Description: <DIV STYLE="text-align:Left;font-size:12pt"><DIV><DIV><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>A smoothed outline of Aotearoa New Zealand’s coast was used to construct coastal segments of roughly 10 km width (depending on complexity of the coastline), extending out to the 12 nm Territorial Sea boundary. Land use information was derived from the Land Use and Carbon Systems (LUCAS) Land Use Map developed by Manaaki Whenua – Landcare Research for the Ministry for the Environment. There are 12 land-use classifications: Natural Forest, Planted Forest (Pre 1990), Planted Forest (Post 1989), Grassland (with woody biomass), Grassland (High producing), Grassland (Low producing), Wetland (Vegetated non-forest), Wetland (Open water), Settlements (built-up area), Cropland (Annual), Cropland (Orchards and vineyards, Perennial), and Other. These were grouped into 4 categories: Urban (Settlements), Intensive Agriculture (High producing Grassland, Annual and Perennial Cropland), Exotic forest (Planted Forest, Pre 1990 and Post 1989), and Native (Grassland with woody biomass and Low producing, Vegetated non-forest and Open water Wetlands, and Other). </SPAN></SPAN><SPAN><SPAN>Land-use can provide an indication of land-based influxes of sediment, nutrients, erosion and pollution into coastal waters. For example, coastal areas adjacent to areas categorised as Urban are likely to have high levels of coastal development.</SPAN></SPAN><SPAN><SPAN> Coastal development results in direct habitat loss, </SPAN></SPAN><SPAN><SPAN>changing water, nutrient and sediment flow into estuarine and coastal habitats. Land clearing, urban and intensive agricultural areas contribute to increased sediments, nutrient enrichment, and other pollutants. </SPAN></SPAN><SPAN><SPAN>Rates of erosion are influenced by land topography (steepness), soil types and precipitation and different land uses can exacerbate or help mitigate this natural process, with pastures</SPAN></SPAN><SPAN><SPAN> (high producing Grasslands) serving as a major contributor to erosion, as do regularly harvested forests (Exotic Forests) particularly in between harvest and new growth reaching canopy closure and root overlap. Native cover provides better estimates of more natural levels of land-based inputs. </SPAN></SPAN><SPAN><SPAN>The values shown are the proportion of land overlapping the 10 km segment covered by that land-use, for example if the value is 0.5, then 50% of the land in the 10 km segment is covered by that specific land-use, with all land-use values adding to a total of 1 for each polygon. Because these segments don’t occur in isolation, a 10 km buffer was used around each coastal segment to capture land use in inland and adjacent coastal areas. </SPAN></SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>Limitations and Uncertainties:</SPAN></SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>We recognise that 10 km coastal segments are arbitrary boundaries for the NZ coastline, and further, that we extended all values for each polygon out to the 12 nm Territorial Sea boundary to allow better visualisation of how land-based inputs and population accessibility vary in NZ. This extension seaward is arbitrary, and does not incorporate likely decreasing impacts offshore from the coast. Segments for Stewart Island were not included and for coastlines with large, narrow inlets, such as in Fiordland, segments do not include the inner fiords as this would increase the segment size, making comparisons between segments less consistent. Land uses are subject to change and major storms can alter processes and input areas. </SPAN></SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>Source: </SPAN></SPAN><A href="https://data.mfe.govt.nz/layer/52375-lucas-nz-land-use-map-1990-2008-2012-2016-v011/" STYLE="text-decoration:underline;"><SPAN><SPAN>LUCAS NZ Land Use Map 1990 2008 2012 2016 v011 - MfE Data Management | | GIS Map Data | MfE Data Service</SPAN></SPAN></A></P><P STYLE="margin:0 0 11 0;"><SPAN>Last updated: 3 Apr 2023</SPAN></P></DIV></DIV></DIV>
Service Item Id: 2cf577d6fce74ff6928d7b55c4e8a0cc
Copyright Text: NIWA, LUCAS NZ, Ministry for the Environment