#Trend analysis

1 post

Map of the Theil-Sen slope of growing-season NDVI from 2001 to 2024 on the Loess Plateau between Yan'an and Yulin, almost entirely teal (greening), with a few brown browning patches near Yan'an and Yulin.

Tutorial Remote Sensing

Mann-Kendall trend test on rasters in Python: Theil-Sen NDVI trends with xarray

Run a pixel-wise Mann-Kendall trend test and Theil-Sen slope on 24 years of MODIS NDVI in Python. Read MOD13A1 from the Microsoft Planetary Computer, mask it with the QA layer, aggregate to growing-season means, vectorise the tests with xarray.apply_ufunc (checked against pymannkendall), compare the seasonal and modified Mann-Kendall tests, control the false discovery rate across 229,229 pixels, and map greening and browning on China's Loess Plateau.

Advanced 16 min read