Ground-water resources of the lower Hillsboro Canal area, Southeastern Florida

This study was done to determine the amount and kinds of water being produced from the lower Hillsboro Canal Area in Palm Beach and Broward counties. All of the potable ground water being produced from the Biscayne aquifer is developed from the canal through infiltration. Rainfall in the area is the ultimate source for all of the water. Careful control and management will allow the development of large quantities of water from the canal toward Lake Okeechobee, but a fresh water head must be maintained along the contact of fresh water with sea water to prevent salt water intrusion. (PDF contains 51 pages.)

Springs and swallets of the lower Santa Fe River

Many of our surface waters go underground to the aquifer via sinkholes (or swallets) and the water is then called groundwater. Most of us rely on groundwater for our drinking water. Springs are where the groundwater comes to the surface to once again become surface waters. Below is a map of the springs and swallets of the Lower Santa Fe River.

Studies of the effects of industrial pollution in the lower Patapsco river area: 1. Curtis Bay Region 1941

Industrial effluents in the lower Patapsco area, which constitutes the navigable portion of the river and includes Baltimore Harbor, are many and include waste acid, distillery waters, tannery wastes and copper as (ferrous sulphate) from pigment and steel industries. (PDF contains 22 pages (2 on 1)

Coastal management measures for the lower Maumee Watershed, Lake Erie

In January 2006 the Maumee Remedial Action Plan (RAP) Committee submitted a State II Watershed Restoration Plan for the Maumee River Great Lakes Area of Concern (AOC) area located in NW Ohio to the State of Ohio for review and endorsement (MRAC, 2006). The plan was created in order to fulfill the requirements, needs and/or use of five water quality programs including: Ohio Department of Natural Resources (DNR) Watershed Coordinator Program; Ohio EPA Great Lakes RAP Program; Ohio DNR Coastal Non-point Source Pollution Control Program; Ohio EPA Total Maximum Daily Load Program; and US Fish & Wildlife Service Natural Resources Damage Program. The plan is intended to serve as a comprehensive regional management approach for all jurisdictions, agencies, organizations, and individuals who are working to restore the watershed, waterways and associated coastal zone. The plan includes: background information and mapping regarding hydrology, geology, ecoregions, and land use, and identifies key causes and sources for water quality concerns within the six 11-digit hydrological units (HUCs), and one large river unit that comprise the Maumee AOC. Tables were also prepared that contains detailed project lists for each major watershed and was organized to facilitate the prioritization of research and planning efforts. Also key to the plan and project tables is a reference to the Ohio DNR Coastal Management Measures that may benefit from the implementation of an identified project. This paper will examine the development of the measures and their importance for coastal management and watershed planning in the Maumee AOC. (PDF contains 4 pages)

The role of women in artisanal fisheries along the Lower Benue River

A questionnaire survey was carried out to assess the role of women in the artisanal fisheries of fish markets sector along the Lower Benue River. Four (4) fishing settlement communities of fish markets along the Lower Benue were selected. They are namely North Bank, Wadata, Abinse and Gbajimba . Structure and unstructured questionnaire were administered to cover areas of personal data, fish production activities, processing and marketing among others. The study revealed that women along the Lower Benue River participate activity in the artisanal fisheries sub-sector. However, the major role played by the women was in the area of processing and preservation, marketing and distribution. These accounted 52 and 42% respectively. The distribution of the women was not tribally based however, Jukun women accounted for 66.20% followed by Agatu women 13.00%. The age bracket of the women mostly involved in fisheries activities was between 31-40 years. About 86% of them was married. The initial capital base was low and mostly by personal saving accounting for 52%. Need for government assistance was the highlight in this study. About 86% sought for Federal Government intervention from the National Poverty Eradication Programme. This they felt will be a welcome development to boost women participation in the Artisanal fisheries sub-sector along the Lower Benue River

