## 4 Results
### Nutrient Export Estimation Using NDR Model
#### 4.8.1 Nutrient Export Estimation of Actual LULC in 2019  
The estimated total and average nutrient (N and P) load and export of actual LULC in 2019 are presented in Table 26. Meanwhile, the amount of nutrient export from each LULC type in 2019 is presented in Table 27.  
As a result, the total nitrogen and phosphorus loads in 2019 were about 1,422,800 kg (1596.23 kg/km\({}^{2}\)) and about 308,268 kg (345.84 kg/km\({}^{2}\)), and the total nitrogen and phosphorus exports were about 193,308 kg (216.87 kg/km\({}^{2}\)) and about 41,979 kg (47.10 kg/km\({}^{2}\)), respectively.  
In the meantime, the highest total nitrogen and phosphorus exports occurred at the paddy field, with values of about 95,829 and 26,135 kg, respectively. In contrast, the lowest total nitrogen export came from waterbody areas, with a value of 2.22 kg, and the lowest  
\begin{table}
\begin{tabular}{l c c} \hline Total N load & 1,422,800.13 & (kg/year) \\ \hline Total P load & 308,267.70 & (kg/year) \\ \hline Average N load & 1596.23 & (kg/watershed in km\({}^{2}\)) \\ \hline Average P load & 345.84 & (kg/watershed in km\({}^{2}\)) \\ \hline Total N export & 193,307.56 & (kg/year) \\ \hline Total P export & 41,978.66 & (kg/year) \\ \hline Average N export & 216.87 & (kg/watershed in km\({}^{2}\)) \\ \hline Average P export & 47.10 & (kg/watershed in km\({}^{2}\)) \\ \hline Watershed area & 891.35 & Km\({}^{2}\) \\ \hline \end{tabular}
\end{table}
Table 26: Nutrient (N and P) load and export of actual LULC in 2019.  
\begin{table}
\begin{tabular}{l c c c c c c} \hline \hline
**LULC Types** & **load\_n** & **eff\_n** & **crit\_len\_n** & **load\_p** & **eff\_p** & **crit\_len\_p** \\ \hline Urban and built-up area & 23.25 & 0.05 & 30 & 1.3 & 0.05 & 30 \\ Paddy field & 33 & 0.25 & 150 & 9 & 0.25 & 150 \\ Field crop & 33 & 0.25 & 150 & 9 & 0.25 & 150 \\ Para rubber & 30 & 0.45 & 150 & 9 & 0.45 & 150 \\ Perennial trees and orchards & 30 & 0.45 & 150 & 9 & 0.45 & 150 \\ Forest land & 5.4 & 0.7 & 150 & 0.033 & 0.7 & 150 \\ Water body & 0.003 & 0.05 & 150 & 0.003 & 0.05 & 150 \\ Rangeland & 6 & 0.5 & 150 & 0.033 & 0.5 & 150 \\ Wetland & 6 & 0.8 & 30 & 0.05 & 0.8 & 30 \\ Miscellaneous land & 12 & 0.05 & 150 & 0.003 & 0.05 & 150 \\ \hline \end{tabular}
\end{table}
Table 25: Adjusted parameter of NDR model for nitrogen and phosphorus calibration.  
\begin{table}
\begin{tabular}{l c c} \hline \hline Total N load & 1,422,800.13 & (kg/year) \\ \hline Total P load & 308,267.70 & (kg/year) \\ \hline Average N load & 1596.23 & (kg/watershed in km\({}^{2}\)) \\ \hline Average P load & 345.84 & (kg/watershed in km\({}^{2}\)) \\ \hline Total N export & 193,307.56 & (kg/year) \\ \hline Total P export & 41,978.66 & (kg/year) \\ \hline Average N export & 216.87 & (kg/watershed in km\({}^{2}\)) \\ \hline Average P export & 47.10 & (kg/watershed in km\({}^{2}\)) \\ \hline Watershed area & 891.35 & Km\({}^{2}\) \\ \hline \end{tabular}
\end{table}
Table 27: Contribution of LULC type on nutrient (N and P) export in 2019.  
total phosphorus export came from miscellaneous land, with a value of 0.14 kg. However, the highest average nitrogen and phosphorus export appeared on field crop and perennial trees and orchards, with values of 454.14 and 127.83 kg/km\({}^{2}\), respectively.