شرح ساينس الصف الخامس الابتدائي لغات - الفصل الدراسي الثاني
شرح ساينس خامسة ابتدائي - ترم ثاني

لينك تحميل الملزمة
https://drive.google.com/file/d/10LYEOvXMpqMGl2Lkan2Z9mkIcAlFWF0x/view?usp=sharing

لينك تليجرام
https://t.me/mrahmedelbashagroup

In This Lesson:
•Poor quality of fresh water leads to:
- The death of thousands of living organisms every year.
- The extinction of some species that live in fresh water such as some fish and amphibians.

• Much of the study of water is focused on fresh water due to its vital importance
to humans.
• Finding and preserving fresh water is one of the major challenges of this century.
• Fresh water resources on Earth are limited, so without the right balance of using
fresh water in a community leads to the occurrence of water imbalance causing
droughts or floods that impact many organisms.
• Humans use some strategies to control and conserve fresh water for their needs
such as building dams across rivers to store water.
• These human activities cause imbalance of water that leads to:
- Drought (shortage of water) in some places.
- Flooding in some other places .The study of freshwater systems focuses on the balance of water in a watershed, where:
- When there is more rainfall, the level of water in rivers or streams will increase
causing floods.
Watershed
It is an area of land where water from different sources flows in one direction towards a common location such as an ocean, a sea or other large water body.

- When there is too little rainfall, the level of water in rivers or streams will decrease, so these water bodies may dry up causing drought.
• But, when there is water balance, rivers or streams will have a constant source of
fresh water.



بالتوفيق
مستر احمد الباشا