土壤演变 meaning in Chinese

soil evolution

The dissertation reviews the agriculture production history , analyzes the status quo , the change of river system , soil evolvement and the forming course of economic position , and discusses the precondition of the agricultural development of the hhh plain . the agricultural system database of the hhh plain is set up by using mapgis software
总体上考察了黄淮海平原农业生产历史、现状形势；浅析了黄淮海平原的水系变迁，土壤演变过程及其经济区位条件的形成，初步探讨了该平原农业发展的先决条件。