Devon and Cornwall Soils Alliance - Lower River Cober by Westcountry Rivers Trust

Lower River Cober Devon and Cornwall Soils Alliance

This document was produced by the Westcountry Rivers Trust for the Devon and Cornwall Soils Alliance (DCSA) project, funded through the Environment Agency Water Environment Grant.

Contents This pack contains maps of the Lower River Cober catchment. This catchment is one of the 7 waterbody catchments being targeted in the feasibility study stage of the Devon and Cornwall Soils Alliance (DCSA) project. There are also 2 Special Area of Conservation catchments being focused on in another part of the project. Each page focuses on a different theme, and uses maps, tables and graphs to provided spatial information about the catchment. Rivers, roads, and settlements are also included in the maps. A full list of data sources can be found on page 23.

Overview

Land Cover

Soils Soil Type

Soil Composition

Soil Hydrology

Soil pH

Geology

Crops

Habitats

CEH Natural Capital Maps Topsoil Carbon

Topsoil Nitrogen

Topsoil Phosphorus

Topsoil Invertebrates

Topsoil Bacteria

Land Ownership

River Condition

Flood Risk

Hydrological Connectivity

Slope

Data Sources

Overview The 9 DCSA catchments are spread across Devon and Cornwall. The Lower River Cober catchment (highlighted in red) is located in south-west Cornwall, on the south coast.

The area mapped in this report is the Lower River Cober Waterbody Catchment, as delineated by the Environment Agency for the Water Framework Directive (WFD). It is part of the Cober and Lizard Operational Catchment, and has two WFD waterbodies which feed into it, the Upper River Cober which feeds in from the top, and Carminowe Creek which joins the Cober via The Loe lake at the southern end of the catchment. The waterbody has one main branch of river which is assessed under WFD. The river runs north to south, fed by several smaller tributaries. The town of Helston lies in the east of the catchment.

Devon & Cornwall Soils Alliance: Lower River Cober 4

Land Cover Land Cover Map 2015 (LCM2015) is derived from satellite images and digital cartography and provides land cover information for the entire UK. Land cover is based on UK Biodiversity Action Plan broad habitats classes.

Freshwater, 2%

Heather, 1%

Broadleaved Woodland, 12%

Urban/Suburban, 13%

Arable and Horticulture, 40% Improved Grassland, 32%

Please note: The Loe and the river network are shown in dark blue on top of all maps

Devon & Cornwall Soils Alliance: Lower River Cober 5

Soil Area Type NATMAP Vector is the principle set of soil data held at Cranfield University. It is a 1:250,000 scale map of England and Wales, showing the locations of 297 distinct soil associations. Within each of the soil associations are multiple soil series.

MORETONHAM PSTEAD - loam over granite, 8% MOOR GATE loam over granite, 8% MANOD - loam over shale, 12%

No Data, 2%

DENBIGH 2 loam over shale, 50%

DENBIGH 1 loam over shale, 20%

Devon & Cornwall Soils Alliance: Lower River Cober 6

Soil Area Composition The map below shows the percentage of sand, silt, and clay in each soil area. Sand is subdivided into fine, medium, and coarse percentages. The table gives additional descriptive information on each soil area.

Soil Series

Series Definition

Soil Subgroups

Soil Layer

Dominant Soils

MOOR GATE loam over granite

Light loamy material over lithoskeletal acid crystalline rock

Humic brown podzolic soils

Mineral topsoil

Well drained humose gritty loamy soils. Occasionally with thin ironpan.

MORETONHAMPS TEAD - loam over granite

Light loamy material over lithoskeletal acid crystalline rock

Typical brown podzolic soils

Mineral topsoil

Well drained gritty loamy soils with a humose surface horizon in places.

MANOD - loam over shale

Medium loamy material over lithoskeletal mudstone and sandstone or slate

Typical brown podzolic soils

Mineral topsoil

Well drained fine loamy or fine silty soils over rock.

Shallow soils in places.

