Land degradation is a global environmental issue, given the various negative impact on socio-economic and ecological implications. It leads to reduced production capacity in addition to soil erosion, physical /chemical /biological /economic land deterioration, and long-term loss (or degradation) of vegetation. When a severe deterioration in drought areas called the process of desertification i.e. arid, dry sub-humid and semi-arid areas. Desertification processes reduces the productivity of the soil and as a result effect on food stocks. The main objective of this study is integrating remote sensing data and a geographic information system (GIS) to evaluate the environmental sensitivity for desertification in Wadi El Natrun, Egypt based on the Mediterranean Desertification and Land Use (MEDALUS) approach. The collected soil data; from description of represented soil profiles and analysis of soil samples, in addition to climate, plant cover, and management data were considered for assessing the sensitivity of desertification. The obtained results showed that 10.4 % of Wadi El Natrun area is considered severe sensitivity to desertification as a result of alkalinity and salinity, while the moderately sensitive area occupies approximately 10.93 % of the study area. The low sensitive one exhibits 76.3 %. This area is described by high soil quality because of the study area is one of the new development areas which were not affected by the factors of desertification. It can be concluded that the desert extension of El-Beheira Governorate (i.e. Wadi El Rayan) is one of the areas that possess valuable land resources which should be considered for future land reclamation projects. Similar international studies are recommended to be achieved with the use of multi-criteria GIS modeling (i.e. MEDALUS) which considered all relevant factors in the form of thematic layers for easier implementation and assessments. Present study represents one of the initial attempts to use the MEDALUS model for desertification assessment in the desert extension of El-Beheira Governorate.

Early blight caused by Alternaria solani (Ell. and Mart.) is one of the most important economic diseases, which caused considerable loss in their yield and quality under Egyptian conditions. Aim the research was to study the relationship between climate change and disease severity for prediction in future seasons. Disease severity was recorded for three growing periods i.e. summer (May. to Aug), autumn (Jul. to Oct) and winter (Nov. to Mar.), at three governorates (Behira, Ismailia, and Assuit) during growing seasons 2016/2017-2017/2018. Severity of early blight disease on tomato has been predicted by regression estimated accumulative disease severity values during 2007/2008 to 2015/2016 season and average max and min temperature and humidity through these seasons. Prediction of disease has been formed as Y= b0+b1x1+b2x2+.......... bqxq. Three models were created to describe the severity disease by multiple regressions (MINITAB® program). The highest value of early blight disease was recorded through season 2017/2018, while the lowest value was recorded during season 2016/2017. Also, highly disease severity was estimated during summer period compared with autumn and winter growing periods, but through winter growing period was the least severity and moderately severity estimated in the autumn growing period. Influence of environmental conditions on the severity of early blight disease during seasons from 2007/2008 to 2015/2016, in Behira governorate, the highest disease severity was showed in season 2010-2011, and the lowest disease was in season 2012-2013, but in Ismailia governorate, highest disease severity was estimated in season 2010-2011and lowest disease was recorded in season 2013-2014 and in Assuit governorate, the highest value of disease was in season 2010-2011, and the lowest value was in season 2013-2014. For Forecasting, significantly differences noticed between disease severity through 2020/2030, 2030/2040 and 2040/ 2050s seasons compared with 2008/2018s seasons and thier relation with climate change in tested governorates, where severity of tomato early blight disease was icreased from 11.8% during 2008/2018s seasons to 2040/ 2050s seasons 15.4% during at Behira governorate, from 18.8% during 2008/2018s seasons to 2040/ 2050s seasons 36.3% during at Ismailia governorate and from 18.8% during 2008/2018s seasons to 2040/ 2050s seasons 40.4% during at Assuit governorate with slight change in maximum or minimum temperatures and percentage of relative humidity.