Using Atmospheric Fallout Radionuclides 137Cs and 210Pbxs to Identify Sources of Suspended Sediment in an Agricultural Watershed

2019 ◽  
Vol 62 (2) ◽  
pp. 529-538
Author(s):  
Jasmeet Lamba ◽  
K. G. Karthikeyan ◽  
Anita M. Thompson ◽  
Kritika Malhotra ◽  
Natalie L. H. Huisman ◽  
...  
Keyword(s):  
Land Use ◽  
Suspended Sediment ◽  
Best Management Practices ◽  
Management Practices ◽  
Transport Processes ◽  
Agricultural Watershed ◽  
Atmospheric Fallout ◽  
Fallout Radionuclides ◽  
South Central ◽  
Mixed Land Use

Abstract. The use of atmospheric fallout radionuclides as sediment tracers can provide valuable information on sediment transport processes within watersheds. Research was conducted in cropland and mixed land use subwatersheds of the Pleasant Valley watershed (50 km2) in south-central Wisconsin to identify sources of suspended sediment using cesium-137 (137Cs) and excess lead-210 (210Pbxs). In the cropland-dominated subwatershed, contributions to suspended sediment from in-stream and agricultural sources ranged from 36% to 81% and from 19% to 64%, respectively. In the mixed land use subwatershed, contributions to suspended sediment from in-stream and agricultural sources ranged from 68% to 100% and from 0% to 32%, respectively. The relative contribution to suspended sediment from agricultural sources was greater in the cropland subwatershed compared to the mixed land use subwatershed. The phosphorus (P) concentration in suspended sediment and fine sediment deposited on the streambed varied from 601 to 1545 mg kg-1, and cropland areas were the dominant sources of P-enriched sediment in streams. The legacy P and sediment in this watershed can result in a lag time between implementation of best management practices and attainment of desired water quality improvement. Depending on the fingerprinting properties considered (metals vs. fallout radionuclides) and suspended sediment source considerations, the source apportionment results may vary. Keywords: Fallout radionuclides, Legacy sediment, Phosphorus, Sediment fingerprinting, Soil erosion, Streambanks.

scholarly journals Watershed Response to Legacy Phosphorus and Best Management Practices in an Impacted Agricultural Watershed in Florida, U.S.A.

Land ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 977
Author(s):  
Yogesh P. Khare ◽  
Rajendra Paudel ◽  
Ruscena Wiederholt ◽  
Anteneh Z. Abiy ◽  
Thomas Van Lent ◽  
...  
Keyword(s):  
Water Quality ◽  
Best Management Practices ◽  
Environmental Planning ◽  
Management Practices ◽  
Soil Phosphorus ◽  
Agricultural Watershed ◽  
Assessment Model ◽  
Evaluation Tool ◽  
South Central ◽  
P Sources

Soil phosphorus (P) built up due to past management practices, legacy P, in the Lake Okeechobee Watershed (LOW) in south-central Florida, U.S.A., is often discussed as the root cause of lake eutrophication. Improvement of the lake’s water quality requires the identification of critical P sources and quantifying their contributions. We performed a global sensitivity analysis of the Watershed Assessment Model (WAM), a common evaluation tool in LOW environmental planning, using the Morris method. A pre-calibrated WAM setup (Baseline) of the LOW sub-watershed, Taylor Creek Nubbin Slough (TCNS), was used as a test case. Eight scenarios were formulated to estimate the contributions of various P sources. The Morris analysis indicated that total phosphorus (TP) loads were highly sensitive to legacy P in improved pastures, the major land use covering 46.2% of TCNS. The scenario modeling revealed that legacy P, inorganic fertilizers, and other sources contribute 63%, 10%, and 32%, respectively, to the Baseline TP load of 111.3 metric tons/y to the lake. Improved pastures, dairies, citrus, and field crops are the top TP load contributors. Our results have important implications for water quality improvement plans in the LOW and highlighted the need for accurate spatial mapping of legacy P and incorporation of such information in modeling efforts for watersheds demonstrating legacy P problems.