DENBIGH 2 - loam over shale

Medium loamy material over lithoskeletal mudstone and sandstone or slate

Typical brown earths

Mineral topsoil

Well drained fine loamy soils over slate or slate rubble.

Some fine loamy soils variably affected by groundwater.

DENBIGH 1 - loam over shale

Medium loamy material over lithoskeletal mudstone and sandstone or slate

Typical brown earths

Mineral topsoil

Well drained fine loamy and fine silty soils over rock.

Some similar soils with slowly permeable subsoils and slight seasonal waterlogging. Shallow soils and some bare rock locally.

Devon & Cornwall Soils Alliance: Lower River Cober 7

Associated Soils

Soil Area Hydrology The map and table below give information on the hydrology of the soil areas.

Soil type Hydrology 4

Free draining permeable soils on hard but fissured rocks with high permeability but low to moderate storage capacity.

Free draining permeable soils in unconsolidated loams or clays with low permeability and storage capacity.

Free draining permeable soils in unconsolidated loams or clays with groundwater at less than 2m from the surface.

Permanently wet peaty topped upland soils over relatively free draining permeable rocks.

Relatively free draining soils with a large storage capacity over hard impermeable rocks with no storage capacity.

Slowly permeable soils with slight seasonal waterlogging and moderate storage capacity over slowly permeable substrates with negligible storage.

Relatively free draining soils with low storage capacity over hard impermeable rocks with no storage capacity.

Devon & Cornwall Soils Alliance: Lower River Cober 8

Soil Area pH The map below shows NATMAP Vector information on the average pH level of each soil area.

5.7 8%

No Data 2% 6.3 8%

6 82%

Devon & Cornwall Soils Alliance: Lower River Cober 9

Geology The map below shows British Geological Society 1:50 000 scale bedrock geology.

Devon & Cornwall Soils Alliance: Lower River Cober 10

Crops The Crop Map of England (CROME) contains approximately 32 million hexagonal cells classifying England into over 20 main crop types, grassland, and non-agricultural land covers, such as woodland, waterbodies, fallow land and other non-agricultural land covers. The classification was created automatically using satellite images in late January 2018 â&#x20AC;&#x201C; September 2018.

Winter Barley, 2%

Water, 2%

Winter Wheat, 2%

Winter Field beans, 3% Potato, 3% Winter Oilseed, 4%

Woodland, 40% Grassland, 15%

Non-vegetated or sparselyvegetated Land, 23%

Devon & Cornwall Soils Alliance: Lower River Cober 11

Habitats Important habitats for wildlife are mapped below using Natural Englandâ&#x20AC;&#x2122;s Priority Habitat Inventory (PHI). Designated sites are also shown, with their condition status where relevant.

180 160

Area (ha)

140 120 100 80 60 40 20 0

Devon & Cornwall Soils Alliance: Lower River Cober 12

CEH Natural Capital Maps Natural England and UKCEH collaborated on a project to map aspects of natural capital. A suite of ten maps have been produced showing different aspects of natural capital, using a range of datasets, including UKCEH sample data from the Countryside Survey (2007). The maps are derived from predictive modelling. Data from sample locations is extrapolated up to an England level using statistical modelling and is mapped at 1km resolution. For more information: https://eip.ceh.ac.uk/naturalengland-ncmaps

Topsoil Carbon The map below shows mean estimates of topsoil (0-15cm depth) carbon density in tonnes per hectare. The map was produced using measurements of carbon from soil collected in the Centre for Ecology & Hydrology Countryside Survey (2007) at 2614 sample locations across Great Britain, within 591 1km squares. Measurements were extrapolated up to a national level using statistical analysis. This extrapolation was based on carbon density values associated with a combination of habitat type and soil parent material: the geological material, bedrock, superficial and drift, from which soil develops.

