Two regions have significant areas that have been changed: Bay of Plenty and Taranaki.
Overview - Bay of Plenty
The new Rotorua Lakes S-map soil survey is an area of approximately 140,000 ha, covering the Rotorua Lakes catchments (excluding Mamaku Plateau which was completed August 2022), and hill country draining to the Bay of Plenty between the Kaituna River in the west, and the Pikowai Stream in the east.
Small areas of lake shore and alluvial deposits adjacent to the Rotorua Lakes, and some small hydrothermal areas were mapped using traditional mapping techniques and utilising legacy data. The remainder of the survey area was mapped using digital soil mapping (DSM) techniques. The new mapping has resulted in a change to both the soil polygons and soil type. It replaces legacy soil surveys around Lake Rotorua, Mamaku Plateau and Rerewhakaaitu, as well as some polygons that were first compiled in the early 2000’s. Metadata for the line work and map unit composition for this early S-map information is lacking, and little is known about how this was developed.
The current survey area focused on soils that have developed from Tarawera scoria, Rotomahana mud and Kaharoa Pumice and is largely defined by the extent of the Kaharoa tephra in the Rotorua Lakes and central Bay of Plenty region. The replaced legacy maps were based on the outdated New Zealand Genetic Classification. The new mapping draws upon advances in both the characterisation and classification of soils, now using New Zealand Soil Classification (NZSC). As a result, many soils are now classified differently from legacy soils mapped in the area, in particular, differences in the way Pumice and Allophanic Soils are now defined. Some of the differences between Pumice and Allophanic soils are being updated with ongoing development of the New Zealand Soil Classification (NZSC) by Manaaki Whenua staff. In the Rotorua Lakes area the transition from Pumice to Allophanic Soils has not been well defined by the NZSC and changes in the NZSC are currently being considered based in part on observations and laboratory data collected during this survey. These changes are yet to flow through into S-map, however, consideration has been made for this with the current map unit construction, and any changes to the NZSC are likely to be incorporated with the 2025 update of S-map.
Changes in soil order
The location of any major changes in the New Zealand Soil Classification are summarised in Figure 1, which compares changes in soil order between the previous 2022 version of S-map, and the December 2023 update. In summary:
- On the west side of Lake Rotorua soils previously classified as Pumice are now Allophanic. This is in line with changes made on the Mamaku Plateau, as outlined in the previous August 2022 briefing report.
- To the south of Rotorua Lake Pumice Soils have replaced Allophanic Soils as the dominant soil, however, sub-dominant Allophanic siblings also remain in these map units
- Recent Soils have replaced Pumice Soils in steep land south of Lake Rotoiti. Better delineation of steep land areas has been achieved by utilising the LiDAR DEM.
- The Rotorua City urban area has been expanded to better match the current urban extent.
Changes in profile available water (PAW)
The location of any major changes in the PAW to 0.6 metre depth are summarised in Figure 2, which compares changes between the previous 2022 version of S-map, and the December 2023 update. Changes in PAW mostly reflect a reduction in the sand fraction based on particle size distribution data collected during the survey, but also in places reflect changes in Soil Order and improved mapping of the depth (thickness) of different tephra layers (which is turn changes the particle size distribution through the soil profile).
Figure 1: Changes in soil order between the previous 2022 version of S-map, and the December 2023 update. Areas coloured grey have no change in the soil order
Figure 2: Differences in profile available water (to 0.6 metre depth) between the previous 2022 version of S-map, and the December 2023 update. Areas coloured grey have no change.
Overview - Taranaki
The new Taranaki S-Map soil survey is an area of approximately 59088 ha, covering the eastern Taranaki Ringplain. The map area covers the Waingongoro and Manganui River catchments from their mouths to the National Park boundary as well as the lower Waitara River, the ringplain section of the upper Pātea River, and the Eltham Swamp and surrounding hills. This delivery is part one of three annual deliverables of similar size.
The new survey partially supersedes a legacy soil survey completed in 1984 and reported on in 1991 (Franks, Neall and Pollock, 1991). This work was conducted against older soil classification and mapping standards and was reinterpreted for entry into S-Map in 2021. This exercise was desktop-based and involved only minor updates to map linework to delineate major streams. The bulk of effort was focused on translating the established soils concepts into the S-Map data model.
