MODELING NORTH CASCADES ANNUAL RUNOFF DISTRIBUTION USING DRAINAGE BASIN ELEVATION DISTRIBUTION1

ABSTRACT: The annual distribution of flow in a drainage basin within a given region is a function of many factors. These may include annual distribution of rainfall, basin orientation, ground cover, or presence of glaciers. Since the North Cascades region of northern Washington State has little variation in precipitation distribution by month, and the region has significant snowpack, one would predict that in an unregulated basin, basin elevation would be one of the most important factors impacting an annual hydrograph distribution. Such a prediction can be made since the higher a drainage basin is, the larger the portion of runoff that would occur as late spring snowmelt. Given that there is a relationship between elevation distribution and annual hydrograph, the problem becomes one of how to use this relationship to model an ungaged basin's hydrograph. This study concludes that, within the North Cascades region and perhaps within other regions, an effective method of determining annual flow distribution is to model ungaged flows in the same manner as flows from a gaged basin with an elevation distribution similar to that of the subject basin.     

Glucosephosphate isomerase genotype frequencies,homozygous excess and size relationships in the sand flounder Rhombosolea plebeia

Genetic variation was studied at two polymorphic loci for 3 yr (November 1978–February 1982) in juvenile sand flounder (Rhombosolea plebeia) in Wellington Harbour, New Zealand. The Gpi-1 locus showed a heterogeneity in genotype frequencies, but this was not clearly related to season or to fish length. At the Gpi-2 locus, genotype frequencies were dependent upon length and showed a significant excess of homozygotes in juveniles but not in adults. This latter phenomenon has been reported previously in several species of marine molluscs, and so may be common to marine organisms producing large numbers of pelagic larvae. Reasons for the excess of homozygotes are discussed, and it is suggested that assortative mating is the most likely explanation and that this is an area of marine population genetic research which has been over-looked.     

National programs to protect genetic diversity — The US example

Summary A country which truly wishes to preserve the full range of genetic diversity with which it has been endowed must look beyond large biosphere reserves. It must inventory and protect individual species and habitat types in smaller preserves as well. The United States provides an example of a country which has a legacy of preserves. Much of the land that would be necessary for an effective preserve system has already been acquired, but basic information and coordination among agencies is lacking.Dr Francis Roy Thibodeau graduated in Environmental Sciences from Boston College. He later took his Masters in Urban, Social and Environmental Policy, and his Doctorate in Ecology and Environmental Policy, both degrees from Tufts University. His research interests are in the field of relationship between ecology and land use, especially as they influence the preservation of genetic diversity.     

What drives plan implementation? Plans,planning agencies and developers

This article investigates the determinants of plan implementation by applying a recently‐developed Plan Implementation Evaluation methodology. The lack of methodology to assess the implementation of plans has so far precluded any systematic analysis of the determinants of the implementation of local environmental plans. The article focuses on the implementation of plans in New Zealand. The key factors of implementation are: the quality of the plan; the capacity and commitment of land developers to implement plans; the capacity and commitment of the staff and leadership of planning agencies to implement plans; and the interactions between developers and the agency. The analysis is based on 353 permits implementing six local environmental plans in New Zealand, and on surveys of the developers who obtained the permits and of the planning agencies that granted the permits. The analysis finds that plan implementation is mainly driven by the resources of the planning agencies and by the quality of the plans, rather than by the characteristics of developers. Investments in plan writing and agency and staff capacity building thus improve the implementation of plans in the long‐run.     

