Location: Watershed Physical Processes Research
2022 Annual Report
Objectives
1. Develop new knowledge and methodologies to quantify soil detachment and sediment transport, transformation, storage, and delivery.
1.a. Determine functional relations among variables (i.e., rainfall, soil moisture, soil texture, bulk density, organic matter, vegetation) with soil erosion.
1.b. Quantify the surface and subsurface processes controlling erosion and depositional features.
1.c. Quantify the effects of mixed-particle sizes and bed forms on roughness and sediment transport.
2. Improve knowledge of processes controlling surface and groundwater movement in agricultural watersheds, and their associated quantification.
2.a. Removed per approved Ad-hoc approval July 2018. See approved post plan.
2.b. Assess the use and management of floodplain water bodies for providing ecosystem services in order to support their use as a sustainable source of water for agriculture.
2.c. Quantify the processes partitioning components of the water budget in upland catchments of the Lower Mississippi River Basin.
3. Translate research into technology to quantify and evaluate management effects on watershed physical processes.
3.a. Develop a GIS-based erosion prediction management system that facilitates database acquisition and input file development, output visualization, and supports multiple scales of focus, including: watersheds, farm fields, and streams.
3.b. Develop technologies and tools to evaluate the benefits of conservation practice plans within and among fields, streams, and watersheds.
3.c. Develop new computer model components to simulate non-uniform sediment transport and stream morphologic adjustment at subreach scales.
4. As part of the LTAR network, and in concert with similar long-term, land-based research infrastructure in the Midsouth region, use the Lower Mississippi River Basin LTAR site to improve the observational capabilities and data accessibility of the LTAR network and support research to sustain or enhance agricultural production and environmental quality in agroecosystems characteristic of the Midsouth region. Research and data collection are planned and implemented based on the LTAR site application and in accordance with the responsibilities outlined in the LTAR Shared Research Strategy, a living document that serves as a roadmap for LTAR implementation. Participation in the LTAR network includes research and data management in support of the ARS GRACEnet and/or Livestock GRACEnet projects.
4.a. Develop the Lower Mississippi River Basin LTAR location addressing issues of long-term agroecosystem sustainability specific to the region, participating in the Shared Research Strategy, and contributing to network-wide monitoring and experimentation goals.
4.b. Enhance the LMRB CEAP watershed long-term data sets and integrate with other long-term data sets in the LMRB to address agroecosystem sustainability at the basin scale.
5. Increase knowledge and understanding of the processes governing movement, storage, and quality of water in the Mississippi River Valley Alluvial Aquifer, and develop technologies to enhance the sustainability of water resources for agriculture. 5.a. and 5.b. See approved post plan.
Approach
In the Lower Mississippi River Valley, groundwater extraction for irrigation has outpaced aquifer recharge, and precipitation is expected to fall in fewer, higher intensity events, thereby increasing runoff and stream peak discharges. This will impact erosion patterns and rates, destabilize streams with consequent loss of arable land, adversely impact ecosystem services, and reduce reservoir usability. These are not only regional but also national concerns. There is a critical need for improved understanding and quantification of the processes that control: the movement of water across the landscape; the detachment and transport of soil and sediment; and the morphologic adjustment of channels. This research will use an integrated approach to watershed management through the development and testing of innovative practices and computational models based on a scientific understanding of hydrogeomorphic processes at the test-plot, farm, watershed, and river-basin scales. Field and laboratory, short- and long-term experiments will be conducted to fill technology and knowledge gaps in USDA erosion models concerning: ephemeral gully and soil pipe erosion; transport of eroded sediments and of sediments introduced by reservoir sediment management actions; and stream system physical integrity. Findings will be used to develop new computer modeling components to optimize conservation measure design and placement for the RUSLE, AnnAGNPS, and CONCEPTS computer simulation models. Long-term monitoring combined with new field experiments will investigate the long-term sustainability of surface and groundwater resources in the Lower Mississippi River Valley.
Progress Report
This is the final report for the project 6060-13000-026-00D which terminated in March 2022. All planned research was completed prior to the start of FY 2022; no research was initiated in this time frame which corresponded to this project. See new project 6060-13000-029-000D for additional information.
During the five years of this project, substantial progress and results were made on improving understanding and technologies for predicting the movement of water and sediment in watersheds at field, channel and watershed scales. Important components in the attainment of this progress have been research components which seek to discover new knowledge related to the movement of water and sediment in watersheds and the development of novel ways to implement this knowledge in tools to allow improved management systems to be implemented.
