The 9th River Management Office, WRAThe 9th River Management Office, WRA

1. Geographical Topography　

The responsible area of The Ninth River Management Office covers the whole Hualien County and partial areas of Che-Shan town and Hai-Ruey town with 140 kilometers long in its north-south and 27 to 43 kilometers wide in its east-west directions. The Central Mountain Range with many high mountains is located in the west boundary with precipitous slopes along the whole valley, and the Coastal Mountain Range with hills of 200 to 600 meters above the sea level is located at the east. The valley plain with 6% riverbed is the finest area which lies between these two ranges and covers only 13% of our responsible area. Hence, mountain landslide mitigation and flood hazard control become our two major tasks.
Hualien River and Shiew-Gu-Luang River are the two major rivers inside the valley area managed by this Bureau. And, Ji-An River, Mei-Loon River, Li-Wu River, and Ho-Ping River are the secondary rivers managed by the Hualien County Government. All these rivers originate from the Central Mountain Range and run into the Pacific Ocean.
Shiew-Gu-Luang River is located in the southern area of the valley, originates from Lun-Tien-Shan of the Central Mountain Range and turns to north inside the valley.  After merging with five branch rivers, it turn to east at Ruey-Shuei Town and run through the Coastal Mountain Range into the Pacific Ocean at the Big Harbor Village.
Hualien River is located in the central area of the valley, originates from Ba-Tse Mountain of the Central Mountain Range and turns to the north inside the valley. After joining with five branch rivers, it flows into the Pacific Ocean at the northern tip of the valley.

Basic information of the main and secondary rivers:

2.Meteorology

Taiwan is located in the sub-tropical area and the Tropic of Center passes through Ruey-Shuei town in the southern area of Hualien. The monthly average temperature is about 17~28 degree centigrade. During the summer ~ autumn seasons, many typhoons forming in the northern Pacific Ocean landfall in Hualien areas very often and bring heavy rainfall. On the other hand, there are not much precipitation in the winter time due to the strong northeast monsoon. Statistically, the annual rainfall quantity of 2,000 mm has about three quarters in May to November and only one quarter in the autumn ~winter time.

3. Water Resource Survey

This Bureau tentatively concentrates the Water Resource Survey in surface hydrology, underground hydrology, rainfall intensity and oceanographic observation in Hualien area.

(1) Surface Hydrology Survey 
The major task of Surface Hydrology Survey is to investigate the water level and flow capacity of each major river in Hualien County. There are two river systems in Hualien. The Hualien River system is located to the northern part of the valley with five branch rivers, i.e., Papaya River, Show-Feng River, Won-Li River, Ma-An River, and Kuang-Fu River. The water level and flow capacity survey stations are set at seven places installed at Hualien Bridg over Hualien River, je-in bridge over Hualien river, Ni-Jan Bridge over Hualien river, Jen-Show Bridge over Papaya River, Feng-Ping Bridge over Show-Feng River, Won-Li River Bridge over Won-Li River, and Ma-An River Bridge over Ma-An River.

The other river in southern part of the valley is called Shiew-Gu-Luang River System which consists of five river branches called Fu-Yuan River, Hong-Yeh River, Feng-Ping River, Chow River, and Le-Le River. There are also seven water level and flow capacity survey stations, which is installed at Yu-Li Bridge and Rue-Suai Bridge over Shiew-Gu-Luang River, Ma-Yuang Bridge over Fu-Yuan River, and Li-Shan over Feng-Ping River, and Chow-Le Bridge over Le-Le River.

 These fourteen survey stations were installed to observe the variation of water level and flow capacity in each major river with the major purposes of measuring the actual flood and draught flow-rate in each year. It will generate the necessary information to be used in the river related projects in terms of its design, construction and management reference. Moreover, they are also very important information in the irrigation, civic and industrial water supply developing plans.

(2) Underground Hydrology Survey　 
By 2015, there were originally 29 observation wells installed to monitor the underground water level within the Hualien areas. Due to the upgrading policy, 18 of these observation wells will be remodel to feature with automatic observation facilities and will be installed in 2017. Nevertheless, its monthly data collection has been conducted for more than twenty continuous years in these 29 observation wells and is very valuable and helpful for the underground water resources development in the future.

(3) Rainfall Survey 
There are twenty rainfall observation stations installed at the major river basins within Hualien County. The purpose of these observation stations is to record the rainfall intensity inside the major river basins area. The twenty stations are Pei-Pu Station of Meilun River Basin, Tung-Men Station of Papaya River Basin, Si-Lin Station and Hsin-Tung-Kwan Station of Show-Feng River Basin, Hsin-Ta-Kwan Station and Hsin-Kau-Lin Station of Won-Li River Basin, Ma-Tai-An Station of Ma-Tai-An River Basin, Ta-Ping Station of Fu-Yuan River Basin, Li-Shan Station of Feng-Ping River Basin, Chow-Lu Station and Wa-La-Bi Station of Le-Le River Basin, Ming-Li Station of Nan-Lun-Tien River Basin, Feng-Bin Station of Feng-Bin River Basin, Liu-Su-Dan Mountain Station, Do-Fu Station, Joo-Jin Station,…plus one on the roof of bureau building. Each station is equipped with both the automated rainfall meters and manual-operated rainfall gauge. In order to get the most precise rainfall records, we take use of data collected from both the automated instrument and manual device.