# Ecological Suitability Evaluation for Conservation and Development in Bac Kan Province, Vietnam
## 2 Materials and Methods
### Ecological dynamics resistance assessment  
The ecological dynamics resistance applies the concept of ecological resilience based on ecological circulation theory and taking great human disturbance into account for representing the temporal dynamic characteristics of a natural ecosystem's self-organization and self-update using the three aspects of resistance, exposure, and interference [14]. These three aspects correspond to specific  
Figure 4: Spatial distribution of potential soil loss (**a**) and actual soil loss (**b**) for soil conservation extraction. \begin{table}
\begin{tabular}{c l l} \hline \hline
**No.** & **Land Use Types** & **C Factor** \\ \hline
1 & Evergreen broadleaf forest & 0.003 \\
2 & Bamboo and wood mixed forest & 0.003 \\
3 & Shrub and grassland & 0.18 \\
4 & Plantation forest & 0.003 \\
5 & Perennial tree and orchard & 0.5 \\
6 & Paddy field and field crop & 0.5 \\
7 & Residential area & 0.0 \\
8 & Water surface & 0.0 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Cropping management factor (C). \begin{table}
\begin{tabular}{l c c c c c} \hline \hline \multirow{2}{*}{**Group of Land Use Types**} & \multicolumn{5}{c}{**Slope (Degree)**} \\ \cline{2-5}  & **0–5** & **5–8** & **8–10** & **10–15** & **>15** \\ \hline Evergreen broadleaf forest, bamboo, and wood mixed forest, shrub and grassland, and water surface & 1.00 & 1.00 & 1.00 & 1.00 & 1.00 & 1.00 \\ Plantation forest, perennial tree and orchard & 0.55 & 0.60 & 0.80 & 0.90 & 1.00 \\ Paddy field and field crop & 0.27 & 0.30 & 0.40 & 0.45 & 0.50 \\ Residential area & 0.003 & 0.003 & 0.003 & 0.003 & 0.003 \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Supporting practice factor (P). indicators include (1) vegetation stability (S\({}_{1}\)), (2) ecological sensitivity (S\({}_{2}\)), and (3) social disturbance intensity (S\({}_{3}\)), respectively. Thus, the ecological dynamics resistance (R) can be expressed as:  
\[\mathrm{R}\ =\frac{\mathrm{S_{1}*S_{2}}}{\mathrm{S_{3}}}. \tag{6}\]  
Brief information about relevant indicators of ecological resilience for ecological dynamics resistance assessment was separately summarized below. (a) Vegetation stability (S\({}_{1}\)). Vegetation stability shows the vegetation capacity to resist interfering and sustain its condition with environmental variations [14]. In this study, vegetation stability was quantified through the variation amplitude of vegetation using the normalized difference vegetation index (NDVI) from MODIS product (MOD13Q1) with support of the TIMESAT 3.3 software (Manufacturer, City, US State abbrev. if applicable, Country). Actually, vegetation stability is the reciprocal of variation amplitude of vegetation. The lower the variation amplitude, the greater the vegetation stability, and therefore the higher the resistance to development activities [14]. In practice, the NDVI dataset of 207 scenes (23 scenes/year) between 2009 and 2018 was used to quantify the variation amplitude of vegetation. The quality of vegetation data was here used to assign the weight for adjusting the NDVI dataset based on the pixel reliability index (Table 10). After weighting vegetation data quality, the Savitsky-Golay filtering algorithm [86] was applied to enhance the quality of the NDVI dataset. At the last step, the variation amplitude of vegetation was extracted from seasonality data and the amplitude value was then classified into 5 classes to represent the vegetation stability using a natural breaks method. The dynamic resistance level caused by this indicator has a positive relationship with its classification. (b) Ecological sensitivity (S\({}_{2}\)). Ecological sensitivity reflects the degree to which human activities and natural changes impact on the ecosystem, as well as the degree to which regional ecological and environmental problems can possibly occur [87]. In general, ecological sensitivity is assessed using distance from important ecological functional areas or key ecological patches [88].