Multi-temporal assessment of land sensitivity to desertification in a fragile agro-ecosystem: Environmental indicators

摘要

Human activities as well as natural events can dramatically affect land degradation negatively or positively. In Egypt, agriculture is a key sector of the economy. Land reclamation seeks to transfer desert areas to agricultural land and support the construction of new villages. The agricultural productivity improvement of these Newlands is slow and requires considerable time due to their fragility and sensitivity to desertification. The main objectives of this study were the assessment, monitoring, and mapping of the areas' most sensitive to desertification in the Bustan 3 area, Egypt; one of the Newlands that was targeted for reclamation during the 1990s. Standard and adjusted Mediterranean desertification and land use (MEDALUS) approaches were applied for two time series (1984 and 2008). The main goals were achieved via: (a) identifying the most environmentally sensitive areas to desertification in the study area, (b) assessing the environmental sensitivity area indices (ESAIs) of 1984 and 2008 to determine the effects of land reclamation processes, (c) adjusting the MEDALUS factors for 2008 to obtain more reliable data at the local level, and (d) monitoring the ESAI change between 1984 and 2008 over the studied area. When the standard MEDALUS approach was applied to both 1984 and 2008, the ESAI results classified 100% and ~78% of the study area as critically sensitive to desertification due to the impact of plant cover, respectively. In the adjusted version of the MEDALUS approach, new parameters were added to the soil quality indicator while irrigation water quality was considered as a new indicator. This approach was applied in 2008 and the results revealed that critical ESAI areas covered ~89% of the study area. Since the Bustan 3 area is intensively cultivated, more attention is required for the most sensitive areas to desertification in order to achieve sustainable land use in such fragile agro-ecosystems.