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Accueil du site → Doctorat → États-Unis → 1998 → Spatial analysis of land use and land-use changes, and simulation of soil erosion in the Oued Laou watershed, Morocco

University of Georgia (1998)

Spatial analysis of land use and land-use changes, and simulation of soil erosion in the Oued Laou watershed, Morocco

Chen, Feng

Titre : Spatial analysis of land use and land-use changes, and simulation of soil erosion in the Oued Laou watershed, Morocco

Auteur : Chen, Feng

Université de soutenance : University of Georgia

Grade : Doctor of Philosophy (PhD) 1998

Résumé
A high proportion of the poor reside in mountainous areas in Morocco. Soil erosion caused by unsustainable land use practice has been accelerating the loss of land productivity. Technologies including remote sensing, geographic information systems (GISs), global positioning system (GPS), and soil erosion model were applied to explore and analyze the processes and mechanisms in spatial and temporal dynamics and characteristics of land use and soil erosion for the Oued Laou watershed of Morocco. Geographic information systems integrated image classification was used for land use classification. Data from GIS layers were extracted to improve the classification result from remotely sensed image classification. A binary coding method was developed to analyze more than three times of data sets in detection of changes in land use. The relationships between land use or changes in land use and spatial characteristics including elevation and slope were examined quantitatively. The soil erosion model USLE was integrated within a GIS with the help of computer programs. Results showed that 40% of the watershed has experienced changes in land use over the past 30 years. The average rate of change in land use between 1986 and 1995 was 3.1%, while this value was only 0.8% between 1966 and 1986. Land use was clearly related to spatial characteristics. Based on the relationships between land use and elevation characteristics, patterns of land use in the watershed can be divided into three elevation regions : elevations lower than 50 m, elevations between 50 and 1,000 m, and elevations higher than 1,000 m. Based on the relationships between land use and slope characteristics, patterns of land use also divided into three slope regions : slopes lower than 3 degrees, slopes between 3 and 20 degrees, and slopes steeper than 20 degrees. However, the relationships between changes in land use and spatial characteristics were more complicated, and there were no such clear patterns. Cropped lands were the major source of soil erosion accounting for 69-80% of the total soil loss amounts from the watershed. The order of total soil loss amounts from different land use categories were cropped lands $>$ shrub lands $>$ bare surfaces $>$ forest lands. Although the total soil loss amounts for the watershed were slightly increased, the total soil loss amounts from cropped lands were decreased since the cropped lands were more concentrated on lower sloped areas now than in the past.

Mots clés : Agronomy, Soil sciences, Applied sciences, Remote sensing, Computer science, GPS Geography, Earth sciences, Biological sciences, GIS

Présentation (PROQUEST)

Page publiée le 11 février 2015, mise à jour le 7 septembre 2017