Transition Pathways to Sustainable Agricultural Water Management: A Review of Integrated Modeling Approaches

Agricultural water management (AWM) is an interdisciplinary concern, cutting across traditional domains such as agronomy, climatology, geology, economics, and sociology. Each of these disciplines has developed numerous process‐based and empirical models for AWM. However, models that simulate all major hydrologic, water quality, and crop growth processes in agricultural systems are still lacking. As computers become more powerful, more researchers are choosing to integrate existing models to account for these major processes rather than building new cross‐disciplinary models. Model integration carries the hope that, as in a real system, the sum of the model will be greater than the parts. However, models based upon simplified and unrealistic assumptions of physical or empirical processes can generate misleading results which are not useful for informing policy. In this article, we use literature and case studies from the High Plains Aquifer and Southeastern United States regions to elucidate the challenges and opportunities associated with integrated modeling for AWM and recommend conditions in which to use integrated models. Additionally, we examine the potential contributions of integrated modeling to AWM — the actual practice of conserving water while maximizing productivity. Editor's note : This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series.     

A framework for assessing vulnerability of inland fisheries to impacts of climate variability in India

In recent years climate variability has threatened the sustainability of inland fisheries and dependent fishers in India. Systematic methodology to assess the vulnerability of the fisheries sector to climate variability is currently not available. Towards this end, the present work deals with the assessment of inland fisheries vulnerability to climate variations in 13 districts of West Bengal state in India. For this purpose, a composite vulnerability index (0.0–1.0) has been developed on the basis of functional relationships amongst sensitivity, exposure and adaptive capacity using 19 indicators related to inland fisheries. The data obtained reflected different spatial combinations of climate exposure, sensitivity and adaptive capacity among the districts. Five districts were highly vulnerable which was attributable to low adaptive capacity of the fishers which played an important role in altering the spatial pattern of vulnerability among the districts. Thus our research will provided an important basis for policy makers to develop appropriate adaptation strategies to minimize the risk of fisheries sector to climate variability.     

Investigating mechanical properties and durability of concrete containing recycled rubber ash and fibers

This article investigates the suitability of utilizing end of life rubber tyre particles in concrete as fine aggregate. Rubber ash and rubber fibers were used to develop two series of rubber ash concrete (series I) and hybrid concrete (series II) mixes. The natural fine aggregate was replaced by rubber ash (by volume of 5%, 10%, 15% and 20%) in series I; whereas in series II, the amount of rubber ash was kept constant at 10% and rubber fiber was introduced as replacement of fine aggregate (by volume of 5%, 10%, 15%, 20% and 25%). The concrete mixes were evaluated for compressive strength, flexural strength, resistance to impact loading, fatigue loading, water penetration and shrinkage strain was evaluated. It was observed that inclusion of rubber ash resulted in the improvement of impact resistance of concrete. The results also show that up to 10% rubber ash and rubber fibers can be utilized as fine aggregate to develop feasible and durable rubberized concrete pavements, crash barriers and paver blocks.

     

The role of automated feedback in training and retaining biological recorders for citizen science

The rapid rise of citizen science, with lay people forming often extensive biodiversity sensor networks, is seen as a solution to the mismatch between data demand and supply while simultaneously engaging citizens with environmental topics. However, citizen science recording schemes require careful consideration of how to motivate, train, and retain volunteers. We evaluated a novel computing science framework that allowed for the automated generation of feedback to citizen scientists using natural language generation (NLG) technology. We worked with a photo‐based citizen science program in which users also volunteer species identification aided by an online key. Feedback is provided after photo (and identification) submission and is aimed to improve volunteer species identification skills and to enhance volunteer experience and retention. To assess the utility of NLG feedback, we conducted two experiments with novices to assess short‐term (single session) and longer‐term (5 sessions in 2 months) learning, respectively. Participants identified a specimen in a series of photos. One group received only the correct answer after each identification, and the other group received the correct answer and NLG feedback explaining reasons for misidentification and highlighting key features that facilitate correct identification. We then developed an identification training tool with NLG feedback as part of the citizen science program BeeWatch and analyzed learning by users. Finally, we implemented NLG feedback in the live program and evaluated this by randomly allocating all BeeWatch users to treatment groups that received different types of feedback upon identification submission. After 6 months separate surveys were sent out to assess whether views on the citizen science program and its feedback differed among the groups. Identification accuracy and retention of novices were higher for those who received automated feedback than for those who received only confirmation of the correct identification without explanation. The value of NLG feedback in the live program, captured through questionnaires and evaluation of the online photo‐based training tool, likewise showed that the automated generation of informative feedback fostered learning and volunteer engagement and thus paves the way for productive and long‐lived citizen science projects.     

Removal of chromium(VI) from electroplating industry wastewater using bagasse fly ash—a sugar industry waste material

A waste product generated in the sugar industry in India has been converted into a cheap potential adsorbent. This has been characterised and utilized for the removal of chromium (VI) from synthetic and actual wastewater. The sorption efficiency decreases with increase in pH. Adsorption of Cr (VI) on bagasse fly ash follows the Freundlich and Langmuir isotherms and these have been used to obtain the thermodynamic parameters of the process. The sorption capacity of this adsorbent for chromium removal is found to be comparable to other low cost adsorbents.     

