugitive dust warning and reporting system was then established according to the background information which can help conducting the emergency response and prevention at the first place.
Hydrological and meteorological background information of Kaoping river region was analyzed according to the contract, the variation trend of PM10 and PM2.5 concentrations was studied in relation to the project. Through the screen analysis of the river fugitive dust event days from the Pingtung station, Kaoping weir onsite station and air quality stations along the Pingtung river (including Linyuan, Daliao and Mino stations), the possible environmental conditions which might cause the fugitive dust events in the Kaoping river region were concluded as following: (1)based on pingtung station, while the wind direction is north-west with grade 2wind speed and PM2.5-10/PM10 ratio is greater than 0.4; (2) based on Daliao station, while the wind direction is south-west with grade 4 wind speed, PM10 concentration is greater than 150 μg/m3 and PM2.5-10/PM10 ratio is greater than 0.8.
Furthermore, a number of 124 field inspections were conducted over the exposed river-bed at the Kaoping river region and a standard operation procedure of Pingtung county Kaoping river field inspection was established accordingly. Meanwhile the satellite images of Kaoping river region were purchased for image analysis which may help understanding the seasonal changes of exposed river-bed, water body and vegetation covered area. The results were provided to the Seventh River Management Office and other units concerned as references for constructing methods. The exposed river-bed areas where likely occur fugitive dust events were determined as following according to the satellite image analysis and field inspections: 1.upstream and downstream of Ligang bridge; 2.Ligang bridge to 1.7km downstream of Cable-stayed bridge; 3.Kaoping Weir to Old Steel bridge; 4.0.5km upstream to 1.5km downstream of the left bank of Wanda bridge; 5.The reach within Tianyang village, Xinyuan township(central exposed river-bed) to Shuangyuan Bridge (exposed river-bed under the Kaoping running water distribution pipe). During the inspections the particulate size and distribution over the exposed river-bed areas were recorded, and the onsite meteorological data was collected to compare with the monitoring data from the air quality stations, which revealed the onsite wind speed was generally stronger than air quality stations’. It is suggested the following project shall carry on differencing the wind speed and wind direction between onsite and air quality station, in advance to control the emission of fugitive particulate matter.
River fugitive dust warning and reporting platform was constructed in this annual project, such platform adopted accessible space concept to build the framework. By holding meeting with units at all levels during the execution of this project, the “warning and reporting standard operation procedure for fugitive dust in Kaoping river region” and “Kaoping river fugitive dust warning and reporting emergency contact list” were built for the receptors to report the river fugitive dust events. In the four river fugitive dust events occurred this year, the river fugitive dust contingency mechanism was activated timely, telephone survey was conducted to follow up the influence on the fugitive dust region and the outcomes were gathered up for the future reference, in respect to decrease influence of the river fugitive dust on the communities.
Three sessions of “Kaohsiung city and Pingtung county river fugitive dust control conference”, two sessions of primary school/junior high school environmental education and three sessions of Kaoping river fugitive dust protection drills were managed this year. These mechanisms allowed all units concerned to further emphasize their responsibilities and recognize the control status, and helped the school teachers and students to improve the awareness of self-protection. Furthermore, by advocating the self-protection awareness through public media such as radio broadcasting and television scrolling text marquee could advance the communities to protect against the fugitive dust. In addition to investigate the communities sitting along the Kaoping river were ever affected by the fugitive dust, the air quality monitoring mobile base was sent to the receptor areas three times each in consecutive 24 hours, allowing studying the impact on the environmental air quality.