Estimation of water quality using GIS data and Landsat TM data
M. Shizukuishi, O. Imai, and H. Takeuchi
Systems Engineering Center, Pasco corporation
No. 13-5, 2-chome Higashiyama,
Meguro-ku, Tokyo Japan
Abstract
Remote Sensing technology offers a wider latitude of potential application when combined with excels in storage, manipulation and analysis of geographic information and socio-economic data. In the study, it was attempted to divide the study area (waters) I sections by means of GIS in dealing with Landsat TM data in a bid to estimate water quality at actual water quality could be emphasized for analysis by dividing the study area instead of dealing in one whole area to make more realistic estimation imagery possible to be developed, thus confirming the usefulness of GIS data.
Introduction
Combination of GIS (Geographic Information System) and remote sensing technologies is a natural development in response to the technological needs of recent years. For GIS, remote sensing data including Ladnsat data are one of the most important sources of information. They provide the latest information in a form readily adaptable to computers and available for use in time series. So that the integration of remote sensing data in GIS is most meaningful for creation of a smaller map scale GIS while eliminating problems involved in the usually cumbersome process of data input in computers.
On the other hand, GIS has an excellent technology to offer in manipulation and analysis of volume data that can be applied most effectively to remote sensing data. GIS is equipped with data in other fields that complement remote sensing data, such as geographic information based on smaller administrative units like cities, towns and villages, and socio-economic data derived form the census. Theses two technologies when combined effectively provide wider attitude of potential applications than when applied individually.
The integration of these two technologies, however, was not free from problems in the past despite the awareness of its greater potential. There were problems due tot eh ever expanding size of computer systems for GIS and remote sensing data processing and, more importantly, the difference in data storage methods between GIS and remote sensing data. Today as a result of rapid progress in hardware and software, the two technologies are feasible on the one same hardware system.
One such example is a combination of ARC/INFO (a proprietary system of ESI, USA), a leading vector type of GIS software, and Erdas (similarly of ERDAS, USA) that are in operation as PASCO where the author belongs. In this study, applicability or usefulness of GIS data was examined for estimation of water quality as a leading indicator of the aquatic environment.
