Detecting Trends in Wetland Extent from MODIS Derived Soil Moisture Estimates
Abstract
:1. Introduction
1.1. Background and Objective
1.2. Optical Soil Moisture Detection
1.3. Validation of Satellite Derived Soil Moisture Products
1.4. Trend Detection
2. Materials and Methods
2.1. Datasets
2.2. Defining the Transformed Wetness Index (TWI)
2.3. TWI Performance Validation
2.4. TWI Compared to Microwave Soil-Moisture Products
2.5. Trend Detection
3. Results
3.1. Model Performance
3.2. Comparison with Microwave Soil Moisture Products
3.3. Soil Moisture Trends
4. Discussion
4.1. Model Performance
4.2. Comparison with Microwave Soil Moisture Products
4.3. Soil Moisture Trends
4.4. Further Development
5. Conclusions
Supplementary Materials
Acknowledgments
Conflicts of Interest
References
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Material | Red | NIR | Blue | Green | SWIRa | SWIRb | SWIRc |
---|---|---|---|---|---|---|---|
610 | 985 | 518 | 631 | 1310 | 1249 | 869 | |
(208) | (397) | (220) | (269) | (676) | (739) | (556) | |
1279 | 1674 | 809 | 1099 | 2102 | 2213 | 1816 | |
(292) | (430) | (226) | (220) | (746) | (909) | (797) | |
493 | 4431 | 296 | 790 | 4040 | 2421 | 1013 | |
(130) | (425) | (78) | (124) | (298) | (209) | (226) | |
290 | 202 | 386 | 402 | 198 | 200 | 135 | |
(326) | (158) | (141) | (283) | (124) | (105) | (82) |
Material | Red | NIR | Blue | Green | SWIRa | SWIRb | SWIRc |
---|---|---|---|---|---|---|---|
563 | 1008 | 147 | 507 | 1531 | 1836 | 1699 | |
0.314812 | 0.320970 | 0.359456 | 0.336364 | 0.249772 | 0.657334 | 0.247078 | |
−0.193666 | 0.798701 | −0.140345 | −0.094762 | 0.390175 | −0.199024 | −0.322562 | |
0.482520 | 0.134057 | −0.025535 | 0.347607 | 0.071952 | −0.653813 | 0.441669 | |
0.188177 | 0.038364 | 0.493917 | 0.350060 | −0.358132 | −0.173122 | −0.662112 |
2∗Region/Network | Pearson Corr. > 0 % of n Stations | Pearson Corr. > 0 and p < 0.05 % of n Stations | Stations n |
---|---|---|---|
Global | 74 | 40 | 459 |
Tropical | 80 | 40 | 15 |
Sub-tropical | 74 | 41 | 417 |
Temperate | 62 | 29 | 27 |
COSMOS | 78 | 31 | 32 |
Model | RMSE | E | n stn | n | |||
---|---|---|---|---|---|---|---|
Global region | |||||||
21.9 a | 9.6 b | 14.0 | 0.02 | −0.56 | 745 | 12,294 | |
19.4 | 11.2 | 8.5 | – | – | 745 | 12,294 | |
Tropical region | |||||||
19.0 b,d | 11.4 b,c | 13.4 | 0.26 | 0.16 | 19 | 372 | |
22.0 c | 14.7 c | 6.3 d | – | – | 19 | 372 | |
Sub-tropical region | |||||||
21.4 a,d | 8.8 b,d | 13.5 d | 0.02 | −0.48 | 657 | 11,036 | |
19.1 d | 11.1 d | 8.5 d | – | – | 657 | 11,036 | |
Temperate region | |||||||
29.6 a,c | 14.1 a,c | 19.4 c | 0.0 | −2.2 | 69 | 886 | |
21.6 c | 10.8 d | 10.2 c | – | – | 69 | 886 | |
COSMOS network (cosmic-ray probes across all regions) | |||||||
24.0 a,c | 11.0 b | 14.3 | 0.07 | −0.50 | 52 | 771 | |
20.3 c | 11.7 c | 5.3 d | – | – | 52 | 771 | |
non Forested sites across all regions | |||||||
18.7 b,d | 6.8 b,d | 11.6 d | 0.05 | −0.09 | 574 | 9679 | |
19.1 d | 11.1 | 8.0 d | – | – | 574 | 9679 |
Sensor | RMSE | E | n stn | n | |||
---|---|---|---|---|---|---|---|
Global | a | b | c | ||||
MODIS (o) | 19.2 | 8.1 | 12.2 | 0.07 | −0.13 | 516 | 6886 |
MODIS (r) | 19.6 | 7.6 | 11.5 | 0.11 | 0.0 | 468 | 6560 |
AMSR-E | 12.8 | 3.3 | 12.0 | 0.15 | −0.11 | 497 | 56,153 |
SMOS | 12.2 | 9.0 | 12.4 | 0.24 | −0.21 | 517 | 52,457 |
Unbiased | d | ||||||
MODIS (o) | 18.8 | 11.4 | 7.1 | – | – | 516 | 6886 |
MODIS (r) | 18.9 | 11.4 | 6.8 | – | – | 468 | 6560 |
AMSR-E | 18.5 | 11.4 | 6.3 | – | – | 497 | 56,153 |
SMOS | 18.9 | 11.3 | 5.6 | – | – | 517 | 52,457 |
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Gumbricht, T. Detecting Trends in Wetland Extent from MODIS Derived Soil Moisture Estimates. Remote Sens. 2018, 10, 611. https://doi.org/10.3390/rs10040611
Gumbricht T. Detecting Trends in Wetland Extent from MODIS Derived Soil Moisture Estimates. Remote Sensing. 2018; 10(4):611. https://doi.org/10.3390/rs10040611
Chicago/Turabian StyleGumbricht, Thomas. 2018. "Detecting Trends in Wetland Extent from MODIS Derived Soil Moisture Estimates" Remote Sensing 10, no. 4: 611. https://doi.org/10.3390/rs10040611
APA StyleGumbricht, T. (2018). Detecting Trends in Wetland Extent from MODIS Derived Soil Moisture Estimates. Remote Sensing, 10(4), 611. https://doi.org/10.3390/rs10040611