ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Satellite Images for Detection of Coastal Landuse and Coastline Change in Mueang Prachuap Khiri Khan District, Thailand during 1987-2009)

ผู้เขียน:ดร.มณฑล อนงค์พรยศกุล, ผู้ช่วยศาสตราจารย์, Sunthari Tharapan, ดร.ภูวดล โดยดี, ผู้ช่วยศาสตราจารย์, Likit Choochit

สื่อสิ่งพิมพ์:pdf

Abstract

Satellite images were used to classify and annotate coastal landuse in Ko Lak and Klongwan subdistricts and to detect changes to the coastline in Ao Noi, Prachuap Khiri Khan, Ko Lak and Klongwan subdistricts, Prachuap Khiri Khan district in Prachuap Khiri Khan province, Thailand. The study used a remotely sensed dataset of LANDSAT-5 TM images with a spatial resolution of 30 ? 30 m acquired during 1987–2009. Areas of coastal landuse and coastline changes were calculated using a pixel-based technique. Eight categories of coastal landuse were identifi ed: 1) agriculture, 2) urban and buildings, 3) mangroves, 4) bare soil, 5) airport, 6) seascape, 7) upland forest and island vegetation, and 8) aquaculture and water bodies. The results found that between 1987 and 2009, areas classifi ed as agriculture, urban and buildings, and mangroves increased by 1,150, 360, and 340 rai (1 rai = 0.16 ha) respectively, while aquaculture and water bodies decreased by 1,850 rai. Moreover, there were changes to the coastline in Ao Noi, Prachuap Khiri Khan, Ko Lak and Klongwan subdistricts based on a mixture of stable and eroded features. Comparing 2009 with 2004, the coastline area in Prachuap Khiri Khan, Ko Lak and Klongwan subdistricts had eroded by 31, 40, and 11 rai, respectively.

Article Info

Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 045, Issue 6, Nov 11 - Dec 11, Page 1064 - 1070 |  PDF |  Page

ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Dissolved Oxygen Dispersion Model Within Green Mussel Farming Area in Sri Racha Bay, Chonburi Province, Thailand)

ผู้เขียน:ดร.มณฑล อนงค์พรยศกุล, ผู้ช่วยศาสตราจารย์, Sunthari Tharapan, นายอลงกต อินทรชาติ, ดร.ภูวดล โดยดี, ผู้ช่วยศาสตราจารย์, Pramot Sojisuporn

สื่อสิ่งพิมพ์:pdf

Abstract

Dissolved oxygen (DO) is a major parameter in the aquatic environment and it is also necessary for all marine organisms, including mollusks. Thus, a case study was developed to model the DO distribution within a green mussel farming area in Sri Racha Bay, Chonburi province, Thailand. The model indicated that the water was well mixed, based on a mass balancing equation. The DO concentration varied depending on the sources and sinks of the DO which were applied to the model. A solution for the model was considered by an implicit method of successive over relaxation. In the model, the velocity of water was computed by the Princeton Ocean Model (POM). The output of the POM revealed that the seawater moved northward during the flood tide, while during the ebb tide, it moved southward with a maximum speed approximately 1 m.sec-1. The model was applied by adding and removing DO terms which were obtained from empirical experiments. On 29 January 2010 at 2100 hours, when low tide occurred, the DO concentration in the center of a floating raft of green mussel (Perna viridis) was lowest while the advection of water was dramatically slackened. Moreover, during night time, when there was no photosynthesis, the DO concentration was lowest. The results obtained from the model were acceptable compared with actual field observations. Similarly, the pattern of DO dispersion from the prediction at low tide also corresponded to the pattern of DO dispersion from the survey at low tide. Thus, the model could be used as a tool for predicting and estimating the amount of DO in a marine culture area in order to increase production and the preservation of the environment.

Article Info

Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 046, Issue 4, Jul 12 - Aug 12, Page 565 - 572 |  PDF |  Page