REP12682 - Laserfiche WebLink

Home Browse Search

2.0 SAMPLING METHODS 2.1 Sample Layout The sample layout protocol for the revegetation evaluations in 2004 largely followed procedures detailed in permitting documents. These procedures are designed to better account for the heterogeneous expression of established vegetation within the various reclaimed areas while precluding bias in the sample site selection process. By design, the procedure is initiated randomly, and thereafter, samples are located in a systematic manner, along grid coordinates spaced at fixed distances, e.g. 125 ft. (see Figure 1, lower left corner and Map 1). In this manner, "representation" from across the entire reclaimed area is "forced" rather than risking the chance that significant pockets (or seedings) are entirely missed, or overemphasized as often occurs with simple random sampling. Sample site selection within the newly established reference areas occurred in a similar manner. The procedure for sample location within the reclaimed area or reference areas occurred as folows. First, a fixed point of reference that could be rekxated from year to year was selected. In 2004, the fixed reference point was the intersection of the Hubbard Creek culvert and centerline of the access road (see Map 1). Use of this point facilitated location of the systematic grid in the field. Second, a systematic grid of appropriate dimensions (e.g., 125 ft. X 125 ft.) was selected to provide approximately 35 coordinate intersections within each sampling unit, which could then be used for sample sites. Third, a scaled, computer generated representation of the selected grid was overlain on a computer generated map of the area utilizing north-south and east-west compass points which could be easily established in the field. This overlain grid also facilitated identification of the vegetation type for each sample point. Initial placement of the grid was controlled by the fourth step, selection of a pair of random numbers (between 0 and 200 ft.) to facilitate location of the initial coordinate point from the intersection of Hubbard Creek and the access road. In 2004 these random coordinates were 55' (East) and 57' (North) for the revegetated Riparian Area and 128' (East) and 52' (North) for the revegetated Grassland Area. Fifth, utilizing a hand held surveying compass and hip-chain (or pacing techniques) all sample points were located in the field and Flagged. The locations of all sample sites utilized during 2004 sampling efforts are indicated on Maps 1 and 2. Once a selected grid point was located in the field, sampling transacts were always oriented in the direction of the next site to be physically sampled to further limit any potential bias while facilitating sampling efficiency. This orientation protocol follows that which is indicated on Figure 1. Depending on logistic, timing, and access points to the target sampling area, the field crew would occasionally layout a ~~~ ~ mss®cuA~~s, iNC. Page 5 81ue Ribbon Mine- Revegefatlon Evaluation