Research Trends and Results

Study to achieve more prioritized and efficientenvironmental conservation measures for plants andanimals in road projects
INOUE Ryoji, Senior Researcher, KADOYU Katsunori, Head, KANDA Mayumi, Researcher
Road Environment Division, Road Department
UENO Yusuke, Researcher, KURIHARA, Masao, Head
Landscape and Ecology Division, Road Department(Key words) Environmental conservation measure, road project, raptors, environmental impact assessment
1. Introduction
During road projects, a variety of environmental
conservation measures are taken to avoid, mitigate, orcompensate for the project’s impacts on rare plants
and animals. These include the following measures of
unconfirmed effectiveness which are taken by roadprojects while hearing the opinions of local experts.
 Showing concern for raptors during works
 Transplanting vegetation
 Relocating amphibian species
The Environmental Impact Assessment Law
obligates surveys (post-project surveys) when
implementing environmental conservation measures of
uncertain effectiveness (below called, “uncertainmeasures”). And the preparation and release of thereport will, under the revision of the Environmental
Impact Assessment Law, be obligated beginning withproject submitting an environmental impact statementin April 2013.
This paper discusses present conditions focusedparticularly on showing concern for raptors during
works, and introduces the state of studies conducted toachieve prioritized and efficient environmental
conservation measures.
2. Present state of consideration for raptors during
work
Protection of raptors is presented in Methods ofProtecting Raptors (Enacted in August 1996, revised
December 2012) from the Ministry of theEnvironment. And the Supplement (TECHNICALNOTE of NILIM No. 721) to the Environment Impact
Assessent Technique for Road Project(ditto No. 714),
explains the method of assessing the environmental
impact on raptors and countermeasure examples. As
part of every road project, based on these documents,
nesting locations and the state of propagation are
surveyed at the same time as a variety ofcountermeasures are studied and executed.
Around nesting locations, work is often done so as
to avoid the nesting period (generally spring to earlysummer) but, when for example, the nesting location
is visually monitored and anything abnormal isobserved while the work is executed, actions are takenin response, including studying the temporary
suspension of the work.
Almost all of the above initiatives are taken to avoid
impacting the propagation of raptors during theexecution of the project (Table). But these surveys andcountermeasures incur annual costs per project in theorder of several tens of millions of yen (trial
calculated as several billions of yen per year forgovernment executed road projects nationwide).
Table. Results of Verification of Impacts of Road
Projects on Raptors (under close examination)
There is Slight
Unclear
impactimpactPropagation failure
by non-project
causes0463
175Note) Number of cases are total number of nests/year(nationwide: 2009 to 2012)

3. Study to achieve prioritization and efficiency
The state of nesting and propagation of raptors are
surveyed and countermeasures taken during works
throughout Japan to prevent impacts on theirpropagation, but the effectiveness of thesecountermeasure is still considered to be uncertain, and
it is difficult to achieve greater prioritization andefficiency. This is assumed to be a result of the factthat for the following reasons, the results of surveys ofeach project are limited to knowledge within each site(or work office).
 Propagation of raptors is linked to various factors
such as natural conditions, type of works,
differences between species of raptors or individualraptors, so decisions must be made independently
for each site. (diversity is high.)
 It is impossible to publicize information including
locations of nests in particular to prevent poaching.

For this reason, the NILIM, by collecting andanalyzing survey reports on uncertain measures on
government executed road projects throughout Japan,intends to clarify the causal relationships between theactions of raptors, the success or failure of theirpropagation and the operation of construction
machinery during works in order to prioritize truly
necessary countermeasures etc.
And for the same reasons, it is also difficult toprioritize the transplantation of vegetation or therelocation of amphibians.
The NILIM aims to achieve so-called formalizationof knowledge and further prioritize or increase theefficiency of effective countermeasures by eachproject so that it will be possible to share knowledge
obtained at each site concerning these uncertain
measures.
4. Use of the successful results
Based on future successful results, the Environment
Impact Assessment Technique for Road Project will
be revised. And by submitting manuscripts, theNILIM will provide information concerning theconservation of wild animals such as Methods ofProtecting Raptors.