Ca. Bush et Jg. Uber, SAMPLING DESIGN METHODS FOR WATER DISTRIBUTION MODEL CALIBRATION, Journal of water resources planning and management, 124(6), 1998, pp. 334-344
Field sampling is sometimes performed to support modeling activities-s
pecifically, to estimate the parameters of a mathematical model or, mo
re accurately, to calibrate the model. In this case, a relevant questi
on for field samplings design is ''how to maximize the confidence in e
stimated parameter values, given a level of sampling effort?'' We appr
oach this question using established ideas in parameter estimation and
sampling design theory and propose general sensitivity-based methods
to rank the locations and types of measurements for estimating the par
ameters of a water distribution network model. The proposed methods ar
e suboptimal, yet practical, and are applied to select good tracer and
pressure measurement locations for estimating pipe roughness coeffici
ents. These particular results suggest that, when compared to pressure
measurements, tracer measurements can be informative for calibrating
network hydraulic parameters but one must take more care in selecting
their location. Using the proposed methods, a selection of both tracer
and pressure measurements improves estimation confidence by a factor
of 2, over that obtained using tracer or pressure measurements alone.