Laserfiche WebLink
organic soil that will be converted to wetlands,so and they will be representative of baseline subsidence <br /> conditions. �'� °'At <br /> eExplanation <br /> ♦ Eddy Covariance Tower <br /> f ' <br /> ` ♦ Previous Tower Location <br /> I ® Extensometers <br /> Eddy Covariance Footprint <br /> Pump stations <br /> _ z• <br /> - Drains <br /> .•..... Elevation(R) <br /> ;6a <br /> a,. <br /> Extensometers' <br /> Y <br /> 's <br /> s <br /> Sampling Station <br /> - Miles <br /> 0 02 0 4 0 l3 12 1 6 <br /> Figure 4:Locations of extensometer and water quality measurements <br /> Metric:Groundwater Elevations <br /> Rationale: Soils with high organic content demonstrate some degree of elasticity from fluctuating <br /> water levels. Ground water levels must be known to account for these shifts and to accurately assess <br /> subsidence caused exclusively by soil oxidation. Groundwater levels are influenced by the hydraulic <br /> gradient from adjacent rivers. drainage and water applied to the land surface as rain or irrigation.The <br /> depth to groundwater on subsided Delta island is controlled by a network of drainage ditches feeding to <br /> drainage pump stations that discharge drainage to the Delta channels.The depth to groundwater is also <br /> an important factor in determining the depth of the organic soil where oxidation will occur(Deverel et <br /> al., 2016). Saturated organic soils are not expected to contribute to subsidence due to the slow <br /> decomposition rates of the anaerobic environment. <br /> Method: A monitoring well will be built at each extensometer location. Water-depth transducers will <br /> be deployed in each well to measure the height of water above the instrument.The transducers (In-situ <br /> Leve Trolls) will record the depth of water every 15 minutes and store the data on the local device <br /> memory.The well elevation will be measured via GPS at the start of monitoring. Manual water level <br /> measurements will be made with an electronic sounding device for comparison with and verification of <br /> the logged data. <br />