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See detailAPPLICATION OF GEOMATICS FOR THE ASSESSMENT OF PASTORAL RESOURCES IN MOROCCO
Mahyou, Hamid ULg

Doctoral thesis (2012)

Rangeland or natural arid pastures of Morocco are defined as ecosystems where there is a natural or semi-natural vegetation composed of steppes, shrubs and grassland used mainly for livestock production ... [more ▼]

Rangeland or natural arid pastures of Morocco are defined as ecosystems where there is a natural or semi-natural vegetation composed of steppes, shrubs and grassland used mainly for livestock production as climate and soil are unsuitable to agriculture. The arid rangelands of Morocco occupy an area of over 33 million hectares between the isohyets of 100 and 400 mm. These areas represent livelihoods for thousands of people and protect the country from desertification. The main objective of this study is to provide scientific community and decision-makers methodological tools for assessing arid rangelands, based on geomatics and biophysics data. This study is divided in four parts: 1. The first part presents an overview of the threat of the desertification, emphasizes on the causes and consequences of rangeland degradation in Morocco, from literature sources, statistics, climate data and maps. Morocco rangelands are located in ten different pastoral zones that differ from each other by their floristic composition, soil and climatic conditions. According to Globcover map these rangelands are mainly composed by bare soil, herbaceous vegetation, shrubs and deciduous savanna mosaic / shrub or forest. The largest pastoral zones are: the Saharan zone, Pre-Saharan, the Oriental plateaus and the Valley of Moulouya. These zones are the most degraded with respectively 97, 89 and 69% of their total area. Available information on several pilot areas shows that the Moroccan rangelands are degraded due to many factors, which include overgrazing, cultivation, population increase and climate variation. 2. The second part of the study demonstrates the usefulness of remote sensing for assessing drought in arid rangelands of Morocco. Bi-weekly TERRA Moderate Resolution Imaging Spectroradiometer (MODIS 250 meters) data were used for this purpose. A Preliminary mapping by using Landsat TM5 of major land cover types was carried out to extract the pasture area. A comparison of annual and seasonal Normalised Difference Vegetation Indices (NDVI), Vegetation Condition Index (VCI) and rainfall during the time period of 2000–2008 were carried out. Results show significant correlations of either NDVI (r= 0.72**) or VCI (r=0.42*) with past season (3 months) rainfall. NDVI variation is a good indicator of vegetation changes and consequently can give a reliable indication on drought conditions in the study area. NDVI values lower than 0.2 are indicative of drought occurrence. NDVI values between 0.20 and 0.28 indicate average weather conditions and values higher than 0.28 correspond to humid conditions. 3. The third part presents an original knowledge-based approach for mapping the degradation of rangelands in North Africa. The study area is located in the high plateaus of eastern Morocco which include 3.5 million hectares of arid rangeland steppes. The approach consists in using datasets derived from Landsat TM satellite imagery, lithology, phytogeographic data and field indicators. The field indicators are: the steppes composition, perennial vegetation cover, annual perennial production, grazing level and the prevalence of rangeland cultivation. Results show that the knowledge-based approach is a valid method for evaluating rangeland degradation. The proposed knowledge-based approach discriminated between rangeland categories that would not have been discernible using only remote sensing. Overall classification accuracy of rangeland degradation obtained using this approach was 93%. This approach revealed that 11, 36 and 30% of the study area have shown very severe, severe and moderate degradation level, respectively. 4. The fourth part concerns the assessment of Alfa grass (Stipa tenacissima) tussocks at various degradation levels of Alfa grass steppes in the high plateaus of eastern Morocco, based on field hyperspectral data (350 – 2500 nm) and digital images during fall and spring seasons. Digital images of Alfa grass tussocks were taken using a digital camera to classify of the tussocks according to their proportion in green leaves (green, mixed and dry tussock). Assess software (Image Analysis Software for Plant Disease Quantification, APS 2002) was used to obtain the proportion of greenness in each tussock. Hyperspectral data of three states of tussocks (Green, Mixed and Dry tussock leaves) were collected within three degradation levels of Alfa grass steppes (Slight, Moderate and Severe degradation) with the ASD FieldSpec® 3 spectroradiometer. Paired t-test, Normalized difference spectral reflectance (NDSR) and Stepwise Discriminate Analysis were used to discriminate between various tussock status and different Alfa grass steppes. The results indicate that Alfa grass had shown an intraspecific variability in reflectance spectra. The proportion of green leaves in Alfa grass tussock strongly influences the spectral response. The discrimination of different Alfa grass tussock status was better during fall than spring. The spectral behavior of Alfa grass tussock is problematic for the mapping and the assessment of Alfa grass steppes by conventional remote sensing techniques. [less ▲]

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See detailDesertification of arid Rangelands in Morocco
Mahyou, Hamid ULg; Tychon, Bernard ULg; Paul, Roger ULg et al

Conference (2011, February 24)

Rangeland or natural arid pastures of Morocco are ecosystems where there is a natural or seminatural vegetation composed of steppes, shrubs and grassland. They cover about 82% of the Moroccan arid lands ... [more ▼]

