"BEFORE-AFTER" SCENARIO ANALYSES
Statistical tools for Cumulative Impact Assessment
Sustainable Land Planning, Mitigation & Restoration measures
Can we predict the impact of an infrastructure before it is built? Or the efficacy of mitigation measures?
Yes, scenario analyses can simulate the consequences of landscape changes. They can predict the cumulative impact of building new infrastructure (e.g. hydropower, tourist cottages, roads and railways..) or of increasing traffic volume on skiing trails. They can also predict the effect of mitigation, restoration or off-set measures, e.g. removing or re-locating industrial areas, roads, tourist resorts or ski trails, or building wildlife bridges. They can quantify cumulative impacts of several infrastructures and activities in an area, highlight priority areas for mitigation or restoration, and rank the most efficient among a set of proposed measures [1,2,3,4,5]. This can support Strategic Impact Assessment of specific infrastructure or of entire area development plans. Scenario analyses can be used proactively, to forecast impacts of development plans before these are implemented, or retroactively, to assess the impact of existing infrastructures, or of their removal. Results are expressed as Km2 of funcional habitat lost (or gained) [12, 1,2,3,4,5]. Science-based maps, especially when supported by local knowledge, can help minimizing the potential for societal conflicts in land planning, and achieving sustainability goals.
Example 1: How much reindeer habitat is lost due to hydropower construction?
Fig 1 - LAND INUNDATED: 110 Km2. Hydropower development caused habitat loss and barriers for reindeer. To estimate its impact, as a baseline scenario we simulate the removal of magazines built after 1973 in Setesdal Ryfylke, Norway [Ref: 1] (see full area overview below, Fig 4).
Fig 1 zooms in one of the largest hydropower complex in Europe (Blåsjø and neighbouring magazines). Moving the slider allows to compare the area flooded BEFORE 1973 (left) & AFTER (right) construction: 110 Km2 were inundated.
Fig 2-3 below show that the reindeer habitat actually lost to hydropower is far larger than the area inundated [1].
For simplicity, all other infrastructure (roads, powerlines, cottages, trails.) are assumed to be unchanged. Image: Dorber et al 2023 (CC BY-SA)
Fig 3 - CORRIDORS LOST. Moving the slider allows to see that an estimated 44% of reindeer movement corridors were lost after the construction hydropower magazines after 1973 [1, 12] (Fig 4).
NB (as above): these values underestimate the total impact of hydropower on reindeer, as they consider only the impact of reservoars (i.e. ignore access roads, dams, powerlines etc), consider only reservoar built after 1973, do not consider changes in other infrastructure, and consider only the impact on summer habitat.
Color code: Lighter color: most important movement corridors (or "pinchpoints", "bottlenecks") needed for reindeer to reach good, functional summer pastures. Dark: Few movements
Image: Dorber et al 2023 (CC BY-SA)
Fig 2 - HABITAT LOST: 222 km2. Moving the slider allows to see that an estimated 222 km2 (or 31 092 soccer fields) of functional reindeer habitat were lost due to construction of hydropower magazines. This corresponds to 47% loss of functional habitat in S. Ryfylke (Fig 4) [1; 12].
NB: these estimates are highly conservative as they consider only the impact of reservoars (i.e. ignore access roads, dams, powerlines etc), consider only reservoar built after 1973, do not consider changes in other infrastructure, and consider only the impact on summer habitat.
Color code: Yellow: hihgly functional habitat (good and easily accessible). Blue: poor quality and/or isolated habitat
Image: Dorber et al 2023 (CC BY-SA)
Fig 4. FULL AREA OVERVIEW. Overview of Setesdal Ryfylke managment area, Norway (Fig 1-3 above zoom-in the central area). 222 Km sq. of funcional reindeer habitat (yellow), and 44% or corridors (orange-lilla) are estimated to be lost due to the construction of reservoirs since 1973 [1, 2, 12].
Suggested mitigation measures (Fig 7, 10) are crucial, but would yield only 2-12 km2 of the habitat lost. Proactive sustainable land planing is crucial [1]
VIDEO desciption in Norwegian [6]
Example 2: Effect of mitigation / restoration: remove roads, cottage & trails
Following the request of a board of local experts, we simulated the effect of a hypotetical scenario: remove a tourist cottage (Reinheim), hiking trails (red) and roads (orange) in the Snøhetta wild reindeer management area. NB: part of these measures were implemented within a habitat restoration project to restore an old military area, and yielded an estiamted ca. 12% of functional habitat [2,3,4, 12]. (move before-after slider, below). Images: Panzacchi et al 2022 (CC BY-SA)
Fig 5. Functional habitat (good quality & well-connected habitat, lighter color) before and after the hypothetical removal of tourist cabin, trails and road. The mitigation action would be expected to recuperate ca. 63.8 km2 of funcional reindeer habitat
Fig 6. Movement corridors (lighter color) before and after the hypothetical removal of tourist cabin, trails and road. According to the scenario analysis, an almost lost movement corridor would be recuperated to a large degree (+26%). Images: Panzacchi et al 2022 (CC BY-SA)
Full list of 76 scenarios assessed in Norway so far
Our aim was to identify a list of the most realistic and effective mitigation and off-set measures to reduce the impact of hydropower on wild reindeer in Norway. Local reindeer experts and stakeholders suggested 76 possible measures that could be helpful to improve the conditions of several wild reindeer ranges. These measures consisted in: closing/restricting access to roads, hiking trails and skiing trials, close or re-locate tourist cottages, and build land bridges over hydropower magazines - and combinations of those. We analytically tested the expected effect of all scenarios suggested, and we ranked their expected efficacy, to guide decision-making and sustaianble land planning. The main results are presented below, and are described in detail in [2].
