The spatiotemporal changes of ecological environmental quality caused by farmland consolidation using Google Earth Engine: A case study from Liaoning province in China

Farmland consolidation (LC) is a human activity that changes the original land ecosystem, and its impact on the eco-environment has always been controversial. In terms of long-term series and large-area analysis, the calculation of a large amount of data makes the analysis of the environmental quality of the land consolidation very difficult.

To solve the problem, our study combined the Google Earth Engine platform and the remote sensing ecological index (RSEI) to analyze the changes in the eco-environment quality in two prefecture-level cities in Liaoning Province over the past 20 years. In addition, we analyzed the impacts of land consolidation projects on the eco-environment from 2006 to 2018 and compared them to the farmland without land consolidation.

The study results show that LC caused negative impacts during the LC period (2006-2018), and the positive effects of the land consolidation take time to develop. In each LC phase, the results showed that LC exhibited negative effects before 2010 because the proportion of RSEI decreasing (0%-47.67%) was higher than that of increasing (9.62%-46.15%) in those LC phases. Since 2011, the area of positive environmental benefits (31.96%-72.01%) brought about by LC is higher than the area of negative impact (2.24%-18.07%). It seems to be triggered by policy evolution. Based on the trend analysis, the proportion of EEQ increasing in LC areas has grown faster (Gini index decreased 0.09) than that of the farmland without LC (Gini index decreased 0.05). The benefits of newly LC projects (2011-2018) are better than those of early projects (2006-2010). However, the newly LC projects (2011-2018) increased dramatic falling areas of EEQ which may be temporal.

In conclusion, we believe that LC could improve the EEQ of farmland whereas some measures are needed to reduce its negative impact. The integrated of RSEI and GEE provided an effective and reliable method to detect LC impacts on farmland EEQ. It could provide the basis and support for the analysis of specific environmental issues in LC areas.