Memorandum submitted by The Survey Association
(FL 61)
1. INTRODUCTION
TO THE
SURVEY ASSOCIATION
1.1 The UK Land & Hydrographic Survey
Association, more generally known as The Survey Association (TSA),
was formed in 1979 to represent the views and look after the interests
of private surveying companies in the United Kingdom.
1.2 TSA currently has 113 members who between
them employ almost four thousand people. Unlike the Royal Institution
for Chartered Surveyors (RICS) and the Institution for Civil Engineering
Surveyors (ICES), TSA represents the company not the individual.
TSA does however sit on a joint panel, the Survey Liaison Group,
with RICS and ICES.
1.3 TSA is run by a full time Secretariat
based in Newark and a Council of twelve people elected from the
membership. Most of the members of Council are senior executives
in the industry. In addition to the Council, the association structure
comprises four committees; Public Relations, Membership, Technical
and Finance. The Technical Committee is responsible for producing
guidance notes on matters of importance for clients.
1.4 In May 2007, TSA held a reception at
the House of Commons aimed at increasing awareness into the effects
of cuts in public spending on flooding, and to alert MPs and Peers
to the role of the modern day surveyor. Almost fifty parliamentarians
and stakeholders attended the event.
1.5 TSA has been working with political
audiences and stakeholders in 2007 to raise awareness of the role
of survey in flood prevention. This includes ongoing liaison with
DEFRA's Flood Management Division and the Associate Parliamentary
Group on Flood Prevention.
2. THE ROLE
OF THE
SURVEYOR IN
FLOODING POLICY
2.1 Modern surveying makes a vital contribution
to effective flood management, risk assessment and prevention.
The role of the modern day surveyor has changed substantially
as technology has developed, allowing surveys to be carried out
which can establish the greatest level of detail about flood risk
to an individual property or an area of land. This information
is a vital part in flood defence planning, flood risk assessment
for large scale infrastructure developments, and is the most effective
way of properly establishing the flood risk of an individual property
or geographical area compared to the broad-brush approach of the
Environment Agency flood map.
2.2 There are generally two methods of acquiring
survey data—from the air and from the ground. The accuracies
of the methods however vary greatly, as does the cost. It is generally
accepted that horizontal accuracy (position) is less important
than vertical accuracy (height above ground) in flood mapping,
as it is height above mean sea level that is most critical for
hydraulic modelling.
2.3 TSA's members offer a vast range of
services from Aerial Survey and LiDAR (aircraft-mounted laser
scanning) for mapping large areas of land, to the precise setting
out of new construction sites and development areas. Aerial survey
has been used by the Environment Agency until recently and is
based on a calibrated camera installed in an aircraft from which
stereoscopic imagery is produced. The data is then collected using
photogrammetry—the science of taking measurements from photographs.
LiDAR collects 3D data of the topography on a pre-determined grid
as an aircraft flies over a site. This is the system commissioned
by Norwich Union to survey the whole of the UK, although the system
adopted provides data at the lower end of the accuracy scale (see
figure 1).
2.4 Ground survey methodologies use a combination
of reflectorless electronic distance measurement and Global Position
Satellites. This system is ideal for precision surveys to fill-in
or validate the data collected by other methods, and is the only
method for collecting accurate data in critical flood areas. Figure
1 below lists the accuracies of different surveying methods.
|
| Type | Accuracies
|
|
| Lidar | +/- 500mm to +/- 5 metres
|
| Aerial Survey (EA spec) | +/- 50mm
|
| Ground survey (EDM) | +/- 10mm
|
| Ground Survey (GPS) | +/- 25mm
|
|
| Figure 1. | |
2.5 A number of TSA members have been employed by the
Environment Agency in recent years to produce the survey data
required for the preparation of accurate hydraulic mapping. The
technology to be utilised in the preparation of survey data will
be determined generally by the accuracies required. No one system
provides a panacea for all. Powerful analysis and mapping utilities
in GIS (Geographic Information Systems) can assist in the planning
and prevention of flooding if the data being analysed is of sufficient
accuracy.
3. THE EFFECT
OF ENVIRONMENT
AGENCY FINANCIAL
CUTS
3.1 Financial cuts to the Environment Agency (EA) budget
have had a devastating impact on many TSA members and their ability
to undertake necessary surveying work following the recent flood
crisis. One member's income on flood mapping has dropped from
£900,000 in one year to £200,000 in the next. This pattern
has been repeated throughout the industry and has given many members
a serious problem. Many surveys already commissioned were cancelled
at short notice, while others were seriously delayed.
3.2 The problem is not just one of decreasing turnover;
it also presents a serious resource difficulty. Most survey companies
try to ensure that all members of staff are qualified to undertake
at least two types of work. If for example a flooding survey project
is cancelled, the staff will be moved onto another project and
are then unavailable for anything else. The inertia caused by
lack of work is difficult to reverse and the efforts then required
to commence a project and get it up and running are immense. Consequently,
cancellations ensure that an immediate restart if funding is available
is almost impossible.
3.3 A number of TSA member companies have been commissioned
to undertake emergency survey work at various sites following
the recent flood crisis. However, due to the resource difficulty
identified above, these companies have not always be available,
which has caused delays in some of the restoration works following
the floods.
4. RECOMMENDATIONS TO
THE COMMITTEE—THE
FUTURE CONTRIBUTION
OF SURVEY
TO FLOOD
PREVENTION
4.1 TSA is able to give guidance to the relevant Government
Departments, executive agencies and local authorities to assist
in the specifying and collection of quality data to assist in
the planning stage of flood defences.
4.2 Our recommendations to the Environment, Food and
Rural Affairs Committee are:
— Sufficient funds must be provided to enable the
EA to undertake the necessary survey work to improve flood defences;
— That the Government issues national guidance to
ensure that the data collected for the purposes of flood risk
assessment and defence planning by public bodies is fit for purpose
and is determined by accuracy requirements, not cost;
— That the Government and relevant agencies, in
cooperation with industry, draw up a programme of planned and
sustainable works to alleviate the resource planning problems
caused by unpredictable timeframes;
— That the Government and relevant agencies establish
a forum for engaging with The Survey Association and other stakeholders
to ensure effective industry consultation and dialogue on flood
prevention policy.
The Survey Association
August 2007
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