scholarly journals The effect of hedgerow wild‐margins on topsoil hydraulic properties, and overland‐flow incidence, magnitude and water‐quality

2021 ◽  
Vol 35 (3) ◽  
Author(s):  
Ethan E. Wallace ◽  
Gareth McShane ◽  
Wlodek Tych ◽  
Ann Kretzschmar ◽  
Thomas McCann ◽  
...  
2021 ◽  
Vol 35 (3) ◽  
Author(s):  
Lin Ding ◽  
Suhua Fu ◽  
Hui Zhao

Soil Research ◽  
2000 ◽  
Vol 38 (2) ◽  
pp. 313 ◽  
Author(s):  
C. Carroll ◽  
L. Merton ◽  
P. Burger

In 1993, a field study commenced to determine the impact of vegetative cover and slope on runoff, erosion, and water quality at 3 open-cut coal mine sites. Runoff, sediment, and water quality were measured on 0.01-ha field plots from 3 slope gradients (10, 20, 30%), with pasture and tree treatments imposed on soil and spoil material, and 2 soil and spoil plots left bare. The greatest soil erosion occurred before pasture cover established, when a large surface area of soil (>0.5 plot area) was exposed to rainfall and overland flow. Once buffel grass (Cenchrus ciliaris) colonised soil plots, there were negligible differences in soil erosion between slope gradients. On spoil, Rhodes grass (Chloris gayana) reduced in situ soluble salt content, and reduced runoff electrical conductivity to levels measured in surrounding creeks. Where spoil crusted there was poor vegetative growth and unacceptably large runoff and erosion rates throughout the study.


2021 ◽  
Author(s):  
Megan Devane ◽  
Brent Gilpin ◽  
Jennifer Webster-Brown ◽  
Louise Weaver ◽  
Pierre Dupont ◽  
...  

<p>The intensification of dairy farming on the agricultural landscape in New Zealand has raised concerns about pollution sources from dairy faecal runoff into waterways. The transport of faecal pollution from farms into waterways is facilitated by overland flow, which can result from rain and flood events, poorly designed irrigation practices and the washing down of milking sheds.</p><p>An important step for mitigation of pollution is the identification of the source(s) of faecal contamination. When elevated levels of faecal indicator bacteria (FIB) such as <em>Escherichia coli </em>are identified in a waterway, faecal source tracking (FST) tools such as microbial source tracking (MST) using quantitative polymerase chain reaction (qPCR), and faecal steroids (for example, cholesterol) provide information about the sources of faecal contamination. The understanding of the fate (degradation/persistence) and transport of these FST markers in the environment is recognised as an important requirement for the interpretation of water quality monitoring in aquatic environments.</p><p>This study investigated the effects of faecal decomposition on bovine faecal indicators (<em>E. coli </em>and FST markers: bovine-associated qPCR markers and ten faecal steroids) by monitoring the effect of flood and rainfall events on simulated cowpats over a five and a half month period under field conditions. Two separate spring/summer trials were conducted to evaluate: Trial 1) the mobilisation under simulated flood conditions of the faecal indicators from irrigated versus non-irrigated cowpats, Trial 2) the mobilisation of faecal indicators from non-irrigated cowpat flood runoff versus runoff after simulated rainfall onto non-irrigated cowpats.</p><p>The microbial community changes within the decomposing cowpat (as illustrated by amplicon-based metagenomic analysis) were expected to impact on the survival/persistence of the bacterial targets of the MST markers, and also alter the ratio between faecal sterols and their biodegradation products, the stanols. It was hypothesised, therefore, that there would be:</p><ul><li>Changes over time in the concentration of<em> E. coli </em>and the bovine-associated MST markers mobilised into the cowpat runoff</li> <li>Alterations in the FST ratio signature of the ten measured faecal steroids, resulting in a change from a bovine faecal steroid signature in fresh cowpat runoff to other animal faecal signatures in the runoff from decomposing cowpats</li> <li>A difference in the mobilisation decline rates of all FST and microbial markers within a treatment regime and between treatments.</li> </ul><p>Linear regression analysis was undertaken to establish mobilisation decline rates for each of the analytes in the mobilisable phase from the cowpat runoff treatments, with calculation of the time taken in days for reduction in 90% of the concentration (T<sub>90</sub>), and statistical comparison of the regression coefficients (slopes) of all analytes. The results will include a discussion of the impacts of the study’s observations on the interpretation of faecal indicator assessments for water quality monitoring in waterways influenced by sources of faecal contamination.</p>


2015 ◽  
Vol 64 (2) ◽  
pp. 339-360 ◽  
Author(s):  
Ya. Pachepsky ◽  
K. Rajkai ◽  
B. Tóth

