Integrated water resources planning

A water resources plan should consider the missions of various governmental units and the interests of those affected beneficially or adversely by the plan. Its development should involve many professional disciplines and should take account of institutional, economic, environmental, social and other effects. For developing countries, water resources development and management should contribute as much as possible to the amelioration of the basic problems of the human condition, while avoiding serious damage to ecological populations and environmental quality. This paper outlines what has and has not worked in the planning of water resources, based on published literature and the unpublished views of United Nations and World Bank staff, and discusses the characteristics of effective integrated water resources planning.     

North East Scotland River Catchment Nitrate Loading in Relation to Agricultural Intensity

Modern agricultural practices have been strongly linked with increased NO₃-N loadings in surface waters. Nitrate leaching increases as land use progresses from forest and moorland through grassland, to arable agriculture. There are, within the UK, few studies on a regional scale capable of displaying a relationship between land cover (agricultural intensity) and water quality. This relationship can be investigated using computer manipulation of spatial geographic information together with conventional river and agricultural census data.

Simple regression analysis against primary land cover suggests that agriculture is reponsible for annual losses of nitrate in North East Scotland river catchments. Further multi-linear regression analysis, using the GIS data and agricultural census returns indicate that most of the outstanding variation can be accounted for if the agricultural variable is related to agricultural practice, such as spring, winter and grass cropping.     

Magnetic and other field effects on prochiral chemical reactions

Experiments are reported in which three prochiral organic reactions were conducted in the presence of a ca. 1T magnetic field which was oriented with reference to the earth's geometric axes. The sign and magnitude of the rotation varied with the macroscopic orientation of the magnetic field and the time that the reaction was performed. Control measurements were in accord with expectations. The fact that the sign of the observed optical rotation of the product was reversed for all three reported reactions when the magnetic field was reversed for reactions conducted on the same day suggests that either the observed asymmetric synthesis was due to the reactions being conducted in a chiral physical field or extremely unusual stochastic processes were involved.     

Nitrate Status of Two Major Rivers in N. E. Scotland with Respect to Land Use and Fertiliser Additions

Land Use and the influence it has upon river water nitrate levels is discussed, for two large relatively unpopulated river systems in the N.E. of Scotland. the catchment areas for the rivers Dee and Don have been further subdivided into a number of sub catchments. Substantial differences in land use and agricultural potential exist both within and between the two areas. Greater agricultural production down stream is associated with increased river nitrate concentrations.     

Dietary selectivity in the field and food preferences in the laboratory for two herbivorous fishes (Cebidichthys violaceus and Xiphister mucosus) from a temperate intertidal zone

Diets and food selectivity of two stichaeid fishes (Cebidichthys violaceus and Xiphister mucosus) from the rocky intertidal zone of the central California coast (USA) were studied at each season of the year by gut content analysis and abundance measurements of potential macrophyte food items. Both fishes, after reaching a standard length of about 44 mm, were almost exclusively herbivorous. The bulk of the diet consisted of 8 to 10 species of chlorophytes and rhodophytes. These main dietary components were chiefly annual seaweeds with high surfaceto-weight ratios (sheetlike forms or small, highly branched forms). Perennial seaweeds were eaten in relatively large amounts only during the winter. Macrophytes eaten in only trace amounts included about 20 species of chlorophytes, chrysophytes, phaeophytes, rhodophytes and a spermatophyte. The small amount of animal material in the diet (never more than 2% by weight) could well have been ingested incidentally while the fishes were feeding on seaweeds. Food preference tests with up to 19 macrophyte species in the laboratory revealed that both fishes chose to eat three annual rhodophytes (Smithora naiadum, Porphyra perforata and Microcladia coulteri) in preference to Ulva lobata, an annual chlorophyte that was more abundant in the diets of field-caught specimens.     

