A comprehensive system for the exploration and analysis of hydrological data

Tsakalias, G; Koutsoyiannis, D

dc.contributor.author	Tsakalias, G	en
dc.contributor.author	Koutsoyiannis, D	en
dc.date.accessioned	2014-03-01T01:14:17Z
dc.date.available	2014-03-01T01:14:17Z
dc.date.issued	1999	en
dc.identifier.issn	0920-4741	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/12977
dc.subject	Blackboard systems	en
dc.subject	Consistency of hydrological data	en
dc.subject	Exploratory data analysis	en
dc.subject	Heuristic algorithms	en
dc.subject	Homogeneity of hydrological data processing	en
dc.subject	Pattern directed programming	en
dc.subject	River stage-discharge relationships	en
dc.subject	Statistical tests	en
dc.subject.classification	Engineering, Civil	en
dc.subject.classification	Water Resources	en
dc.subject.other	Blackboard systems	en
dc.subject.other	Exploratory data analysis	en
dc.subject.other	Heuristic algorithms	en
dc.subject.other	Pattern directed programming	en
dc.subject.other	Algorithms	en
dc.subject.other	Computer aided engineering	en
dc.subject.other	Data processing	en
dc.subject.other	Data reduction	en
dc.subject.other	Set theory	en
dc.subject.other	Statistical tests	en
dc.subject.other	Systems analysis	en
dc.subject.other	Hydrology	en
dc.subject.other	data management	en
dc.subject.other	hydrology	en
dc.subject.other	methodology	en
dc.subject.other	surface water	en
dc.title	A comprehensive system for the exploration and analysis of hydrological data	en
heal.type	journalArticle	en
heal.identifier.primary	10.1023/A:1008197511426	en
heal.identifier.secondary	http://dx.doi.org/10.1023/A:1008197511426	en
heal.language	English	en
heal.publicationDate	1999	en
heal.abstract	A new approach is developed for the automatic (computer based) exploration and analysis of hydrological data, particularly focused on the identification of shifting relationships among hydrological variables. The methodology developed is applicable to many hydrological problems, such as identification of multiple stage-discharge relationships in a river section, data homogeneity analysis, analysis of temporal consistency of hydrological data, detection of outliers, and determination of shifts and trends in hydrological time series. Such problems are examined here as particular applications of the single methodology developed. A general mathematical representation of the data exploration problem is initially proposed, based on set theory considerations. Several statistical tests, as well as auxiliary information of physical conditions, are systematically combined to form an objective function to be optimised. This objective function represents the performance of a solution, (where a solution is a specific partitioning of a data set into subperiods), in a manner, that holds in each subperiod a single relationship among data values. It is shown that an exhaustive search of all candidate solutions is intractable. Therefore, a heuristic algorithm is proposed, which emulates the exploratory data analysis of the human expert. This algorithm encodes a number of search strategies in a pattern directed computer program and results in an automatic determination of a satisfactory solution.	en
heal.publisher	KLUWER ACADEMIC PUBL	en
heal.journalName	Water Resources Management	en
dc.identifier.doi	10.1023/A:1008197511426	en
dc.identifier.isi	ISI:000083826300003	en
dc.identifier.volume	13	en
dc.identifier.issue	4	en
dc.identifier.spage	269	en
dc.identifier.epage	302	en