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2461. [Article] Coastal sand dunes of Oregon and Washington
In Part I the environment of the coastal dunes of Oregon and Washington is analyzed. Most of the substratum is a narrow foreland or terrace, in part submerged, that borders the mountain front. Temperature ...Citation Citation
- Title:
- Coastal sand dunes of Oregon and Washington
- Author:
- Cooper, William Skinner, 1884-
In Part I the environment of the coastal dunes of Oregon and Washington is analyzed. Most of the substratum is a narrow foreland or terrace, in part submerged, that borders the mountain front. Temperature is relatively low in summer and rarely reaches the freezing point in winter. Winter precipitation is heavy, and there is almost no snow; there is a pronounced deficiency in precipitation in summer. The summer wind is a very constant afternoon sea breeze from north to northwest; winter winds are variable but include frequent southwest gales. Longshore currents are governed by the seasonal winds, moving southward in summer and northward in winter. The regional vegetation is dense, tall conifer forest. The influence of man has been comparatively slight: in prehistoric times the starting of forest fires; in historic time moderate disturbance due to grazing and recent efforts to control the movement of the sand. Part II deals with forms and processes. The simplest combination of elements comprises sand, wind, and water. Interaction of these produces two patterns. In the transverse-ridge pattern the individual unit is a ridge essentially normal to the summer wind and moving with it; it is asymmetric in profile with gentle windward slope and steep leeward slope (slipface). Origin and maintenance of this profile are explained in accordance with principles developed in the field of aerodynamics, and conclusions arrived at deductively are confirmed by slow-motion photography of smoke streams on the dunes. The oblique-ridge pattern occurs only where there is full exposure to both seasonal winds, plenty of space, and plenty of sand. These conditions are met only in Region III (Coos Bay dune sheet). The units are much more massive than the transverse ridges and are essentially stationary. Their trend lies between the means of summer and winter winds. A theoretical explanation of their origin and maintenance is presented, and the oblique ridges and the "longitudinal dunes" of certain desert regions are compared. Neither transverse nor oblique ridge is found in stabilized condition. The factor vegetation added to the other three-sand, wind, and water-promotes stabilization. On a prograding shore, successive beach ridges are quickly captured and fixed, and retain their initial form indefinitely. On a retrograding shore the processes are exceedingly complex and involve repeated stabilization and rejuvenation. Two cases are presented: flat shore, with and without abundant sand supply; stabilized dune masses undergoing erosion. In the latter case, the commoner, development involves the following phases: trough blowout, merging of troughs, reduction to deflation base, and precipitation ridge, which may in time become completely stabilized while still retaining its characteristic form. In places sheltered from one or the other of the seasonal winds, usually the summer wind, giant parabola dunes, which may likewise become fixed by vegetation, develop. Part III is a description of the dune localities of the Oregon-Washington coast and an account of their history. Forty per cent of this coast bears dunes of greater or lesser magnitude. Thirty dune localities are grouped in four regions. Region I includes four localities north of Tillamook Head, Oregon, making a continuous strip 53 km long, that bears the parallel beach-dune-ridge pattern associated with progradation. The forms in Regions II, III, and IV, heterogeneous and complex, are those characteristic of retrograding shores. The two principal stabilized forms are the precipitation ridge and the parabola dune. In Regions II, III, and IV the existing features came into being mainly during the last grand period of sea-level rise, and the seaward portions of massive parabola complexes have been sliced away in varying degree by the advancing sea. The beach-ridge dunes of Region I were formed during the period of comparatively stable sea level, with a probable small net lowering, which followed the maximum of sea advance and has extended to the present. Progradation here during this period, in contrast with almost none south of Tillamook Head, has been possible because of the ample bed load carried to the coast by the Columbia River. South of Tillamook Head there is, in a number of well-distributed localities, evidence of three episodes of advance. The first is represented by the strip of thoroughly stabilized dunes that nearly everywhere forms the inner marginal part of the dune complexes. This episode reached its culmination before the sea had attained its maximum of advance-attested by the slicing away of portions of completely stabilized masses. The second advance for the most part fell short of the first, though in a few places it overpassed the limits of the latter; present condition ranges from complete stabilization to vigorous activity. The third episode is represented by active dunes with open access to the shore. In certain localities there are only an inner strip of stabilized dunes and an outer zone of active dunes. It is assumed that in these the visible effects of the second and third episodes have merged. An earlier cycle of dune development, similar to the modern one in character and extent, is proved by eolian sediments containing altered podzolic soils, which make a minor part of the mantle of unconsolidated materials that lies upon the rock platform of the 30-m terrace. The dunes of which these masses are remnants were formed during the next-to-the-last grand period of submergence. Development of the dunes of Regions II, III, and IV, associated with the grand period of submergence, is assigned to the period of deglaciation that followed the Wisconsin maximum, and mainly to the period of rapid deglaciation that began after the Valders-Mankato advance. The beach-ridge dunes of Region I, on the other hand, have developed in their entirety in the time since sea-level rise was succeeded by stability. By analogy, the earlier cycle of dune development was associated with the waning phase of Illinoian glaciation, and it may be assumed that similar dune cycles were associated with the earlier glaciations of the Pleistocene.
