Summary

Description

This dataset shows the frequency or number of times that an area has been actively cropped in the southern and northern region of the western Strategic Cropping Lands (SCL) in Queensland for the winter and summer growing seasons from 1987 to 2014. It is based on the dataset - Active crop mapping - Western Queensland cropping zone1988-2014 derived from USGS Landsat images.Two predefined growing seasons were used for winter (June to October) and summer (November to May), and actively growing crops with a green vigour were classified for each season separately. Temporal (within season) and spectral information were used in a regression tree based classifier (Random Forest), utilising field observations as training data.The frequency of active crops for the winter and summer season were calculated for the previous intervals of 10, 20 and 27 years of Landsat data.An additional annual frequency data layer is also provided which combines the winter and summer growing seasons. Where two crops in one year have been detected, these are only counted once in the annual data layer.The crop frequency count for each interval (i.e. 10, 20 and 27 years) is calculated by summing the probability of an active crop over time and rounding to the nearest whole number. Only areas where two or more active crops have been detected in each interval are represented in the dataset. This is to minimise commission error due to a single wet season where active crop detection is confounded by greening up effects in pasture and other areas surrounding cropping areas.