Simulated interior floods and the flood experience in urban communities

The Hydrologic Engineering Center (HEC-1) model was used to construct synthetic hydrographs for isolated interior urban floods. Flood peak and lag time were very well preserved in simulated flows. Total volume was not adequately expressed. Lag time varied inversely with both urban development and storm intensity. Peak discharge varied with storm intensity, but this variability was well defined only at very high urbanization levels. An 175% increase in storm intensity produced a change of about 15% in peak discharge. Claims for flood damage correlated well with estimates of peak flow and lag time combined. Other measures of flood experience also correlated with the two features. Within the range of storms utilized, urban development factors consistently outranked storm intensity as a determining factor in flood damage.     

Can developing countries benefit from innovative pricing in the power sector?

This study explores electricity pricing as a demand-side management (DSM) strategy, looking to the developed country experience for insights into the types of approaches currently used, their effects, and the direction in which electricity pricing is headed. The discussion should be especially useful for electric utilities in developing countries that are exploring alternatives to capacity expansion to meet current and future electric power demand. For these electric utilities, demand-side options are especially important under today's conditions in which the capital cost of new generating capacity is increasing rapidly, international funds for expanding power sectors are not expected to be sufficient for meeting projected capacity needs and environmental concerns over fossil fuel emissions have raised new questions about constructing thermal power plants.     

POTENTIAL,ACTUAL, AND EQUILIBRIUM EVAPOTRANSPIRATION IN A WHEAT FIELD 1

ABSTRACT: This paper examines the relationship between both potential (E*) and nonpotential evapotranspiration and equilibrium evapotranspiration (EQ) in an irrigated wheat field in southcentral Alberta, Canada. The control exercised by surface wetness and root reservoir moisture content in determining the value of the Priestley-Taylor constant a is explored. Also investigated is the relationship between a and the vapor flux fraction ET/(R-G) where ET is the actual evapotranspiration, R the net radiation, and G the soil heat flux. It is shown that evapotranspiration occurred at the potential rate (E*) when the available soil moisture (ASM) within the root zone was ≥3 percent. a varied from 0.84 for a dry soil to 1.49 for a saturated soil. The mean a for E* was 1.24. Surface wetness sustained evapotranspiration at the potential rate when such wetting exceeded 2mm d^?1 following a period of prolonged drawdown of soil moisture, α and ET/(R-G) were positively correlated and this correlation strengthened with increasing soil moisture for constant values of the energy partitioning factor s+γ/s where s is the slope of the saturation humidity-temperature curve and γ is the psychrometric constant. ET=EQ when ETI(R-G) lay within the range of 0.59 to 0.82 corresponding to Bowen ratio (β) values of 0.22 and 0.69, respectively.     

PHOSPHATE IN WATERS: II. PLANT AVAILABILITY OF LIGNITE FLY ASH EXTRACTED FORMS IN GREENHOUSE TRIALS1

ABSTRACT: Orthophosphate P was removed from municipal waste water, lake waters, and P-spiked solutions by contact with fly ash from lignite burning electric power generating plants. The recovered ash was increased in total P content 3-fold, and Bray No. 1 soluble P, 9-fold. Phosphorus enriched ash so prepared was used in greenhouse trials with sand or soil as the major substrate material. Recovery of added P by barley plants ranged from 3 to 26 percent in the sand cultures and from 2 to 17 percent for soil cultures. Phosphorus contained in normal ash was partially available to barley under the conditions of these experiments. High B and the pozzolanic effect induced by ash reduced plant growth significantly.     

DISINFECTION WITH QUATERNARY AMMONIUM COMPOUNDS1

ABSTRACT: The most common disinfection method is chlorination, however, it has been known that the practice of chlorination for water treatment in the Mississippi River area has caused a significant increase in mortality. The objective of this research was to search for effective disinfectants to replace chlorine. Three cationic surfactants have been tested for their bactericidal properties under various conditions. It has been found that 1 mg of cetyldimethyl-benzylammonium chloride can destroy about 4500 coliforms in one liter water within 10 minutes, under neutral pH conditions and room temperature. Cationic quaternary ammonium compound, therefore, can be a potential candidate disinfectant for replacing chlorine when necessary.     

Quantifying natural resource injuries and ecological service reductions: challenges and opportunities

The natural resource damage assessment (NRDA) provisions of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the Oil Pollution Act (OPA) are complex and have been difficult to implement. The complexity and difficulty in implementation arise both from the assessment procedures specified in agency NRDA guidance and from the limited ability of ecologists to quantify impacts of hazardous substances on natural resources. This paper explores the scientific aspects of NRDA implementation, and discusses conceptual and methodological relationships between NRDA and the much broader field of ecological risk assessment (ERA). We discuss three critical components of the NRDA assessment approach: measuring natural resource injuries and reductions in resource services; evaluating causality; and establishing baseline conditions. We identify (1) specific approaches drawn from ERA practice that could improve each of these components, and (2) research needs and institutional changes that may improve the ability of the NRDA process to achieve its stated objectives. We recommend the acceleration of the ongoing dialogue among NRDA practitioners from the Trustee and PRP communities as a first step toward resolving the procedural and technical deficiencies of the NRDA process.     

Virgil, Vigilance, and Voice: Agrifood Ethics in an Age of Globalization

Some 2000 years ago, Virgil wroteThe Georgics, a political tract on Romanagriculture in the form of a poem. Today, as aresult of rising global trade in food andagricultural products, growing economicconcentration, the merging of food andpharmacy, chronic obesity in the midst ofhunger, and new disease and pest vectors, weare in need of a new Georgics that addressesthe two key issues of our time: vigilance andvoice. On the one hand, vigilance must becentral to a new Georgics. Enforceablestandards for food safety, food quality,environmental protection, worker health andsafety, sanitary and phytosanitaryrequirements, animal welfare, and appellationsmust be addressed. On the other hand, a newGeorgics must increase the range of persons whohave voice in the democratic governance of anew global agrifood system. New organizationsand institutions will be needed to accomplishthis task.     

BIOLOGICAL AND ECONOMIC IMPLICATIONS OF SACRAMENTO WATERSHED MANAGEMENT OPTIONS1

ABSTRACT: This paper brings together spatially and temporally explicit mechanistic models of hydrodynamic, water quality, and ecological processes with an economic model to examine water management alternatives for California's Sacramento River and Delta ecosystem, a large‐scale watershed. Overallocated water supplies in most years, combined with increasing demand for water for environmental purposes, have created a politically charged atmosphere and a need for quantitative assessment of the implications of policy alternatives. By developing and analyzing a common set of policy scenarios, this integrated framework allows us to consider tradeoffs between agricultural economic factors, water quality, and population dynamics for two at‐risk fish species. We analyze two rather extreme types of policy options; one involves structural modifications to change the flow of water within the watershed but no change in water diversions, while the other reallocates water from agricultural users to fish and wildlife. Results suggest that substantial environmental improvements could be made at a relatively modest cost to farmers (1 to 4 percent reductions in revenues) but that those costs could be significant locally. In addition to tradeoffs between farmers and environmental interests, results suggest that policy makers may need to balance competing environmental objectives.