방법 비교

	Universal Soil Loss Equation	NDVI	SWAT 모델
분야	지구물리학	지구물리학	지구물리학
계열	Process / pipeline	Process / pipeline	Process / pipeline
기원 연도	1978	1973	1998
창시자	Waldo Wischmeier and Dwight Smith	Rouse, Haas, Schell, and Deering	Jeff Arnold and others at USDA-ARS
유형	Empirical soil erosion prediction model	Spectral index for vegetation assessment	Process-based watershed and water quality simulation
원전	Wischmeier, W. H., & Smith, D. D. (1978). Predicting rainfall erosion losses: A guide to conservation planning. USDA Agricultural Handbook 537.	Rouse, J. W., Haas, R. H., Schell, J. A., & Deering, D. W. (1973). Monitoring vegetation systems in the Great Plains with ERTS. Third Earth Resources Technology Satellite Symposium Proceedings, 1, 309-317.	Arnold, J. G., Srinivasan, R., Muttiah, R. S., & Williams, J. R. (1998). Large area hydrologic modeling and assessment part I: Model development. Journal of the American Water Resources Association, 34(1), 73-89.
별칭	USLE, Revised USLE	NDVI	SWAT
관련	3	3	3
요약	The Universal Soil Loss Equation (USLE) is an empirical model that estimates annual soil loss due to sheet and rill erosion on hillslopes caused by rainfall and runoff. Developed by Wischmeier and Smith in 1978 from decades of erosion plot experiments, USLE has become a standard tool for erosion risk assessment, conservation planning, and best management practice design. The Revised USLE (RUSLE) updated the original model with improved factor algorithms.	The Normalized Difference Vegetation Index (NDVI) is a spectral index computed from satellite or aerial multispectral imagery that quantifies vegetation greenness and vigor. Introduced by Rouse and colleagues in 1973 using Landsat data, NDVI has become the most widely used remote sensing metric for vegetation monitoring, drought assessment, crop productivity forecasting, and land cover change detection.	The Soil and Water Assessment Tool (SWAT) is a process-based watershed model that simulates the hydrological cycle, sediment transport, nutrient cycling, pesticide fate, and land management impacts across a watershed or large basin. Developed by Jeff Arnold and colleagues at USDA-ARS in 1998, SWAT has become a standard tool for evaluating non-point source pollution, assessing climate change impacts on water resources, and designing best management practices.