2022 Missouri Natural Resources Conference

Mining Contamination and Legacy Floodplain Sedimentation in Turkey Creek, Tri-State Mining District, Southwest Missouri

  • Hannah Eades
  • Faculty Advisor: Dr. Robert T. Pavlowsky
  • Poster [.pdf]

Historic mining activities often leave a legacy of metal contamination in channel sediments and floodplain soils that can degrade water quality long after mine closure. The Tri-State Mining District (1870-1950) was a global producer of zinc (Zn) and lead (Pb) in Missouri, Kansas and Oklahoma. Several studies have assessed metal contamination risk in active channel sediments. However, none have evaluated the role of floodplain deposits as storages and long-term sources of metal pollution. This study evaluates the vertical and downstream trends in Zn and Pb contamination in floodplain deposits along Turkey Creek (30 km long) which drains heavily mined areas in Missouri. Landform characteristics, deposit stratigraphy, and
mining/land-use trends will be used to assess dispersal and storage patterns of legacy sediment and metals at the watershed-scale. Channel and floodplain surveys were completed at 11 sites at each site 2-3 overbank profiles sampled in 10 and 20 cm intervals then analyzed for Zn and Pb, sand, and organic content. Spikes in metal profiles are expected to occur during the heaviest mining periods with depths and thicknesses of contaminated deposits increasing downstream. Floodplain sedimentation rates were likely highest along Turkey Creek during periods with highest soil erosion rates and ore production.

 

Long-Term Impact of Exploitative Logging on Forest Watershed Hydrology in the Missouri Ozarks

  • Elande’ Engelbrecht, Shoukat Ahmed, Sierra N. Casagrand
  • Faculty Advisor: Marc R. Owen and Dr. Robert T. Pavlowsky
  • Poster [.pdf]

Stream channels adjust to human-induced landscape disturbance by expanding to
accommodate increases in runoff. Headwater stream channels in the Ozarks show
signs of instability as bank erosion, incision, and bed aggradation are common even in
watersheds that are mostly forested. This study explores the idea that stream
channels are adjusting to the reduction in shortleaf pines in the region contributing to
increased runoff in the winter and early spring. Shortleaf pines intercept 3x more
rainfall than bare deciduous tree and runoff is slowed by decreasing throughfall and
stem flow rates. Implications are that climate change could exacerbate
instability as the number of high intense rainfall events is increasing in southeast
Missouri.

 

River-floodplain Connectivity and Riparian Management for Nonpoint Source in Blue River, Metropolitan Kansas City, Missouri

  • Hannah Alkier, Katie Grong
  • Faculty Advisor: Dr. Robert T. Pavlowsky
  • Poster [.pdf]

Riparian corridors can provide water quality benefits through nonpoint source (NPS) reductions. However, few studies have examined the influence of human activities on channel floodplain connectivity and riparian buffering capacity. As part of a larger NPS load modeling project, this study will evaluate the effects of land use change and riparian corridor characteristics on NPS loads in the Blue River watershed near Kansas City, Missouri. In addition, the Blue River Channel Modification Project was authorized by Congress under the
Flood Control Act of 1970 resulting in the channelization of a 12 mile urban segment including numerous concrete slope stability structures along banks, grade controls, and flood walls.
While channelization aims to contain flood events within the channel, it can degrade a healthy riparian vegetation zone and increase the risk of downstream floods. This presentation
describes two studies aimed to assess the effects of past and present land use and channel modifications on the role of riparian corridors as NPS filters, buffers, and sources. The first
will examine how hydrologically connected floodplain areas along the Blue River have been functioning as sinks and sources for sediment historically as land use has changed. The
second study will focus on evaluating the effectiveness of riparian buffers in reducing contemporary NPS loads in the Blue River. These studies will provide information to better
understand the NPS buffering capacity of riparian corridors and possible options for NPS management.