Fourthly , on the basis of specifying the interaction between population carrying capacity and sustainable development of regional economy , the new concept " ecological energy " was put forward and its index system was established in the paper . factor analysis and ward cluster analysis were used to explore the sustainable development of regional economy . as far as the divided types of " ecological energy " were concerned , we held that it was necessary to take the unequal development pattern in the area 第四,晉西黃土丘陵溝壑區(qū)人口容量與區(qū)域經(jīng)濟可持續(xù)發(fā)展研究,是在明確二者相互關(guān)系的基礎(chǔ)上,提出了區(qū)域人口“生態(tài)活力”的新概念,建立了區(qū)域人口“生態(tài)活力”的指標體系,并用因子分析和聚類分析等多元分析法,劃分了該區(qū)域人口“生態(tài)活力”的類型,據(jù)此提出了區(qū)域經(jīng)濟發(fā)展的“一中兩軸四帶”的不平等發(fā)展模式。