IPN-ISRAEL, 17 th -19 th Sep, 2014 The WaTrend System Meir Rom, D.Sc. Statistician and System Analyzer

IPN-ISRAEL, 17 th -19 th Sep, 2014 The WaTrend System Rapid Characterization and Prediction of Long Term Water Quality Changes in Ground Water and Surface Water Resources 2 2 Contributors: Sharon Hassid, Evgeny Kleiman, Ami Einav Mekorot, System Information Unit

IPN-ISRAEL, 17 th -19 th Sep, 2014 Facts and Figures 3 3 3,000 Facilities 12,000 km of water lines 1,070 Water well drillings

IPN-ISRAEL, 17 th -19 th Sep, 2014 Objectives 4 4 Characterize and Identify large number of water resources, thru historical records in few seconds Predict values of water quality using simple statistical tools No need to have special skills in Statistics. Background calculations. Interactive, friendly multi-utilities GIS environment

IPN-ISRAEL, 17 th -19 th Sep, 2014 Usages (Already Operational) 5 5 Hydrological surveys Reveal potential contamination and its source Prepare for new regulations and standards Exploratory Data Analysis (EDA) tools

IPN-ISRAEL, 17 th -19 th Sep, 2014 Input 6 6 Mekorot’s water-quality data-base: spatial and temporal historical data of all quality parameters. User must indicate, district, time-window and choose specific quality parameter. Mekorot’s water supply data-base mainly for filter-out “inactive” water resources

IPN-ISRAEL, 17 th -19 th Sep, 2014 Why use robust measures? % 116% 207% 267% Leverage Points Nitrate (NO3) – Ein-Hod

IPN-ISRAEL, 17 th -19 th Sep, 2014 Trend measure 8 8 Calculate robust measure of trend monotony Here we used “kendall’s tau”( ): a well known statistical measure. In map, Adjust the “raduis” of the “star” shape label in proportion to the value of. Use Green color to indicate decrease of values. Important: High level of does not necessarily indicate high slope level !

IPN-ISRAEL, 17 th -19 th Sep, 2014 SD measure 9 9 Categorize all values into 5 groups, corresponding to the threshold concentration acceptance level. Process the relative-frequencies of each category in the specified time-window. Transform the results into [0,1] index means that all values in the time- window exceed the standard level. In map, Adjust the radius of the “diamond” shape label in proportion to

IPN-ISRAEL, 17 th -19 th Sep, 2014 Theil-Sen’s robust measure of slope 10 Use robust measure (Theil-Sen slope estimator) to estimate the trend’s rate and test for its statistically significance. Determine linearity of trend by halving the time-window and perform a significant comparison test. In case of non- linearity report slope results of the window’s second half. Set icon for each water resource to illustrate its dynamic behavior in time which corresponds to the specific quality parameter

IPN-ISRAEL, 17 th -19 th Sep, 2014 Spatial GIS maps 11

IPN-ISRAEL, 17 th -19 th Sep, 2014 Summary table 12 Summary for all characteristics associated with each water resource is given in dynamic table:

IPN-ISRAEL, 17 th -19 th Sep, 2014