Comparison of Morphometric Parameters for Jonk Watershed Derived from Integrated Tool Developed in ArcGIS and QGIS Platform

Abstract

AbstractIn the present study, an automatic integrated tool has been developed for morphometric parameters using a proprietary software, Aeronautical Reconnaissance Coverage Geographical Information System (ArcGIS) developed by Environmental Systems Research Institute (ESRI) and an open-source software, Quantum Geographical Information System (QGIS). Seven morphometric parameters have been evaluated that are drainage density (DD), Compound Topographic Index (CTI), stream order, form factor, elongation ratio, circulatory ratio and Lemniscate’s ratio. All parameters have been computed and compared between developed tool in ArcGIS, QGIS and a reference study. Fifteen randomly chosen points have been considered based on different elevation zones of watershed namely high elevation (HP) zone, moderate elevation (MP) zone and low elevation (LP) zone. Obtained results from both the tools show a variation in values of 2° in the slope. The average difference in slope obtained from ArcGIS tool and QGIS tool at high elevation zone is 5.32%, at moderate elevation zone is 2.72%, and at low elevation zone is 5.47%. The change in total stream length is found to be 2.56%. The average difference in drainage densities at high elevation zone is 33.79%, at moderate elevation zone is 25.86% and at low elevation zone is 16.69%. The average difference in CTI values obtained at high elevation zone is 11.61%, at moderate elevation zone is 14.75% and at low elevation zone is 13.87%. The percentage difference in elongation ratio is 14.80%, for circulatory ratio is 6.5%, for form factor is 17% and Lemniscate ratio is 0.74%, respectively. Results were compared with the reference study done on the same watershed, and it was found that for stream order, ArcGIS and QGIS tools match with the reference study. For drainage density, form factor and elongation ratio, ArcGIS tool produces better results and for circulatory ratio, QGIS tool is producing better results when compared with reference study. Although there are discrepancy in the obtained results, this method generates a reliable database of morphometric parameters and is very useful in the field of hydrology and watershed analysis.KeywordsMorphometric parametersArcGISQGISReliable database