# Hydropower Functional Zoning with Crowdsourced Geospatial Data: A Case Study in Sichuan Province
## 4 Discussion  
### Framework of Hydropower Functional Zoning  
[PERSON] et al. (2017); [PERSON] et al. (2018) proposed some valuable and notable studies for Chinese eco-function zones. Currently, ecological regions, ecological sub-regions, and ecological functional regions are divided based on natural conditions. In addition, regional zoning results ([PERSON] et al., 2018; [PERSON] et al., 2018) have been afforded more attention for terrestrial ecosystem functions or services based on ecological sensitivity and importance.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Basin**} & \multirow{2}{*}{**Area (km2)**} & \multicolumn{4}{c}{**Quantity of Pollutants Discharged (g m\({}^{-2}\))**} & \multirow{2}{*}{**No. of Level 1 Zone**} \\ \cline{3-6}  & & **COD** & **NH3-N** & **TN** & **TP** \\ \hline Yangtze River & 97,376 & 1.911 & 0.100 & 0.257 & 0.027 & 16,17 \\ Ya-lung River & 107,826 & 0.299 & 0.014 & 0.036 & 0.004 & 14,15 \\ Anning River & 11,086 & 1.606 & 0.090 & 0.262 & 0.018 & 1 \\ Dadu River & 68,002 & 0.610 & 0.025 & 0.072 & 0.007 & 2,3 \\ Qingyi River & 12,902 & 2.503 & 0.124 & 0.333 & 0.039 & 11 \\ Qu River & 45,444 & 3.534 & 0.196 & 0.603 & 0.051 & 9,10 \\ Tuo River & 25,510 & 8.656 & 0.447 & 1.313 & 0.114 & 13 \\ Fu River & 31,985 & 4.805 & 0.247 & 0.647 & 0.069 & 4 \\ Jialing River & 34,939 & 3.532 & 0.175 & 0.498 & 0.049 & 6,7,8 \\ Qu River & 33,820 & 5.370 & 0.257 & 0.659 & 0.068 & 12 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Emission volumes of pollutants and corresponding zoning in 10 large river basins in Sichuan Province.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Basin**} & \multirow{2}{*}{
\begin{tabular}{c} **Planning** \\ **Installed** \\ **Capacity** \\ **(10,000 kw)** \\ \end{tabular} } & **No. of** & **No. Built or** & **Percentage** \\ \cline{2-4}  & & **Hydropower** & **Under** \\ \cline{2-4}  & & **Stations** & **Construction** & **(\%)** \\ \hline Jinsha River & 8258 & 27 & 18 & 66.7 \\ Ya-lung River & 2883 & 22 & 7 & 31.8 \\ Dadu River & 2697 & 28 & 21 & 75.0 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Hydroelectric-development programming and construction in the Jinsha River, Ya-lung River, and Dadu River.  
Compared with the eco-function zoning method, aquatic ecological-function zoning is a method that aims to maintain the biodiversity and health of an aquatic ecosystem. [PERSON] et al. [2] proposed that the reservoir capacity can be used as level 4 aquatic ecological functional zoning in lake basins, which mainly expresses the spatial-difference characteristics of an aquatic ecological system at the river scale. However, this method ignores the cumulative effect of hydropower development.  
In this research, we propose eco-function zoning that emphasizes the coupling of aquatic and terrestrial ecosystems and takes the basin as a unit under the view of hydropower development. The indicators of level 1 and level 2 zoning include landform, climate, soil, vegetation, land use, and social economy. The spatial-aggregation statistical method is used to effectively consider the cumulative eco-environmental impacts among hydropower-development basins in level 3 zoning [40]. As shown in Table 3, the spatial distribution showed a significant clustering in terms of quantity. In addition, it is shown that there were differences in the different hydroelectric-development intensities (Table 6). In order to further demonstrate the rationality of the hydropower functional zoning system, a Kruskal-Wallis H test was conducted and it was found that the total installed capacity and number of power stations showed significant differences (\(p<0.05\)) among the seven types of hydroelectric-development intensity. In addition, this hydropower-functional-zoning strategy is not appropriate in situations in which there are few hydropower stations or no significant agglomeration of hydropower development because the framework is based on the quantity and installed capacity of hydropower stations (Table 3).