✦ LIBER ✦

Detecting changes in trends in water quality using modified Kendall's tau

✍ Scribed by P. F. Darken; G. I. Holtzman; E. P. Smith; Carl E. Zipper

Publisher: John Wiley and Sons
Year: 2000
Tongue: English
Weight: 93 KB
Volume: 11
Category: Article
ISSN: 1180-4009
DOI: 10.1002/1099-095x(200007/08)11:4<423::aid-env423>3.0.co;2-l

No coin nor oath required. For personal study only.

✦ Synopsis

A method for testing the equivalence of two modi_ed Kendall|s tau nonparametric correlation coe.cients\ neither necessarily equal to zero\ is presented[ Several estimators of the variance of t ¼ mod were evaluated using simulation[ A bootstrap estimate\ the standard null!case variance estimate\ and a delta method variance estimate are shown to provide reasonable estimates in di}erent circumstances[ The results of a power study are also given\ including a comparison with the test of equivalence of two Pearson correlation coe.cients[ The variance estimators and their corresponding Wald!type tests were studied under di}erent conditions\ including the presence of varying degrees of serial correlation\ di}erent distributions\ and di}erent percentages of tied data[ The power study revealed that in the presence of serial correlation\ a new method for estimating variance\ called the effective sample size bootstrap\ allowed the hypothesis test to consistently hold its level while no other method of estimating the variance did[ Finally\ through the use of an example\ it is demonstrated how this test can be used to detect changes in trend of water!quality variables over time [ Copyright Þ 1999 John Wiley

📜 SIMILAR VOLUMES

Trend detection in water quality data us

Trend detection in water quality data using time series seasonal adjustment and statistical tests

✍ A. G. Awadallah; Hussam Fahmy; H.G. Karaman 📂 Article 📅 2011 🏛 John Wiley and Sons 🌐 English ⚖ 509 KB

## Abstract Detection of temporal and spatial trends can be considered one of the primary objectives of environmental monitoring networks. The overall goal of this paper is to make full use of water quality data available on Nile Delta drains in order to support the decision makers in managing the

Forecasting the changes in lake water qu

Forecasting the changes in lake water quality in response to climate changes, using past relationships between meteorological conditions and water quality

✍ Takehiko Fukushima; Noriatsu Ozaki; Hiroaki Kaminishi; Hideo Harasawa; Kazuo Mat 📂 Article 📅 2000 🏛 John Wiley and Sons 🌐 English ⚖ 258 KB 👁 2 views

In order to forecast the eects of global warming on the water environment, the relationship between meteorological conditions and lake water quality was investigated statistically using 17 years of monitoring data obtained from a shallow eutrophic lake, Lake Kasumigaura. The usefulness of the DPY (d

Estimation of Surface Water Quality Chan

Estimation of Surface Water Quality Changes in Response to Land Use Change: Application of The Export Coefficient Model Using Remote Sensing and Geographical Information System

✍ Nandish M. Mattikalli; Keith S. Richards 📂 Article 📅 1996 🏛 Elsevier Science 🌐 English ⚖ 193 KB

A trend of increasing solute (i.e. nitrogen and phosphorus) concentrations in surface water has been observed in the recent past. Solute concentrations have often exceeded the World Health Organization directives on the quality of drinking water. In predominantly rural watersheds of developed countr