2026-09-24T20:46:41Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/125693 2026-02-03 col_2142_5131 col_2142_16322 com_2142_5130 com_2142_16321 com_2142_13459 com_2142_8903

application/pdf en text Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2026-08-01 The student, Nol Srivichainun, accepted the attached license on 2024-07-05 at 07:19. The student, Nol Srivichainun, submitted this Thesis for approval on 2024-07-05 at 07:40. This Thesis was approved for publication on 2024-07-08 at 09:34. DSpace SAF Submission Ingestion Package generated from Vireo submission #20951 on 2025-02-04 at 21:16:22 Spatial distribution of post-settlement alluvium in the Middle Fork Vermillion River Valley, Illinois, USA Srivichainun, Nol 2024-07-08 Anders, Alison M Rhoads, Bruce L Post-settlement Alluvium Fly Ash Middle Fork Vermilion River Basin Illinois eng Human actions significantly impact landscapes’ evolution, influencing sediment production, transport, and storage. Previous work on the Upper Sangamon River Basin (USRB) in central Illinois demonstrated that the fly ash methodology for mapping Post-Settlement Alluvium (PSA) is relatively simple, effective, and inexpensive. We applied this method to 11 sites in the Middle Fork Vermillion River Basin (MFVRB) adjacent to the USRB. PSA in the MFVRB is 40-80 cm thick, like that of the USRB, indicating regional consistency in response to land use changes. However, PSA in the MFVRB is thicker in narrower valleys and thinner in wider valleys, displaying the opposite trend in the USRB. PSA thickness in the MFVRB is not linearly correlated with drainage area, stream power per unit area, or river slope. We propose a non-linear relationship between PSA thickness and valley width, where PSA thickness increases to a certain valley width before decreasing as the valley widens further. The differing relationships between PSA thickness and valley width and the scaling of valley width with drainage area in the two adjacent basins underscore the importance of local geological and geomorphic histories, which lead to differences in valley sedimentation and river responses to Euro-American agricultural land use changes. 2024-08 Thesis https://hdl.handle.net/2142/125693 Copyright 2024 Nol Srivichainun Earth Sci & Environmental Chng Geology University of Illinois at Urbana-Champaign M.S. Thesis