Browsing by Author "Gran, Karen, B"
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Item High-resolution topographic data (TLS and SfM) of river bluffs in Amity Creek and the Knife River, Minnesota, USA, 2016-2018(2020-01-08) Kelly, Sara, A; Brown, Elizabeth; Gran, Karen, B; kgran@d.umn.edu; Gran, Karen, B; University of Minnesota Earth & Environmental SciencesOver the past few years, more and more river bluffs on North Shore (Minnesota, USA) streams are being stabilized using a technique wherein a bankfull bench is created adjacent to an eroding bluff using a combination of toe wood, rock, and soil lifts. One of the goals of this technique is to reduce the amount of fine sediment entering the river from bluff erosion, both by removing river access to the toe of the bluff and by providing a bench for eroding sediment to deposit on. In order to determine how much erosion and deposition were occurring on these bluffs, we monitored six river bluffs on the Knife River and Amity Creek from 2016-2018. We report data on four bluffs in Amity Creek and two in the Knife River: 4 bluffs that were stabilized in the 2014 and 2015 using a bankfull bench design and 2 additional bluffs that have not had work done on them for comparison. Each bluff was surveyed 2-3 times each between 2016 and 2018 using a Faro Focus 3D terrestrial laser scanner (TLS), and all four stabilized bluffs were surveyed once via photogrammetry from a DJI Phantom 4 UAV (uncrewed aerial vehicle). The photogrammetry data were turned into high-resolution topographic data using Structure-from-Motion (SfM) processing. Repeat data at each site were compared using Geomorphic Change Detection to calculate volumes of change. In addition, SfM and TLS data collected simultaneously are compared to test the efficacy of using photogrammetry data to monitor bluff erosion.Item Northshore Stream Restoration Assessment Physical Habitat Survey Data(2023-08-17) Baldus, David, B; Gran, Karen, B; baldu024@d.umn.edu; Baldus, David, BThese data are the result of a field season of physical habitat surveys conducted on control and treatment reach pairs at six stream restoration projects. Physical habitat characterization survey procedures were adapted from the NRSA Physical Habitat Characterization Survey and the Minnesota Stream Quantification Tool. They include longitudinal and cross-sectional survey data, grain size distribution data, as well as riparian and in-channel habitat data. The treatment reach of each pair was restored and the control reach was not. The control reach was not treated as a degraded pre-restoration reach nor as the standard to be restored to but rather as a representative reach undisturbed by restoration efforts. These surveys were conducted as part of an effort to assess the effects that restoration practices have on a stream ecosystems.Item Sargent Creek Nutrient Injection Breakthrough Curve(2022-09-15) Baldus, David, B; Gran, Karen, B; baldu024@d.umn.edu; Baldus, David, BBreakthrough curve data from nutrient injection tracer tests conducted at Sargent Creek on 2021-09-15 and 2021-09-22. The tests were conducted in two stream reaches, the treatment reach which was restored with a full channel realignment in 2019 and the control reach which was not restored. These tracer tests were conducted as part of an effort to assess the effects that restoration practices have on a stream ecosystems. A solution of nutrients (Potassium Nitrate (KNO3), Ammonium dihydrogen phosphate ((NH4)H2PO4)) and a conservative tracer (Sodium Chloride (NaCl)) dissolved in stream water was injected into the stream at the top of the reach as an instantaneous release. Water samples were collected in the thalweg at downstream end of the reach to describe reach-scale nutrient spiraling. Additionally water samples were collected at two sites located mid-reach at the upstream and downstream end of a representative riffle type habitat unit to describe the nutrient cycling within these individual habitat units. Timing of sampling was determined by a conductivity meter in order to capture rising, peak, and falling concentrations and generate a breakthrough curve (BTC).