气候变化领域集成服务门户

High suspended sediment concentrations (SSCs) from natural and anthropogenic sources are responsible for biological impairments of many streams, rivers, lakes, and estuaries, but techniques to estimate sediment concentrations or loads accurately at the daily temporal resolution are not available. This paper presents a time series separation and reconstruction technique (TSSR) that separates time series data (e.g., streamflow or SSC series) into two components: magnitude or duration curve and time sequence or simply sequence as referred throughout this paper. This technique uses only magnitude to estimate sediment rating curves (SRCs) and sediment duration curves (SDCs) and uses both components to estimate daily SSC series for gauged and ungauged sites. Nash-Sutcliffe model efficiency between observed and TSSR estimated SDCs for study watersheds ranged from 0.89 to 0.99. For two selected gauged sites, model efficiencies between observed and TSSR estimated SSC series were 0.96 and 0.98, and for two ungauged sites model efficiencies were 0.65 and 0.88. TSSR's improved performance is attributed to its ability to separate time series into two components, build individual SRCs, complete SDCs from the magnitude, and convert the estimated SDCs to SSC series using stored sequence to reshuffle the SDCs. For gauged sites, sequence embedded in the observed SSC series of the site itself is used, but for ungauged sites, sequence is obtained from nearby gauged sites. (C) 2014 American Society of Civil Engineers.