# Ecological Suitability Evaluation for Conservation and Development in Bac Kan Province, Vietnam
## 2 Materials and Methods
### Ecological structural resistance assessment  
Ecological elements create the ecological structural resistance included (1) elevation, (2) slope, (3) geological hazard frequency, and (4) distance to fracture zones. The weight of each element was determined using the analytical hierarchy process (AHP) from 10 experts. This method is useful for obtaining a single assessment value based on different indicators or criteria [63]. Herein, the standard numeric scale used for the AHP is on a 1-9 scale that lies between \"equal importance\" to \"extreme importance\", the value 1 indicates equal importance, while value 9 indicates that one indicator is extremely important than others [64]. To implement the AHP, the Super Decisions software (version, Manufacturer, City, US State abbrev. if applicable, Country) was used to calculate the weight and the inconsistency index. If the inconsistency index is less than 0.10, no correction of judgments is needed [65].  
To prepare ecological elements for ecological structural assessment, elevation and slope were first extracted from DEM and then reclassified into 5 classes using the natural breaks method. By using the  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Round 1 for Delphi Questionnaire** & **Round 1 + 1** & **Round 1 + 2** \\ \hline Rating mean (qj) \(\geq\) 3.5 & If rating mean (qj) \(\geq\) 3.5 and \(\text{Q}\)\(\leq\) 0.5 and rating variant (qj) \(<\) 15\%, then, qj is accepted, and no further discussion concerning qj is needed. & If rating mean (qj) \(\geq\) 3.5 and \(\text{Q}\)\(\leq\) 0.5 and rating variant (qj) \(\leq\) 15\%, then qj is accepted, and no further discussion concerning qj is needed & \\ Rating mean (qj) \(<\) 3.5 & Rating mean (qj) \(\geq\) 3.5 or rating variant (qj) \(>\) 15\% & 0.5 and rating variant (qj) \(\leq\) 15\%, then qj is accepted, and no further discussion concerning qj is needed & \\ Rating mean (qj) \(<\) 3.5 & If rating mean (qj) \(<\) 3.5 and \(\text{Q}\)\(\leq\) 15\%, mean \(\text{qj}\) is rejected, and no further discussion concerning qj is needed & \\ \hline \hline \end{tabular}
\end{table}
Table 2: Rules to analyze the ratings from multiple experts using a Delphi method.  
natural breaks method, similar values are grouped and therefore the differences between classes are maximized [66]. The resistance level has a positive relationship with elevation and slope classification. Meanwhile, the spatial characteristics of the geological hazard frequency, which was represented by historical landslides and flash flood records of Hung [67], was first extracted using the kernel method for surface interpolation under ESRI ArcMap software and reclassified into 5 classes using the natural breaks method. The resistance level of this indicator has a positive relationship with its classification. In the meantime, the distance to fracture zones, which are in crustal strata along where adjacent rocks have been displaced, was extracted based on a Bac Kan geological map using the Euclidean distance method under ESRI ArcMap software (version, Manufacturer, City, US State abbrev. if applicable, Country) and reclassified into 5 zones (0-200 m, 200-500 m, 500-1000 m, 1000-2000 m, and greater than 2000 m). The resistance level of this indicator has a negative relationship with its classifications.  
Finally, the ecological structural resistance was assessed using the simple additive weighting (SAW) method (Equation (2)), and it was classified into 5 levels using the natural breaks method. The SAW method is one of the most widely used models for creating composite maps in GIS [68]:  
\[S=\ \sum_{i}w_{i}x_{i}, \tag{2}\]  
where \(S\) is the total score, \(w_{i}\) is a normalized weight of ith indicator, and \(x_{i}\) is the score of the ith indicator (\(i=1,2,\ldots,\text{n}\)).