Below we present: (1) an overview of the 76 scenarios tested in 3 wild reindeer management areas (Setesdal Ryfylke, Snøhetta and Nordfjella). (2) an overview of the main results, for summer; (3) a table with all results of the expected effect of each of the 76 simulations in Setesdal [1,2], Snøhetta [2,3,4], Nordfjella [2] for summer and winter. A detailed description of all results, in Norwegian, is presented in [2]
Note that additional simulations have been made for Hardangervidda (4 mitigation measures tested, see: [5], and in the Brokke-Suleskard area (Setesdal Ryfylke), where we supported local land-planing processes by testing for the effect of 37 land-planning alternatives (results in [2, Appendix 2])
1. Scenario overview
Below we present a description of the main mitigation measures tested in Setesdal Ryfylke (SR), Snøhetta (SN) and Nordfjella (NF) wild reindeer management areas. Blue dots represent GPS data. Each scenario is identified with a code (specifying the area and a progressive number), and is illustrated in waht local experts identified as the focal area of interest (yellow). Here we show proposed mitigation measures for the summer season (e.g. removal of hiking trail), but scenario for winter (involving for instance the removal of ski trails) have also been tested. All results are reported in the table below. Details in: [2]
NB: in addition to scenario SR-1 (Brokke-Suleskard), where we tested the effect of removing the cabin Øyulvsbu and associated trail network, we tested also 37 land planning alternatives to support local communities achieving a more sustaianble development of recreational activities in the area, by relocating the cabin and trails in areas where their impact of reindeer would be smaller; these results are shown in [2, Appendix 2]. All images: Panzacchi et al 2022 (CC BY-SA)
Fig 7
Fig 8
Fig 9
2. Results overview
3. Full list of results overview
The table below synthesises the results of all simulations tested in Setesdal Ryfylke, Snøhetta, and Nordfjella wild reindeer management areas within the project RenewableReindeer (a detailed description of each result is presented in [2]). In addition, we tested for 37 land-planning alternatives in the that additional simulations for mitigation measures in Hardangervidda are shown in [5]. Each result is identified with the same code as above (SR = Setesdal Ryfylke, . Results are presented for the entire wild reindeer managment area, for each sub-areas, and for each focal areas (though results for focal areas are only indicative, as their delineation is arbitrary). Results are presented for summer and for winter, where it has been requested by the users. Results areexpressed both as % (% funcional habitat gained, or % movement flow gained), and in Km2 Equivalent Connected Habitat, as explained in [1].
REFERENCES
[0] Niebuhr, B.B., Panzacchi, M., van Moorter, B., Gundersen, V., & Tveraa, T. 2023. Scenarioanalyser – evaluering av effekten av avbøtende tiltak for villrein i Rondane Nord. NINA Rapport 2359. Norsk institutt for naturforskning.
[1] Dorber, M., Panzacchi, M., Strand, O., B. van Moorter (2023) New indicator of habitat functionality reveals high risk of underestimating trade-offs among sustainable development goals: The case of wild reindeer and hydropower. Ambio 52, 757–768 (2023).
[3] Hagen D, Evju M, Henriksen PS, Solli S, Erikstad L, Bartlett J. (2022). From military training area to National Park over 20 years: Indicators for outcome evaluation in a large-scale restoration project in alpine Norway. Journal for Nature Conservation, 66
[4] Hagen, D., Henriksen, P. S., Solli, S., Løkstad, V. & Evju, M. 2022. Fra skytefelt til nasjonalpark. Restaurering av Hjerkinn skytefelt på Dovrefjell. NINA Temahefte 86. Norsk institutt for naturforskning
[5] Villrein-ferdselsanalyser på Hardangervidda. Anbefalinger og tiltak. Gundersen, V., van Moorter, B. Panzacchi, M., Rauset, G.R. & Strand, O. 2021. Villrein-ferdselsanalyser på Hardangervidda - Anbefalinger og tiltak. NINA Rapport 1903. Norsk institutt for naturforskning. [in Norwegian]
[6] M.Panzacchi, Fornybar energi og reinsdyr: nye metoder for å simulere effekten av inngrep, forstyrrelser og kompenserende tiltak Energi Norge - Produksjonsteknisk konferanse 2021 (here)
[7] 2020 Unikt verktøy beregner hvordan mennesker påvirker naturen. Panzacchi M, Landrø J. NINA nyhettsak (here)
[8] Van Moorter B, Kivimäki I, Panzacchi M, Særens M (2021). Review & Synthesis: defining and quantifying Effective Connectivity. Ecography44, 6: 870-884
[9] Dorber, M., R. May, and F. Verones. 2018. 'Modeling Net Land Occupation of Hydropower Reservoirs in Norway for Use in Life Cycle Assessment', Environmental Science & Technology, 52: 2375-84.
[10] Gundersen, V., van Moorter, B. Panzacchi, M., Rauset, G.R. & Strand, O. 2021. Villrein-ferdselsanalyser på Hardangervidda - Anbefalinger og tiltak. NINA Rapport 1903. Norsk institutt for naturforskning. [in Norwegian]
[11] Panzacchi M. et al 2023. Vannkraft spiser mer av villreinens leveområder enn mange tror. Nyheter (nina.no) [popular science - in Norwegian]
[12] Van Moorter B, Kivimäki I, Panzacchi M, Saura S, Niebuhr B.B., Strand O, Saerens M. (2023) Habitat Functionality: integrating environmental and geographic space in niche modelling for conservation planning. Ecology 104(7): e4105