Pesticide Contamination of Groundwater in Virginia: BMP Impact Assessment

1993 ◽  
Vol 28 (3-5) ◽  
pp. 379-387 ◽  
Author(s):  
S. Mostaghimi ◽  
P. W. McClellan ◽  
R. A. Cooke
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Best Management Practices ◽  
Water Samples ◽  
Management Practices ◽  
Water Quality Monitoring ◽  
Pesticide Contamination ◽  
Cropping Patterns ◽  
Creek Watershed ◽  
Surface And Groundwater

The Nomini Creek Watershed/Water Quality monitoring project was initiated in 1985, as part of the Chesapeake Bay Agreement of 1983, to quantify the impacts of agricultural best management practices (BMPs) on improving water quality. The watershed monitoring system was designed to provide a comprehensive assessment of the quality of surface and groundwater as influenced by changes in land use, agronomic, and cultural practices in the watershed over the duration of the project. The primary chemical characteristics monitored include both soluble and sediment-bound nutrients and pesticides in surface and groundwater. Water samples from 8 monitoring wells located in agricultural areas in the watershed were analyzed for 22 pesticides. A total of 20 pesticides have been detected in water samples collected. Atrazine is the most frequently detected pesticide. Detected concentrations of atrazine ranged from 0.03 - 25.56 ppb and occurred in about 26 percent of the samples. Other pesticides were detected at frequencies ranging from 1.6 to 14.2 percent of all samples collected and concentrations between 0.01 and 41.89 ppb. The observed concentrations and spatial distributions of pesticide contamination of groundwater are compared to land use and cropping patterns. Results indicate that BMPs are quite effective in reducing pesticide concentrations in groundwater.

An ecosystem-based approach to support water quality assessment and management under climate and land-use condition

2020 ◽  
Author(s):  
Andrea Critto ◽  
Hung Vuong Pham ◽  
Anna Sperotto ◽  
Silvia Torresan ◽  
Elisa Furlan ◽  
...  
Keyword(s):  
Land Use ◽  
Ecosystem Services ◽  
Best Management Practices ◽  
Water Demand ◽  
Management Practices ◽  
Freshwater Ecosystems ◽  
Water Yield ◽  
Management Scenarios ◽  
Nitrogen And Phosphorus ◽  
Change Models

<p>Freshwater ecosystems can be negatively affected by climate change and human interventions through the alteration of water supply and demand. There is an urgent need to protect the ecosystems, and the services they provide, to maintain their essential contribution to human wellbeing and economic prosperity, especially in a rapid and unpredictable global change context. In this work, we developed an integrated approach, coupling the outputs of ecosystem services (InVEST), climate (COSMO-CLM) and land use (LUISA) change models utilizing Bayesian Networks (BNs), to map freshwater-related Ecosystem Services (ESs), namely, water yield, nitrogen and phosphorus retention, and to assess their changes until 2050 under different management scenarios. First, InVEST was calibrated and validated with climate and land-use data to map and quantify ESs. Second, outputs of the ES model were integrated into the BN and the changes induced by different learning techniques and input settings were investigated. Finally, thousands of different scenarios were simulated testing multiple input variables configurations, thus allowing to describe the uncertainty of climate conditions, land-use change and water demand. Two types of inferences were conducted, namely, diagnostic and prognostic inference. The former permitted to find the best combination of the key drivers (i.e.  precipitation, land-use, and water demand) so that ESs are maximized while the latter concentrated on the quantification of ESs under different scenarios. This approach was applied and validated in the Taro River basin in Italy. The results show that the values of all the three types of ESs would decline in the medium-term period under most scenarios. Moreover, there would be a limit of space to improve those values, especially for nutrient retention services. The obtained results provide valuable support to identify and prioritize the best management practices for sustainable water use, balancing the tradeoffs among services. This analysis allows decision-makers to pick up one scenario with a specific configuration of land-use and water demand to optimize relevant ESs within their basin. Finally, these decisions are transformed into a “decision space” where the values of selected services are plotted in the space of ES to represent the gain/loss of each decision.</p>

The effects of forest harvesting and best management practices on streamflow and suspended sediment concentrations during snowmelt in headwater streams in sub-boreal forests of British Columbia, Canada

2003 ◽  
Vol 33 (8) ◽  
pp. 1397-1407 ◽  
Author(s):  
J S Macdonald ◽  
P G Beaudry ◽  
E A MacIsaac ◽  
H E Herunter
Keyword(s):  
British Columbia ◽  
Suspended Sediment ◽  
Best Management Practices ◽  
Boreal Forests ◽  
Management Practices ◽  
Complete Removal ◽  
Sediment Concentration ◽  
Forest Harvesting ◽  
Clear Cut ◽  
Best Management

