Quick and easy Mann Kendall Trend and Linear Regression Analysis
ESdat Environmental Data Management Software is used to validate, import, analyze and report a broad spectrum of Environmental Data as Exceedance Tables, Graphs, Maps, and statistics. ESdat includes modules to calculate Mann Kendall Trend Analysis and Linear Regression Analysis on your dataset.
Mann-Kendal trend analysis, commonly referred to as M-K test, is an analysis that explores data collected over a period (Neeti & Eastman, 2011). The data, in this case, needs to have monotonic trends, where it is either increasing or decreasing in the Y values. M-K tests are primarily non-parametric thereby can analyses data on various distributions. Although it provides a trend on data from a few as four samples, the test is more accurate with more samples. An M-K test with a null hypothesis holds that the series lacks a monotonic trend whereas that of an alternative hypothesis posits that a there is a trend.
When running an M-K test one should ascertain that data is collected continuously rather than seasonally. This ensures that there is a constant trend of data collected. The data should be independent and have no covariant. The only factors that influence the data should be relevant to the series. Additionally, one should ensure that they use one data point at a time and if they are to use multiple data points, they should consider the median value.
As the test uses data from a series, it analyses the different signs present between the recorded and current data. As it follows a monotonic trend, it is likely that the points will be increasing or decreasing, thereby creating a constant series for analysis. The values are compared to those preceding them, which presents the data as n (n-1)/2, where n represents the total observations made. Notably, the M-K test is dependent on the number of observations made from a series of observations within a period.
One can choose to run the data manually or through software. Using ESdat software is easier and time conservative. Features include:
- Mann Kendal or Linear Regression
- Annotated on the graph (TUp, TDn, and LH stand for Trending Up/Down, Last value Highest)
• Environmental guidelines / trigger levels
• Produced in Excel - save and open directly in Excel
For more information on Mann Kendal and Linear Regression software
ESdat, Environmental Data Management Software, is developed by Earth Science Information Systems (EScIS), and used for a variety of applications including contaminated/industrial sites, groundwater investigations, general site environmental management and landfill. https://esdat.net
EScIS provide environmental and groundwater database software, consultancy, advisory, programming, customization, implementation, and training services.
EScIS also develop and resell the ESdat suite of software. ESdat is used worldwide and is the most widely used environmental and groundwater data management and analysis package in the Asia / Pacific.