Mass load estimation errors utilizing grab sampling strategies in a karst watershed

Journal of the American Water Resources Association
By: , and 

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Abstract

 Developing a mass load estimation method appropriate for a given stream and constituent is difficult due to inconsistencies in hydrologic and constituent characteristics. The difficulty may be increased in flashy flow conditions such as karst. Many projects undertaken are constrained by budget and manpower and do not have the luxury of sophisticated sampling strategies. The objectives of this study were to: (1) examine two grab sampling strategies with varying sampling intervals and determine the error in mass load estimates, and (2) determine the error that can be expected when a grab sample is collected at a time of day when the diurnal variation is most divergent from the daily mean. Results show grab sampling with continuous flow to be a viable data collection method for estimating mass load in the study watershed. Comparing weekly, biweekly, and monthly grab sampling, monthly sampling produces the best results with this method. However, the time of day the sample is collected is important. Failure to account for diurnal variability when collecting a grab sample may produce unacceptable error in mass load estimates. The best time to collect a sample is when the diurnal cycle is nearest the daily mean.

Publication type Article
Publication Subtype Journal Article
Title Mass load estimation errors utilizing grab sampling strategies in a karst watershed
Series title Journal of the American Water Resources Association
DOI 10.1111/j.1752-1688.2003.tb04423.x
Volume 39
Issue 6
Year Published 2003
Language English
Publisher Wiley
Description 12 p.
First page 1361
Last page 1372
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