Parameters governing the retention and movement of water and chemicals in soils are notorious for the difficulties and high labor costs involved in measuring them. Often, there is a need to resort to estimating these parameters from other, more readily available data, using pedotransfer relationships. This work is a mini-review that focuses on trends in pedotransfer development across the World, and considers trends regarding data that are in demand, data we have, and methods to build pedotransfer relationships. Recent hot topics are addressed, including estimating the spatial variability of water contents and soil hydraulic properties, which is needed in sensitivity analysis, evaluation of the model performance, multimodel simulations, data assimilation from soil sensor networks and upscaling using Monte Carlo simulations. Ensembles of pedotransfer functions and temporal stability derived from “big data” as a source of soil parameter variability are also described. Estimating parameter correlation is advocated as the pathway to the improvement of synthetic datasets. Upscaling of pedotransfer relationships is demonstrated for saturated hydraulic conductivity. Pedotransfer at coarse scales requires a different type of input variables as compared with fine scales. Accuracy, reliability, and utility have to be estimated independently. Persistent knowledge gaps in pedotransfer development are outlined, which are related to regional soil degradation, seasonal changes in pedotransfer inputs and outputs, spatial correlations in soil hydraulic properties, and overland flow parameter estimation. Pedotransfer research is an integral part of addressing grand challenges of the twenty-first century, including carbon stock assessments and forecasts, climate change and related hydrological weather extreme event predictions, and deciphering and managing ecosystem services. Overall, pedotransfer functions currently serve as an essential instrument in the science-based toolbox for diagnostics, monitoring, predictions, and management of the changing Earth and soil as a life-supporting Earth system.


Author(s):  
Zane KALVITE ◽  
Zane LIBIETE ◽  
Arta BARDULE Arta BARDULE

Rise in human population, industrialization, urbanization, intensified agriculture and forestry pose considerable risks to water supply and quality both on global and regional scale. While freshwater resources are abundant in Latvia, during recent years increased attention has been devoted to water quality in relation to anthropogenic impacts. Forest cover in Latvia equals 52% and forest management and forest infrastructure building and maintenance are among the activities that may, directly or indirectly, affect water quality in headwater catchments. Sedimentation, eutrophication and export of hazardous substances, especially mercury (Hg), are of highest concern. To address these topics, several initiatives have started recently. In 2011, cooperation programme between Latvian State Forest Research Institute (LSFRI) “Silava” and JSC “Latvia’s State Forests” was launched to evaluate the impact of forest management on the environment. This programme included research on the efficiency of water protection structures used at drainage system maintenance (sedimentation ponds, overland flow) and regeneration felling (bufferzones). In 2016, within the second stage of this cooperation programme, a study on the impact of forest management on water quality (forest road construction, drainage system maintenance, felling) was started on a catchment scale. Since 2016 LSFRI Silava is partner in the Interreg Baltic Sea Region Programme project “Water management in Baltic forests”. By focusing on drainage systems, riparian zones and beaver activity, this project aims at reducing nutrient and Hg export from forestry sites to streams and lakes. While this project mostly has a demonstration character, it will also offer novel results on Hg and methylmercury (MeHg) concentrations in beaver ponds in all participating states. This paper aims at summarizing most important challenges related to the impact of forest management on water quality and corresponding recent initiatives striving to offer solutions.


2021 ◽  
Author(s):  
◽  
Stuart Easton

<p>Poor water quality is currently a major environmental issue worldwide and in New Zealand, where reactive Nitrogen (N) and Phosphorous (P) lost from agricultural fields are significant drivers of water quality degradation in rural catchments. Irrigation application to crops is essential to agricultural production however irrigation inputs can increase N and P losses to waterways via drainage and/or overland flow directly and as a result of reduced soil capacity to buffer rainfall events. Indirect nutrient losses are also increased following irrigation implementation due to amplified farming intensity. Furthermore, irrigation applications represent the world’s greatest consumptive use of water. Improving irrigation efficiency with regard to water use represents a synergistic opportunity for the improvement of a number of different ecosystem services including water quality, water supply, and food production.  Spatially explicit modelling of irrigation is needed to determine inefficiencies in water delivery and target these inefficiencies for management or mitigation at sub-field scales. A complimentary need exists for irrigation modelling within ecosystem service decision support tools so that nutrient and water movement can be accurately quantified in irrigated environments.   This thesis describes the development and implementation of SLIM – the Spatially-explicit LUCI Irrigation Model. SLIM adapts existing lumped hydrological and irrigation modelling techniques and practices to a fully distributed, spatially explicit framework, so that sub-field variations in water flows resulting from variable soil properties are accounted for. SLIM is generally applicable across New Zealand, using readily available national scale datasets and literature derived parameters. SLIM is capable of predicting irrigation depth and timing based on common management strategies and irrigation system characteristics, or can replicate irrigation applications where information is available. Outputs from SLIM are designed to assist irrigation management decisions at the field level, and to inform the hydrology component of the Land Utilisation and Capability Indicator (LUCI) ecosystem service assessment framework. Standalone SLIM outputs include time-series files, water balance plots, and raster maps describing the efficiency and efficacy of the modelled irrigation system.   SLIM has been applied in three different agroecosystems in New Zealand under surface, micro, and spray irrigation systems, each characterised by different levels of data availability. Results show that SLIM is able to accurately predict the timing of irrigation applications and provide usable information to inform irrigation application decisions. SLIM outputs emphasise the importance of soil variability with regard to water loss and risk of nutrient leaching. Opportunity exists for irrigation water use efficiency to be improved through targeted management at sub-field scales in New Zealand farming systems.</p>


