This paper introduces the concept of potential function into the multiply-connected region and provides its method of computation in order to solve some complex problems concerning line integrals.

To compute the intersection of arbitrary polygonal regions effectively,the seam technique is used to remove all the holes in a polygonal region and the multiple connected region is transformed into a single one.

The Abel equation integrability in complex domain is analyzed.

This paper analyses the current situation of Dalian region and identifies Ecological problems may appear with region development,and then presents a summarization of some related landscape ecology theories.