One word substitute for 'Study of handwriting' is -

Graphology (noun).
- English meaning: handwriting analysis.
- Bangla meaning: হস্তলেখবিজ্ঞান।

অন্যদিকে,
• Geography
- the study of the systems and processes involved in the world's weather, mountains, seas, lakes, etc. and of the ways in which countries and people organize life within an area
- ভূগোলবিদ্যা বা ভূবিজ্ঞান।

• Geology
- the study of the rocks and similar substances that make up the earth's surface
- ভূস্তর, শিলা ইত্যাদি ভিত্তিক পৃথিবীর সম্পর্কিত বিজ্ঞান; ভূতত্ত্ব।

Source: Britannica, Cambridge Dictionary and Accessible Dictionary.