At the field scale there has been progress made in the understanding of the fractional sediment transport capacity of soil pipes. Laboratory experiments on the impacts of combined pipeflow and surface runoff in the presence of a headcut showed that the combined runoff accelerated headcut migration rates and sediment concentrations by nearly 50%. In the field, over 50 flow events were sampled for pipeflow rate and sediment concentrations, which indicated that sediment rating curves were highly hysteretic with high suspended sediment concentrations during the initial flush when pipeflow commenced. Laboratory experiments to study soil erodibility found the hysteresis loop in soil erodibility with respect to packing and water content. Two values of soil erodibility are possible dependent upon whether the sample is wetting or drying. Field technology was developed to study rill and gully erosion processes using temporal acquisitions of remotely sensed data acquired by Unoccupied Aerial Systems (UAS). Total landscape change within the coverage area and erosion process distinction were instrumental to rill and gully model prediction development. At the scale of channels and receiving water bodies, progress on improving the technology to measure gravel sediment transported along the bed of streams and rivers has been made. Impact plates installed on channel beds allows continuous measurements of the rate and size of the gravel in transport in laboratory and field channels of agricultural watersheds. A series of laboratory experiments aimed at detailed measurements of the effect of rapid decreases and increases in flow rate quantified the lag between flow rate and changes in bed form roughness development and sediment transport rate, which is important to determine flood levels. Laboratory experiments developed process understanding of wind wave-generated erosion profile of irrigation-reservoir levees constructed from both cohesive and cohesionless materials. Additional experiments resulted in the design of cable-restrained floating pipe breakwaters to reduce wave energy acting on levees. At the watershed and basin scale, a pilot project was constructed to test managed aquifer recharge technology utilizing riverbank filtration and groundwater transfer and injection. Successful operation was indicated by an increase of up to 7 ft in groundwater levels near the injection wells and 2 ft at a distance of 2,000 ft, while smaller impacts were observed near the extraction well where groundwater levels decreased up to 5 ft and 2 ft at a distance of 1,500 ft. Long-term monitoring of the Goodwin Creek Experimental Watershed, MS, added five years of precipitation, runoff, sediment transport rate, water quality parameters, stream geomorphology, and land use and management data to its currently 40-year record of hydrologic and water quality data. This data set supports the ARS Conservation Effects Assessment Project (CEAP). Long-Term Agroecosystem Research (LTAR) common experiment sites were secured, and eddy-covariance towers and soil moisture sensors were installed in the aspirational and “business-as-usual” fields at two farms in the late summer and early fall of 2020. Historical datasets from both the Goodwin Creek and Beasley Lake watersheds were uploaded into a common data management platform and the data are currently under quality assurance/quality control checks. We are currently in the second year of field biomass collection, and this project will continue into the next five-year project plan.
Improvements have been made in the technology employed for the simulation of water movement and soil and sediment erosion. Enhancements to the Revised Universal Soil Loss Equation (RUSLE2), USDA’s conservation management planning tool, have included mapping the spatial distribution of soil loss at the field scale and the development of an accompanying next-generation user interface. At the watershed and basin scale there has been progress on understanding the impact of small surface water bodies such as ponds and reservoirs on hydrologic conditions using AnnAGNPS simulation technology. Small water bodies are often not considered within a watershed modeling framework but were found on the Goodwin Creek Experimental watershed to decrease streamflow by 4% at the watershed outlet, 8% at the sub-watershed scale and an average of 56% immediately downstream of a water body. Peak discharge was also impacted by an average of 2%. Utilization of improved irrigation characterizations through basin-scale simulations with AnnAGNPS have provided evidence of the sensitivity of streamflow and groundwater levels to irrigation strategies. Simulation results indicate that a reduction of irrigation application rates of 20-40% can impact aquifer long-term water levels. Improvements were made to Conservational Channel Evolution and Pollutant Transport System (CONCEPTS) model to handle nearly dry beds and to increase its robustness for supercritical flow conditions, which is required to simulate hydraulics and sediment transport in urbanizing, rural watersheds where mixed earthen and concrete channels may occur. The computational bank erosion algorithms in the CONCEPTS and Bank Stability and Toe Erosion Model (BSTEM) computer models were enhanced to perform risk-based analyses to support the design of stable banks and assessment of levee failure.
Accomplishments
1. RUSLE2 continues to serve farmers and the Natural Resources Conservation Service (NRCS). The USDA-NRCS is responsible for protecting soil natural resources in the U.S. Each farm within the U.S. must have a conservation management plan that is guided by erosion technology, RUSLE2. In 2016, NRCS announced the replacement of RUSLE2 by the Water Erosion Prediction Project (WEPP) technology. ARS Headquarters, in collaboration with ARS researchers in Oxford, Mississippi and West Lafayette, Indiana, presided over a joint comparison project of RUSLE2 and WEPP, which concluded that RUSLE2 should continue to serve NRCS as the soil erosion prediction technology for conservation planning. NRCS awarded development and maintenance contracts to RUSLE2 that will lead to a WebApp containing two-dimensional and ephemeral gully forms of RUSLE2, as well as the standard version.
