ESII Tool User Inquires

This document outlines questions posed by actual ESII Tool users through the support email account or the iPad support widget.  While a list of general FAQs are publicly available on the ESII Tool website, this list contains questions that are more specific to operation and interpretation of the ESII Tool and its results from the perspective of ESII Tool users.  For this reason, we are placing this list inside the ESII Tool commons where it is primarily accessible to those entities who have already invested some level of effort into using and understanding the ESII Tool system.  our intention is that this page should grow as more users explore the tool and if you know of a question or explanation that you feel would be useful to others in this space, please contact us at support@esiitool.com and we will consider adding your suggestion to this page.

Question:

I’m getting low scores for the Mass Wasting model, this model is focused on soil composition, correct?

Response:

For mass wasting the model looks at a combination of soil composition (where coarser soils are more likely to move in a mass wasting event), vegetative cover (which helps to hold soils in place), water inundation or saturation (which increases the potential for mass wasting), and finally slope.  Regardless of the values entered for the other attributes, the most common way to get low Mass Wasting scores is to give a map unit a low slope, which limits the likelihood of soils moving in a mass wasting event.  Level ground doesn’t generally tend to move in a mass wasting event.

Question:

How is the water provisioning calculated? I am getting a very low score and trying to understand what we could alter in our location to improve the score.

Response:

The Water Provisioning model looks at how much water you are likely to be storing in a map unit depressional area for use on the site.  This one is a little tricky because it includes a set of switches that zero out the score if certain criteria are not met.  These criteria outline the attributes that would need to be in place for a waterbody on a map unit to be useful for water provisioning for the original users of the tool.  First, the map unit must be either seasonally or permanently inundated, merely saturated will not provide useful water in this context; second, the predominant depth of depressions in the map unit must be greater than 2 feet, this is intended to allow potential users to sink a pump in the waterbody and successfully draw water without drying out; third, the overall volume of a depressional area in the map unit must be capable of holding at least 10,000 gallons of water; and fourth, only still water bodies, not streams and rivers, will result in a water provisioning score.  Once all of these criteria have been satisfied, the dominant attributes that contribute to water provisioning are dominant substrate, percent depressional area, predominant depth, water regime type and inundation type.

Question:

For the Water Quality score, is the score based on the amount of submerged plants which would filter water?

Response:

The water filtration model looks at two primary components, horizontal filtration by plant matter such as stems, and vertical filtration that occurs when water carrying suspended material infiltrates and deposits those materials on, or in, the soil.  Horizontal filtration is driven by slope (low slope is better), basal cover for herbs (more is better), microtopography (more is better) and length along the fall line (more is better).  The vertical filtration component performs the best when soils have a high percentage of sands and gravels which promote infiltration, the performance of vertical filtration gets turned down significantly in areas where man made soil compaction has occurred.