Desertification in the Sahel Region: A Product of Climate Change or Human Activities? A Case of Desert Encroachment Monitoring in North-Eastern Nigeria Using Remote Sensing Techniques
Abstract
:1. Introduction
2. Materials and Methods
2.1. Study Area
2.2. Data and Pre-Processing
2.3. The Generation of Reference Data
2.4. Land Cover Mapping and Accuracy Assessment
2.5. Time Series Assessments and Projections
2.6. Climate Change and Land Cover Conversions
3. Results
3.1. Land Cover Changes from 1990 to 2015
3.2. Land Cover Conversions from 1990 to 2015
3.3. Relationship of Land Covers Conversions and Climate Parameters between 1990 and 2015
3.4. Land Covers Probabilistic Projections for 2030 and 2045
4. Discussion
4.1. Land Cover Changes from 1990 to 2015
4.2. Land Cover Conversions from 1990 to 2015
4.3. Relationship between Land Cover Conversions and Climate Parameters between 1990 and 2015
4.4. Land Cover Probabilistic Projections for 2030 and 2045
5. Conclusions
Author Contributions
Funding
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Reference (Field Data) | |||||||||
---|---|---|---|---|---|---|---|---|---|
Land Cover | Bare Surface/Sand Dunes | Built-Up | Farmland | Vegetation | Oasis/ Wetlands | Total | User’s Accuracy | Commission Error | |
Classified Image (Map) | Bare surface/ sand dunes | 51 | 4 | 5 | 0 | 0 | 60 | 0.85 | 0.15 |
Built-up | 0 | 34 | 1 | 0 | 0 | 35 | 0.97 | 0.03 | |
Farmland | 4 | 2 | 94 | 2 | 2 | 104 | 0.90 | 0.10 | |
Vegetation | 0 | 1 | 2 | 41 | 4 | 48 | 0.85 | 0.15 | |
Oasis/ Wetlands | 1 | 1 | 2 | 4 | 53 | 61 | 0.87 | 0.13 | |
Producer’s accuracy | 0.75 | 0.94 | 0.84 | 0.76 | 0.87 | - | - | - | |
Omission Error | 0.25 | 0.06 | 0.16 | 0.24 | 0.13 | - | - | - | |
Overall accuracy | 0.81 (81%) | - | - | - | - | - | - | - |
Land Cover | 1990 (ha) | % | 2000 (ha) | % | 2010 (ha) | % | 2015 (ha) | % |
---|---|---|---|---|---|---|---|---|
Bare Surface/ sand dunes | 31,369 | 4.1 | 35,663 | 4.6 | 41,732 | 5.4 | 69,462 | 9 |
Built-up | 2519.8 | 0.3 | 4512.4 | 0.6 | 7527 | 1 | 7893 | 1 |
Farmland | 591,175 | 76.4 | 601,112 | 77.7 | 601,048 | 77.7 | 621,411 | 80.3 |
Vegetation | 92,126 | 11.9 | 75,409 | 9.7 | 69,120 | 8.9 | 28,143 | 3.6 |
Oasis/wetlands | 56,563 | 7.3 | 57,110 | 7.4 | 54,330 | 7 | 46,857 | 6.1 |
Total | 773,752 | 100 | 773,806 | 100 | 773,757 | 100 | 773,766 | 100 |
Land Cover Conversions | Area (ha) |
---|---|
* Vegetation to Farmland | 62,411 |
Vegetation to Wetland and Oasis | 6432 |
Vegetation Unchanged | 21,783 |
* Vegetation to Bare/Sand dunes | 1013 |
* Vegetation to Built-Up | 394 |
Wetland and Oasis to Farmland | 21,922 |
Wetland and Oasis Unchanged | 33,142 |
Wetland and Oasis to Vegetation | 996 |
* Wetland and Oasis to Bare/Sand dunes | 309 |
Wetland and Oasis to Built-Up | 163 |
Farmland Unchanged | 519,371 |
Farmland to Wetland and Oasis | 7143 |
Farmland to Vegetation | 5265 |
* Farmland to Bare/Sand dunes | 54,455 |
Farmland to Built-Up | 4624 |
Bare/Sand dunes to Farmland | 17,270 |
Bare/Sand dunes to Wetland and Oasis | 69 |
Bare/Sand dunes to Vegetation | 72 |
Bare/Sand Dunes Unchanged | 13,656 |
Bare/Sand Dunes to Built-Up | 291 |
Built Up to farmland | 61 |
Built Up to Wetland and Oasis | 39 |
Built Up to Bare/Sand dunes | 0.2 |
Built Up Unchanged | 2419 |
Total | 773,298 |
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Ibrahim, E.S.; Ahmed, B.; Arodudu, O.T.; Abubakar, J.B.; Dang, B.A.; Mahmoud, M.I.; Shaba, H.A.; Shamaki, S.B. Desertification in the Sahel Region: A Product of Climate Change or Human Activities? A Case of Desert Encroachment Monitoring in North-Eastern Nigeria Using Remote Sensing Techniques. Geographies 2022, 2, 204-226. https://doi.org/10.3390/geographies2020015
Ibrahim ES, Ahmed B, Arodudu OT, Abubakar JB, Dang BA, Mahmoud MI, Shaba HA, Shamaki SB. Desertification in the Sahel Region: A Product of Climate Change or Human Activities? A Case of Desert Encroachment Monitoring in North-Eastern Nigeria Using Remote Sensing Techniques. Geographies. 2022; 2(2):204-226. https://doi.org/10.3390/geographies2020015
Chicago/Turabian StyleIbrahim, Esther Shupel, Bello Ahmed, Oludunsin Tunrayo Arodudu, Jibril Babayo Abubakar, Bitrus Akila Dang, Mahmoud Ibrahim Mahmoud, Halilu Ahmad Shaba, and Sanusi Bello Shamaki. 2022. "Desertification in the Sahel Region: A Product of Climate Change or Human Activities? A Case of Desert Encroachment Monitoring in North-Eastern Nigeria Using Remote Sensing Techniques" Geographies 2, no. 2: 204-226. https://doi.org/10.3390/geographies2020015