SMALL DAMS PETITS BARRAGES

the others weir gauges need to be installed at the lower points of the foundation, along the
longitudinal section, in which there are the possibility of water leakage, after the reservoir
filling. Usually it is not possible to evaluate correctly all the places in which it will have water at
the dam toe previously, then it is recommended to install the weir gauges of the central section
before the reservoir filling, and the other during or after the reservoir filling.
6.4.3 Data Analysis and Reporting
Data management and analysis are fundamental to understanding the behavior of the
monitored dam, for detecting unsafe development, and for determining the performance of the
instrument system. The plan should indicate the frequency of data collection, the extent and
timeliness of processing, the level of analysis and the reporting requirements.
Data Management
The management of data consists of data collection, reduction and processing, and
reporting. Data collection should begin with a well-defined established schedule. Data
collection procedures should adhere to the following guidelines:
� Data will be most consistent if collected by the same person;
� Using the same device or readout unit to read an instrument every time give the most
consistent readings;
� Instrumentation data should include the instrument reading and also any information
that identifies the project, instrument, reader, date, visual observations, climate, remarks, and
any site conditions that might affect the value of the reading;
� Recording reading in field books allows for comparison of current readings with
previous readings at the time the readings are collected. The readings in field books should be
transferred to data sheets or computer files as soon as possible after being obtained;
� Readings that exceed established levels should be reported immediately. The first
action should be to control the condition of the measuring device and to perform a new
measurement. If the measurement is confirmed, appropriate personnel should be notified
because a change in instrument reading or in visual observation reveals that a problem or
dangerous situation has occurred, or is occurring.
Data processing and reduction consists of converting the raw data into meaningful
engineering parameters necessary for graphical presentation, analysis and interpretation.
Calibration constants may be needed to convert the field reading to engineering values.
Checking for errors in instrumentation data should be accomplished at each level of
collection and processing, from reading of instruments in the field to final interpretation of the
instrumentation data. Instrumentation readings should be compared with ranges specified by
the design office and with previous readings under similar conditions. Conformance with
previous established trends should be determined.
Data Presentation – Numerically tabulated data are not conducive to detecting
trends, evaluating unanticipated behavior, and comparison with design values. Plots of the
data are needed to provide visual comparisons between actual and predicted behavior, a
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