Identifying Dry Season Rice Cultivation Areas around Bueng Boraphet using Multi-temporal Landsat-8 Imagery

Abstract

Bueng Boraphet is Thailand's largest freshwater lake. Agricultural areas surrounding the lake are outside irrigation systems that lack clearly defined boundaries of lake water usage zones. This limits the assessment of water consumption, particularly during dry seasons, resulting in critically low water levels and ecosystem impacts. This research used remote sensing techniques to identify rice cultivation areas, the primary water-consuming activities during dry seasons. The analysis utilized composite imagery of Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) derived from multi-temporal Landsat-8 satellite imagery from May 2019 to August 2020. Land classification was conducted using K-Means clustering, with optimal cluster numbers determined through Dendrogram analysis. Results show that within the Royal Decree designated area of 132,737 rai, four distinct land use categories were identified: water bodies covering 11,774.70 rai (8.87%), dry season rice cultivation areas of 91,438.05 rai (68.89%), non-rice cultivation zones of 28,460.55 rai (21.44%), and no data areas of 1,063.70 rai (0.80%). Classification accuracy was verified through Google Street View. These findings can be utilized to assess agricultural water requirements and enhance the efficiency of water resource management in Bueng Boraphet.