{"version":"1.0","type":"rich","title":"Steps used to make map of California rivers","description":"A map of California rivers displays stream networks color-coded by Strahler stream order, with line widths scaled by order and zoom level. The visualization is built from NHD Plus flowline data processed via SQL queries in CartoDB, which join river attributes and merge segments using `ST_LineMerge` and `ST_Union`. CartoCSS rules define zoom-dependent stroke widths for each order class, while a second optional version applies directional coloration to the same underlying geometry. The map relies on CartoDB’s spatial index for rendering performance.","provider_name":"VizHub AI Studio","provider_url":"https://next.vizhub.com","html":"<iframe src=\"https://next.vizhub.com/viz/gist-acc28ed000a62de4d234?mode=embed\" width=\"960\" height=\"500\" scrolling=\"no\" frameborder=\"1\"></iframe>","width":960,"height":500,"cache_age":3600}