Union land use maps to identify transitions from harmonized land-use classes to create baseline SWAT luse input map

Workflow 1. Land use change transitions to crease baseline map + manegment scheduleS Input land-use and TRC forestry mapsResources:General Land-use map (2015) Forestry maps for 2004, 2018, and 2021 (LU_2004,LU_2018, LU_2021)Forestry-priority soils map (MGAP). Harmonize land-use classes and clean attribute tablesFirst, we cleaned attribute tables for all input layers. Then we used the defined land-use classification scheme to assign a unique land-use code per class ( see Table 2 in the appendix).<br>Union all time slices to create a multi-year change map.We generated the union map using the union tool in QGIS to merge: 2004 forestry map, 2015 general land use (with ESC), 2018 forestry map, 2021 forestry map. This allowed the creation of polygons representing unique combinations of land use across all layers (homogeneous numeric codes). The union result layer is LU_union_2004_2015_2018_2021.shp <br>Assign temporal land-use codes and create 13 final classesWe analysed the union layer to identify unique temporal sequences (e.g. pine forest → pine forest, grassland → pine forest, euca or pine forest → grassland, see table in the manuscript). Using these transitions, we assigned a new land-use code that summarises the temporal trajectory for each polygon—mapped these trajectories using numeric codes. After map union, we obtained a total of 13 final classes (see Table 3 in the manuscript appendix).<br>Link final land-use classes to management types in the modelAfter this, we assigmed a .mgt to each of the 13 land-use classes in terms of management and forest dynamics (e.g. persistent plantation, new plantation, conversion to non-forest).Metadata:Intermediate Union map layers - <i>LUSE_2004_LUSE2015Union04_15fixgeometres</i>, Union map from foresty map 2004 and geneal landuse 2015-<i>LUSE2018_LUSE_2021Union1821fixgeom</i>, Union map from foresty map 2018 and geneal landuse 2018-<i>Union_04_21_raw_Step6 </i>Union of LUSE_2004_LUSE2015Union04_15fixgeometres &amp;LUSE2018_LUSE_2021Union1821fixgeom-<i>Union_04_21_dis Dissolved</i> polygon classes from Union_04_21_raw_Step6-Script to modify lookup tables (<i>codestonewcodes2.R</i>) and processing luse codes - <i>Union_finalSWATinput_10m_filled.ZIP </i>Final layer input for SWAT, 10m pixel, catchment boundary area filled with grassland value to avoid luse issues during catchment delineation and HRU creation<br>