Page 64 - Freshwater-Biology-and-Ecology-Handbook

CHAPTER 1 5.5 – 5.6 5.5 Hydromorphological quality elements

For high status to be achieved, the Directive requires that there are no

more than very minor human alterations to the hydromorphological
quality elements.

At good, moderate, poor and bad status, the required values for the hydromorphological quality elements must support the
required biological quality element values for the relevant class. The standards and condition limits recommended by UKTAG
are intended to help assess the risk of failing to achieve the necessary values.
Table 1.11
Hydromorphological quality elements

Rivers Lakes Transitional waters Coastal waters

(i) Quantity and dynamics (i) Quantity and dynamics (i) Depth variation (i) Depth variation
of water flow of water flow

(ii) Connection to (ii) Residence time (ii) Quantity, structure and (ii) Structure and substrate
groundwater bodies substrate of the bed of the coastal bed

(iii) River continuity (iii) Connection to (iii) Structure of the (iii) Structure of the
groundwater bodies intertidal zone intertidal zone

(iv) River depth and (iv) Lake depth variation (iv) Freshwater flow (iv) Direction of dominant
width variation currents

(v) Structure and substrate (v) Quantity, structure and (v) Wave exposure (v) Wave exposure
of the river bed substrate of the lake bed
(v) Structure of the riparian (v) Structure of the lake
zone shore

64 | Freshwater Biology and Ecology Handbook
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