Sediment Accumulation in Prairie Wetlands under a Changing Climate: the Relative Roles of Landscape and Precipitation

Abstract

Sediment accumulation threatens the viability and hydrologic functioning of many naturally formed depressional wetlands across the interior regions of North America. These wetlands provide many ecosystem services and vital habitats for diverse plant and animal communities. Climate change may further impact sediment accumulation rates in the context of current land use patterns. We estimated sediment accretion in wetlands within a region renowned for its large populations of breeding waterfowl and migrant shorebirds and examined the relative roles of precipitation and land use context in the sedimentation process. We modeled rates of sediment accumulation from 1971 through 2100 using the Revised Universal Soil Loss Equation (RUSLE) with a sediment delivery ratio and the Unit Stream Power Erosion Deposition model (USPED). These models predicted that by 2100, 21-33 % of wetlands filled completely with sediment and 27-46 % filled by half with sediments; estimates are consistent with measured sediment accumulation rates in the region reported by empirical studies. Sediment accumulation rates were strongly influenced by size of the catchment, greater coverage of tilled landscape within the catchment, and steeper slopes. Conservation efforts that incorporate the relative risk of infilling of wetlands with sediments, thus emphasizing areas of high topographic relief and large watersheds, may benefit wetland-dependent biota.

Dynamic Management of Water Storage for Flood Control in a Wetland System: A Case Study in Texas

“…Furthermore, as can be observed in Figure 13 and as is expected, the most downstream wetlands have a larger number of pipes in comparison to the most upstream wetlands (see pipe network in Figure 4). To evaluate how the number of pipes changes with the pre-specified releasing time, Figure 14 compares the solutions of optimal pipe diameters for 80% water release and five different releasing times (2,3,6,12, and 18 h). As it is expected, the larger the releasing time, the smaller the number of pipes required.…”

“…In the watershed approach, the entire watershed becomes the objective of management so that for example human activities (e.g., land development) upstream can be associated to inundation in a downstream area (e.g., [2]). It has been recognized that within a watershed, wetlands can play a significant role in flood control, while providing other benefits such as creating habitats for flora and fauna, improving water quality, and providing opportunities for recreation and public appreciation (e.g., [3][4][5][6][7][8][9][10][11][12][13][14]). It is recognized that wetlands can help in flood reduction by storing, holding, and percolating water [4,7], however their effectiveness is constrained due to their limited storage capacity and the fact that some or all of this capacity may be occupied when a flood is imminent.…”

Assessment of Depressional Wetland Degradation, Spatial Distribution, and Geological Aspects in Southern Brazil

“…However, after a rainy period, for the same rainfall amount, eight areas were still dry, and 10 wetlands had water below the surface, demonstrating that the water dynamics and hydrological functions of these wetlands were affected in some way by anthropogenic interferences. These wetlands were located in areas with intense anthropogenic activities in both the catchment and wetland areas such as the presence of extensive agricultural management, landscape modifications, pumping, and artificial drainage channels, which are well known to change the water dynamics and hydrological functions of wetlands including water storage and groundwater discharge and recharge [10,14,70,74]. Although these results are strongly indicative of wetland degradation, future studies to model wetland hydrology and consider geological material variability are essential because many of the wetlands that are experiencing high anthropogenic pressure are located in clay soils.…”

Midcontinent Prairie-Pothole Wetlands and Climate Change: an Introduction to the Supplemental Issue

“…Bansal et al (2016) explore wetland greenhouse gas fluxes through a detailed investigation into the effects of temperature and ponded water permanence on methane emissions from prairie-pothole wetlands. In a nod towards sustainability issues, Skagen et al (2016) explore how sediments might enter wetlands at an accelerated rate under future climate-change scenarios, thereby putting at risk the future functionality of prairiepothole wetland ecosystems.…”