Why did the british occupy egypt in 1882?

Egypt controlled a major trading routes and canals(most famous is sina)

Suez canal: opened in 1869. it became very important to trade. in 1882,80% of trade going through it was British. number of ton passing through it every day increased, from 400,000 to 5 million between 1870 and 1882.provided a thoroughfare to Britain's colonies in asia.
Egyptian cotton trade: british focus moved to Egyptian cotton because...
technological improvements eg.eli whitney's "cotton gin" in 1793
American civil war(1861-1865)
Egyptian efforts to increase cotton production eg.egyptian cotton production increased 4-fold in the 1860s, cotton represented 75% of exports by 1870s