Application of geospatial technology and interpolation algorithms to simulate water quality of West Lake

Abstract

This study applies geospatial technologycombined with two popular interpolation methods, IDW and Kriging, to simulate and evaluate the spatial distribution of water quality parameters in West Lake, including DO, total Nitrogen (TN) and total Phosphor (TP). Data were collected from 22 monitoring points on the lake surface, then processed and analyzed using QGIS software. The results show that the IDW method provides higher simulation accuracy than Kriging, as shown by statistical indicators such as R² and NSE -especially for DO and TP parameters,IDW achieved NSE > 0.85 (very good), while Kriging was only at "good". The interpolation map clearly reflects areas at high risk of organic pollution and eutrophication in the South and Northwest of the lake. The integration of GIS and interpolation has effectively supported water quality simulation, contributing to improving the ability to monitor and manage urban water environment. The research results are the scientific basis for choosing the appropriate interpolation method in similar studies and practical applications.