This paper examines suspended sediment concentration and stream discharge during freshet in three small sub-boreal forest streams (<1.5 m in width) in the central interior of British Columbia for 1 year prior to (1996) and for 5 years following forest harvesting (1997–2001). Harvesting prescriptions in a 20-m strip beside one stream required complete removal of merchantable timber (>15 cm diameter at breast height (DBH) for pine and >20 cm for spruce), while all stems <30 cm DBH were retained beside a second stream. A third stream remained unharvested as a control. The two riparian treatments were prescribed to test the efficacy of current British Columbia legislation that allows for varying amounts of riparian retention as best management practices for the management of windthrow. Both treated watersheds were clear-cut harvested (approximately 55% removal) in January 1997, and in the following year, temporary access roads were deactivated, including two stream crossings in the low-retention watershed. An increase in peak snowmelt and total freshet discharge was first noted in the second spring following harvest in both treatments and remained above predicted in all subsequent years. Suspended sediment also increased during freshet following harvest but returned to levels at or below preharvest predictions within 3 years or less in the high-retention watershed.

scholarly journals Case study of extracting soil and land use maps to determine agricultural best management practices that can be applied to prevent erosion and fertile soil loss

2020 ◽  
Vol 61 (4) ◽  
pp. 313-327
Author(s):  
Akıner Ernur
Keyword(s):  
Land Use ◽  
Best Management Practices ◽  
Management Practices ◽  
Assessment Tool ◽  
Management Practice ◽  
Global Climate ◽  
Residential Areas ◽  
Filter Strips ◽  
Land Type ◽  
Agricultural Areas

The Büyük Melen river in the Melen Basin meets Istanbul's drinking water needs. Protecting the basin against nutrient pollution is vital in this regard as well. This study focuses on the best possible management practice (BMPs) in the Melen Basin to reduce the export of nutrients from the agricultural areas. A region comprising industrial, farming, and residential zones is the Melen basin. There is a forecast of global climate change in Turkey, and scientists and also governors must know which areas are no longer farming zones and which will be more appropriate for agriculture. Turkey's territory is a high-risk desertification area. In Melen Basin, the soil type and land use properties have been determined and mapped using GIS and Soil and Water Assessment Tool (SWAT). Buffer BMP filter strips can be used effectively for nutrient protection that can be carried from residential areas and motorways by runoff. The region in the basin is steep, and its clay and sandy soil structures are ideal for parallel terraces, grade stabilization, strip, and contour cultivation. Unless the ground can not retain or store water, the soil can undergo sudden floods, causing an erosion of the soil's productive surface layer. When we protect the land, this condition is reduced. The land type and land use mapping should be drawn up as soon as possible for the remaining Turkish basins by scientific methods. This research is intended to be an illustration for researches on other agricultural basins in Turkey and the world for this reason.

scholarly journals Gender, Educational Attainment, and Farm Outcomes in New Zealand

Land ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 18 ◽  
Author(s):  
Philip Brown
Keyword(s):  
Land Use ◽  
New Zealand ◽  
Best Management Practices ◽  
Management Practices ◽  
Risk Tolerance ◽  
Decision Makers ◽  
Survey Respondent ◽  
Novel Technologies ◽  
Best Management ◽  
And Gender

Empirical studies of farm outcomes that rely on survey data often find important roles for education and gender. However, relatively few studies consider either field of study or gender of the decision maker (as opposed to gender of the survey respondent). This paper evaluates how the field of education and gender of decision makers correlate with profitability, farm management, future intentions, risk and norms, and adoption of novel technologies in New Zealand, explicitly accounting for the fact that many farming households make decisions jointly. Findings show that post-secondary education in a relevant field is a strong predictor of farm outcomes such as adoption of best management practices, plans to convert or intensify land use, risk tolerance, and adoption of novel technologies. Male sole decision makers (vis-à-vis joint decision makers) are more likely to have adopted best management practices and to have greater risk tolerance while female sole decision makers have adopted fewer novel technologies. These results have important implications for policy makers and extension officers who wish to encourage the uptake of best management practices and who wish to better understand future land-use change.

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