As the ground thaws and the snow melts, Vermont’s robust recreation culture will thrive once again on the Burlington waterfront, bike path and skate park. The lakefront concrete landscape reunites with the light of day, and so do Burlington artist Derbes’ so-called “self-commissioned” works. A selection of aerial photographs of these large-scale public paintings will be on view at the Queen City’s Karma Bird House Gallery beginning April 7. At ground level, the geometric abstractions are a bit like hopscotch gone wonky, waiting for creative minds to come and play. Seen from overhead, they carry some of the gravitas of crop circles and show how simple lines can reconfigure a city as canvas.