Did you mean 'providence' or 'province' in your heading? This name seems to be the name of the region around Tarnopol (now in Ukraine), formerly the capital of the Tarnopol voivodship (province) in 1921-1939. To call an area (region) with the name of the city plus the '-szczyzna' suffix is common in Polish.
You have 'Lubelszczyzna' (Lublin), 'Opolszczyzna' (Opole), 'Wileńszczyzna' (Wilno), 'Kieleczczyzna' (Kielce), Pińszczyzna (Pińsk) and so on. The term 'Tarnopolszczyzna' (Tarnopol) is formed on the same basis. You will, however, never have 'Warszawszczyzna' (Warszawa), 'Wrocławszczyzna' (Wrocław), 'Krakowszczyzna' (Kraków) or 'Gdańszczyzna' (Gdańsk) and so on.