Improved MambdaBDA Framework for Robust Building Damage Assessment Across Disaster Domains
Authors: Alp Eren Gençoğlu, Hazım Kemal Ekenel
Organizations: Department of Computer Engineering, Istanbul Technical University, Türkiye · Division of Engineering, New York University Abu Dhabi, UAE
Reliable post-disaster building damage assessment (BDA) from satellite imagery is hindered by severe class imbalance, background clutter, and domain shift across disaster types and geographies. In this work, we address these problems and explore ways to improve the MambaBDA, the BDA network of ChangeMamba architecture, one of the most successful BDA models. The approach enhances the MambaBDA with three modular components: (i) Focal Loss to mitigate class imbalance damage classification, (ii) lightweight Attention Gates to suppress irrelevant context, and (iii) a compact Alignment Module to spatially warp pre-event features toward post-event content before decoding. We experiment on multiple satellite imagery datasets, including xBD, Pakistan Flooding, Turkey Earthquake, and Ida Hurricane, and conduct in-domain and crossdataset tests. The proposed modular enhancements yield consistent improvements over the baseline model, with 0.8% to 5% performance gains in-domain, and up to 27% on unseen disasters. This indicates that the proposed enhancements are especially beneficial for the generalization capability of the system.
Figures & tables
Figure 1: Network structure of MambaBDA, adapted from [ 5 ] .
Damage Level
Name
Pixel Value
L1
No Damage
1
L2
Minor Damage
2
L3
Major Damage
3
L4
Destroyed
4
Table 1: Damage Levels
Figure 2: Sample data from xBD consisting of image pairs and mask pairs.
Damage Level
Training
Valid
Test
Number of Images
L1
4624
569
570
L2
1785
277
244
L3
1797
320
294
L4
2041
332
288
Total
9168
933
933
Pixel Ratio
L1
76.35 %
73.29 %
76.67 %
Table 2: xBD Dataset Statistics.
Damage Level
Training
Valid
Test
Number of Images
L1
800
177
174
L2
317
70
67
L3
155
36
42
L4
510
106
119
Total
2478
531
531
Pixel Ratio
L1
79.58 %
80.87 %
79.86 %
Table 3: Pakistan Flooding Dataset Statistics.
Damage Level
Training
Valid
Test
Number of Images
L1
489
154
166
L2
80
22
19
L3
48
13
11
L4
102
33
30
Total
566
189
189
Pixel Ratio
L1
95.35 %
96.36 %
97.04 %
Table 4: Turkey Earthquake Dataset Statistics.
Damage Level
Test
Number of Images
L1
438
L2
168
L3
79
L4
35
Total
528
Pixel Ratio
L1
88.67 %
Table 5: Hurricane Ida Dataset Statistics.
Model / Module
Params (M)
GFLOPs
Baseline
87.76
195.43
FOCAL
+ 0
+ 0
AGBD
+ 0.10
+ 0.71
AGB
+ 0.05
+ 0.36
ALIGN
+ 0.63
+ 0.65
Table 6: Model Complexity Comparison
Model
F1loc
F1clf
F1oa
F1L1
F1L2
F1L3
F1L4
Baseline
84.86
75.23
78.12
95.23
57.36
73.02
86.66
AGBD
84.48
74.98
77.83
95.13
55.55
75.17
86.74
AGB
85.42
76.29
79.03
94.75
59.32
74.71
85.92
ALIGN
85.14
75.76
78.57
95.45
57.27
75.19
86.48
FOCAL
84.84
75.77
78.49
94.56
57.97
74.30
86.90
FOCAL + ALIGN
84.68
76.12
78.69
95.38
58.41
75.10
85.99
Table 7: In-Domain Evaluation Results on xBD Dataset (Group 1)
Figure 3: Example attention gate outputs. Heatmaps are overlayed on ground truth masks. Attention increases from blue to green to red. The top right heatmap belongs to AGB, the AGs in building decoder, and the bottom right heatmap belongs to AGD, the AGs in damage decoder. AGB mostly focuses on building borders improving performance, while AGD mostly focuses on spaces between the buildings, which does not increase the scores.