## 4 Results
### Application of the KEIDP Calculation Model  
Figure 4 shows the trend in the proportion of environmentally friendly projects according to each indicator. Here, environmentally friendly means that the normalized index result calculated from Equation (2) presented a positive value. These projects reduced the value of indicators affecting the environment after their completion, and it could be assumed that the project outcomes reflect the EIA results. The proportion of projects with reduced PM10, nitrogen dioxide, sulfur dioxide, ozone, hydrogen ion concentration, suspended solids, total nitrogen, total phosphorus, total coliforms, cadmium, copper, arsenic, lead, zinc, and fluorine indexes increased by more than 2% per year. The proportion of projects with reduced carbon monoxide, dissolved oxygen, chemical oxygen demand, biochemical oxygen demand, mercury, and nickel indexes increased by less than 2% per year. Overall, the percentage of environmentally friendly projects according to each indicator steadily increased compared to the past. It was found that the percentage of environmentally friendly projects did not exceed 50% in 2007, but exceeded 50% by the end of the study period.  
Figure 3: Error convergence, validation and distribution of factors weights results of produced MLP based ANN model: (**a**) error convergence graph; (**b**) model validation graph; (**c**) distribution of factor weightings.  
Figure 4: Proportion of environmentally friendly projects trends according to each indicator. The y-axis means proportion of environmentally friendly development projects.  
Figure 5 shows the mean KEIDP trend calculated using the MLP-ANN model with EIA Big Data for all 611 projects. The error bars shown in Figure 5 represent one standard deviation of the mean value for the projects carried out each year. Because the input data of the MLP-ANN model were normalized indicators, an increase in the proportion of projects with positive values was reflected. The mean value of KEIDP gradually increased. The rate of increase was 0.007 per year, with an R\({}^{2}\) value of 0.8. This means that the number of environmentally friendly projects (which worked to minimize their environmental impact) gradually increased during the study period. Although there is still a difference from the ideal KEIDP, it has increased from about 0.1 in 2007 to about 0.18 in 2016.  
Figure 6 shows a graph of the overall KEIDP trends by organization. The organizations that were analyzed were the Ministry of Environment, Daegu Province Environmental Agency, Han River Basin Environmental Agency, Geumgang Basin Environmental Agency, Jeonbuk Province Environmental Agency, Nakdong River Basin Environmental Agency, Wonju Province Environmental Agency, and Yeongsan River Basin Environmental Agency. Because these organizations performed an EIA and measured environmental data, it was possible to confirm which institution's EIAs most strongly considered the environmental impact of the development project. As a result of the analysis, the KEIDP trends managed by the Ministry of Environment, Han River Basin Environmental Agency, Jeonbuk Province Environmental Agency, and Yeongsan River Basin Environmental Agency were found to increase by more than 0.007 per year. However, the KEIDP trends managed by the other agencies were found to change only slightly or not at all. There was even a decrease in the KEIDP for projects managed by the Daegu Province Environmental Agency.  
Figure 5: Development projects trend calculated using the MLP based ANN model with EIA Big Data for all 611 projects.  
Figure 6: Development projects trends by EIA agency: (**a**) direct management by the Ministry of Environment; (**b**) Daegu Province Environmental Agency; (**c**) Han River Basin Environmental Agency; (**d**) Geumgang Basin Environmental Agency; (**e**) Jeonbuk Province Environmental Agency; (**f**) Nakdong River Basin Environmental Agency; (**g**) Wonju Province Environmental Agency; (**h**) Yeongsan River Basin Environmental Agency.