Korea has been implementing Total Maximum Daily Loads(TMDL) for science-based water quality management since it was introduced in the early 2000s. Also, non-point pollution source management is being highlighted as the key to successful TMDL managemen...
Korea has been implementing Total Maximum Daily Loads(TMDL) for science-based water quality management since it was introduced in the early 2000s. Also, non-point pollution source management is being highlighted as the key to successful TMDL management, according to the first-stage diagnostic evaluation. The present TMDL is using the cadastral data-based unit load method to estimate land pollution loads, which occupy the majority of non-point pollution sources. However, land pollution loads different from the actual condition are estimated, since this only reflects the changes of lot-based land use. To solve this problem, there was an attempt to use the landcover map, which could show the actual state of land use, but it is impossible to use the landcover map without processing data, because of the long and irregular updating cycle.
Therefore, this study aimed to develope a landcover map updating method to be helpful in estimating loads. For achieving this purpose, the year-of-year landcover map updating method was divided into total four-steps of updating process and the study was conducted in Bupyeong-gu, Incheon Metropolitan City. At the first-step, spatial data necessary for updating were defined and pre-processing was carried out to use each data. After that, medium-classified landcover map was updated through overlay analysis-based visual assessment and screen digitizing using pre-processed spatial data. This time, updating of the medium-classification spatial resolution was defined as the second-step and updating of the sub-classification spatial resolution was defined as the third-step. At the fourth-step, the updating result was finally determined and considered through evaluating the accuracy of the updated landcover map.
The year-of-year landcover map updating method developed in this study can provide more accurate basic data for estimation of land pollution loads, in place of existing cadastral data by using various spatial data. In future, this study result could be restrictively applied to a study area, so there would be a need to choose a broader target area to evaluate the validity of the updating method.