Anomaly Gallery - 'Circular Fields?'

Another 'circular field' anomaly from what was one of my favourite 'anomaly sites' on Google Earth. However, I discovered last night that the number of 'circular fields' to explore in this locality has lessened dramatically. The area in question has been updated on Google Earth and where there was once masses of circular fields, many of questionable designs, there is now only sand, sand, desert and more desert? Strange. Why, if these are only the innocuous agricultural fields that google searches suggest, is there a need for literally hundreds of them to disappear from view and gone from further scrutiny?