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Seminar on The applications of Satellite NDVI to Forest and Rice Management

Đăng lúc: 16:11:08 23/11/2017 - Người đăng bài viết: Admin CTTT - Đã Đọc: 153

The International Programs Office, Thai Nguyen University of Agriculture and Forestry (TUAF) successfully organised the Seminar on The applications of Satellite NDVI to Forest and Rice Management which represented by Ass. Prof. Hsuan Ren, Center for Space and Remote Sensing Research –National Central University (NCU). It was held on Wednesday, August 30th, 2017 at the TUAF central house. 

Attending in the seminar, TUAF has a number of lecturers participated: Dr. Duong Van Thao - Director of International Program Office, Assoc. Prof. Dam Xuan Van- Director of CFI, Dr. Tran Thi Pha- Lecturer of Environment Department, Dr. Arinafril-  Lecturer of  Universitas Sriwijaya.

Ass. Prof. Hsuan Ren introduced the advantage of Satellite images

In his study, the advantage of satellite image  is to estimate the water depth and island area without touching. Taiwan suffered  several earthquakes and typhoon which caused landslide each year, infrared image is used to observe landslide and plant cover. When landslide occurs, coastal line change year by year. Applying satelite image to detect boundary between land and water, also water depth ad bottom materials and water attenuation coeefficient.

Due to the economic development and population size, the transportation and natural resource are observed to have better development plan. Formosat 2 can use for natural resource classifications. Estimating the water depth can use three methods: SONAR, LIDAR and satellite image (Stereo Pair (2image taking from 2 angles), Beer-lambert law, empirical model).

SONAR: based on speed of sound in water to measure the time difference of transmit and receive sound …Using the multibeam can only estimate on  the track cover. LIDAR: up to 50m if water is clear but it is not easy to observe large area. Using stereo images taking form different angles and then find the tie points the water (normally it is coral reef).

Using the Beer-Lanbert law: sunlight  go to water, some will reflect water signal, some will reflect coral reef or sand. Higher error will appear if it is over 30m. Empirical Model: Applying satellite image to estiamte water depth and bottom materials. It needs to have errorr assessment (difference between Lidar an Neutral network). Ground truthing, hand measurement using to verify the images estimation. Using satellite images can observe large areas, especailly coastal area, sea grass, live coral, rock, sand, they found that some coral reef did not turn white. Using satellite image can also oberve the scrated coral reef because of boat passing.

Landslide: factors affects the landslide: rain(direction of speed), surface and undergroud water; topographic (slope, gradient); geology (fault, rock characteristics); Tectonic (earhquake, volcano); land use (vegetation type, construction). In Taiwan, people do deforestation to grow food… it is the reason how landslide can destroy house, road…