60 - 70 5%

70 - 80 1%

No Data 15%

40 - 50 79%

Devon & Cornwall Soils Alliance: Lower River Cober 13

Topsoil Nitrogen The map below shows mean estimates of total nitrogen concentration in topsoil (0-15cm depth) in percent dry weight of soil. The map was produced by using measurements of nitrogen concentration from soil collected in the Centre for Ecology & Hydrology Countryside Survey (2007), at 1024 sample locations across GB within 256 1km squares. Measurements were extrapolated up to a national level using statistical analysis. This extrapolation was based on total nitrogen concentration values associated with a combination of habitat type and soil parent material: the geological material, bedrock, superficial and drift, from which soil develops.

0.50 - 0.75, 11% No Data, 14% 0.25 0.50, 75%

Topsoil Phosphorous The map below shows mean estimates of Olsen-phosphorus concentration in topsoil (0-15cm depth) in milligrams per kg dry soil. This was calculated using the Olsen-phosphorus method, which is a measure of the amount of soil phosphorus available to plants. The map was produced by using measurements of Olsen-phosphorus from soil collected in the Centre for Ecology & Hydrology Countryside Survey (2007), at 1054 sample locations across GB, within 256 1km squares. Measurements were extrapolated up to a national level using statistical analysis. This extrapolation was based on phosphorus concentration values associated with a combination of habitat type and soil parent material: the geological material, bedrock, superficial and drift, from which soil develops.

50 - 60, 5%

40 - 50, 1%

10 - 20, 5% No Data, 14%

30 - 40, 75%

Devon & Cornwall Soils Alliance: Lower River Cober 14

Topsoil Invertebrates The map below shows mean estimates of total abundance of invertebrates in topsoil (0-8cm depth). This map was produced by using measurements of total number of invertebrates extracted from soil cores in the Centre for Ecology & Hydrology Countryside Survey (2007) at 927 sample locations across GB within 238 1km squares. Measurements were extrapolated up to a national level using statistical analysis. This extrapolation was based on the total number of invertebrates extracted associated with a combination of habitat type and soil parent material: the geological material, bedrock, superficial and drift, from which soil develops.

75 - 100, 5%

25 - 50, 5%

50 - 75, 1%

No Data, 14%

0 - 25, 75%

Topsoil Bacteria The map below shows mean estimates of bacterial diversity in topsoil (0-15cm depth) measured using the Shannon diversity index, a mathematical measure of species diversity in a given community. The map was produced by using measurements of bacterial diversity from soil in the Centre for Ecology & Hydrology Countryside Survey (2007), at 1280 sample locations across GB within 256 1km squares. Measurements were extrapolated up to a national level using statistical analysis. This extrapolation was based on soil bacterial diversity values associated with a combination of habitat type and soil parent material: the geological material, bedrock, superficial and drift, from which soil develops.

3.5 - 3.6, 5%

3.6 - 3.7, 1%

No Data, 14%

3.9 - 4.0, 18%

Devon & Cornwall Soils Alliance: Lower River Cober 15

3.8 - 3.9, 62%

Land Ownership The map below shows anonymised land ownership data from the RPA CLAD dataset. Nonanonymised data will be available upon commencement of the work.

Devon & Cornwall Soils Alliance: Lower River Cober 16

River Condition The map below show Environment Agency Water Framework Directive overall status, category 1 and 2 water pollution incidents and consented discharges. The following pages give more information from the Catchment Data Explorer on WFD status, Reasons for Not Achieving Good status and upstream catchments. Note: Under the Water Framework Directive, waterbodies are given an overall status of High, Good, Moderate, Poor or Bad. Anything below Good is a failing waterbody.

Devon & Cornwall Soils Alliance: Lower River Cober 17

River Condition cont. This information has been sourced from the Catchment Data Explorer. The page for this waterbody is: https://environment.data.gov.uk/catchment-planning/WaterBody/GB108048001172

Lower River Cober Overview Id

GB108048001172

Type

River

Hydromorphological designation

Heavily modified

Catchment area

1928.729 ha

Length

6.36 km

Classification Cycle 2 Classification Item

2013

2014

2015

2016

Overall Water Body

Moderate

Ecological

Moderate

Chemical

Good

Reasons for Not Achieving Good and Reasons for Deterioration SWMI

Activity