Stream Suspended Mud as an Indicator of Post-Mining Landform Stability in Tropical Northern Australia

Mining can cause environmental disturbances and thus mined lands must be managed properly to avoid detrimental impacts in the future. They should be rehabilitated in such a way that post mining landforms behave similarly as the surrounding stable undisturbed areas. A challenge for government regulators and mine operators is setting closure criteria for assessment of the stability of the elevated post-mining landforms. Stability of a landform is often measured by the number and incision depth of gullies. This can assess mass stability and bulk movement of coarse material. However, there is a need for a more sensitive approach to assess catchment disturbances using the concept of waves of fine suspended sediment and thus determine the dynamics of recovery of a post mining landform. A more environmentally meaningful approach would be to assess the fine suspended sediment (FSS, silt + clay (0.45 µm < diameter < 63 µm)) leaving the system and entering downstream waterways. We propose assessing stability through relationships between rainfall event loads of FSS and event discharge (Q) in receiving streams. This study used an innovative approach where, instead of using instantaneous FSS concentration, it used total FSS load in waves of sediment driven through the system by rainfall runoff events. High resolution stream monitoring data from 2004 to 2015 in Gulungul and Magela Creeks, Northern Territory, Australia, were used to develop a relationship between sediment wave and event discharge, ∑FSS α f(Q). These creeks are adjacent to and receive runoff from Ranger Mine. In 2008, a 10 ha elevated waste rock landform was constructed and instrumented in the Gulungul Creek catchment. The earthworks required to build the landform created a considerable disturbance in the catchment, making a large volume of disturbed soil and substrate material available for erosion. Between 2008 and 2010, in the first two wet seasons immediately after construction, the downstream monitoring site on Gulungul Creek showed elevated FSS wave loads relative to discharge, compared with the upstream site. From 2010 onwards, the FSS loads relative to Q were no longer elevated. This was due to the establishment of vegetation on the site and loose fine sediment being trapped by vegetation. Large scale disturbance associated with mining and rehabilitation of elevated landforms causes elevated FSS loads in receiving streams. The predicted FSS loads for the stream as per the relationships between FSS and event discharge may not show a 1:1 relation with the observed loads for respective gauging stations. When downstream monitoring shows that FSS wave loads relative to rainfall runoff event discharge reduce back to pre-construction catchment levels, it will indicate that the landform is approaching equilibrium. This approach to assess landform stability will increase the sensitivity of assessing post-mining landform recovery and assist rehabilitation engineers to heal the land and benefit owners of the land to whom it is bestowed after rehabilitation.

AVALIAÇÃO DA INTEGRIDADE BIÓTICA DE RIACHOS A PARTIR DA ICTIOFAUNA

Almost four decades ago, ecologist James R. Karr published the first version of the Index of Biotic Integrity (IBI) to assess the health of aquatic ecosystems from fish assemblages. Since then, numerous adaptations, criticisms, and reinterpretations have emerged from this seminal study, covering diverse world biomes. In Brazil, the first versions of IBI for streams were developed in the South (in 2004). Over time, scientific production on this topic has shown a significant increase in the complexity of the approaches and methods used, mainly due to the advance in the basic knowledge about stream fish diversity, ecology, and biology. These studies include, for example, tests of metrics already proposed, proposals for new metrics, adaptations for different basins, and tests of the ecological responses of the ichthyofauna to different human-originated impacts. Even so, there are no standardized protocols for defining the metrics, nor for the introduction of these indexes in the stream monitoring routine. The objective of this article is to present a theoretical framework on the development of IBI for Brazilian streams, based on ichthyofauna, to discuss whether it is possible and feasible to standardize protocols for the development of IBIs and the prospects of applicability in Brazilian streams.

