From Upstream to Downstream: Ecological Zonation of Water Courses

2019 ◽  
pp. 117-138
Author(s):  
Eugene Angelier ◽  
James Munnick
Keyword(s):  
Water Courses ◽  
Ecological Zonation

Challenges of Aircraft and Drone Spray Applications

2020 ◽  
Vol 31 (2) ◽  
pp. 83-88 ◽  
Author(s):  
Fernando K. Carvalho ◽  
Rodolfo G. Chechetto ◽  
Alisson A. B. Mota ◽  
Ulisses R. Antuniassi
Keyword(s):  
Smallholder Farmers ◽  
Crop Protection ◽  
Crop Canopy ◽  
Target Species ◽  
Buffer Zones ◽  
Correct Dose ◽  
Knapsack Sprayer ◽  
Water Courses ◽  
Low Toxicity ◽  
Heavy Loads

Crop protection on major crops is now required to follow the principles of integrated pest management so the timing and accuracy of any application of a pesticide or biopesticide has to be more precise to minimize adverse effects on non-target species. The development of UAVs (unmanned aerial vehicles) provides a means of providing a more targeted application of the correct dose, especially by using formulations that are more persistent, thus minimizing loss of spray in areas subject to rain. Avoiding use of too high a dosage allows greater survival of natural enemies and reduces the selection pressure for pests becoming resistant to specific modes of action. The downward flow of air from a UAV should also provide better distribution and impaction of droplets within a crop canopy, reduce soil impaction caused by taking heavy loads of spray applied with 200 l ha–1 of water, and allow treatments when fields are too wet to access with ground equipment. In Asia, many smallholder farmers are using a drone in preference to using a knapsack sprayer. According to Matthews, it has been shown that ULV spraying can be effective, but it needs a narrow droplet spectrum with the droplets remaining stable and not shrinking to become too small. Formulation research can reduce the volatility of the spray, hence the success of oil-based sprays. However, instead of petroleum-based oils, there is a chance to develop vegetable oil carriers with micro-sized particle suspensions to deliver low toxicity pesticides in droplets that can be deposited within the crop and not drift beyond the crop boundary. Oil deposits will be less prone to loss after rain so less should be lost in neighbouring ditches and water courses, especially as rainfall patterns are forecast to change. More studies are needed to evaluate the swath for deposition, buffer zones, formulation, nozzle selection, to guide future specific legislation for UAV applications.

scholarly journals Adsorption, desorption and fractionation of As(V) on untreated and mussel shell-treated granitic material

Solid Earth ◽  
2015 ◽  
Vol 6 (1) ◽  
pp. 337-346 ◽  
Author(s):  
N. Seco-Reigosa ◽  
L. Cutillas-Barreiro ◽  
J. C. Nóvoa-Muñoz ◽  
M. Arias-Estévez ◽  
E. Álvarez-Rodríguez ◽  
...  
Keyword(s):  
Food Chain ◽  
Soluble Fraction ◽  
Mussel Shell ◽  
Weakly Bound ◽  
Retention Capacity ◽  
Adsorption Data ◽  
Water Courses ◽  
Ph Range ◽  
Adsorption Desorption ◽  
Langmuir And Freundlich Models

