Mapping and evaluating cultivated land fallow in Southwest China using multisource data

Area of Science:

• Agricultural Science
• Environmental Science
• Remote Sensing

Background:

• Cultivated land fallow mapping in China is crucial but current methods using statistical data or single-aspect remote sensing are inadequate.
• Systematic regional analysis of cultivated land fallow is limited, hindering effective land management and policy development.

Purpose of the Study:

• To develop and validate an integrated index of cultivated land fallow (ILF) for mapping and evaluating fallow land in Southwest China.
• To analyze the spatial distribution of cultivated land fallow at regional, provincial, and metropolitan scales.
• To identify key factors influencing cultivated land fallow and provide a scientific basis for policy-making.

Main Methods:

• Development of an integrated index of cultivated land fallow (ILF) using multisource spatial data.
• Validation of the ILF performance against Google Earth imagery and the ecological carrying capacity of cultivated land (TEC).
• Spatial analysis of cultivated land fallow distribution and influencing factors.

Main Results:

• The ILF provides a reliable method for evaluating cultivated land fallow in Southwest China.
• High ILF values correlate with cultivated land prioritized for fallowing when compared to Google Earth images.
• A significant correlation (R² > 0.65) was found between ILF and TEC at the prefectural level in Sichuan.
• Highly appropriate fallow (HAF) land constituted 5.73% of total cultivated land in Southwest China in 2010.
• Inappropriate fallow (IF) land varied significantly across provinces, with Sichuan and Chongqing showing higher percentages than Yunnan and Guizhou.
• Guiyang and Kunming exhibited notably high proportions of HAF, requiring special attention.
• Human activities were identified as the primary impact factor for cultivated land fallow.

Conclusions:

• The integrated index of cultivated land fallow (ILF) offers a robust approach for mapping and evaluating fallow land in Southwest China.
• The study highlights regional disparities in fallow land management and identifies areas needing targeted interventions.
• Understanding the impact of human activities is critical for developing effective and sustainable cultivated land fallow policies.