2021 ◽  
Author(s):  
◽  
Stuart Easton

<p>Poor water quality is currently a major environmental issue worldwide and in New Zealand, where reactive Nitrogen (N) and Phosphorous (P) lost from agricultural fields are significant drivers of water quality degradation in rural catchments. Irrigation application to crops is essential to agricultural production however irrigation inputs can increase N and P losses to waterways via drainage and/or overland flow directly and as a result of reduced soil capacity to buffer rainfall events. Indirect nutrient losses are also increased following irrigation implementation due to amplified farming intensity. Furthermore, irrigation applications represent the world’s greatest consumptive use of water. Improving irrigation efficiency with regard to water use represents a synergistic opportunity for the improvement of a number of different ecosystem services including water quality, water supply, and food production.  Spatially explicit modelling of irrigation is needed to determine inefficiencies in water delivery and target these inefficiencies for management or mitigation at sub-field scales. A complimentary need exists for irrigation modelling within ecosystem service decision support tools so that nutrient and water movement can be accurately quantified in irrigated environments.   This thesis describes the development and implementation of SLIM – the Spatially-explicit LUCI Irrigation Model. SLIM adapts existing lumped hydrological and irrigation modelling techniques and practices to a fully distributed, spatially explicit framework, so that sub-field variations in water flows resulting from variable soil properties are accounted for. SLIM is generally applicable across New Zealand, using readily available national scale datasets and literature derived parameters. SLIM is capable of predicting irrigation depth and timing based on common management strategies and irrigation system characteristics, or can replicate irrigation applications where information is available. Outputs from SLIM are designed to assist irrigation management decisions at the field level, and to inform the hydrology component of the Land Utilisation and Capability Indicator (LUCI) ecosystem service assessment framework. Standalone SLIM outputs include time-series files, water balance plots, and raster maps describing the efficiency and efficacy of the modelled irrigation system.   SLIM has been applied in three different agroecosystems in New Zealand under surface, micro, and spray irrigation systems, each characterised by different levels of data availability. Results show that SLIM is able to accurately predict the timing of irrigation applications and provide usable information to inform irrigation application decisions. SLIM outputs emphasise the importance of soil variability with regard to water loss and risk of nutrient leaching. Opportunity exists for irrigation water use efficiency to be improved through targeted management at sub-field scales in New Zealand farming systems.</p>


2003 ◽  
Vol 48 (7) ◽  
pp. 97-103 ◽  
Author(s):  
C.M. Kao ◽  
F.C. Wu ◽  
K.F. Chen ◽  
T.F. Lin ◽  
Y.E. Yen ◽  
...  

The Kaoping River Basin, located in southern Taiwan, flows through approximately 171 km and drains towards the South Taiwan Strait. It is the largest and the most intensively used river basin in Taiwan. Based on the results from the pollutant sources investigation and water quality analysis, the main water pollution sources of the Kaoping River were livestock wastewater from hog farms, municipal wastewater, industrial wastewater, leachate from riverbank landfills, and non-point source (NPS) pollutants from agricultural areas in the upper catchment. Concern about the deteriorating condition of the river led the Government of Taiwan to amend the relevant legislation and strengthen the enforcement of the discharge regulations to effectively manage the river and control the pollution. The following remedial strategies have been taken to improve the river water quality since 2001: (1) hog ban in the upper catchment of the Kaoping River Basin, thus, 510 thousand hogs have been removed/relocated; (2) removal of riverbank landfills; (3) enforcement of the industrial wastewater discharge standards; (4) sewer system construction in five cities along the river corridor; (5) application of best management practices for NPS pollutant control; (6) application of natural wastewater treatment systems (e.g. land treatment, constructed wetland, overland flow, riverbank sedimentation/aeration pond) for domestic wastewater treatment in rural areas; and (7) construction of the watershed geographical information system (GIS) and real time water quality monitoring system to effectively monitor and manage the watershed. Recent water quality investigation results indicate that the biochemical oxygen demand (BOD) and nutrient loadings to the Kaoping River have been significantly reduced and the water quality has been improved after the implementation of the remedial strategies described above. Results and experience obtained from this study will be helpful in designing the watershed management strategies for other similar river basins.


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