Vegetation Change On Navajo Farmlands Along The San Juan River After The Gold King Mine Spill Using Remote Sensing

After the Gold King Mine Spill (GKMS) in August 2015, Navajo communities were concerned about using the San Juan River for farming, ranching, recreation and cultural practices. Although, the river was deemed to meet agricultural standards several weeks after the spill, many Navajo farmers did not resume farming activities or use of irrigation water. However, the decrease in farming activities on the Navajo Nation due to the Spill is not quantified as a whole due to lack of records for farming before and after the Spill. The objective of this study is to determine change in vegetation greenness and water stress level to examine change in farming practices and evaluate its impact on farmland productivity. The primary research method is to use Landsat 8 satellite images to calculate different Vegetation Indices (VIs) to classify land cover via supervised classification. VIs of interest are the Normalized Difference Vegetation Index and the Enhanced Vegetation Index. Preliminary results showed that one year after the GKMS, there was a 20% decrease in total croplands along the San Juan River on the Navajo Nation between Upper Fruitland and Shiprock chapters. The findings of this study will help researchers and policy makers understand the risk perception of the Navajo farming communities along the San Juan River.