# Agricultural Evolution: Process, Pattern and Water Resource Effect
## 5 Conclusions  
Time series Landsat images were used in our study to characterize the agricultural evolution processes from 1990 to 2015. Our results reveal a rapid increase in cultivated land, especially paddy field expansion, in the West Songnen Plain. An integrated method was applied in our study to analyze the spatiotemporal changes of agricultural land. Paddy and dry farmland were separated from cultivated land to better understand the processes of agricultural evolution. The water resource effect of agricultural expansion was also analyzed and discussed to describe its ecological effect. Results indicate that cultivated land changes greatly affect landscape patterns and water resources.  
\begin{table}
\begin{tabular}{c c c c} \hline
**Type** & **Paddy Field** & **Dry Farmland** & **Total** \\ \hline
1990 & 15,1328.68 & 37,7720.29 & 52,9048.97 \\
2000 & 23,7902.81 & 42,4062.18 & 66,1964.99 \\
2010 & 26,7195.10 & 43,4040.03 & 70,1235.12 \\
2015 & 35,1852.24 & 42,4000.05 & 77,5852.29 \\ \hline \end{tabular}
\end{table}
Table 8: Water consumption of cultivated land in different period (Unit: m\({}^{3}\)/km\({}^{2}\)).  
Located in the agro-pastoral ecotone, the West Songnen Plain is a typical ecologically fragile area. Therefore, although our results are specific to the West Songnen Plain, our methods can be an exemplary for other agro-pastoral ecotone or ecologically fragile areas in other regions worldwide, highlighting the application of an integrated method for land-use change analysis. Agriculture could also affect the biogeochemical processes, regional climate as well as carbon recycling. In this study, we only discussed water resource effects. Future studies should also pay attention to other ecological effects. Additionally, optimizing future land-use structure and configuring water and soil resources in areas with rapid agricultural expansion are necessary and urgent to achieve green and sustainable development.  
The following are available online at [[http://www.mdpi.com/2076-3417/10/15/5065/s1](http://www.mdpi.com/2076-3417/10/15/5065/s1)]([http://www.mdpi.com/2076-3417/10/15/5065/s1](http://www.mdpi.com/2076-3417/10/15/5065/s1)), Table S1: Trajectory changes of paddy field (>0.02%), 1990-2015., Table S2: Trajectory changes of dry farmland (>0.02%), 1990-2015.  
Conceptualization, F.Y. and F.S.; methodology, F.Y. and J.N.; data curation, F.Y. and J.N.; writing--original draft preparation, F.Y.; writing--review and editing, F.Y., J.N. and F.S.; funding acquisition, F.S. and F.Y. All authors have read and agreed to the published version of the manuscript.  
This research was jointly supported by the National Natural Science Foundation of China (41890854, 41901383) and the major consulting project of China Academy of Engineering (NO. 2018-ZD-08-5).  
The authors thank the Research Group of Land System by Remote Sensing in Northeast Institute of Geography and Agricultural Ecology, Chinese Academy of Sciences for data preparation for this study. The authors thank the three reviewers for their constructive comments and suggestions which greatly improved this study.  
The authors declare no conflict of interest.