Delaware Rapid Assessment Procedure (DERAP) v6.0
Description and method logic
The DERAP is designed to be a rapid field assessment of wetland condition at a wetland site. It is designed for any type of wetland, results in a single score of condition, and can be validated with the Delaware Comprehensive Assessment Procedure (DECAP). Scoring produces one overall score of condition developed through a process of calibrating the presence of stressors at a site to comprehensive wetland condition data using the DECAP Index of Wetland Condition (IWC).
The Delaware Rapid Assessment Procedure (DERAP) v6.0 is a rapid assessment method designed for assessing the condition of all non-tidal wetlands in the Outer Coastal Plain regions of Delaware and Maryland, USA. This method is designed as a rapid field site assessment and can be used in conjunction with the Delaware Comprehensive Assessment Procedure (DECAP).
DERAP contains provisions for classification and assessment. The desktop component of DERAP largely takes place during the pre-visit site evaluation. The DERAP procedure is as follows:
1.Determine stream order (for riverine assessment)
3.Print and review maps
4.Classify the wetland for assessment
5.Define assessment area using random probabilistic sampling design
6.Conduct field assessment
7.Compute final DERAP scores using assessment procedures
8.Determine a condition class from DERAP score.
A Qualitative Disturbance Rating (QDR) is assigned to the assessment area by the entire field crew upon the assessment completion. The QDR is rated from 1-6, categorised as:
DERAP rates assessment areas using weighted scoring dependant on the hydrogeomorphic (HGM) class and sub-class of the wetland. These weights were determined through refinement of DECAP index measures. Condition classes based on the DERAP total score:
For reporting purposes breakpoints are determined from scores QDR ratings of over 200 sites. Sites in the 25th percentile DERAP score with a QDR of 1 or 2 are rated as minimally or not stressed. Sites in the 75th percentile DERAP score with a QDR of 5 or 6 are rated as severely stressed. All other scores can be defined as moderately stressed.
Criteria groupings of the method
The assessment criteria for DERAP are based on measures of stressors to wetland condition.
This methodology requires the collection of limited background data, including thematic maps, aerial photographs and information specific to each assessment area. The assessment is primarily qualitative.
DECAP should be completed by practitioners who have completed a training course on how to properly perform the method. Experience and/or education in wetland classification and assessment, and native flora and soil properties is desired. It usually requires a two person team.
Access to supporting maps and information and land access. General survey equipment is required, as well as provisions for measuring vegetation, soil and hydrology attributes.
The DERAP can produce the following outputs:
Criteria by category
Physical and chemical
Management and planning
Potential users of the DECAP (or of the information generated by its use) include field staff and managers.
Others who might be interested in using the outputs from DECAP include researchers and staff from science-based non-governmental organisations, and environmental and advocacy groups. Consulting firms, educators, academic researchers, and reporters for written and broadcast media, along with the general public, will also find results from the DECAP to be useful to their interests in wetland science and management. This technique is recommended for government agencies involved in regional wetland monitoring. Land managers and NRM practitioners may find this methodology useful as it is a broadly applicable rapid assessment of wetland condition.
Last updated: 7 February 2019
This page should be cited as:
Department of Environment and Science, Queensland (2019) Delaware Rapid Assessment Procedure (DERAP) v6.0, WetlandInfo website, accessed 27 October 2023. Available at: https://wetlandinfo.des.qld.gov.au/wetlands/resources/tools/assessment-search-tool/delaware-rapid-assessment-procedure-derap-v6-0/