Abstract. As(V) adsorption and desorption were studied on granitic material, coarse and fine mussel shell and granitic material amended with 12 and 24 t ha−1 fine shell, investigating the effect of different As(V) concentrations and different pH as well as the fractions where the adsorbed As(V) was retained. As(V) adsorption was higher on fine than on coarse shell. Mussel shell amendment increased As(V) adsorption on granitic material. Adsorption data corresponding to the unamended and shell-amended granitic material were satisfactory fitted to the Langmuir and Freundlich models. Desorption was always <19% when the highest As(V) concentration (100 mg L−1) was added. Regarding the effect of pH, the granitic material showed its highest adsorption (66%) at pH <6, and it was lower as pH increased. Fine shell presented notable adsorption in the whole pH range between 6 and 12, with a maximum of 83%. The shell-amended granitic material showed high As(V) adsorption, with a maximum (99%) at pH near 8, but decreased as pH increased. Desorption varying pH was always <26%. In the granitic material, desorption increased progressively when pH increased from 4 to 6, contrary to what happened to mussel shell. Regarding the fractionation of the adsorbed As(V), most of it was in the soluble fraction (weakly bound). The granitic material did not show high As(V) retention capacity, which could facilitate As(V) transfer to water courses and to the food chain in case of As(V) compounds being applied on this material; however, the mussel shell amendment increased As(V) retention, making this practice recommendable.

Biomass, nutrients and nutritive value of Persicaria salicifolia Willd. in the water courses of Nile Delta, Egypt

2013 ◽  
Vol 25 (2) ◽  
pp. 167-179 ◽  
Author(s):  
Kamal H. Shaltout ◽  
Tarek M. Galal ◽  
Thanaa M. El-Komi
Keyword(s):  
Nutritive Value ◽  
Nile Delta ◽  
Water Courses

scholarly journals Stratigraphy, mammalian paleontology, paleoecology, and age correlation of the Wasatch Formation, Fossil Butte National Monument, Wyoming

2016 ◽  
Vol 90 (5) ◽  
pp. 981-1011 ◽  
Author(s):  
Gregg F. Gunnell ◽  
John-Paul Zonneveld ◽  
William S. Bartels
Keyword(s):  
New Species ◽  
New Genus ◽  
Green River Formation ◽  
Main Body ◽  
Green River ◽  
National Monument ◽  
Forested Areas ◽  
Water Courses ◽  
Three New Species ◽  
Abundance And Diversity

AbstractFieldwork conducted in the Wasatch Formation in and around Fossil Butte has yielded a diverse assemblage of early Eocene vertebrates. Fossil vertebrates are distributed through three discrete stratigraphic intervals within the uppermost 180 m of the main body of the Wasatch Formation underlying the Green River Formation. These assemblages were derived primarily from fluvial overbank mudstone units overprinted with variably well-developed paleosols. The lowest (20 m) and highest (60 m) sections are characterized by less mature and more hydromorphic paleosols, whereas the middle section (100 m) is typified by more mature paleosols and more abundant channel sandstones.The combined assemblages contain at least 46 species of mammals. Faunal characteristics include high abundances of equid perissodactyls and a relatively high abundance and diversity of notharctines primates, an apparent absence of omomyid primates, relatively high rodent diversity, and relatively diverse and abundant artiodactyls. One new genus (Eoictopsnew genus) and three new species (Eoictops novacekinew species,Palaeosinopa lacusnew species, and ?Notoparamys blochinew species) are included in the Fossil Butte assemblage. Also recorded are late occurrences of two hyopsodontid condylarths and an early occurrence of a rare phenacodontid condylarth. The relatively high abundances of equids and notharctines suggest that vertebrate samples were derived from relatively open paleohabitats that included forested areas along water courses.All three assemblages contain characteristic Lysitean (Wasatchian biochron Wa-6) elements, but the occurrence of the palaeotheriid perissodactylLambdotheriumin the uppermost horizon indicates a Lostcabinian (Wa-7) age for at least the top of the Wasatch Formation. The overlying predominantly fish-bearing Fossil Butte Member of the Green River Formation also containsLambdotheriumand is therefore Wa-7 in age as well.

scholarly journals Impacts of Industrial Effluent on River Kabul

2012 ◽  
Vol 8 ◽  
pp. 44-47
Author(s):  
Ghazal Nosheen ◽  
Muhammad Ullah ◽  
Kashif Ahmad Khan ◽  
Attiq Ur Rehman
Keyword(s):  
Industrial Effluent ◽  
Oxygen Demand ◽  
High Strength ◽  
Textile Mills ◽  
Energy And Environment ◽  
The North ◽  
Water Courses ◽  
Receiving Stream ◽  
River Kabul ◽  
Industrial Units

