Search Results (5)

Aquatic invasive plants (AIPs) are a global threat to local biodiversity due to their rapid adaptation to the new environments. Lythrum salicaria, commonly known as purple loosestrife, is a predominant AIP in the upper Midwestern region of the United States and has been designated as a deadly threat to the wetlands of this region. Accurate estimation of its current extent is a top priority, but regular monitoring is limited due to cost-, labor-, and time-intensive field surveys. Therefore, the goal of the present study is to accurately detect purple loosestrife from very high-resolution UAV imagery using deep neural network-based models. As a case study, this study implemented U-Net and LinkNet models with ResNet-152 encoder in the wetlands of the upper Mississippi River situated in La Crosse County, Wisconsin. The results showed that both models produced 88–94% training accuracy and performed better in landscapes that were occupied by smaller, disaggregated, and more equitably distributed purple loosestrife. Furthermore, the study adopted a transfer learning approach to implement a trained purple loosestrife model of the first study site and implemented it for the second study site. The results showed that the pre-trained model implementation generated better accuracy in less than half the time of the original model. Therefore, the transfer learning approach, if adapted efficiently, can be highly beneficial for continuous monitoring of purple loosestrife and strategic planning for application of direct biocontrol measures. Full article

Risks from flooding and poor water quality are evident at a range of spatial scales and climate change will exacerbate these risks in the future. Natural infrastructure (NI), consisting of structural or perennial vegetation, measures that provide multiple ecosystem benefits have the potential to reduce flood and water quality risks. In this study, we intersected watershed-scale risks to flooding and nitrate export in the Mississippi-Atchafalaya River Basin (MARB) of the central U.S. with potential locations of seven NI practices (row crop conversion, water, and sediment control basins, depressional wetlands, nitrate-removal wetlands, riparian buffers, and floodplain levees and row crop change) to prioritize where NI can be most effective for combined risk reduction at watershed scales. Spatial data from a variety of publicly-available databases were analyzed at a 10 m grid cell to locate NI practices using a geographic information system (GIS). NI practices were presented at the regional basin scale and local Iowa-Cedar watershed in eastern Iowa to show individual practice locations. A prioritization scheme was developed to show the optimal watersheds for deploying NI practices to minimize flooding and water quality risks in the MARB. Among the 84 HUC4 basins in the MARB, 28 are located in the Upper Mississippi and Ohio Rivers basins. The Wabash and Iowa-Cedar basins (HUCs 0512 and 0708, respectively) within these basins were found to rank among the uppermost quintile for nearly all practices evaluated, indicating widespread opportunities for NI implementation. Study results are a launching point from which to improve the connections between watershed scale risks and the potential use of NI practices to reduce these risks. Full article

Here we review an extensive series of studies of Barataria Basin, an economically and ecologically important coastal basin of the Mississippi Delta. Human activity has greatly altered the hydrology of the basin by decreasing riverine inflows from leveeing of the river and its distributaries, increasing runoff with high nutrient concentrations from agricultural fields, and channelization of wetlands of the basin interior that has altered flow paths to often bypass wetlands. This has resulted in degraded water quality in the upper basin and wetland loss in the lower basin. Trophic state analysis found the upper basin to be eutrophic and the lower basin to be mesotrophic. Gross aquatic primary production (GAPP) was highest in the upper basin, lowest in the mid basin, and intermediate in the lower basin. Forested wetlands in the upper basin have degraded over the past several decades due to increased periods of flooding, while there has been massive loss of emergent wetlands in the lower basin due to increasing water levels and pervasive alteration of hydrology. Restoration will entail reconnection of waterways with surrounding wetlands in the upper basin, and implementation of river sediment diversions, marsh creation using dredged sediments and barrier island restoration. Findings from this review are discussed in terms of the functioning of deltas globally. Full article

Here we examine a combined dataset of water quality dynamics in the Barataria Basin, Louisiana based on transect studies from 1977 to 1978 (Seaton) and from 1994 to 2016. The Davis Pond river diversion into Lake Cataouatche began discharging Mississippi River water into the mid-basin in 2005, and so the later dataset was divided in Pre- and Post-diversion periods. The stations from these three datasets (Seaton, Pre- and Post-diversion) were combined into eleven station groupings for statistical analysis that included ANOVA and principal component analysis. In addition, Trophic State Index (TSI) scores were calculated for each grouping during the three time periods. Lake Cataouatche changed the most with the opening of the Davis Pond river diversion, becoming clearer and less eutrophic with addition of river water, which passed through a large wetland area where sediments were retained before entering the lake. The TSI results for the Seaton re-analysis were very similar to the original analysis and to that of the Pre- and Post-diversion datasets, indicating that the trophic status of the basin waters has remained relatively unchanged. The upper-basin has remained eutrophic with degraded water quality while the lower-basin has remained more mesotrophic without significant water quality deterioration. A main cause of water quality deterioration is agricultural runoff and pervasive hydrologic alteration that bypasses wetlands and causes most runoff to flow directly into water bodies. Full article

The Future Midwest Landscape (FML) project is part of the US Environmental Protection Agency (EPA)’s new Ecosystem Services Research Program, undertaken to examine the variety of ways in which landscapes that include crop lands, conservation areas, wetlands, lakes, and streams affect human well-being. The goal of the FML project is to quantify current and future ecosystem services across the region and to examine changes expected to occur as a result of the growing demand for biofuels. This study is one of several pilots taking place under the umbrella of the FML research project. In this study, the USDA Annualized Agricultural Non-Point Source Pollution (AnnAGNPS) model was applied to the East Fork Kaskaskia River watershed (289.3 km²) located in the Kaskaskia River Basin within the Upper Mississippi River Basin in Illinois. The effect of different spatial resolutions on model performance was investigated by comparing the observed runoff with the AnnAGNPS simulated results. Alternative future scenarios such as meeting future biofuel target were also simulated and analyzed. All delineations of the study area (coarser to finer) produced satisfactory results in simulating monthly and annual runoff. However, the size of the delineation does impact the simulation results. Finer delineations better represented the actual landscape and captured small critical areas that would be homogenized in coarser delineation. Those small critical areas are important to target to achieve maximum environment benefit. Simulations of alternative future scenarios showed that as corn production increases to meet future biofuel needs, total nitrogen loss increases. For this watershed, total N loss would be more than doubled if converting all corn/soybean rotation (15,871.2 ha) to continuous corn comparing with the base year total N loss which is 11.2 kg/ha. Conservation practices are needed to reduce total nitrogen loss from the watershed. This study provides an important foundation for the larger FML region modeling effort by addressing challenging FML landscape modeling issues such as model selection, need for further model development, and spatial resolution. Full article