TY - BOOK AU - Akhtar,Muhammad Ashraf AU - Suphat Vongvisessomjai, AU - Nishimura,Hitoshi AU - Prida Thimakorn, ED - British Government and Habour Department of Thailand, TI - River siltation due to tin mining T2 - Thesis PY - 1975/// CY - Bangkok PB - Asian Institute of Technology KW - Tin mines and mining KW - Thailand KW - Ranong KW - Sedimentation and deposition N1 - A thesis submitted in partial fulfillment of the requirements for the Degree of Master of Engineering at the Asian Institute of Technology, Bangkok, Thailand; Thesis (M.Eng.) - Asian Institute of Technology, 1975 N2 - The primary purpose of this research was to investigate and evaluate tin mining activities as a source of sediments in the rivers which were causing a severe siltation problem in the Ranong estuary of Thailand. The study was conducted on the three rivers, draining from tin mining areas and were responsible for transporting a huge quantity of sediments into the estuary. As there were no gaging stations on the rivers before the present study, a tank model was calibrated and developed to simulate long term run-off in one of the rivers using-nine-year daily rainfall as input. Unit hydrograph of Thailand was, then, used to find the long term runoff in the other two rivers in order to develop flow duration curves. Functional relationships between water discharge and sediment load were developed to determine sediment rating curves. From the flow-duration and sediment rating curves of the rivers, it was estimated that about 1.7 million tons of sediments were being transported and silted in the estuary and river mouths every year. In this quantity, tin mining areas contributed about 99 percent of the sediments and only 1 percent sediments were from the forest land. Predicted sediment load and sediment dredging data for the silting reach were compared to estimate distribution of sediments in the estuary. It was found that about 34 percent of sediments were being deposited in the silting reaches at the river mouths and remaining 66 percent passed to the estuary UR - http://203.159.5.9/ait-thesis/detail.php?q=B23987 ER -