Phrasing your research question in hypothesis format is a question of taste in my experience. However, your sponsor, promoter or journal may have a distinct preference. For example, I have come across a  journal explicitly discouraging the use of hypotheses to organise your narrative.

Attached three examples of forest cover change studies with RS and GIS with different levels of explicit hypothesis.

enjoy the read

Article What Drives Conversion of Tropical Forest in Carrasco Provin...

Article Forecasting the pattern and pace of Fagus forest expansion i...

Article Pinus mugo Krummholz Dynamics During Concomitant Change in P...

As mentioned above, the inclusion of a hypothesis or research question will depend on what the research is being used for and the audience who will be reading it.

Agree with above. Often a statement of goals is sufficient.

Thanks Hein for the helpful answer...and ye thanks  to Jonathan and James also for your answers it helps.

Stating and testing hypotheses are a matter of choice in any research. However,  researchers are often encouraged to formulate and test hypotheses when they engage in quantitative research. Qualitative research generally does not require hypothesis testing. Research questions are preferable for qualitative studies. 

Thanks Kayode for your answer.