The new mapping (Figure 3) has considerably increased spatial and conceptual detail in the overlapping area (approx. 10880 ha), based on the newly available Taranaki LIDAR elevation model and targeted fieldwork conducted on a series of farms in the region. Most map units now contain at least two siblings, generally highlighting short-range variation in drainage conditions that can’t be separated at the target map scale. Areas along streams previously mapped as ‘water – no soil data’ are now parameterised with appropriate siblings, reducing the extent of ‘water’ units by 95% in the overlapping area. The Eltham urban footprint has also been aligned to contemporary data published by TRC (Taranaki Regional Council, 2023). Finally, map units more closely delineate observable landscape features, in particular separating hilly lands and steep slopes into their own units.
Part of the legacy Eltham county survey data remains in S-Map, covering areas to the east and west of the new mapping, but the western portion will also be replaced in August 2025.
Figure 3: Map of the newly replaced area in Taranaki.
Changes in soil order
The nature of the ringplain means that much of the mapped area remains classified as Typic Orthic Allophanic soils (LOT). One exception is an area between Lowgarth and Mangatoki previously mapped as LOA (Acidic Orthic Allophanic). This was remapped as LOT when fieldwork failed to reveal the required acidic subsoils. Another change is apparent in the hills surrounding Eltham Swamp, which were previously mapped as shallow with a rooting barrier (an effect of directly translating the ‘Stratford Hill Soils’ concept). This limitation was not commonly observed during fieldwork. Changes to S-Map parameters are otherwise concentrated at the base property level, for example more locally accurate estimates of clay content verified by laboratory assessment.
Some soil order changes in specific landscapes can be seen, e.g. among the lowest Waingongoro River terraces, where Recent and Raw orders have been observed. Some small areas of poorly to imperfectly drained soils (LGT or LOM) have also been observed on the ringplain surface around springs and seeps, and fibric peats (OFM) have been observed around the edges of the Eltham swamp that are distinct from the humic peats (OHM) in the centre of the area.
Changes in soil properties
As a result of the updates, some of the overlapping area has had an increase in Profile Available Water. The soil depth is now more consistently mapped as Deep. Drainage class has changed to include more moderately well drained and imperfectly drained soils. Note that most map units now have 2 or 3 siblings in place to account for in-unit variability rather than just one. Map users may find one of those siblings will provide more appropriate estimates for specific locations.
References
Franks, A.M., Neall, V.E., Pollok, J.A., 1991. Soils of Part Eltham County, North Island, New Zealand (DSIR Land Resources Scientific Report No. 14), DSIR Land Resources Scientific Report. Department of Scientific and Industrial Research, Lower Hutt, New Zealand. https://doi.org/10.7931/DL1-DLRSR-14
Taranaki Regional Council (2023) ‘LocalMaps: Main Urban Areas’. https://maps.trc.govt.nz/arcgis/rest/services/LocalMaps/MainUrbanAreas/MapServer
Last updated: 30th November 2023
Two regions have significant areas that have been changed: Bay of Plenty and Taranaki.
Overview - Bay of Plenty
The new Rotorua Lakes S-map soil survey is an area of approximately 140,000 ha, covering the Rotorua Lakes catchments (excluding Mamaku Plateau which was completed August 2022), and hill country draining to the Bay of Plenty between the Kaituna River in the west, and the Pikowai Stream in the east.
Small areas of lake shore and alluvial deposits adjacent to the Rotorua Lakes, and some small hydrothermal areas were mapped using traditional mapping techniques and utilising legacy data. The remainder of the survey area was mapped using digital soil mapping (DSM) techniques. The new mapping has resulted in a change to both the soil polygons and soil type. It replaces legacy soil surveys around Lake Rotorua, Mamaku Plateau and Rerewhakaaitu, as well as some polygons that were first compiled in the early 2000’s. Metadata for the line work and map unit composition for this early S-map information is lacking, and little is known about how this was developed.