Rangeland or natural arid pastures of Morocco are ecosystems where there is a natural or seminatural vegetation composed of steppes, shrubs and grassland. They cover about 82% of the Moroccan arid lands. These areas represent livelihoods for thousands of people and protect the country from desertification. Despite the importance of the rangelands and the threat of desertification, it is surprising that up to date there is no comprehensive assessment of their condition and their evolution, hindering any plan for desertification alleviation. However, the available information on selected pilot areas shows that these rangelands are threatened by desertification. It’s associated with biodiversity loss and contributes to climate change. The leading causes of land degradation are the human actions combined with climate. The establishment of a comprehensive surveillance system based on remote sensing, biophysics and socio-economic data must be envisaged to provide policymakers with an operational tool adapted to the spatio-temporal monitoring of desertification. [less ▲]

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See detailDrought risk assessment in pasture arid Morocco through remote sensing
Mahyou, Hamid ULg; Karrou, Mohamed; Mimouni, Jamal et al

in African Journal of Environmental Science and Technology (2010), 4(12), 845-852

During the last three decades, Morocco has experienced several stern and extended episodes of drought that severely affected pasture production. To cope with this phenomenon, the policy makers have put ... [more ▼]

During the last three decades, Morocco has experienced several stern and extended episodes of drought that severely affected pasture production. To cope with this phenomenon, the policy makers have put emphasis on a reactive short term management approach rather than on pro-active risk-based management measures. The purpose of this study is the assessment of drought by remote sensing, which is an important step in the design and implementation of drought management plan. To reach this objective we used bi-weekly TERRA Moderate Resolution Imaging Spectroradiometer (MODIS 250 m) data in arid pasture of Morocco. A preliminary mapping using Landsat TM5 of major land cover types was carried out to extract the pasture area. A comparison of annual and seasonal Normalised Difference Vegetation Indices (NDVI), Vegetation Condition Index (VCI) and rainfall during the time period of 2000 - 2008 were carried out. Results showed that stronger relationship of NDVI with previous seasonal rainfall as compared to VCI indicating that NDVI variation is a good indicator of vegetation changes and consequently can give a better idea on drought conditions in the study area. [less ▲]

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See detailKnowledge-based approaches for degradation mapping in arid rangeland
Mahyou, Hamid ULg; Tychon, Bernard ULg; balaghi, Riad

Poster (2010, September 28)

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See detailDésertification des parcours arides au Maroc
Mahyou, Hamid ULg; Tychon, Bernard ULg; Balaghi, Riad et al

in Tropicultura (2010), 28(2), 107-114

Rangeland or natural arid pastures of Morocco are ecosystems where there is a natural or seminatural vegetation composed of steppes, shrubs and grassland. They cover about 82% of the Moroccan arid lands ... [more ▼]

Rangeland or natural arid pastures of Morocco are ecosystems where there is a natural or seminatural vegetation composed of steppes, shrubs and grassland. They cover about 82% of the Moroccan arid lands. These areas represent livelihoods for thousands of people and protect the country from desertification. Despite the importance of the rangelands and the threat of desertification, it is surprising that up to date there is no comprehensive assessment of their condition and their evolution, hindering any plan for desertification alleviation. However, the available information on selected pilot areas shows that these rangelands are threatened by desertification. It’s associated with biodiversity loss and contributes to climate change. The leading causes of land degradation are the human actions combined with climate. The establishment of a comprehensive surveillance system based on remote sensing, biophysics and socio-economic data must be envisaged to provide policymakers with an operational tool adapted to the spatio-temporal monitoring of desertification. [less ▲]

Detailed reference viewed: 173 (18 ULg)
See detailMonitoring of the dynamics of the natural resources by the geomatic in Morocco
Mahyou, Hamid ULg; Tychon, Bernard ULg

Scientific conference (2008, January 29)

Drylands cover about 40 % of Earth’s land surface and are inhabited by more than 2 billion people who depend mainly on the exploitation of these dryland ecosystem natural resources. However, it is largely ... [more ▼]

Drylands cover about 40 % of Earth’s land surface and are inhabited by more than 2 billion people who depend mainly on the exploitation of these dryland ecosystem natural resources. However, it is largely recognized that these areas are threatened by the desertification. Desertification is associated with biodiversity loss and contrib-utes to global climate change. In spite of the importance of this phenomenon, it is surprising that there is no consensus on an appropriate method to assess this degradation process. One part of the literature announces catastrophic statistics on the rate of desert extension and surface affected. Others, doubt about the methodology used by these first studies and do not find any obviousness of such an extent of desertification. The overall goal of our study is to develop remote sensing based indicators and models for the assessment of desertification in drylands. For this purpose, the monitoring of vegetation and soil is based on information resulting from the remote sensing and the biophysics data. Hyperspectral (field and remote sensing) and biophysics parameters will be established for the study area through large field campaigns combined with HR-remote sensing data. The Land Cover will be mapped using the Landsat TM images in conjunction with measurements of vegetation parameters such as biomass and vegetation cover. Hyperspectral reflectances of the vegetation and soil inside the study zone will be measured by a Spectroradiometer. Each site will be located by Global Positioning System (GPS). Several RS vegetations indices appropriate for rangeland will be studied and others will be developed. Regression analyses, between the different vegetation indices retained by remote sensing and the biophysics data will be carried out so as to establish a spatio-temporal model linking these indices to the vegetation parameters. This research has started in November 2007 [less ▲]

Detailed reference viewed: 18 (2 ULg)