This study was carried out to apply the UAV(Unmanned Aerial Vehicle) coupled with Multispectral sensor for the algae bloom monitoring in river. The study acquired remote sensing data using UAV on the midstream area of Gum River, one of four major rivers in South Korea. Normalized difference vegetation index (NDVI) is used for monitoring algae change. This study conducted water sampling and analysis in the field for correlating with NDVI values. Among the samples analyzed, the chlorophyll concentration exhibited strong and significant linear relationships with NDVI, and thus NDVI was chosen for algae bloom index to identify emergence aspect of phytoplankton in river. Aerial remote sensing technology can provide more accurate, flexible, cheaper, and faster monitoring methods of detecting and predicting eutrophication and therefore cyanobacteria bloom in water reservoirs compared to currently used technology. As a result, there was high level of correlation in chlorophyll-a and NDVI. It is expected that when this remote water quality and pollution monitoring technology is applied in the field, it would be able to improve capabilities to deal with the river water quality and pollution at the early stage.

Recently, advanced metering infrastructure (AMI) has been recognized as a core technology of smart water grid, and the relevant market is growing constantly. In this study, we developed all-in-one smart water meter of the AMI system, which was installed on the test-bed to verify both effectiveness and field applicability in office building water usage. Developed 15 mm-diameter smart water meter is a magneto-resistive digital meter, and measures flow rate and water quality parameters (temperature, conductivity) simultaneously. As a result of the water usage analysis by installing six smart water meters on various purposes in office building water usage, the water usage in shower room showed the highest values as the 1,870 L/day and 26.6 liter per capita day (LPCD). But, the water usage in laboratory was irregular, depending on the many variables. From the analysis of the water usage based on day of the week, the water usage on Monday showed the highest value, and tended to decrease toward the weekend. According to the PCA results and multivariate statistical approaches, the shower room (Group 3) and 2 floor man’s restroom sink (Group 1-3) have been classified as a separate group, and the others did not show a significant difference in both water use and water quality aspects. From the analysis of water usage measured in this study, the leak or water quality accident did not occur. Consequently, all-in-one smart water meter developed in this study can measure flow rate and water quality parameters (temperature, conductivity) simultaneously with effective field applicability in office building water usage.

Most of the extensive areas in the lower parts of the Nakdonggang River are characterized as zones of the diversely geomorphological features: the riparian wetland and floodplains, the riverine sand island on the river channel and riverine wetlands along the river. It aims to introduce the floodplains of the Nakdonggang River and its tributary (Hwapocheon Stream), and to evaluate their utilities in the process of the watershed management and the stream restoration in future. The lowland floodplains are developed over the 1,000 ha area beyond the riverbank in the middle and lower parts of the river. Furthermore, the 19 sand islands distribute on the river channel and the riverine wetlands are situated over 11 locations along the riverside. The most floodplains along the river had been converted to agricultural and other land uses, especially paddy fields, and two wetlands - the Hwaponeup Wetland in the Hwapocheon Stream and the Wooponeup Wetland in the Topyeongcheon Stream - barely keep in existence of the natural type one. In the Hwapocheon Watershed, the lowland below the 50 m elevation covers 61% of the basin area and the wetland interiorly spread along the stream bank. The area of the Hwaponeup Wetland is 250 ha to rank second level next to Wooponeup Wetland in sizes or scopes of inland ones. The Hwaponeup Wetland displays a unique landscape with the various willowtree population and waterside plants to have the high biological diversity. The 448 ha floodplain area in the lower zone and the 259 ha area in the mid-zone of the stream had been already reclaimed in the past, and in the present, the lowland floodplains around the stream-type wetland had been exclusively occupied with the paddy farms. In recent year, as the wetland and floodplain restoration have emerged as a key component in local watershed management programs over the world, these lands should have the greatest potential for future ecosystem recovery and restoration because the ecological values of the Hwapocheon Stream could increase more than those of the other areas. The restoration, creation and enhancement of the wetland provides opportunities for solving existing flood control or erosion, ecological habitat or biological diversity, other water resource problem. In these context, the network systems to connect the stream channels and riparian floodplains are a basic concept in the watershed management. In view of the natural resources, the Hwapocheon Stream will have the better advantage to control the flooding and water quality in the process of the stream restoration or watershed management in the local area.