الملخص باللغة العربية

الملخص باللغة الإنجليزية

The rapid population growth in Egypt necessitates maximizing the utilization of available water resources. Generally, rapid, unplanned construction of urban communities, uncontrolled construction of buildings, and major land-use changes can influence the spatial and temporal pattern of flood hazards. Morphometric analysis is vital to prioritize sub-watershed for flood hazard assessment in drainage basins for proper planning and management of natural resources for sustainable development. Therefore, the main objectives of the present study are to compute the morphometric parameters of Heliopolis sub-basins based on applying the Arc GIS 10.5 and WMS 10.1 software, determine the hazard degree of sub-basins to generate a flooding risk susceptibility map, and prioritize sub-watersheds to detect the most vulnerable sub-watershed to soil erosion and to generate a flooding priority map. Besides, Understanding the hydrological properties and estimate volumes of flows, Peak Flow, and Time of arrival of the flows by applying the model Hydrological (HEC-1) of the (WMS) Program using Unit Hydrograph namely SCS. Increasing urban activities in flood plain areas will increase peak discharge, decrease the time to peak, and increase runoff volume, therefore, a better understanding and evaluation of land use changes that have a direct impact on watershed hydrologic processes has become crucial for planning, management, and sustainable development of the watershed. Chapter three aims to identify the land cover changing for the study area during the three last decades (1990, 2000, 2010, 2020); we attend to the extraction of the land covers depending on GIS and remote sensing techniques. Results revealed that, the bare land class was changing in the area from 1029.34 km2 (89 %), to 553.58 km2 in 1990, and 2020 years, respectively. The urban class was different from 102.34 km2 to 466.06 km2 in 1990, and 2020 years, respectively. The vegetation class was different from 18.26 km2 to 132.95 km2 in 1990, and 2020 years, respectively. The water pond class was different from 4.96 km2 to 2.48 km2 in 1990, and 2020 years. Heliopolis basins has been classified into ten sub-watersheds; three groups of morphometric parameters: basic, derived, and shape parameters were measured and calculated quantitatively using Arc GIS and WMS10.1 package. The morphometric hazard degree assessment method has been employed to generate a flooding risk susceptibility map. Results reveal that W. Al-Nasory Al-Kabir constituting 24.74% of the total area has a ‘high hazard degree’, and thus represents dangerous sub-basins with high flooding susceptibility, whereas the susceptibility of the other sub-watersheds has been found as ‘moderate’ [W. El Forn trunk, W. Al-Aqabia, W. El-Halazony, W. Al-Debah, W. Al-Yahmoum, and W. Al-Monaqee (62.03%)], and ‘slight hazard’ [W. Abu Dorma, W. El-Daltan, and W. Elwiat El-Widian (13.23%)]. Ten morphometric parameters have been selected and used for ranking and prioritizing sub-watersheds to detect the most vulnerable sub-watershed to soil erosion and to generate a flooding priority map. In this regard, W. Al-Aqabia, El -Forn trunk, W. El-Halazony, W. Al-Yahmoum, W. Al-Nasory Al-Kabir, and W. Al-Debah sub-watersheds have categorized into higher priorities, therefore, these sub-watersheds are relatively affected by runoff and soil erosion. Chapter five aims to identify the relation between the rainfall and runoff of the Heliopolis watershed and its sub-basins, to estimate the volumes of flows, Peak Flow, and Time of arrival for the storm events (12 March 2020), besides predicting the runoff volume and peaked discharge for different return periods. of the flows by applying the model Hydrological (HEC-1) of the (WMS) Program using Unit Hydrograph namely SCS. The Geographical information systems (GIS) are used for the production and monitoring of soil and geology maps, the hydrological soil group and the and the land cover/use to record urban expansions to show their impact. The maximum daily amount of rainfall per year for t three stations (Cairo airport, El Qattamia and Helwan stations) were collected for 39 years covered the period from 1982 to 2020 and analyzed and estimated for different return periods (5, 10, 25, 50, and 100 year), using the statistical analysis program Hyfran. The results of the study revealed that the volume of floods of the Heliopolis watershed amount to 53752968 m3, and the peak discharge value was 742.16 m3/s for 100 years, return periods. Al-Nasory Al-Kabir sub-basin has the highest flood volume (11680214 m3), and followed by W. El-Halazony, with an average volume of floods amounting to 8013001m3, during the regression period of 100 years. Al-Nasory Al-Kabir sub-basin has the highest peak discharge value (210.69 m3/s), and followed by W. El-Halazony, with an average volume amounting to 208.11m3/s. The results of the study revealed the danger posed by the Al-Nasory Al-Kabir and El-Halazony sub-basins to the urban expansion of in the study area.