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2462. [Image] Data from pumping and injection tests and chemical sampling in the geothermal aquifer at Klamath Falls,
DATA FROM PUMPING AND INJECTION TESTS AND CHEMICAL SAMPLING IN THE GEOTHERMAL AQUIFER AT KLAMATH FALLS, OREGON By S. M. Benson? , C. J. Janik ? , D. C. Longi , R. D. ...Citation Citation
- Title:
- Data from pumping and injection tests and chemical sampling in the geothermal aquifer at Klamath Falls,
- Author:
- Benson, S. M
- Year:
- 1984, 2007, 2005
DATA FROM PUMPING AND INJECTION TESTS AND CHEMICAL SAMPLING IN THE GEOTHERMAL AQUIFER AT KLAMATH FALLS, OREGON By S. M. Benson? , C. J. Janik ? , D. C. Longi , R. D. Solbaui- , P. J. Lienau^, G. G. Culver^, E. A. Sanmel-^, S. R. Swanson^, D. M. Hart-5/, Andrew Yeei/, A. F. White!', M. L. Stallard^, A. P. Brown^, M. C. Wheeler?', T. L. Winnett? , Grace Fong?', and G. B. ^' ABSTRACT A seven-week pumping and injection test in the geothermal aquifer at Klamath Falls, Oregon, in 1983 provided new information on hydraulic properties of the aquifer* The Open-File Data Report on the tests includes graphs of water levels measured in 50 wells, temperature measurement In 17 wells, daily air-temperatures in relation to discharge of thermal water from more than 70 pumped and artesian wells, tables of monthly mean air temperatures and estimates of discharges of thermal water during a normal year, and tables of chemical and isotopic analyses on samples from 12 wells. The water-level measurements reflect the effects of pumping, injection, and recovery over about 1*7 square miles of the hot-well area of Klamath Falls. The pumped well, City Well #1, and the injection well at the Klamath County Museum are components of a proposed District Heating Plan. The study was funded principally under contracts from the U.S. Department of Energy to the Lawrence Berkeley Laboratory, Stanford University, and the Oregon Institute of Technology, with coordination and chemical sampling provided under the Geothermal Research Program, U.S. Geological Survey. Support was received from the City of Klamath Falls, Klamath County Chamber of Commerce, Citizens for Responsible Geothermal Development, and many citizen volunteers. ? Lawrence Berkeley Laboratory, Berkeley, California 2/ ? U.S. Geological Survey, Menlo Park, California ? Energyman, Inc., Klamath Falls, Oregon 4/ ? Oregon Institute of Technology, Klamath Falls, Oregon ? Citizens for Responsible Geothermal Development, Klamath Falls, Oregon
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2463. [Image] The geology and petrography of Crater Lake National Park
maps; Geology by J.S. Diller. Petrography by H.B. PattonCitation -
2464. [Image] Dear concerned citizen
"Bureau of Land Management's (BLM) proposed decision and finding of no significant impact for the Lost River Management Framework Plan amendments."-- P. [1]; August 19, 1988."; "BLM-OR-PT-88-12-1792"--P. ...Citation -
2465. [Article] A Comparison of Socio-Political Attitudes of Older Urban Women: The 1910-1924 Cohorts
The central theme of this study is that because of the changing life styles and the macro-events which occurred after World War I these years were a watershed. The women born in the three five-year cohorts ...Citation Citation
- Title:
- A Comparison of Socio-Political Attitudes of Older Urban Women: The 1910-1924 Cohorts
- Author:
- Ikehara, Elizabeth Slack
- Year:
- 1991
The central theme of this study is that because of the changing life styles and the macro-events which occurred after World War I these years were a watershed. The women born in the three five-year cohorts from 1910 through 1924 were at different stages of maturity and awareness as particular economic and political events occurred. The social and political climates were different for each of these cohorts of women. Therefore there would be discernible differences in attitudes and opinions among the cohorts. A literature review indicated three models for the formation of social attitudes and political opinions. The "Personality Types" is based on the premise that attitudes formed early in life remain fixed. The "Aging/Conservative" model considers that attitudes become increasingly conservative as the person ages. This study, however, was based on the "Historical Change" model. Beliefs and attitudes may change in response to personal experiences throughout the life course. Four research questions were developed. 1. How have macro-events affected the life experiences of women in these cohorts? 2. How have social pressures affected their experiencing of employment, matrimony, and motherhood? 3. How do the opinions of women in these three cohorts with regard to social and political issues differ and change? 4. Can differences of opinions among the women of the three cohorts be traced to dissimilarities in life experiences? Census data literature was researched to provide background documentation on technological and demographic changes in the United States during the 20th century. Questions for cohort comparisons were selected from the National Opinion Research Council Surveys of 1972 through 1989. These considered individual and family demographics, labor force participation, social attitudes, and political orientation. For the 2,814 respondents analysis was done by five-year cohorts to determine differences and by six-year periods to point out trends. Both ANOVA and Chi-square were used to verify statistical significance. Focus group sessions, with 41 participants, met at senior centers and housing units in the Portland metropolitan area. A questionnaire completed by each participant confirmed that the focus group demographics corresponded to those of the national sample. Individual life experience time lines provided material for opening the discussion. Other discussion topics were based on differences noted among the three cohorts in the NORC data analysis. These were in the areas of education, work experience, family life patterns, political orientation, and attitudes toward societal changes. A brief finding for each research question follows. 