Assume you need to analyse land use and land cover change in Debre Markos city, which remote sensing images and classification methods would you use? Explain your choice and out line steps for image ?

For analyzing land use and land cover change in Debre Markos city, I would use high-resolution satellite images such as those from Landsat or Sentinel-2. These images provide detailed information about the land cover and land use patterns in the city, making them suitable for this type of analysis.

I would use a supervised classification method, such as Maximum Likelihood Classification or Support Vector Machine (SVM), to classify the satellite images into different land cover classes. This method allows for the creation of accurate and detailed land cover maps, which can then be used to analyze changes over time.

The steps for analyzing land use and land cover change in Debre Markos city using remote sensing images and classification methods would be as follows:

1. Acquire satellite images: Obtain high-resolution satellite images of Debre Markos city from Landsat or Sentinel-2 archives.

2. Preprocess the images: Preprocess the satellite images to remove any noise or artifacts that may affect the classification accuracy. This may include radiometric and atmospheric corrections.

3. Image segmentation: Segment the satellite images into homogeneous regions based on spectral and spatial characteristics. This step helps to reduce the complexity of the classification process.

4. Training data collection: Collect training data for each land cover class in the study area. This data should be representative of the different land cover types present in Debre Markos city.

5. Classification: Use a supervised classification method, such as Maximum Likelihood Classification or SVM, to classify the satellite images into different land cover classes. This step involves assigning each pixel in the image to a specific land cover class based on its spectral characteristics.

6. Accuracy assessment: Assess the accuracy of the classification results by comparing the classified land cover map with ground truth data or high-resolution aerial imagery. This step helps to evaluate the reliability of the classification results.

7. Change detection: Analyze the classified land cover maps from different time periods to identify and quantify land use and land cover changes in Debre Markos city. This may involve comparing the classified maps visually or using change detection algorithms.

8. Interpretation and reporting: Interpret the results of the analysis and prepare a report outlining the land use and land cover changes in Debre Markos city. This report can be used to inform urban planning and land management decisions in the city.

Remote Sensing Images:

- Landsat 8 OLI/TIRS: High spatial resolution (30 m) and multispectral bands suitable for land use classification.
- Sentinel-2 MSI: High spatial resolution (10 m) and multispectral bands with additional near-infrared bands for vegetation analysis.
- SPOT 6/7: High spatial resolution (1.5 m) and panchromatic and multispectral bands for detailed land use mapping.

Classification Methods:

- Supervised Classification:
- Maximum Likelihood Classification (MLC): Uses statistical models to assign pixels to known land use classes.
- Support Vector Machine (SVM): Uses a hyperplane to separate land use classes based on their spectral signatures.
- Unsupervised Classification:
- K-Means Clustering: Groups pixels into clusters based on their spectral similarity, which can later be assigned to land use classes.
- Object-Based Image Analysis (OBIA):
- Segments the image into objects based on spectral and textural properties, and then classifies the objects into land use classes.

Steps for Image Processing and Classification:

1. Pre-processing:
- Radiometric calibration and atmospheric correction to remove noise and atmospheric effects.
- Geometric correction to align the images with a known coordinate system.
2. Image Enhancement:
- Band ratioing to highlight specific land use features.
- Principal Component Analysis (PCA) to reduce data dimensionality and enhance interpretability.
3. Image Segmentation (for OBIA):
- Use algorithms like Mean Shift or Watershed to segment the image into objects.
4. Feature Extraction:
- Extract spectral, textural, and shape features from the pixels or objects.
5. Land Use Classification:
- Train supervised classifiers using reference data or use unsupervised classification algorithms.
6. Accuracy Assessment:
- Compare the classification results with reference data to assess accuracy and identify potential errors.
7. Post-Processing:
- Remove small isolated pixels or merge adjacent pixels with similar land use classes to smooth the results.

Choice of Images and Classification Methods:

- For a detailed analysis requiring high spatial accuracy, SPOT 6/7 with an OBIA approach would be suitable.
- For a cost-effective option with good spatial and spectral resolution, Landsat 8 OLI/TIRS with a supervised classification (MLC or SVM) would be appropriate.
- For a comprehensive analysis with a wide range of spectral bands, Sentinel-2 MSI complemented with OBIA or a combination of supervised and unsupervised classification techniques would be optimal.