There is plenty of work (for us) shovelling snow.

There is plenty of work (for us) to shovel snow.

书上说第一句是限制性同位语-ing分句， 怎么理解shovelling snow ? 是 work 的同位语吗？

第二句是我自己改动的，第二句to shovel snow也是不定式作work的同位语呢，还是定语呢？

如果to shovel snow是work的同位语，那么2句话ing和to do 都作同位语，含义理解上究竟有何区别？