Tsunami tatbikatı sırasında acil durum ekipleri GPS ve pusula kullanarak tahliye rotalarını hızlıca belirledi.

tatbikatı = tatbikat (drill) + -ı (3rd-person possessive) → “the drill”
sırasında = sıra (time/turn) + -sı (possessive) + -nda (locative) → “during its time”
Together tatbikatı sırasında literally “in the time of the drill,” i.e. during the drill.

• sırasında comes from a noun (sıra + -sı + -nda) and means “during X,” where X is a noun event (e.g. toplantı sırasında = during the meeting).
• -iken attaches to a verb stem and means “while doing X” (e.g. yapılırken = while it was being done).
  Both convey overlapping time, but sırasında is preferred when you refer to the timing of a noun-based event.

ekip = team
-ler = plural → ekipler (“teams”)
-i = 3rd-person singular possessive → ekipleri (“the teams”)
In Turkish, adding a possessive suffix often makes a noun definite (“the teams” rather than “teams” in general). Subjects can carry this suffix to indicate that they are known/specific.

rota = route
-lar = plural → rotalar (“routes”)
-ını = definite direct-object marker (accusative; also overlapping with 3rd-person possessive)
So rotalarını marks “the specific evacuation routes” as a definite object of belirledi (“determined”). The accusative suffix shows that these routes are concrete/specified.

hızlı = fast/rapid
-ca = adverbial suffix
Combined hızlıca = quickly/rapidly. Here it modifies belirledi, telling us the teams determined the routes swiftly.

Turkish typically follows Subject-Object-Verb (SOV) order. In this sentence the sequence is:
1) Time phrase: Tsunami tatbikatı sırasında
2) Subject: acil durum ekipleri
3) Means participle: GPS ve pusula kullanarak
4) Object: tahliye rotalarını
5) Adverb: hızlıca
6) Verb: belirledi
The verb comes last, with all modifiers and objects placed before it.