# Presentation: 114556

## Rule-based models for uniform assessments on the Biological Condition Gradient 

- Jeroen Gerritsen, Kevin Berry, Dean Bryson, Jonathan G. Kennen, James Kurtenbach, Erik W. Leppo, Victor Poretti

## New Jersey TALU development 

- Define and describe BCG for New Jersey streams
- Develop model for automated assessment
- (Next) Integrate BCG into uses and standards (TALU)

## 1

- <date/time>

**Biological Condition **

**Stressor Gradient**

- Low

- High

**1**

**Native or natural condition**

**2**

**Minimal loss of species; some density changes may occur**

**3**

**Some replacement  of sensitive-rare species; functions fully maintained**

**4**

**Some sensitive species maintained but notable replacement by more tolerant taxa; altered distributions; functions largely maintained**

**5**

**6**

**Tolerant species show increasing dominance; sensitive species are rare; functions altered**

**Severe alteration of structure and function**

- Natural

- Degraded

## Second order stream in a minimally disturbed, forested watershed

**Second order stream in a minimally disturbed, forested watershed**

- Source:  Maine DEP, Susan P. Davies

**Notes:**
Stinking Brook T5R9 NWP Log 1002 ( 2001)

## Third order stream draining a shopping mall

**Third order stream draining a shopping mall**

- Source:  Maine DEP, Susan P. Davies

**Notes:**
Penjajawock Stream Bangor below I-95 (2001)

## Taxa Attributes

- I:  Historic, endemic, long-lived
- II:  Highly sensitive
- III: Intermediate sensitive
- IV: Intermediate tolerance (indifferent)
- V:  Tolerant taxa
- VI: Non-native taxa

##    TIER 6 COMMUNITY

II - Highly sensitive, specialist
none
III - Sensitive - ubiquitous, generalist
none
IV - Intermediate tolerance, opportunistic
none
V - Tolerant Taxa
Helisoma	48	
Thienemannimyia	16
Physa	4
Cricotopus	2
Ablabesmyia	1
Helobdella	1

**II - Highly sensitive, specialist**
- none
**III - Sensitive - ubiquitous, generalist**
- none
**IV - Intermediate tolerance, opportunistic**
- none
**V - Tolerant Taxa**
**Helisoma****	****48****	**
**Thienemannimyia****	****16**
**Physa****	****4**
**Cricotopus****	****2**
**Ablabesmyia****	****1**
**Helobdella****	****1**

**     **_**TIER 2 COMMUNITY**_
**II – Highly sensitive, specialist**
**Taeniopteryx****	****48**
**Epeorus****	****13**
**Hexatoma****	****8**
**Probezzia****	****8**
**Isoperla****	****7**
**Pteronarcys****	****1**
**Capniidae****	****1**
**Chloroperlidae****	****1**
**Glossosoma****	****1**
**Brachycentrus****	****1**
**III - Sensitive - ubiquitous, generalist**
**Ephemerella****	****127**
**Acentrella****	****13**
**Stenonema****	****8**
**IV - Intermediate tolerance, opportunistic**
**Polypedilum****	****24**
**Cheumatopsyche****	****5**
**V - Tolerant Taxa**
**Hydropsyche****	****8**

**Vs.**

- Data Source:  Maine DEP, Susan P. Davies

## Tiers

- Exceptional

- Good

- Fair

- Poor

- Very poor

## Assessment

- Exceptional

- Good

- Fair

- Poor

- Very poor

- Uncertain zone

**x**

- Impaired or not?

## Challenge

- What are the boundaries of categories?
- Nature doesn’t have hard boundaries between categories
- Experts use strength of evidence

## The set of long riversLong rivers are > 2000 km

- The Nile (6688 km) is long
- The Hudson (490 km) is long
- The Mississippi (3756 km) is long
- The Rhine (1312 km) is long
- The Columbia (2044 km) is long

- TRUE
- FALSE
- TRUE
- FALSE
- ???

- What is the probability that the Columbia is long?

