Anthropogenic Ecotope Mapping (AEM)

Ecotope Feature Mapping

Ecotope features are mapped by a multi-stage scale-explicit, rule-based, direct interpretation of land use and vegetation features in georeferenced high resolution remotely sensed imagery by a trained mapper, combined with direct verification of features in the field (groundtruthing) by the mapper in collaboration with local land managers who assist wherever features are confusing or present only in the past. 



Standard Feature Mapping Strategy

Ecotope features must be mapped before they are classified.  Feature mapping proceeds in five distinct stages that follow the ease of detecting and mapping features in high resolution imagery. These five stages are followed, in sequence, to map features across sample cells, as part of the feature mapping and classification process.

1. Linear features
Features with length ≥4 × width, with crisp edges, such as roads, paths, ditches, canals, streams, and some managed hedgerows and regrowth field borders
2. Hard areal features
Features with crisp edges and relatively homogenous interiors; examples are constructed, barren, and water surfaces and rice paddies.
3. Soft areal features
Features with fuzzy edges and variable cores, such as vegetation cover in crop plots and patches of trees.  Prior mapping of linear and hard features "cuts out" and leaves behind the soft features.  As a result, some small soft features are mapped automatically by being enclosed within linear and hard features, including some too small to map as separate soft features.
4. Soft features with clear edges
Soft features with relatively crisp edges along land management boundaries, vegetation planting patterns, burning and other causes.
5. Soft features without clear edges
Soft features with fuzzy edges and relatively heterogeneous cores, usually caused by gradual variation in vegetation cover.  These features are the most difficult to map consistently by image interpretation and groundtruthing.

Specific Mapping Rules

provide more detailed guidance where needed to ensure consistent mapping under challenging conditions.

Citation for AEM: Ellis E. C., H. Wang, H. Xiao, K. Peng, X. P. Liu, S. C. Li, H. Ouyang, X. Cheng, and L. Z. Yang. 2006. Measuring long-term ecological changes in densely populated landscapes using current and historical high resolution imagery. Remote Sensing of Environment 100(4):457-473.