Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Master → Pays Bas → Irrigation performance of Gezira scheme, Sudan : assessment of land and water productivity using satellite data

UNESCO-IHE Institute for Water Education, Delft (2010)

Irrigation performance of Gezira scheme, Sudan : assessment of land and water productivity using satellite data

Mamad, N.

Titre : Irrigation performance of Gezira scheme, Sudan : assessment of land and water productivity using satellite data

Auteur : Mamad, N.

Etablissement de soutenance : UNESCO-IHE Institute for Water Education, Delft

Grade : Master of Science (MS) 2010

Résumé
The Gezira irrigation scheme in Sudan is amongst the largest and the oldest irrigation schemes in the world. According to several studies, productivity of the main crops (cotton, wheat, sorghum and groundnut) in the scheme is far below potential level, and also below worldwide productivity averages with regard to unit area as well as unit water use. An accurate assessment of productivity at different scales would provide key information for improved land and water management. This paper presents an assessment of the land and water productivity at different spatial scales within the Gezira scheme using satellite data. First, the ET and biomass maps derived from ETLook provided by Waterwach were used in this study. Secondly, the Landsat-7 ETM+ images with 30 m spatial resolution were used to identify crop type and cultivated area by using unsupervised classification. Finally, these maps were used to assess the land and water productivity of the Gezira scheme for the growing season 2007/2008. The average land productivity derived from remote sensing for the Gezira scheme are 1288, 1071, 855, and 851 kg/ha for cotton, wheat, groundnut and sorghum, respectively. While, the water productivity of the scheme are 0.28 kg/m3for cotton, 0.47 kg/m3for wheat, 0.22 kg/m3for groundnut, and 0.23 kg/m3for sorghum. However, the value for these indicators shows variability at different spatial scales at the head, middle, and tail the scheme. The land productivity varying from 1174 to 1424 kg/ha for cotton, 1060 to 1360 kg/ha for wheat, 648 to 1008 kg/ha for groundnut, and 688 to 1037 kg/ha for sorghum. While, the water productivity from head to tail varying from 0.26 to 0.30 kg/m3for cotton, 0.46 to 0.51 kg/m3for wheat, 0.18 to 0.22 kg/m3for groundnut, and 0.20 to 0.25 kg/m3for sorghum. The main conclusion is that land and water productivity of the Gezira scheme are low and shows clear spatial variability within the scheme. Thus, the opportunities to improve the performance of the scheme undoubtedly exist. The proposed remote sensing technology can significantly contribute to quantify the land and water productivity across the Gezira scheme in Sudan. Though, the quality of the images may affect the results during cloudy conditions. Intensive ground truthing will improve the image classification.

Sujets  : irrigation schemes ; land productivity ; remote sensing ; performance indicators ; Sudan

Présentation

Version intégrale

Page publiée le 6 janvier 2017, mise à jour le 16 octobre 2018