## Membership functions(mathematical fuzzy set theory)

- Length, km

- Degree of membership

- 0

- 1

- Not Long Rivers

- Long Rivers

- 2000

- 1000

- 4000

- 3000

## BCG Development (NJ)

- Taxa assignment to attribute groups I-VI
- Site assignments to tiers of BCG
- Conceptual tier descriptions
- Determine decision rules
- Develop membership functions
- Apply rules in model

## Slide 14

## Decision Rules

- Expert panel assigned sites to Tiers
- Nominal Tier: majority choice
- Elicit rules
- Quantify rules
- Model choice follows rules

## Rule development: Tier 2 ExampleHighly Sensitive Taxa (Attribute II)

- Taxa: *Tvetenia, Epeorus, Leuctra, Glossosoma, Helicopsyche*
- Richness is moderate compared to other attributes
**Linguistic Rule**: Richness is half or more of any other single attribute group
**Quant. Rule**: Taxa (II) > 40-60%  of any other attribute

## Highly Sensitive Taxa (Attribute II)

**Degree of membership**

- 0

- 1

**Att II / max of others**

- Tier 3

- Tier 2

- Tiers 4-6

## Tolerant taxa (Attribute V)

- Taxa: *Limnodrilus, Cricotopus, Tanytarsus,* *Physella*
- Occurrence and densities of Tolerant taxa are as naturally occur. Typically present but a moderate fraction of organisms. *  *
**Linguistic Rule:**  Tolerant individuals comprise a low fraction or less of all organisms
**Quant. Rule**: Individuals (V )  < (15-25%)

## Tolerant Taxa (Attribute V)

- Degree of membership

## Rule Application

- Tier 2:  All rules apply (total taxa, Attrib II, Attrib III, Attrib. V)
- Tier 3:  Any Tier 2 failure, plus Tier 3 rules
- And so on, a downward cascade to Tier 6

## And the winners are...

- Nominal Tier: Tier with the highest membership
- Ties are possible
- “Runner-up” tiers exist

## Model Performance at Matching Panel

|  | High gradient | Low gradient |
| --- | --- | --- |
| Model result 1 Tier higher | 2 | 3 |
| Model tied, higher Tier  | 1 | 2 |
| Match | 46 | 34 |
| Model tied, lower Tier | 5 | 2 |
| Model result 1 Tier lower | 4 | 4 |
| Total | 58 | 45 |

## Performance (2): non-matches

- Ties (10): expert group nominal and minority choices = tied tiers
- Flip-flops (10): model and group nominal, minority choices flip-flopped
- Complete mismatch (1 Tier): 3
- 78% exact;  97% close

## Advantages of quantitativefuzzy-set models (after Klir 2004)

- Capture “irreducible measurement uncertainty”
- Capture vagueness of linguistic terms
- Cost effective for complex, nonlinear models
- Enhance the ability to model human reasoning and decision-making

## Quantitative Models for BCG

- Quantitative rules replicate expert judgment
- Quantitative rules are transparent and can be followed by anyone – no black boxes
- Rules and metrics can be nonlinear, nonmonotonic
- Robust to missing information

## Slide 26

## Rule development: Tier 2 ExampleWhole assemblage

- Overall taxa richness is as naturally occurs; density is not excessively low
**Linguistic Rule****:**  Taxa richness is somewhat moderate to high and subsample count is near target
**Quantitative Rule 1**: Total taxa > (10-14) genera
**Quantitative Rule 2**: Total individuals > (40-50% of target)

## Intermediate Sensitive Taxa(Attribute III)

- Taxa:*Parametriocnemus*, *Baetis, Acroneuria, Neophylax*
- Richness and abundance of intermediate sensitive taxa is high.  Some may have increased due to slightly elevated production
**Linguistic rule****:**  All sensitive taxa (highly sensitive + intermediate sensitive):  comprise nearly half or more of all taxa
**Quant. rule**:  Taxa (II + III) > Taxa IV+V+VI (-3 to +2)

## Intermediate tolerant taxa (Attribute IV; Indifferent taxa)

- Taxa: *Nais*, *Gammarus*, *Optioservus*, *Polypedilum*, *Ceratopsyche*
- May be slight increases in densities of some macroinvertebrate taxa
**RULE****:**  None