The current survey area focused on soils that have developed from Tarawera scoria, Rotomahana mud and Kaharoa Pumice and is largely defined by the extent of the Kaharoa tephra in the Rotorua Lakes and central Bay of Plenty region. The replaced legacy maps were based on the outdated New Zealand Genetic Classification. The new mapping draws upon advances in both the characterisation and classification of soils, now using New Zealand Soil Classification (NZSC). As a result, many soils are now classified differently from legacy soils mapped in the area, in particular, differences in the way Pumice and Allophanic Soils are now defined. Some of the differences between Pumice and Allophanic soils are being updated with ongoing development of the New Zealand Soil Classification (NZSC) by Manaaki Whenua staff. In the Rotorua Lakes area the transition from Pumice to Allophanic Soils has not been well defined by the NZSC and changes in the NZSC are currently being considered based in part on observations and laboratory data collected during this survey. These changes are yet to flow through into S-map, however, consideration has been made for this with the current map unit construction, and any changes to the NZSC are likely to be incorporated with the 2025 update of S-map.
Changes in soil order
The location of any major changes in the New Zealand Soil Classification are summarised in Figure 1, which compares changes in soil order between the previous 2022 version of S-map, and the December 2023 update. In summary:
- On the west side of Lake Rotorua soils previously classified as Pumice are now Allophanic. This is in line with changes made on the Mamaku Plateau, as outlined in the previous August 2022 briefing report.
- To the south of Rotorua Lake Pumice Soils have replaced Allophanic Soils as the dominant soil, however, sub-dominant Allophanic siblings also remain in these map units
- Recent Soils have replaced Pumice Soils in steep land south of Lake Rotoiti. Better delineation of steep land areas has been achieved by utilising the LiDAR DEM.
- The Rotorua City urban area has been expanded to better match the current urban extent.
Changes in profile available water (PAW)
The location of any major changes in the PAW to 0.6 metre depth are summarised in Figure 2, which compares changes between the previous 2022 version of S-map, and the December 2023 update. Changes in PAW mostly reflect a reduction in the sand fraction based on particle size distribution data collected during the survey, but also in places reflect changes in Soil Order and improved mapping of the depth (thickness) of different tephra layers (which is turn changes the particle size distribution through the soil profile).
Figure 1: Changes in soil order between the previous 2022 version of S-map, and the December 2023 update. Areas coloured grey have no change in the soil order
Figure 2: Differences in profile available water (to 0.6 metre depth) between the previous 2022 version of S-map, and the December 2023 update. Areas coloured grey have no change.
Overview - Taranaki
The new Taranaki S-Map soil survey is an area of approximately 59088 ha, covering the eastern Taranaki Ringplain. The map area covers the Waingongoro and Manganui River catchments from their mouths to the National Park boundary as well as the lower Waitara River, the ringplain section of the upper Pātea River, and the Eltham Swamp and surrounding hills. This delivery is part one of three annual deliverables of similar size.
The new survey partially supersedes a legacy soil survey completed in 1984 and reported on in 1991 (Franks, Neall and Pollock, 1991). This work was conducted against older soil classification and mapping standards and was reinterpreted for entry into S-Map in 2021. This exercise was desktop-based and involved only minor updates to map linework to delineate major streams. The bulk of effort was focused on translating the established soils concepts into the S-Map data model.
The new mapping (Figure 3) has considerably increased spatial and conceptual detail in the overlapping area (approx. 10880 ha), based on the newly available Taranaki LIDAR elevation model and targeted fieldwork conducted on a series of farms in the region. Most map units now contain at least two siblings, generally highlighting short-range variation in drainage conditions that can’t be separated at the target map scale. Areas along streams previously mapped as ‘water – no soil data’ are now parameterised with appropriate siblings, reducing the extent of ‘water’ units by 95% in the overlapping area. The Eltham urban footprint has also been aligned to contemporary data published by TRC (Taranaki Regional Council, 2023). Finally, map units more closely delineate observable landscape features, in particular separating hilly lands and steep slopes into their own units.
Part of the legacy Eltham county survey data remains in S-Map, covering areas to the east and west of the new mapping, but the western portion will also be replaced in August 2025.
Figure 3: Map of the newly replaced area in Taranaki.
Changes in soil order
The nature of the ringplain means that much of the mapped area remains classified as Typic Orthic Allophanic soils (LOT). One exception is an area between Lowgarth and Mangatoki previously mapped as LOA (Acidic Orthic Allophanic). This was remapped as LOT when fieldwork failed to reveal the required acidic subsoils. Another change is apparent in the hills surrounding Eltham Swamp, which were previously mapped as shallow with a rooting barrier (an effect of directly translating the ‘Stratford Hill Soils’ concept). This limitation was not commonly observed during fieldwork. Changes to S-Map parameters are otherwise concentrated at the base property level, for example more locally accurate estimates of clay content verified by laboratory assessment.