2. Successfully conducted two long-term pumping/injection experiments. Reliance on groundwater for irrigation has resulted in long-term declines in the Mississippi River Valley alluvial aquifer (MRVAA) water levels. The Groundwater Transfer and Injection Pilot (GTIP) project was constructed near the Little Tallahatchie River, Mississippi, to test the feasibility of withdrawing groundwater from near a large river and injecting the water into an area where the aquifer is depleted to be used later for irrigation. ARS researchers in Oxford, Mississippi, studied groundwater levels near the withdrawal and injection sites during 3- and 6-month long experiments, during which the system was operated continuously. Groundwater levels recovered by up to 7 ft in near the injection wells and up to 2 ft at a distance of 2,000 ft. River water infiltrated into the aquifer near the extraction well, suggesting extracted water was composed of river water leakage and local groundwater. A wide variety of stakeholders have expressed keen interest in the GTIP project, including the Delta Council, Mississippi Department of Environmental Quality, Mississippi River Commission, Mississippi Soil and Water Conservation Commission, Natural Resources Conservation Service, U.S. Army Corps of Engineers, U.S. Geological Survey, and Yazoo Mississippi Delta Joint Water Management District.
3. Ephemeral gully erosion produces serious water quality and economic problems in Midwest watersheds of the United States. A critical barrier to effective gully soil conservation practice development is information needed to describe the evolution of gullies in agricultural fields. There is also limited technology available to describe the relationship between the implementation of conservation practices and the potential erosion from ephemeral gullies. ARS researchers in Oxford, Mississippi, evaluated the corresponding parameters of an ephemeral gully erosion model to estimate soil loss in an Iowa field. The most sensitive ephemeral gully parameters found in existing gully erosion technology were gully depth, critical shear stress, and headcut migration erodibility. The study showed that improved ephemeral gully erosion components are needed to evaluate the evolution of gullies on conservation tillage systems, since many of the components describing gully processes were developed for tilled agricultural conditions or larger channel systems. Future research is needed to study gully headcut, soil erodibility and width functions that will be different on conservation tillage systems compared to tilled fields in order to develop effective conservation management planning tools for use by agencies such as Natural Resources Conservation Service.
Review Publications
Gudino-Elizondo, N., Brand, M., Biggs, T., Hinojosa-Corona, A., Gomez-Gutierrez, A., Langendoen, E.J., Bingner, R.L., Yuan, Y., Sanders, B. 2022. Rapid assessment of abrupt urban mega-gully and landslide events with structure-from-motion photogrammetric techniques validates link to water resources infrastructure failures in an urban periphery. Natural Hazards and Earth System Sciences. 22(2):523-538. https://doi.org/10.5194/nhess-22-523-2022.
Xu, X., Zheng, F., Tang, Q., Wilson, G.V., Wu, M., Han, Y., Xiao, P., Zhang, X.J. 2021. Upslope sediment-laden flow impacts on ephemeral gully erosion: evidences from field monitoring and laboratory simulations. Catena. 209:105802. https://doi.org/10.1016/j.catena.2021.105802.
Ebabu, K., Tsunekawa, A., Haregeweyn, N., Tsubo, M., Adgo, E., Fenta, A.A., Meshesha, D.T., Berihun, M.L., Sultan, D., Vanmaercke, M., Panagos, P., Borrelli, P., Langendoen, E.J., Poesen, J. 2022. Global analysis of cover management and support practice factors that control soil erosion and conservation. International Soil and Water Conservation Research. 10(2):161-176. https://doi.org/10.1016/j.iswcr.2021.12.002.
Li, M., Liu, Q.J., Zhang, H.Y., Wells, R.R., Wang, L., Geng, J. 2022. Effects of antecedent soil moisture on rill erodibility and critical shear stress. Catena. 216(A):106356. https://doi.org/10.1016/j.catena.2022.106356.
Tebebu, T.Y., Zegeye, A.D., Langendoen, E.J., Ayele, G., Tilahun, S.A., Ayana, E.K., Steenhuis, T.S. 2013. Arresting gully formation in the Ethiopian highlands. In Mekuria, W., editor. Rainwater Management for Resilient Livelihoods in Ethiopia. Nairobi, Kenia: ILRI. p. 196-203.
Amare, S.D., Keesstra, S., Van Der Ploeg, M., Langendoen, E.J., Steenhuis, T.S., Tilahun, S.A. 2019. Causes and controlling factors of valley bottom gullies. Land. 8(9):141. https://doi.org/10.3390/land8090141.
Gratzer, M., Davidson, G.R., O'Reilly, A.M., Rigby Jr, J.R. 2019. Groundwater recharge from an oxbow lake-wetland system in the Mississippi Alluvial Plain. Hydrological Processes. 34(6):1359-1370. https://doi.org/10.1002/hyp.13680.
