MONITORING OF ENVIRONMENTAL SENSITIVITY TO DESERTIFICATION IN SOME AREAS AT WEST OF DELTA, EGYPT

Current study aimed at classifying the environmental sensitivity to desertification using quantitative indices of soil, groundwater, erosion, and vegetation qualities. In addition to monitor the changing trends of the environmental sensitivities regarding their intensity and quality with time. Two studied areas were chosen to model soils of West of Delta. The first located at Sugar beat area over 21300 faddans while the second located at El-Bostan area over 14800 faddans. A comparison between their sensitivity qualities was performed during a period of 25 years starting in 1990 till 2015. Using an ETM image, DEM was processed in which slope gradient was extracted. Field investigations were undertaken. Soil mapping units were sampled at representative profiles. Laboratory analyses were carried out for collected soil samples. MEDALUS model published by the European Commission (Kosmas et al., 2003) was used for sensitivity evaluation, in addition to some modification done by Desert Research Center (DRC) staff (Hegazi et al., 2009). Results of calculating the environmental sensitivity areas (ESAs) for desertification indicated that Sugar beat area was classified as moderate sensible where ESIs ranged between 1.327-1.374 over 38.0% in 1990, while being between 1.354-1.386 over 38.3% in 2015. Meanwhile, the moderate ESIs at El-Bostan vary between 1.313-1.357 over 39.9% in 1990, which surpass to be between 1.335-1.373 above 41.5% in 2015. Studied areas were partially classified as very sensitive and sensitive to desertification. It was grown up at Sugar beat as accounted for 9.1% in 1990 and 13.4% in 2015 of the total area. While it was completely renovated into moderate sensitive at El-Bostan due to ground leveling and existence of sufficient vegetation cover. Percentages of sensitivity classes at Sugar beat in 1990 found to be very close to corresponding values in 2015, but with different spatial distributions. Further, the study achieved more positive changes of El-Bostan sensitivity than occurred in Sugar beat which had more intensive limitations i.e. shallow profile depth, saline groundwater as sea water intrusion, soil salinization, and difficulty of leveling due to ground hardness as affected by high lime content rather than rock exposures. It can be concluded that implementing maps of sensitivity to desertification is rather useful in the newly reclaimed desert areas as they give more likely quantitative trend for frequency of sensitivity. Applied agricultural systems affect negatively on increase the environmental sensitivity to desertification in some locations at both of studied areas. Therefore, it is necessary to re-evaluate current practices and/or land uses to prevent that degradation.