Some soil order changes in specific landscapes can be seen, e.g. among the lowest Waingongoro River terraces, where Recent and Raw orders have been observed. Some small areas of poorly to imperfectly drained soils (LGT or LOM) have also been observed on the ringplain surface around springs and seeps, and fibric peats (OFM) have been observed around the edges of the Eltham swamp that are distinct from the humic peats (OHM) in the centre of the area.
Changes in soil properties
As a result of the updates, some of the overlapping area has had an increase in Profile Available Water. The soil depth is now more consistently mapped as Deep. Drainage class has changed to include more moderately well drained and imperfectly drained soils. Note that most map units now have 2 or 3 siblings in place to account for in-unit variability rather than just one. Map users may find one of those siblings will provide more appropriate estimates for specific locations.
References
Franks, A.M., Neall, V.E., Pollok, J.A., 1991. Soils of Part Eltham County, North Island, New Zealand (DSIR Land Resources Scientific Report No. 14), DSIR Land Resources Scientific Report. Department of Scientific and Industrial Research, Lower Hutt, New Zealand. https://doi.org/10.7931/DL1-DLRSR-14
Taranaki Regional Council (2023) ‘LocalMaps: Main Urban Areas’. https://maps.trc.govt.nz/arcgis/rest/services/LocalMaps/MainUrbanAreas/MapServer
Last updated: 30th November 2023
Two regions have significant areas that have been changed: Bay of Plenty and Taranaki.
Overview - Bay of Plenty
The new Rotorua Lakes S-map soil survey is an area of approximately 140,000 ha, covering the Rotorua Lakes catchments (excluding Mamaku Plateau which was completed August 2022), and hill country draining to the Bay of Plenty between the Kaituna River in the west, and the Pikowai Stream in the east.
Small areas of lake shore and alluvial deposits adjacent to the Rotorua Lakes, and some small hydrothermal areas were mapped using traditional mapping techniques and utilising legacy data. The remainder of the survey area was mapped using digital soil mapping (DSM) techniques. The new mapping has resulted in a change to both the soil polygons and soil type. It replaces legacy soil surveys around Lake Rotorua, Mamaku Plateau and Rerewhakaaitu, as well as some polygons that were first compiled in the early 2000’s. Metadata for the line work and map unit composition for this early S-map information is lacking, and little is known about how this was developed.
The current survey area focused on soils that have developed from Tarawera scoria, Rotomahana mud and Kaharoa Pumice and is largely defined by the extent of the Kaharoa tephra in the Rotorua Lakes and central Bay of Plenty region. The replaced legacy maps were based on the outdated New Zealand Genetic Classification. The new mapping draws upon advances in both the characterisation and classification of soils, now using New Zealand Soil Classification (NZSC). As a result, many soils are now classified differently from legacy soils mapped in the area, in particular, differences in the way Pumice and Allophanic Soils are now defined. Some of the differences between Pumice and Allophanic soils are being updated with ongoing development of the New Zealand Soil Classification (NZSC) by Manaaki Whenua staff. In the Rotorua Lakes area the transition from Pumice to Allophanic Soils has not been well defined by the NZSC and changes in the NZSC are currently being considered based in part on observations and laboratory data collected during this survey. These changes are yet to flow through into S-map, however, consideration has been made for this with the current map unit construction, and any changes to the NZSC are likely to be incorporated with the 2025 update of S-map.
Changes in soil order
The location of any major changes in the New Zealand Soil Classification are summarised in Figure 1, which compares changes in soil order between the previous 2022 version of S-map, and the December 2023 update. In summary:
- On the west side of Lake Rotorua soils previously classified as Pumice are now Allophanic. This is in line with changes made on the Mamaku Plateau, as outlined in the previous August 2022 briefing report.
- To the south of Rotorua Lake Pumice Soils have replaced Allophanic Soils as the dominant soil, however, sub-dominant Allophanic siblings also remain in these map units
- Recent Soils have replaced Pumice Soils in steep land south of Lake Rotoiti. Better delineation of steep land areas has been achieved by utilising the LiDAR DEM.
- The Rotorua City urban area has been expanded to better match the current urban extent.
