Grain size distribution of modern beach sediments in Sri Lanka  

作　　者：U.L.H.P.Perera Amila Sandaruwan Ratnayake W.A.D.B.Weerasingha H.C.S.Subasinghe T.D.U.Wijewardhana 

机构地区：[1]Department of Applied Earth Sciences,Faculty of Applied Sciences,Uva Wellassa University,Passara Road,Badulla 90000,Sri Lanka

出　　处：《Anthropocene Coasts》2023年第1期117-125,共9页人新世海岸(英文)

基　　金：financial assistance for this study by an Accelerating Higher Education Expansion and Development(AHEAD)Development Oriented Research(DOR)grant funded by the World Bank.

摘　　要：Grain size distributions are widely used to describe sedimentary geochemistry,depositional environment,and sedi-ment transportation.The objective of this study is to analyze grain size distributions of modern sandy beach sedi-ments in Sri Lanka.Sediment samples(n=90)were collected from beach berm,representing the entire coastline of Sri Lanka.Grain sizes were determined by the dry-sieving method.Statistical parameters such as mean size,sorting,skewness,and kurtosis were calculated using GRADISTAT_(V9.1) software for all the sieved sediment samples.Grain size variations(108.2-609.8μm)show that Sri Lanka mainly consists of medium sand,whereas the northeast part of the country mixes with fine sand due to the influence of Bengal fan sediments.The variations of skewness(-0.229-0.446)and sorting(1.305-2.436)indicate symmetrical distributed moderately sorted samples.These variations specify a moderate energy depositional environment/wave action around the coastline of Sri Lanka.In addition,grain size analysis confirmed relatively high and low energy deposition environments on the west and east coasts,respectively.Accordingly,the west coast is more vulnerable to coastal erosion compared to the east coast of Sri Lanka.Therefore,this study provides the baseline grain size distribution data that can be used in decision-making for coastal zone management by mitigating beach erosion.

关 键 词：Sediment grain size SKEWNESS KURTOSIS Coastal erosion Beach nourishment 

分 类 号：P73[天文地球—海洋科学]