EFFECTS OF DAM IMPOUNDMENT ON THE FLOOD REGIME OF NATURAL FLOODPLAIN COMMUNITIES IN THE UPPER CONNECTICUT RIVER1

ABSTRACT: Understanding the effects of dams on the inundation regime of natural floodplain communities is critical for effective decision making on dam management or dam removal. To test the implications of hydrologic alteration by dams for floodplain natural communities, we conducted a combined field and modeling study along two reaches in the Connecticut River Rapids Macrosite (CRRM), one of the last remaining flowing water sections of the Upper Connecticut River. We surveyed multiple channel cross sections at both locations and concurrently identified and surveyed the elevations of important natural communities, native species of concern, and nonnative invasive species. Using a hydrologic model, HEC‐RAS, we routed estimated pre‐and post‐impoundment discharges of different design recurrence intervals (two year through 100 year floods) through each reach to establish corresponding reductions in elevation and effective wetted perimeter following post‐dam discharge reductions. By comparing (1) the frequency and duration of flooding of these surfaces before and after impoundment and (2) the total area flooded at different recurrence intervals, our goal was to derive a spatially explicit assessment of hydrologic alteration, directly relevant to natural floodplain communities. Post‐impoundment hydrologic alteration profoundly affected the subsequent inundation regime, and this impact was particularly true of higher floodplain terraces. These riparian communities, which were flooded, on average, every 20 to 100 years pre‐impoundment, were predicted to flood at 100 ? 100 year intervals, essentially isolating them completely from riverine influence. At the pre‐dam five to ten year floodplain elevations, we observed smaller differences in predicted flood frequency but substantial differences in the total area flooded and in the average flood duration. For floodplain forests in the Upper Connecticut River, this alteration by impoundment suggests that even if other stresses facing these communities (human development, invasive exotics) were alleviated, this may not be sufficient to restore intact natural communities. More generally, our approach provides a way to combine site specific variables with long term gage records in assessing the restorative potential of dam removal.     

AN ANALYSIS OF SEASONAL FECAL COLIFORM LEVELS IN THE TCHEFUNCTE RWER1

ABSTRACT: A model for estimating seasonal fecal coliform concentrations in the Tchefuncte River as a function of river discharge was developed. Data on fecal coliform concentration were obtained from the Louisiana Department of Health and Hospitals and were available for a period of 15 years (1975 through 1992) from three locations. Stream flow data were obtained from a gaging station of the U. S. Geological Survey at Folsom, Louisiana. These data were available for 49 years (1943 through 1991). The climate of the area is characterized by different precipitation/runoff mechanisms for the summer and winter seasons. The division for seasons used in this analysis was May through October (summer season), and November through April (winter season). Because of the combined effects of climatic mechanisms causing precipitation and the seasonal variation of evapotranspiration, runoff is greater in the winter season resulting in higher fecal coliform counts in the Tchefuncte River. Statistical analysis revealed a statistically significant relationship between fecal coliform concentration and discharge for each season, at each of three sites on the Tchefuncte River.     

The world conservation strategy: Environmental education and local initiative

Summary In the spring of 1981, Tufts University and the International Union for the Conservation of Nature began teaching the World Conservation Strategy to environmentalists working at the local level. The fourteen-week course that they offered was the first of a series of initiatives to increase public awareness of the need for local action toward the solution of global environmental problems. The success of the first course has encouraged other groups to adapt it to their own social and ecological settings, but there is a pressing need for even more public education. While several aids to teaching the World Conservation Strategy are now being developed to give local conservation educators access to the Strategy, the initiative for bringing the World Conservation Strategy to the public should continue to come from these local leaders. Frank Thibodeau is an environmental biologist and policy analyst with MA and PhD degrees from Tufts University. He is currently a Research Associate in the Department of Urban and Environmental Policy at Tufts, preparing a book on the World Conservation Strategy as a foundation for local environmental initiative under the auspicies of IUCN and the World Wildlife Fund. In addition to his writing and teaching related to the Strategy, he maintains an active research program examining the development of national and international strategies for the preservation of genetic diversity. Hermann H. Field, an urban planner and Fellow of the American Institute of Architects, was director of the Planning Office of the Tufts-New England Medical Center in downtown Boston for 12 years. In 1972 he initiated and then directed a new graduate department of Urban and Environmental Policy at Tufts University. Since 1978 he has been Professor Emeritus in Environmental Planning there. In addition to continued involvement in his department he is active on a range of levels in conservation from the local to the international, including membership on IUCN's Commission on Environmental Planning.