Changes in profile available water (PAW)
The location of any major changes in the PAW to 0.6 metre depth are summarised in Figure 2, which compares changes between the previous 2022 version of S-map, and the December 2023 update. Changes in PAW mostly reflect a reduction in the sand fraction based on particle size distribution data collected during the survey, but also in places reflect changes in Soil Order and improved mapping of the depth (thickness) of different tephra layers (which is turn changes the particle size distribution through the soil profile).
Figure 1: Changes in soil order between the previous 2022 version of S-map, and the December 2023 update. Areas coloured grey have no change in the soil order
Figure 2: Differences in profile available water (to 0.6 metre depth) between the previous 2022 version of S-map, and the December 2023 update. Areas coloured grey have no change.
Overview - Taranaki
The new Taranaki S-Map soil survey is an area of approximately 59088 ha, covering the eastern Taranaki Ringplain. The map area covers the Waingongoro and Manganui River catchments from their mouths to the National Park boundary as well as the lower Waitara River, the ringplain section of the upper Pātea River, and the Eltham Swamp and surrounding hills. This delivery is part one of three annual deliverables of similar size.
The new survey partially supersedes a legacy soil survey completed in 1984 and reported on in 1991 (Franks, Neall and Pollock, 1991). This work was conducted against older soil classification and mapping standards and was reinterpreted for entry into S-Map in 2021. This exercise was desktop-based and involved only minor updates to map linework to delineate major streams. The bulk of effort was focused on translating the established soils concepts into the S-Map data model.
The new mapping (Figure 3) has considerably increased spatial and conceptual detail in the overlapping area (approx. 10880 ha), based on the newly available Taranaki LIDAR elevation model and targeted fieldwork conducted on a series of farms in the region. Most map units now contain at least two siblings, generally highlighting short-range variation in drainage conditions that can’t be separated at the target map scale. Areas along streams previously mapped as ‘water – no soil data’ are now parameterised with appropriate siblings, reducing the extent of ‘water’ units by 95% in the overlapping area. The Eltham urban footprint has also been aligned to contemporary data published by TRC (Taranaki Regional Council, 2023). Finally, map units more closely delineate observable landscape features, in particular separating hilly lands and steep slopes into their own units.
Part of the legacy Eltham county survey data remains in S-Map, covering areas to the east and west of the new mapping, but the western portion will also be replaced in August 2025.
Figure 3: Map of the newly replaced area in Taranaki.
Changes in soil order
The nature of the ringplain means that much of the mapped area remains classified as Typic Orthic Allophanic soils (LOT). One exception is an area between Lowgarth and Mangatoki previously mapped as LOA (Acidic Orthic Allophanic). This was remapped as LOT when fieldwork failed to reveal the required acidic subsoils. Another change is apparent in the hills surrounding Eltham Swamp, which were previously mapped as shallow with a rooting barrier (an effect of directly translating the ‘Stratford Hill Soils’ concept). This limitation was not commonly observed during fieldwork. Changes to S-Map parameters are otherwise concentrated at the base property level, for example more locally accurate estimates of clay content verified by laboratory assessment.
Some soil order changes in specific landscapes can be seen, e.g. among the lowest Waingongoro River terraces, where Recent and Raw orders have been observed. Some small areas of poorly to imperfectly drained soils (LGT or LOM) have also been observed on the ringplain surface around springs and seeps, and fibric peats (OFM) have been observed around the edges of the Eltham swamp that are distinct from the humic peats (OHM) in the centre of the area.
Changes in soil properties
As a result of the updates, some of the overlapping area has had an increase in Profile Available Water. The soil depth is now more consistently mapped as Deep. Drainage class has changed to include more moderately well drained and imperfectly drained soils. Note that most map units now have 2 or 3 siblings in place to account for in-unit variability rather than just one. Map users may find one of those siblings will provide more appropriate estimates for specific locations.
References
Franks, A.M., Neall, V.E., Pollok, J.A., 1991. Soils of Part Eltham County, North Island, New Zealand (DSIR Land Resources Scientific Report No. 14), DSIR Land Resources Scientific Report. Department of Scientific and Industrial Research, Lower Hutt, New Zealand. https://doi.org/10.7931/DL1-DLRSR-14
Taranaki Regional Council (2023) ‘LocalMaps: Main Urban Areas’. https://maps.trc.govt.nz/arcgis/rest/services/LocalMaps/MainUrbanAreas/MapServer
Last updated: 30th November 2023