Managing Stormwater by Accident: A Conceptual Study

Stormwater-driven road salt is a chronic and acute issue for streams in cold, urban environments. One promising approach for reducing the impact of road salt contamination in streams and adjacent aquifers is to allow “accidental wetlands” to flourish in urban areas. These wetlands form naturally as a byproduct of human activities. In this study, we quantified the ability of an accidental wetland in northwestern North Carolina, USA, to reduce the timing and peak concentration of road salt in a stream. Monitoring suggests that flow and transport processes through the wetland reduce peak concentrations and delay their arrival at the adjacent stream. We expand these findings with numerical simulations that model multiple meltwater and summer storm event scenarios. The model output demonstrates that small accidental wetland systems can reduce peak salinities by 94% and delay the arrival of saltwater pulses by 45 days. Our findings indicate that accidental wetlands improve stream water quality and they may also reduce peak temperatures during temperature surges in urban streams. Furthermore, because they find their own niche, accidental wetlands may be more effective than some intentionally constructed wetlands, and provide opportunities to explore managing stormwater by letting nature take its course.

Adding DNA barcoding to stream monitoring protocols – What’s the additional value and congruence between morphological and molecular identification approaches?

Although aquatic macroinvertebrates and freshwater fishes are important indicators for freshwater quality assessments, the morphological identification to species-level is often impossible and thus especially in many invertebrate taxa not mandatory during Water Framework Directive monitoring, a pragmatism that potentially leads to information loss. Here, we focus on the freshwater fauna of the River Sieg (Germany) to test congruence and additional value in taxa detection and taxonomic resolution of DNA barcoding vs. morphology-based identification in monitoring routines. Prior generated morphological identifications of juvenile fishes and aquatic macroinvertebrates were directly compared to species assignments using the identification engine of the Barcode of Life Data System. In 18% of the invertebrates morphology allowed only assignments to higher systematic entities, but DNA barcoding lead to species-level assignment. Dissimilarities between the two approaches occurred in 7% of the invertebrates and in 1% of the fishes. The 18 fish species were assigned to 20 molecular barcode index numbers, the 104 aquatic invertebrate taxa to 113 molecular entities. Although the cost-benefit analysis of both methods showed that DNA barcoding is still more expensive (5.30–8.60€ per sample) and time consuming (12.5h), the results emphasize the potential to increase taxonomic resolution and gain a more complete profile of biodiversity, especially in invertebrates. The provided reference DNA barcodes help building the foundation for metabarcoding approaches, which provide faster sample processing and more cost-efficient ecological status determination.

HLola: a Very Functional Tool for Extensible Stream Runtime Verification

We present , an extensible Stream Runtime Verification (SRV) tool, that borrows from the functional language Haskell (1) rich types for data in events and verdicts; and (2) functional features for parametrization, libraries, high-order specification transformations, etc.SRV is a formal dynamic analysis technique that generalizes Runtime Verification (RV) algorithms from temporal logics like LTL to stream monitoring, allowing the computation of verdicts richer than Booleans (quantitative values and beyond). The keystone of SRV is the clean separation between temporal dependencies and data computations. However, in spite of this theoretical separation previous engines include hardwired implementations of just a few datatypes, requiring complex changes in the tool chain to incorporate new data types. Additionally, when previous tools implement features like parametrization these are implemented in an ad-hoc way. In contrast, is implemented as a Haskell embedded DSL, borrowing datatypes and functional aspects from Haskell, resulting in an extensible engine (The tool is available open-source at http://github.com/imdea-software/hlola). We illustrate through several examples, including a UAV monitoring infrastructure with predictive characteristics that has been validated in online runtime verification in real mission planning.

A lightweight convolutional neural network model for quantitative analysis of phosphate ore slurry based on laser-induced breakdown spectroscopy

The phosphorus content is an important control parameter in the flotation process of phosphate ore slurry. The real-time and on-stream monitoring of the phosphorus content can improve the control stability...