The disposal of untreated industrial effluent into receiving water courses has become a major environmental challenge being faced by most of the developing countries. The high-strength and toxic wastes are responsible for a variety of water-borne diseases. In Pakistan numerous industrial units that dispose their effluent directly into receiving stream without any treatment. This study was, therefor designed to assess the wastewater characteristics of some major industrial units in the surrounding area of River Kabul, which is one of the most signifi cant resources of water in the north region of the country.The main objectives of this study were to evaluate the wastewater characteristics of some major industrial units in terms of BOD (Biochemical Oxygen Demand), COD (Chemical Oxygen Demand), and TSS (Total Suspended Solids) etc. For this purpose, various representative samples were collected from the major industrial units like sugar, paper, ghee (Butter) and textile mills, and were analyzed using standard laboratory techniques. The results indicates that the BOD of sugar, paper, ghee (butter) and textile mills is in the range of 2235mg/L, 1150mg/L, 844mg/L and 745mg/L, respectively. Whereas, the COD of sugar, paper, ghee and textile mills was noticed to be 3945mg/L 2045mg/L, 2240mg/L and 1244mg/L respectively. Owing to the disposal of such highstrength wastes water without treatment, a remarkable increase in the TSS from 96 to 382mg/L, and decrease in DO (Dissolved Oxygen) concentration from 8.8 to 6.7mg/L of River Kabul was observed. The results of this study suggest that all the wastewater coming from the industrial sources should be properly treated as an integral part of their production before their fi nal disposal into River Kabul to secure its natural water quality.DOI: http://dx.doi.org/10.3126/hn.v8i0.4924Hydro Nepal: Journal of Water, Energy and Environment Issue No. 8, 2011 JanuaryPage: 44-47Uploaded date: 23 June, 2011

scholarly journals Performance Advantages of Labyrinth Weir

2019 ◽  
Vol 9 (2S2) ◽  
pp. 26-29
Keyword(s):  
Control Flow ◽  
Water Bodies ◽  
Labyrinth Weir ◽  
Common Structure ◽  
Water Courses ◽  
Coefficient Of Discharge ◽  
Labyrinth Weirs

Weir is a very common structure across water courses to control flow and to release surplus water from water bodies. Simple straight weirs are less efficient compared to labyrinth weir where the weir length is increased by folds. In this research, experiments were conducted in the laboratory to find the increase in discharge due to labyrinth or decrease in coefficient of discharge due to labyrinth. Further two labyrinth weirs were analyzed to understand the efficiency with respect to the shape of the labyrinth weir. Compared to the ogee weir, the labyrinth weir discharges more water (more than 60%) for the same head of flow.

scholarly journals About Liquid Filtration Under a Point Dam with a Vertical Weakly Permeable Film

2021 ◽  
Vol 16 (3) ◽  
pp. 69-74
Author(s):  
Efimova Irina A. ◽  
Keyword(s):  
Porous Medium ◽  
Half Plane ◽  
Horizontal Line ◽  
Filtration Process ◽  
Liquid Filtration ◽  
Fourier Expansions ◽  
Water Courses ◽  
Filtration Area ◽  
Homogeneous Porous Medium ◽  
Convolution Method

The problem of groundwater filtration under a point dam in a piecewise homogeneous porous medium in the presence of a weakly permeable film under the dam is considered. The filtration area is considered in the form of a vertical half-plane with a horizontal line of water courses. A weakly permeable film divides the filtration area into two quadrants with different constant permeability. By the convolution method of Fourier expansions, the solution of the problem is obtained explicitly. The influence of a weakly permeable film on the filtration process is investigated. It is shown that the presence of a weakly permeable film reduces the filtration rates in the downstream.

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