MediaWiki API result

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        "main": {
            "*": "Subscribe to the mediawiki-api-announce mailing list at <https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce> for notice of API deprecations and breaking changes."
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    "query": {
        "pages": {
            "24": {
                "pageid": 24,
                "ns": 0,
                "title": "Removal of weirs",
                "revisions": [
                    {
                        "contentformat": "text/x-wiki",
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                        "*": "[[file:icon_habitat.png|right|150px|link=[[Habitat]]]]\n=Introduction=\n[[file:weirs_nea.png|250px|thumb|Figure 1: Nea river in mid-Norway where several weirs were built as a compensation measure some decades ago, with the function of creating larger water-covered areas, first of all for aesthetical purposes. Removal of weirs imply that these weirs are removed]]\n[[file:weir_removal_ex.png|250px|thumb|Figure 2: Water depths (in meters) to the left and water velocities (in m/s) to the right in a section of Mandal river in southern Norway after lowering a weir]]\n\nWeirs were considered an important measure to mitigate the impacts from hydropower regulations some decades ago. The purpose of these were, to create larger water-covered areas, to stabilize the river bed or other reasons. It might also be that they were considered improving the conditions for fish. We would underline that removal of weirs in this context refers to removal of installations within the river used to mitigate impacts from regulations, and not a small dam used as the inlet structure of a hydropower plant. \n\nThe perceptions on use of weirs as measures to reduce impacts have now changed, as they represent a shift in types of habitats in the favour other species than naturally present, with the consequence that weirs are removed. Weirs can also be a barrier for migration and hence contribute to a fragmentation of the river, and also act as a trap of sediments, as these area as usually slow-flowing areas. \n\nThe removal of a weir is not a goal in its own unless a careful design of the areas after the removal is made. The area must hence undergo restoration to meet the habitat qualities of the fish species of concern (Pulg et al. 2017).  \n\nThe actual removal of the weir would be to simply use heavy machinery in the river and tear down the physical construction. \nRemoval of weirs is just the first start of the measure, and must be followed up by improvement of substrate, creation of a river-in-river, etc. \n\n\n=[[Methods, tools, and devices]]=\n\n==During planning==\nThe procedure to assess the impact of weirs on the fish species of concern would be to follow the prescriptions given in the Environmental Design handbook (Forseth and Harby, 2013) where the bottlenecks of the population are identified. In the case that areas with weirs limit the fish population, removal of weirs should be considered. \n\nHydraulic tools are useful in analysing the hydraulic conditions in a river with weirs, and the effect on the hydraulics if the weir is removed. A high number of hydro-dynamic tools are available for such analysis with different functionality and data needs, ranging from more simplistic 1-dimensional (1D) hydraulic tools, to highly advanced 3-dimensional (3D) tools solving a range of partial differential equations (Navier-Stokes) in all directions. The all require detailed description of the bottom topography of the areas the gravel might be placed, and a flow regime the river will undergo. As average flow velocities (in depth and across the river) will not be sufficiently detailed to identify the best locations, 2D- or 3D models will be required. Examples of such models are [[River2D]], [[HEC-RAS]] 2D, Flo2D/3D, Mike21c, [[OpenFOAM]] and [[TELEMAC]] 2D and 3D.