Time Series Analysis of High Resolution Remote Sensing Data to Assess Degradation of Vegetation Cover of the Island of Socotra (Yemen)

Time Series Analysis of High Resolution Remote Sensing Data to Assess Degradation of Vegetation Cover of the Island of Socotra (Yemen)

Time Series Analysis of High Resolution Remote Sensing Data to Assess Degradation of Vegetation Cover of the Island of Socotra (Yemen) Dissertation To Fulfill the Requirements for the Degree of „Doctor of Philosophy“ (PhD) Submitted to the Council of the Faculty of Biology and Pharmacy of the Friedrich Schiller University Jena by M.Sc. Alhemiary, Abdulmaged born on 01.01.1968 in Taiz (Yemen) Jena, October 2016 Defense Date: 04.05.2017 PD Dr. Gottfried Jetschke, Head of the Dendro Ecology Group, Institute of Ecology, Friedrich Schiller University Jena, Germany PD Dr. Sören Hese, Head of the VHR Section, Institute for Geography, Department of Earth Observation, Friedrich Schiller University Jena, Germany Prof. Dr. Sebastian Schmidtlein, Heading the Vegetation Science and Biogeography Lab, Karlsruhe Institute of Technology, Institute of Geography and Geoecology Content Introduction ............................................................................................................................... III Problem description .............................................................................................................................. III Objectives and aims of the study .............................................................................................................. V Thesis Organization ............................................................................................................................... VI Chapter 1: Theoretical background .................................................................................................. 1 1.1. Characterization of ecosystems dynamics in semiarid regions ....................................................... 1 1.2. Vegetation changes and their explanatory factors based on remote sensing investigations ............... 2 Chapter 2: Study area and geographical location ................................................................................ 7 2.1 Physiographical characterisation and ecological zonation ............................................................. 8 2.2 Climatic characteristics ...........................................................................................................10 2.3 Soils Characteristics ................................................................................................................11 2.4 Vegetation ............................................................................................................................12 2.5 Land use ...............................................................................................................................14 Chapter 3: Data used and data pre-processing ................................................................................. 17 3.1 Data collection .......................................................................................................................17 3.1 Rainfall data and pre-processing ..............................................................................................17 3.2 Satellite data .........................................................................................................................19 3.3 Data pre-processing ...............................................................................................................24 3.3.1 Geometric corrections ............................................................................................................25 3.3.2 Noise and de-striping in image data ..........................................................................................26 3.3.3 Atmospheric correction ..........................................................................................................26 3.3.4 Multi Date Cloud Masking and Gap Filling ..................................................................................28 3.3.5 Topographic data and DEM .....................................................................................................29 3.4 Socio-economic data ..............................................................................................................29 3.5 Maps and Field data ...............................................................................................................29 Chapter 4: Methodology of data analysis ........................................................................................ 31 4.1. Variability of vegetation distribution and change in space and time ..............................................31 4.2. Methods of geostatistical analysis ............................................................................................31 4.2.1. Autocorrelation ........................................................................................................................31 4.2.2. Spatial autocorrelation .............................................................................................................31 4.2.3. Kriging with an external drift.....................................................................................................32 4.2.4. Convolution Spatial Filtering .....................................................................................................32 4.2.5. Correlation coefficient ..............................................................................................................33 4.2.6. Multiple correlation coefficients ...............................................................................................33 4.2.7. Simple linear regression model .................................................................................................33 4.2.8. Multiple linear regression model ..............................................................................................34 4.2.9. Quantifying relationship between variables by analyzing spatial relationship ............................34 4.2.10. Geographically weighted regression (GWR) ..............................................................................35 4.3. Evaluation of vegetation cover’s changes in relation to the driving forces ......................................36 4.3.1. Post classification comparison ..................................................................................................36 I 4.3.2. Unsupervised Classification ......................................................................................................37 4.3.3. Supervised Classification ...........................................................................................................38 4.3.4. Training stage and ground truth data ........................................................................................39 4.3.5. Selection of Change Detection Algorithms ................................................................................40 4.3.6. Change detection methods and requirements ..........................................................................41 4.3.7. Estimation of the vegetation activity trends ..............................................................................42 4.3.8. Vegetation index differencing ...................................................................................................43 4.3.9. Vegetation covers change and its driving forces ........................................................................44 4.3.10. Recognition of rainfall and anthropogenic signals in the vegetation time-series ........................45 4.3.11. Analysis of regression residuals for identification of areas experiencing anthropogenic impact .46 Chapter 5: Results, part 1 – Analysis of climatic conditions and NDVI .................................................... 47 5.1. Network of climate stations in the study region .........................................................................47 5.2. Statistical Analysis of Rainfall Data............................................................................................47 5.2.1. The inter-seasonal variability of rainfall.....................................................................................47 5.2.2. Rainfalls variabilities and seasonal trends .................................................................................50 5.2.3. Within season trends of rainfall ................................................................................................53 5.3. Variability of vegetation distribution .........................................................................................53 5.3.1. Average characteristics of NDVI ................................................................................................53 5.3.2. Inter annual variations difference vegetation index (NDVI)........................................................54 5.3.3. Within season variations in NDVI ..............................................................................................56 5.4. Dynamics of vegetation activity and rainfall relationships ............................................................59 5.4.1. Temporal behaviour of rainfall and vegetation within the growing season ................................59 5.4.2. Temporal behaviour of rainfall and vegetation between the growing season.............................60 5.5. Modelling spatial patterns in rainfall parameters ........................................................................64 5.6. Spatial distribution of (NDVI) and Rainfall in the study area .........................................................66 5.7. Conclusion ............................................................................................................................67

View Full Text

Details

  • File Type
    pdf
  • Upload Time
    -
  • Content Languages
    English
  • Upload User
    Anonymous/Not logged-in
  • File Pages
    145 Page
  • File Size
    -

Download

Channel Download Status
Express Download Enable

Copyright

We respect the copyrights and intellectual property rights of all users. All uploaded documents are either original works of the uploader or authorized works of the rightful owners.

  • Not to be reproduced or distributed without explicit permission.
  • Not used for commercial purposes outside of approved use cases.
  • Not used to infringe on the rights of the original creators.
  • If you believe any content infringes your copyright, please contact us immediately.

Support

For help with questions, suggestions, or problems, please contact us