A STUDY ON GRAIN-SIZE DISTRIBUTION OF SEDIMENTS WITH USE OF PROBABILITY CONCEPT

Abstract

河川における土砂流送の形態は一様ではないが・河床に残された砂礫の粒度組成は・その地点における土砂流送の形態を推察するうえに有力な手掛りを与えるであろう。本研究はこのような観点から, 河床材料の粒度組成に確率論的な考察を試みたものである。It may be expected that a clue for explaining the conditions of sediments in riverstream is grain-size distributions of bed materials which are the results of sieving due tothe stream flow. In this paper the mathemarical expressions of grain-size distributionsof bed materials are considered with use of probability concept. A grain-size distributionfunction is proposed under a simple condition that the grains are related to the hydraulicproperties with a single relationships. The actual grain-size distributions at Yasuokareservoir which has been filled with sediments show that the proposed distributionfunction can be applied to the bed materials composed of settlings.河川における土砂流送の形態は一様ではないが・河床に残された砂礫の粒度組成は・その地点における土砂流送の形態を推察するうえに有力な手掛りを与えるであろう。本研究はこのような観点から,河床材料の粒度組成に確率論的な考察を試みたものである。It may be expected that a clue for explaining the conditions of sediments in riverstream is grain-size distributions of bed materials which are the results of sieving due tothe stream flow. In this paper the mathemarical expressions of grain-size distributionsof bed materials are considered with use of probability concept. A grain-size distributionfunction is proposed under a simple condition that the grains are related to the hydraulicproperties with a single relationships. The actual grain-size distributions at Yasuokareservoir which has been filled with sediments show that the proposed distributionfunction can be applied to the bed materials composed of settlings