3.1.1. Difficulties in systematic environmental assessment
It is important to be able to predict the likely environmental effects
of plans, programs, and projects in order to promote environmentally
sustainable development (Sheate et al., 2001; Jones et al., 2005). Since
it assesses the environmental effects of plans and programs affecting
the initial stages of a development project, PERS can act as a means to
create sustainable development. However, systematic approaches to
environmental assessment for high-level administrative plans could
not proceed because the PERS systemwas conducted on a too restricted
set of plans and programs. For example, in the area of urban development,
there is a hierarchy of administrative plans; each has a role and
scope stipulated in law. Generally the higher level of plan has a wider
scope than the lower level of plan.