Environmental Considerations spatial datasets for marine planning. These datasets are derived from multiple datasets indicating the presence of protected features in Welsh waters. The data is presented on 1 km2 hexagonal grids.

Operational phase was considered for all sectors for all feature groups, and includes maintenance activities. The construction phase was only considered for sectors where potential construction impacts are substantially different from those during operation (tidal stream, wave, tidal range, Floating offshore wind and cabling). However, for the Bird feature group, construction phase was only considered for tidal range and cabling. The scoring methodology included three main stages:

1. The occurrence score reflects either the presence or absence, or standardized abundance (where abundance data was available) of features (i.e., species, habitats, or protected sites) and were scored from 1 to 3 on a continuous scale where 1 was the lowest density and 3 the highest for each feature.

2. The conservation importance score is an estimate of the level of protection each feature has based on the legislation that confers a feature protection. It is important to note that all the features included in this work are conferred protection under various legislation and all are important considerations in the planning of developments. This step was scored from 1 to 5.

3. An impact score to reflect potential impacts on features based on the likely pressures generated by each sector was applied for the operational pressures of each of the focus sectors and, separate to this, construction pressures for some sectors. Where there was considered to be a lack of evidence then a higher score was applied. The current approach did not assess specific technologies individually but considered the potential pressures that could originate from a sector and their potential to negatively affect each of the features. This step was scored from 1 to 3.

A total score was calculated for each feature in each cell, and these were summed for each 1 km2 hexagonal grid cell, providing a relative ‘environmental considerations’ score for each feature group per sector. The approach taken to the scoring differed slightly between feature groups based on the available evidence

Mae'r setiau data hyn yn deillio o nifer o setiau data sy'n nodi presenoldeb nodweddion gwarchodedig yn nyfroedd Cymru. Cyflwynir y data ar gridiau hecsagonol 1 km2.

Ystyriwyd y cyfnod gweithredol ar gyfer pob sector ar gyfer pob grŵp nodwedd, ac mae'n cynnwys gweithgareddau cynnal a chadw. Dim ond ar gyfer sectorau lle mae effeithiau adeiladu posibl yn wahanol iawn i'r rhai gweithredu (ynni llif y llanw, ynni’r tonnau, ynni amrediad y llanw, ynni gwynt arnofiol ar y môr a cheblau) y cafodd y cam adeiladu ei ystyried. Fodd bynnag, ar gyfer grŵp nodwedd Adar, dim ond ar gyfer amediad llanw a cheblau y cafodd y cam adeiladu ei ystyried. Roedd y fethodoleg sgorio yn cynnwys tri phrif gam:

1) Mae'r sgôr digwyddiad yn adlewyrchu naill ai presenoldeb neu absenoldeb, neu helaethrwydd safonedig (lle’r oedd data helaethrwydd ar gael) o nodweddion (h.y., rhywogaethau, cynefinoedd, neu safleoedd gwarchodedig) ac fe'u sgoriwyd o 1 i 3 ar raddfa barhaus lle mai 1 oedd y dwysedd isaf a 3 yr uchaf ar gyfer pob nodwedd.

2) Mae'r sgôr pwysigrwydd cadwraeth yn amcangyfrif o lefel yr amddiffyniad sydd gan bob nodwedd yn seiliedig ar y ddeddfwriaeth sy'n gwarchod nodwedd. Mae'n bwysig nodi bod yr holl nodweddion a gynhwysir yn y gwaith hwn yn cael eu gwarchod o dan ddeddfwriaeth amrywiol ac mae pob un ohonynt yn ystyriaethau pwysig wrth gynllunio datblygiadau. Sgoriwyd y cam hwn o 1 i 5.

3) Cymhwyswyd sgôr effaith i adlewyrchu effeithiau posibl ar nodweddion yn seiliedig ar y pwysau tebygol a gynhyrchir gan bob sector ar gyfer pwysau gweithredol pob un o'r sectorau ffocws ac, ar wahân i hyn, pwysau adeiladu ar gyfer rhai sectorau. Lle ystyriwyd bod diffyg tystiolaeth, yna cymhwyswyd sgôr uwch. Nid oedd y dull gweithredu presennol yn asesu technolegau penodol yn unigol ond ystyriodd y pwysau posibl a allai ddeillio o sector a'u potensial i effeithio'n negyddol ar bob un o'r nodweddion. Sgoriwyd y cam hwn o 1 i 3.

Cyfrifwyd cyfanswm sgôr ar gyfer pob nodwedd ym mhob cell, a chyfunwyd y rhain ar gyfer pob cell grid hecsagonol 1 km2, gan ddarparu sgôr 'ystyriaethau amgylcheddol' cymharol ar gyfer pob grŵp nodwedd fesul sector. Roedd y dull a ddefnyddiwyd i sgorio ychydig yn wahanol rhwng grwpiau nodwedd yn seiliedig ar y dystiolaeth sydd ar gael.