Effect of mixing soil aggregates on the phosphorus concentration in surface waters

At any time, the phosphorus (P) concentration in surface waters is determined by a complex interaction of inputs of soluble P and sorption-desorption reactions of P with sediments. This study investigated what factors control P in solution when various soil aggregates were mixed, seen as being analogous to selective soil erosion events, transport, and mixing within river systems. Fifteen soils with widely differing properties were each separated into three aggregate size fractions (2-52 microm, 53-150 microm, and 151-2,000 microm). Resin P, water-soluble phosphorus (WSP), and the phosphorus buffer capacity (PBC = resin P/WSP) were measured for each aggregate size fraction and WSP was also measured for 11 mixes of the aggregate fractions. The smallest aggregates tended to be enriched with resin P relative to the larger aggregates and the whole soils, while the opposite was true for WSP. As the PBC was a function of resin P and WSP, the PBC was greatest in the 2- to 52-microm aggregate size fraction in most cases. When two aggregate size fractions were mixed, the measured WSP was always lower than the predicted WSP (i.e., the average of the WSP in the two individual aggregates), indicating that WSP released by one aggregate fraction could be resorbed by another aggregate fraction. This resorption of P may result in lower than expected solution P concentration in some surface waters. The strength with which an eroded aggregate can release or resorb P to or from solution is in part determined by that aggregate's PBC.     

Evidence of differences in the biotransformation of organic contaminants in three species of freshwater invertebrates

Acute static bioassays were performed using three freshwater invertebrate species (the oligochaete Lumbriculus variegatus, the fingernail clam Sphaerium corneum and the larvae Chironomus riparius) exposed separately to a variety of 14C radiolabelled contaminants. The aim of this work was to investigate if the chemicals remained as parent compounds after the treatments. Chemicals used were 2,4-dichlorophenol; 2,4,5-trichlorophenol; pentachlorophenol; pyrene; Fenpropidin, and Trifluralin. Homogenates of the whole body tissue of each organism were prepared and total radioactivity was measured. Contaminants were then extracted into organic solvents and analysed by high-pressure liquid chromatography techniques. Chromatograms showed that most of the substances extracted were present as parent compounds in S. corneum and in L. variegatus. In contrast, for C. riparius a low proportion of the chemicals was recovered as parent compounds. These results suggest that different metabolic processes could take place in the different species.     

A micrometeorological technique to monitor total hydrocarbon emissions from landfarms to the atmosphere

Landfarming is used to treat petroleum hydrocarbon-contaminated soils and a variety of waste streams from industrial operations. Wastes are applied to a soil surface and indigenous soil microorganisms utilize the hydrocarbons in the applied waste as a carbon source for metabolism, thereby biodegrading the applied material. Concerns have been expressed that abiotic losses, such as volatilization, play a significant role in hydrocarbon reduction within the soil. To assist in better defining atmospheric releases of total hydrocarbons from landfarms treating petroleum hydrocarbons, a flux gradient micrometeorological approach was developed and integrated with a custom-built total hydrocarbon detector, and a novel air sampling system and averaging algorithm. The micrometeorological technique offers unobtrusive spatially averaged real-time continuous measurements, thereby providing a time history of emissions. This provides opportunities to investigate mechanisms controlling emissions and to evaluate landfarm management strategies. The versatility of the technique is illustrated through measurements performed at a remote landfarm used to treat diesel fuel-contaminated soil in northern Ontario and during routine operations at two active refinery landfarms in southwestern Ontario.     

Effects of water-soluble oil fractions on metabolism,growth and carbon budget of the shrimp Crangon crangon

Juvenile shrimp, Crangon crangon L., were maintained in water-soluble crude oil fractions at 10°, 15° and 20°C. During chronic exposure to oil fractions, a reduction in respiration and growth rate occurred which was related to strength of the extract. Mortality increased with strength of oil fraction and was highest at 20°C. Calculation of carbon budgets indicated that the extract reduced net carbon turnover at each temperature. Physiological consequences resulting from exposure to the oil fractions are discussed.