Spatial and Temporal Distribution of Areas With Drainage Problems as Estimated by Different Interpolation Techniques

Abstract

This study used spatial interpolation methods and a geographic information system that examines spatial and temporal variations in areas with drainage problems. Monthly groundwater depths were measured from 2005 to 2009, and the lowest depths were used to create groundwater maps for each year using five different interpolation. Cross-validation using root mean squared error (RMSE) and the correlation coefficient (r) as indices were used to compare the accuracy of each method. A comparison of interpolated and observed values indicated radial basis function (RBF) to be the optimal method for interpolating lowest groundwater depth in 2005, whereas simple kriging (SK) was found to be the optimal method for 2006, 2007, 2008 and 2009. With the exception of 2007, from 2005 to 2009, approximately 8% of the study area was determined to have a groundwater depth ranging from 0 to 1m. Between 2005 and 2009, the percentage of the area found to have drainage problems that negatively affected plant growth varied from 60.83% to 86.53%. © 2012 CIWEM.