2D modeling of lower mantle structure with WKM synthetics

The Earth is very heterogeneous, especially in the region close to the surface of the Earth, and in regions close to the core-mantle boundary (CMB). The lowermost mantle (bottom 300km of the mantle) is the place for fast anomaly (3% faster S velocity than PREM, modeled from Scd), for slow anomaly (-3% slower S velocity than PREM, modeled from S,ScS), for extreme anomalous structure (ultra-low velocity zone, 30% lower inS velocity, 10% lower in P velocity). Strong anomaly with larger dimension is also observed beneath Africa and Pacific, originally modeled from travel time of S, SKS and ScS. Given the heterogeneous nature of the earth, more accurate approach (than travel time) has to be applied to study the details of various anomalous structures, and matching waveform with synthetic seismograms has proven effective in constraining the velocity structures. However, it is difficult to make synthetic seismograms in more than 1D cases where no exact analytical solution is possible. Numerical methods like finite difference or finite elements are too time consuming in modeling body waveforms. We developed a 2D synthetic algorithm, which is extended from 1D generalized ray theory (GRT), to make synthetic seismograms efficiently (each seismogram per minutes). This 2D algorithm is related to WKB approximation, but is based on different principles, it is thus named to be WKM, i.e., WKB modified. WKM has been applied to study the variation of fast D" structure beneath the Caribbean sea, to study the plume beneath Africa. WKM is also applied to study PKP precursors which is a very important seismic phase in modeling lower mantle heterogeneity. By matching WKM synthetic seismograms with various data, we discovered and confirmed that (a) The D" beneath Caribbean varies laterally, and the variation is best revealed with Scd+Sab beyond 88 degree where Sed overruns Sab. (b) The low velocity structure beneath Africa is about 1500 km in height, at least 1000km in width, and features 3% reduced S velocity. The low velocity structure is a combination of a relatively thin, low velocity layer (200 km thick or less) beneath the Atlantic, then rising very sharply into mid mantle towards Africa. (c) At the edges of this huge Africa low velocity structures, ULVZs are found by modeling the large separation between S and ScS beyond 100 degree. The ULVZ to the eastern boundary was discovered with SKPdS data, and later is confirmed by PKP precursor data. This is the first time that ULVZ is verified with distinct seismic phase.

Monitoring fish populations in Lower Lough Erne, Northern Ireland: applicability of current methods and implications for future monitoring under the EC Water Framework Directive

The proposed EC Water Framework Directive (WFD) will require member states to monitor both biotic and abiotic components of lake environments. With adoption of the WFD some measurement of fish populations will also be required. This paper describes work carried out since 1971, and particularly since 1991, on the status of fish populations in Lower Lough Erne, Northern Ireland, with an emphasis on defining change over time due to human impacts on the lake. This offers a reasonable starting point from which to develop a monitoring programme suitable for the needs of the WFD in this lake. The implications for as yet unmonitored fish populations in lakes are also determined.

Comparative drift studies on streams in lower Austria (Flysch, gneiss and chalk formations) [Translation from: Schweizerische Zeitschrift fur Hydrobiologie 30 138-185, 1968.]

Seasonal changes and flooding have an extraordinarily great influence on the drift of organisms. The free water space plays the main part in the provision of food for some fish (Salmo trutta - trout): drift and content of the stomach are balanced here (Simuliidae): whereas others (Thymallus vulgaris) only selectively chose certain animals living at the bottom (molluscs). The total drift, drift of organisms and drift of organic material and minerals, plays a main role in the rate of production in streams. Besides the biology of the organisms living on the river bed, also the geological and hydrographical situation of the area plays a very important role for the composition of the drift. During the years 1964-1966 three streams in the characteristical geological formations flysch, gneiss and chalk of lower Austria were studied in regard to their drift. The Tulln (above St. Christopen), the Krems (above Senftenberg) and the Schwarza (above Hirschwang) seemed to be ideal for this comparative study because they are easy to reach. After summarising the hydrography and chemistry of examined rivers, the author examines the relationship between water level and total drift and the stratification of the total drift before analysing the drift of living organisms. Also considered are seasonal changes of drift of organisms and drift of exuviae.

Effects of process on microstructure and properties of translucent Dy-alpha-SiAlON sintered at lower temperatures

Hot pressing (HP) at higher sintering temperature has been a traditional and prevalent technique for the fabrication of alpha-SiAlON. In order to prepare translucent SiAlON more easily, LiF was used as a non-oxide sintering additive to lower the sintering temperature to <= 1650 degrees C. As a result, all of the samples possessed a good hardness and fracture toughness. At the same time, the lower temperature sintered samples showed a higher optical transmittance in the range of 2.5-5.5 mu m wavelength (0.5 mm in thickness). The maximum infrared transmission reached 68% at a wavelength of 3.3 mu m. The present work shows that the sintering process has a strong effect on microstructure and property of alpha-SiAlON. To be exact, a lower sintering temperature and longer holding time can produce some fully-developed microstrcture, which is beneficial for the optical transmittance. (C) 2008 The Ceramic Society of Japan. All rights reserved.