Typhoon Suli hit Taiwan and its heavy rainfall eroded the river beds of Daan River, Dajia River, and Wu River, making them bare and prone to producing flying dust if the northeast monsoon blows strong. To prevent dust from flying from the bare river beds to affect the health of nearby residents, the Environmental Protection Bureau (EPB) of Taichung City Government has been cooperating with the Third River Management Office (TRMO), Water Resources Agency, Ministry of Economic Affairs (經濟部水利署第三河川局) and the Dongshih Forest District Office, Forestry Bureau, Council of Agriculture (行政院農委會林務局東勢林區管理處) to reduce the concentration of suspended particles caused by flying dust.

The EPB has been continuously monitoring the erosion status of the river beds and passing the monitoring data to the TRMO for its reference in designing environmental improvement projects. For example, the TRMO may use the data to decide the locations to implement its sprinkler engineering methods, to set up the net and fence to fight against sand and dust, to plant vegetation, and to apply the vein-type water coverage control methods. Meanwhile, the Forestry Bureau may use the EPB data to design its reforestation programs to break wind fields, reduce wind speed, and block the sand wind. For the a forestation programs, our EPB has been investigating the needs of related government agencies and private enterprises and arrange annual budgets for new plantation and fostering programs. In addition to setting up the early warning system to monitor flying dust from bare land of rivers, our EPB has also been pilot-testing an “Area Transformation Demonstration” program in the Dajia River this year, in which we have been assisting TRMO-licensed farmers to plant in the fallow watermelon fields two hectares of pumpkin, which is expected to ripen during the northeast monsoon period and the pumpkin vines shall grow in to a green cover until February in the following year, thus effectively protecting the bare river-bed areas. Our EPB has at the same time strengthened horizontal links by regularly holding cross-government and cross-departmental meetings in a hope that we can enhance inter-agency cooperation to effectively reduce or even curb the flying dust from bare land of rivers.

Liu Bang-Yu (劉邦裕), Director-general of Environmental Protection Bureau, said, “After typhoon and heavy rainfall, many river beds are exposed and dust is prone to flying from there, especially under the influence of air circulation caused by typhoon and northeast monsoon. If suspended particles increase too much in the air, the health of residents will be harmed. That is why our EPB holds regular cross-agency meetings to coordinate and deal with the flying dust issue. All the related agencies have been sparing no effort in the past and have produced good results. For example, the frequency of PM10 greater than 150μg/m3 (When PSI is greater than 100, the air adversely affects the public health) in Shalu Station dropped to 2 times during the period between September and December 2012. This is a giant reduction from 39 times in 2007 and it shows that we have been relatively successful over the years in controlling flying dust from the bare river beds. We will continue to work together with other related agencies in minimizing flying dust from the bare river beds.”