Development of a satellite-based dynamic regional vegetation model for the Drâa catchment

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XII 1 VEGETATION MONITORING IN SEMI ARID AREAS ..................................................... 13 1.1 Scientific Goals ...................................................................................................................................... 19 1.2 Outline .................................................................................................................................................. 21 2 THE DRÂA VALLEY IN SOUTHERN MOROCCO ............................................................. 22 2.1 Natural Formations ............................................................................................................................... 23 2.2 Climate and Meteorological Monitoring ............................................................................................... 24 2.3 Geology and Soil ................................................................................................................................... 27 2.3.1 Geology .............................................................................................................................................. 27 2.3.2 Soil ...................................................................................................................................................... 31 2.4 Vegetation formations inside the Drâa Catchment ............................................................................... 34 2.4.1 High Atlas Mountain, Jebel Siroua and Jebel Saghro (2200 m and up) .............................................. 35 2.4.2 South slopes of the Atlas Mountain range (1400 to 2400 m) ............................................................ 35 2.4.3 Presaharian/Saharan Flora ................................................................................................................. 36 2.4.4 Extrazonal vegetation ........................................................................................................................ 36 2.5 Pastoral land use ................................................................................................................................... 36 3 SPATIO TEMPORAL VEGETATION MODELLING .......................................................... 41 3.1 Vegetation Modelling conception ......................................................................................................... 41 3.2 MOVEG Drâa, a Dynamic Vegetation model .......................................................................................... 44 3.3 From Images and Meteorological Stations to Vegetation monitoring ................................................... 46 3.4 NDVI: Introduction and Relationship to other factors ........................................................................... 48 3.5 Primary Productivity and C-fixing with the remote eye ......................................................................... 54 II 4 DATA COLLECTION ............................................................................................................... 59 4.1 Meteorological Data ............................................................................................................................. 59 4.2 Field Measurement ............................................................................................................................... 63 4.2.1 Ground Truth Points........................................................................................................................... 63 4.2.2 Long Term Exclosure .......................................................................................................................... 64 4.2.3 Cage Experiment ................................................................................................................................ 65 4.3 MODIS satellite data ............................................................................................................................. 66 4.3.1 Sensor MODIS .................................................................................................................................... 66 4.3.2 Data format and handling .................................................................................................................. 67 4.3.3 MODIS NDVI ....................................................................................................................................... 72 5 DEVELOPMENT OF THE DYNAMIC REGIONAL MODEL MOVEG DRÂA ................. 75 5.1 General structure of MOVEG Drâa ........................................................................................................ 75 5.2 Enumeration of Input Parameters and Sampling Strategy ..................................................................... 76 5.3 Conversion MOVEG Drâa to IDL ............................................................................................................ 77 5.3.1 Programming with IDL ....................................................................................................................... 78 5.3.2 Parameterisation and Automation .................................................................................................... 79 5.4 Digital Elevation Model ......................................................................................................................... 80 5.5 Steering Module ................................................................................................................................... 82 5.6 Module Climate .................................................................................................................................... 84 5.7 Module Runoff Curvenumber................................................................................................................ 87 5.8 Development of Time Series using ENVI IDL .......................................................................................... 90 5.9 Module LAG .......................................................................................................................................... 91 5.10 Module Regression ........................................................................................................................... 92 5.10.1 Input and flow Indicator..................................................................................................................... 92 5.10.2 Projection Sub Module....................................................................................................................... 92 5.11 Module ANPP ................................................................................................................................... 97 5.12 Subroutines ...................................................................................................................................... 99 5.13 Quality Criteria ............................................................................................................................... 100 5.14 Module Forecast ............................................................................................................................. 102 5.15 Output format ................................................................................................................................ 106 6 RESULTS OF MOVEG DRAA............................................................................................... 107 6.1 Results Climate Data ........................................................................................................................... 107 6.1.1 Wind ................................................................................................................................................. 108 6.1.2 Temperature .................................................................................................................................... 108 6.1.3 Precipitation ..................................................................................................................................... 110