This is the 9333rd most frequent Japanese word.
県下
Under the jurisdiction or area of a prefecture.
In this sentence, "県下" refers to all institutions, specifically schools, within the geographical jurisdiction of the prefecture. It is used here to collectively describe these entities.
県下の学校は今年、新しいプロジェクトを始めます。
Schools in the prefecture will start a new project this year.
Here, "県下" is employed to denote the location of the tourist attractions, emphasizing that these places are situated within the boundary of the prefecture.
県下の観光名所を訪れる観光客が増えています。
Tourists visiting scenic spots in the prefecture are increasing.
The term "県下" in this context specifies the scope, indicating that the transportation network improvements are intended within the boundary of the prefecture.