An Online Stream Monitoring Algorithm for Fraud Detection in the Transport of Goods

The process of monitoring vehicles used in road transports plays an important role in detecting fraud committed by drivers. Algorithm designers face a number of challenges, including large number of vehicles monitored, demands related to online calculations, and ability to easily explain fraud alarms triggered to supervisors who make final decisions about actions to be taken. In this paper, we propose rather general, lightweight stream, online heuristics. The vehicle’s position is periodically controlled by a GNSS device. The algorithm detects potential illegal activities along the route between the origin and the destination. Anomalies in the vehicle’s trajectory are detected, based on a multi-resolution analysis of the economy of routes. The economy metric is easily understood and verifiable by controllers. The solution is also capable of identifying clearly suspicious trajectories that popular geofencing approaches would overlook. The scale on which the solution may be adopted is obtained thanks to the stream – like nature of the algorithm: essentially, the resources used do not increase along with the size of the input stream (the number of GNSS frames generated for the vehicle). An experiment illustrating the algorithm’s viability is presented as well.

Influence of sediment and stream transport on detecting a source of environmental DNA

Environmental DNA (eDNA) can be used for early detection, population estimations, and assessment of potential spread of invasive species, but questions remain about factors that influence eDNA detection results. Efforts are being made to understand how physical, chemical, and biological factors—settling, resuspension, dispersion, eDNA stability/decay—influence eDNA estimations and potentially population abundance. In a series of field and controlled mesocosm experiments, we examined the detection and accumulation of eDNA in sediment and water and the transport of eDNA in a small stream in the Lake Michigan watershed, using the invasive round goby fish (Neogobius melanostomus) as a DNA source. Experiment 1: caged fish (average n = 44) were placed in a stream devoid of round goby; water was collected over 24 hours along 120-m of stream, including a simultaneous sampling event at 7 distances from DNA source; stream monitoring continued for 24 hours after fish were removed. Experiment 2: round goby were placed in laboratory tanks; water and sediment were collected over 14 days and for another 150 days post-fish removal to calculate eDNA shedding and decay rates for water and sediment. For samples from both experiments, DNA was extracted, and qPCR targeted a cytochrome oxidase I gene (COI) fragment specific to round goby. Results indicated that eDNA accumulated and decayed more slowly in sediment than water. In the stream, DNA shedding was markedly lower than calculated in the laboratory, but models indicate eDNA could potentially travel long distances (up to 50 km) under certain circumstances. Collectively, these findings show that the interactive effects of ambient conditions (e.g., eDNA stability and decay, hydrology, settling-resuspension) are important to consider when developing comprehensive models. Results of this study can help resource managers target representative sites downstream of potential invasion sites, thereby maximizing resource use.

Stream Monitoring and Preliminary Co-Treatment of Acid Mine Drainage and Municipal Wastewater along Dunkard Creek Area

This study investigated coal-mine drainage (AMD) and municipal wastewater (MWW) contaminant concentrations and conducted the combined treatment in phases I and II: phase I, evaluating effects of mixing the two based on extent of acid neutralization and metals removal; phase II: conducting anaerobic batch reactor treatment of AMD and MWW under varying COD/sulfate ratios (0.04-5.0). In phase I, acid mine drainage water quality conditions are as follows: pH 4.5, acidity 467.5 mg/L as CaCO3, alkalinity 96.0 mg/L as CaCO3, Cl- 11.8 mg/L, SO42- 1722 mg/L, TDS 2757.5 mg/L, TSS 9.8 mg/L, BOD 14.7 mg/L, Fe 138.1 mg/L, Mg 110.8 mg/L. Mn 7.5 mg/L, Al 8.1 mg/L, Na 114.2 mg/L, and Ca 233.5 mg/L. Results of the mixing experiments indicated significant removal of selected metals (Fe 85~98%, Mg 0~65%, Mn 63~89%, Al 98~99%, Na 0~30%), acidity (77~95%) from the mine water and pH was raised to above 6.3. The Phase II results suggested under the wide range of COD/sulfate ratios, COD and sulfate removal varied from 37.4%-100% and 0%-93.5% respectively. During biological treatment, alkalinity was generated which leads to pH increase to around 7.6-8.5. The results suggested feasibility of the proposed technology for co-treatment of AMD and MWW. A conceptual design of co-treatment system which is expected to remove a matrix of pollutants has been provided to utilize all the locally available water resources to achieve the optimum treatment efficiency. The technology also offers an opportunity to significantly reduce capital and operating costs compared to the existing treatment methodologies used.