Characterization of Biodegradable Packaging Films Derived from Potato Starch and LDPE Grafted with Maleic Anhydride–LDPE Composition. Part-II

LDPE has been mixed with LDPE-g-mA (LDPE grafted with (0.5%) maleic anhydride) in 1:1 ratio containing a polar group in the LDPE backbone. Blown film samples containing various percentages of Potato Starch 0, 2.5, 5.0, 7.5, 10.0, 12.5 and 15% and LDPE grafted with maleic anhydride/LDPE (1:1), have been prepared using extrusion film blowing under temperature profile ranging from 120 to 160 °C. Characteristics of prepared packaging films up to 15% Potato Starch were analysed for their mechanical properties (Tensile strength, Elongation at break, Bursting strength and Tear strength), water absorption properties and morphology. The compatibility of the system with the introduction of 50% LDPE grafted with maleic anhydride with various ratios of starch, have been verified with the help of resulting datasets. The resulting datasets were placed in theoretical models of Willet modifies Kerner’s equation and Nicolais and Narkis models. Procedure adopted above could make thermally stable, highly flexible, crystalline resultant material, which can be adopted as an alternative of LDPE material especially for packaging applications.     

Water Aided Fabrication of Whey and Albumin Plastics

Development of polymeric materials that can reduce the reliance on petroleum derived synthetic polymers involves biopolymers such as proteins, starch, cellulose and lipids which can be obtained as agricultural co-products or by-products. Specifically, bioplastics from protein feedstock may have significant advantages over traditional plastics, especially in areas such as packaging, agriculture, horticulture and medical materials. This article focuses on fabricating plastics from whey and albumin proteins and describing properties of plastics made from them. These protein biomasses were plasticized using water and compression molded into plastic samples. Results indicated the importance of water on plasticization during fabrication and on mechanical performance later due to densification during drying.     

Overlooked involvement of phosphate radicals in the degradation of the atrazine herbicide by sulfate radical-based advanced oxidation

Environmental Chemistry Letters - The persistence of recalcitrant pollutants in water is a major health issue calling for advanced and green techniques to clean polluted waters. For instance,...     

Zooplankton community structure across an eddy-generated upwelling band close to a tropical bay-mangrove ecosystem

Mesoscale eddies in the world’s oceans are ubiquitous and bring about episodic pulses of nutrients into the photic zone. Transient in nature, the role of eddy pumping in coastal enrichment via plankton production, and subsequent organic flux is not yet fully realised. In the context of a cyclonic cold-core eddy that propagates annually under the influence of the East India Coastal Current and enriches coastal waters in the western Bay of Bengal north of 16°N, a detailed study on zooplankton community structure along with phytoplankton composition and associated water quality was undertaken during April–May 2002 coinciding with the spring intermonsoon. Zooplankton samples were collected at 32 hydrographically different (salinity 24.5–35.6 PSU) GPS fixed locations representing bay-mangrove areas and nearshore waters (30 m) close to the River Godavari, which is one of India’s largest estuarine systems. During the study, the bay-coastal waters were typified by elevated nutrient levels (nitrate 10.73–22.04 μM), high salinity (27.98–35.52 PSU), and relatively low temperatures (30.63–31.40°C). Altogether, 95 zooplankton taxa were encountered with copepods forming the predominant population. Agglomerative Hierarchical Cluster Analysis (AHCA) and Non-metric Multidimensional Scaling (NMDS) based on Bray–Curtis similarity (PRIMER) analysis revealed appreciable alterations in zooplankton structure across bay-mangrove locations and coastal waters (Stress 0.11; ANOSIM test Global R: 0.94, P = 0.1%). Similarity Percentage (SIMPER) analysis revealed zooplankton associations through “discriminating species” for each location (Kakinada Bay, Cluster I, 27.9 ± 3.0 PSU; upwelling band, cluster II, 35.5 ± 0.2 PSU; offshore waters, cluster III, 34.2 ± 0.4 PSU; mangrove outlets, cluster IV, 32.7 ± 1.3 PSU and mangrove creeks, cluster V, 33.5 ± 0.6 PSU). The index of multivariate dispersion (IMD) illustrated high variability in zooplankton standing stock for mangrove/sea locations relative to the bay. Concurrent observations on phytoplankton revealed the importance of diatoms (r: 0.640, P ≤ 0.05). Within the eddy-generated band of upwelled water, a significant top-down control of diatoms by herbivorous zooplankton resulted in a comparative increase in abundance of dinophyceans. Based on zooplankton abundance data and species association patterns, it was possible to distinguish different zooplankton/copepod communities in accordance with mesoscale variability in physical, chemical and biological processes under tropical conditions. This was confirmed through canonical correspondence analysis (CCA) that represented coastal-offshore waters and the Bay environment in this area.     

Recent trends of the emission characteristics from the road construction industry

Bitumen is a black, thermoplastic, hydrocarbon material derived from the processing of crude oil. At ambient temperature, bitumen is solid and does not present any health/environmental risks. This is one of the main reasons that bitumen is widely used for road construction all over the world. But during manufacturing/modification according to its application, storage, transportation, and use of bitumen is heated giving off various hydrocarbons emissions. In recent years, there has been increasing interest in investigating the potential of bitumen emissions to cause health effects. This is mainly because of the reason that bitumen has small amount of poly-aromatic hydrocarbons, along with some other volatiles like benzene, toluene, etc., which are known to be carcinogenic in nature. Thus, assessment of the emission characteristics and health hazards of bitumen fumes may have far reaching industrial economic and public health implications. In this review, we will discuss about the emission characteristics from bitumen, asphalts, or road construction, which is mainly contributed by bitumen fumes. Sampling strategies and analytical methods employed are also described briefly.