\n\n==During implementation==\nThe removal of the weirs would be to simply use heavy machinery in the river and tear down the physical construction. The removal of the weir should be followed up by new measures, which could be to develop a 'river-in-the-river', re-placement of substrate, etc. An evaluation of the hydraulic effect of the removal of the weirs can be done by measuring the area where the weirs have been removed, and then configuring and applying a hydraulic model. An evaluation of the biological effect could be done with standard biological methods, such as for instance electro-fishing which will give the densities of juvenile fish. \n\n==During operation==\nHabitat measures in regulated rivers must often be maintained unless the natural functions related to flow and sediments are restored, such as flood events and connectivity of the sediments. The frequency of the maintenance will be very site-specific. \n\n=Relevant MTDs and test cases=\n{{Suitable MTDs for Removal of weirs}}\n\n=Classification table=\n{{Removal of weirs}}\n\n=Relevant Literature=\n*Pulg, U., Barlaup, B.T., Skoglund, H., Velle, G., Gabrielsen, S.E., Stranzl, S.F., Espedal, E.O., Lehmann, G.B., Wiers, T., Sk\u00e5r, B., Normann, E., Fjeldstad, H-P. 2017. Tiltaksh\u00e5ndbok for bedre fysisk vannmilj\u00f8: God praksis ved milj\u00f8forbedrende tiltak i elver og bekker. Uni Research AS.\n*Forseth, T., and Harby, A. 2014. Handbook for Environmental Design in Regulated Salmon Rivers. NINA Special Report 53. Trondheim: Norwegian Institute for Nature Research.\n\n\n[[category:Solutions]][[category:habitat measures]]"
                    }
                ]
            },
            "79": {
                "pageid": 79,
                "ns": 0,
                "title": "Restoration of the riparian zone vegetation",
                "revisions": [
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                        "contentmodel": "wikitext",
                        "*": "[[file:icon_habitat.png|right|150px|link=[[Habitat]]]]\n=Introduction=\n[[file:restoration_riparian_stjordal.png|thumb|250px|Figure 1: Riparian zone vegetation along Stj\u00f8rdalselva and one of its tributaries in central Norway. The riparian is on most section in place, providing shelter and reducing runoff of particles and nutrients from the agriculture]]\n\nThe riparian zone or riparian area is the interface between land and a river or stream. The vegetation along the riparian zone provides multiple functions to the river and its ecosystem. The vegetation will provide allochthonous, organic material to the river, shelter and shading to the areas near the shore, and stabilize the soil by the river, thus reduce the runoff of erodible particles, nutrients and potentially other pollutants from the land areas. Vegetation along the river can lead to higher biodiversity in the river, as well as along the shore. \nThis measure simply refers to reinstate the vegetations along the river in order to provide the benefits of vegetation to the river and its ecosystem, hence reducing the impacts of lack of vegetation along the river.  \n\n=[[Methods, tools, and devices]]=\n\n==During planning==\nThe easiest way to assess the potential for introducing this measure is simply by having a site visit and see if there are any parts of the riparian areas where vegetation has been removed and where trees, bushes and other vegetation can be reinstated. Re-planting of vegetation should be made from local plants.\n\nIt should be assessed if the reinstating of vegetation will affect the peaks of the floods in the rivers, as vegetation can lead to lower capacities to convey floods. Vegetation might increase the roughness of the river channel, preventing the water from flowing into the areas beside the river in situations with high flows. Such assessments can be made with use of hydraulic tools, such as [[HEC-RAS]].\n\n==During implementation==\nNo specific device should be needed to re-plant vegetation along the river. As soon as local plants are re-instated, they would naturally reproduce. It should be avoided to plant mono-cultures, but rather a mix of local plants. As new planted trees and bushes are less resistible to floods, the timing the vegetation is re-established should consider the risk of being flushed out, if planted in a flood-prone area. If grazing animals are nearby, the area of the new vegetation should be protected. \n\n==During operation==\nThe growth of the new vegetation can be controlled simply by a site visit, or by analysing satellite or aerial photos. No maintenance should be needed if a natural flood regime controls the expansion of the vegetation. If the vegetation grows into the river channel and this might be a risk to the flood capacity of the river, the vegetation at these locations should be cut regularity, e.g. every 2-3 years.  \n\n=Relevant MTDs and test cases=\n{{Suitable MTDs for Restoration of the riparian zone vegetation}}\n\n=Classification Table=\n{{Restoration of the riparian zone vegetation}}\n\n=Relevant Literature=\n\n[[category:Habitat measures]][[category:Solutions]]\n[[category:Habitat measures]][[category:Solutions]]"
                    }
                ]
            }
        }
    }
}