INTERFACING GIS WITH WATER RESOURCE MODELS: A STATE‐OF‐THE‐ART REVIEW1

Two distinctive, independently developed technologies, geographic information systems (GIS) and predictive water resource models, are being interfaced with varying degrees of sophistication in efforts to simultaneously examine spatial and temporal phenomena. Neither technology was initially developed to interact with the other, and as a result, multiple approaches to interface GIS with water resource models exist. Additionally, continued model enhancements and the development of graphical user interfaces (GUIs) have encouraged the development of application “suites” for evaluation and visualization of engineering problems. Currently, disparities in spatial scales, data accessibility, modeling software preferences, and computer resources availability prevent application of a universal interfacing approach. This paper provides a state‐of‐the‐art critical review of current trends in interfacing GIS with predictive water resource models. Emphasis is placed on discussing limitations to efficient interfacing and potential future directions, including recommendations for overcoming many current challenges.     

DISTRIBUTION OF SEDIMENT PHOSPHORUS POOLS AND FLUXES IN RELATION TO ALUM TREATMENT1

ABSTRACT: The distribution of sediment physical characteristics, sediment phosphorus (P) pools, and laboratory‐based rates of P release from the sediments were used to identify regions and dosage for alum treatment in Wind Lake, Wisconsin. Using variations in sediment moisture content, we identified an erosional zone at depths < 1.4 m and an accumulation zone at depths > 2.6 m. Mean concentrations of porewater P, loosely‐bound P, iron‐ and aluminum‐bound P, and mean rates of P release from sediments under anoxic conditions were high in the accumulation zone compared to sediment P characteristics in the erosional zone, indicating focusing of readily mobilized sediment P pools from shallow regions and accumulation to deep regions. We determined that a future alum treatment for control of internal P loading would be most effective at depths > 2.6 in the accumulation zone. The mean rate of anoxic P release from sediments encountered in the accumulation zone (8.3 mg m^‐2 d^‐1) was used in conjunction with a summer anoxic period of 122 d, and a treatment area of 1.6 km² to estimate an internal P load of 1,600 kg to be controlled. Our results suggest that an understanding of the distribution of sediment P pools and P fluxes in lakes provides a strategy for estimating alum dosage and application areas.     

The voluntary approach to externality problems: A survey of the critics

The literature critical of the Coase Theorem is synthesized. One conclusion is that bilateral bargaining in a voluntary, frictionless setting results in optimality only by accident, if at all. This is because of the problem of threats and the problem of small numbers bargaining behavior (it is not marginal). The second conclusion is that the placement of liability in general affects the allocation of resources. The exception is when there are no income effects, no transactions costs, and no nonseparabilities. But the existence of externalities implies transaction costs are high, which in turn implies that liability matters.     

Oviposition site guarding by male walnut flies and its possible consequences for mating success

Field studies showed that male Rhagoletis juglandis and R. boycei flies guard egg-laying punctures (and the eggs within) on host walnut (Juglans major) fruit and defend those sites from conspecific and heterospecific males. In field experiments with artificially punctured fruit,as well as field observations on unmanipulated fruit, males were consistently more likely to be sighted and stayed longer on damaged fruit than on undamaged fruit. On artificially punctured fruit, they consistently spent more time in the vicinity of a puncture than expected by chance alone. Males together on damaged fruit were more likely to engage in contests over those fruit than males together on undamaged fruit. Copulations were consistently more frequent for either species on damaged than undamaged fruit, both in observations of unmanipulated fruit and in artificial puncture experiments. Analyses which controlled for the longer male residence time on damaged fruit suggested strongly that copulations were consistently achieved at higher per capita rates on damaged than on undamaged fruit, indicating that puncture-guarding functions to increase access to females. An exception to the pattern in male mating success was noted at a site where both species used host fruit on the same trees. In this case, R. juglandis males were only slightly more common on punctured fruit than on control fruit and male success in copulation did not differ significantly between the two types of fruit. This anomalous result was apparently due to an almost absolute advantage enjoyed by R. boycei males in on-fruit contests with R. juglandis males. A likely basis for improvements in mating success associated with puncture guarding was a propensity for females to deposit eggs into existing punctures. Both in observations of unmanipulated fruit and in artificial puncture experiments, females consistently attempted oviposition more often in damaged than undamaged fruit. In artificial puncture experiments, both species at both sites deposited most clutches in damaged fruit. Mating generally took place as females initiated oviposition. The possible functions of puncture use by females as well as alternative functions of puncture guarding by males are discussed.     

Seasonal variation in paediatric blood lead levels in Syracuse,NY, USA

Venous blood lead values for 2,633 children aged 0–4 years in Syracuse, New York, collected between 1 April 1992 and 31 March 1993 were summarised by census tract for study of geographic variability. A demographic exposure model is presented showing housing stock and SES (socioeconomic status) parameters as the most significant predictor variables. A seasonal trend in blood lead levels was observed with late summer values about 40% higher than late winter values for census tracts with the highest geometric mean PbB levels. Seasonal variation is compared with a biokinetic uptake model to examine hypotheses about temporal variations in soil and dust lead exposure patterns.     

RUNOFF SIMULATION USING RADAR RAINFALL DATA1

ABSTRACT: Rainfall data products generated with the national network of WSR-88D radars are an important new data source provided by the National Weather Service. Radar-based data include rainfall depth on an hourly basis for grid cells that are nominally 4 km square. The availability of such data enables application of improved techniques for rainfall-runoff simulation. A simple quasi-distributed approach that applies a linear runoff transform to grid-ded rainfall excess has been developed. The approach is an adaptation of the Clark conceptual runoff model, which employs translation and linear storage. Data development for, and results of, an initial application to a 4160 km² watershed in the Midwestern U.S. are illustrated.