1. NORC data indicated that each successive cohort held increasingly liberal sociopolitical opinions, and that women of all three cohorts became less conservative over the years. The focus group participants related these changes to specific macro-events in their life experiences. 2. Focus group discussions disclosed that the 1910-1914 cohort realized later in life that societal pressure had limited their educational achievement. Women of the 1915-19 cohort came to understand that their acceptance of the homemaker role was somewhat based on societal expectations. The 1920-24 cohort were aware that discrimination in the work arena was based on societal norms of the time. 3. Analysis of both NORC data and opinions expressed in the focus groups indicated that each successive cohort was increasingly broadminded and tolerant. 4. The women participating in the focus groups exhibited an awareness of the differential effects of life experiences. They specified the effects of macro-events (chiefly the Great Depression), education, mobility, and workforce participation. This research has tentatively confirmed that a generational watershed occurred for women born before World War I and those born after. As the women of the 1910 through 1924 cohorts matured they experienced differing social and political climates. This resulted in cohort differences. Further investigation may reveal more precise cohort boundaries for the 1910 through 1924 years. It should be remembered also that cohort boundaries for men may not coincide with those of women.
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2466. [Article] Homestead Neighborhood and the Oregon Health Sciences University Background and Recommendations Report
The Homestead Neighborhood is located in southwest Portland. It was first studied as part of the Marquam Hill Plan in 1977. Since that time two major health providers, the Shriners and the Veterans Administration,have ...Citation Citation
- Title:
- Homestead Neighborhood and the Oregon Health Sciences University Background and Recommendations Report
- Author:
- Bizeau, Thomas, Crawford, Jim, Delacy, Barton, Massoudifar, Yousef, McConnell, Tom, Rahman, Foziah, Rassoli, Ezzat, Sochacka, Barbara
- Year:
- 1988
The Homestead Neighborhood is located in southwest Portland. It was first studied as part of the Marquam Hill Plan in 1977. Since that time two major health providers, the Shriners and the Veterans Administration,have built new facilities on the hill. The Oregon Health Sciences University is now poised and ready for major expansion of its medical schools, hospital and research facilities. Meanwhile, area residents and property owners, have voiced concerns about increased traffic, and building density. Oregon Health Sciences University (OHSU) contracted with the School of Urban and Public Affairs at Portland State University to draft a comprehensive neighborhood plan, to supplement its own long rang planning on Marquam Hill. Graduate students in the Masters in Urban Planning (MUP) program, under the direction of Michael S. Harrison AICP, Chief Planner for the City of Portland, prepared this plan over a ten week time period. This plan will also be presented to the Homestead Neighborhood Association to provide a basis for further studies. The recommendations presented in the following section, are solely those of the students in the USP 528 Comprehensive Planning Workshop. As presented here, they represent many rounds of in-class discussion, fieldwork and input from residents.The Advisory Committee contributed review and advice. The document makes reference to several sites. The "medical complex" is considered the Oregon Health Sciences University, the Shriners Hospital and the Veterans Administration Hospital. The "campus" refers to the same area as the medical complex. The "Homestead Plat" refers to the residential and commercial area just west of the campus up to SW 14thStreet. The Homestead neighborhood is a political jurisdiction recognized by the City of Portland which surrounds the areas platted as Homestead on Marquam Hill, but also embraces parts of Portland Heights and the Hillsdale area. Marquam Hill is a geographical term which relates to a much wider area than just the Homestead neighborhood. The background section covers the history, characteristics and patterns of land use in the Homestead Neighborhood. It provides a factual basis for determining alternatives,making recommendations and establishing policy. It also may be used as a general reference.The background is organized into seven sections: historical perspective; sumary of planning activities; overview of transportation patterns; analysis of development and infrastructure; discussions of amenities and topography; and an overview of demographics. A comprehensive property inventory detailing individual parcel ownership and physical characteristics has also been compiled and included as an addenda to this report. The fourth section of the report describes and analyzes the planning methodology used to research this project. Property data was collected and tabulated using Multnomah County records which were then checked and enhanced through field observation. Citizen participation was fostered by impanelling an advisory committee consisting of neighborhood representatives of the neighborhood, medical complex and the City Park Bureau, conducting a workshop with the neighborhood and distributing surveys to all residences. The findings of the class are presented in the final section of this report. The findings and recommendations contained in this report are solely those of the class and do not necessarily represent the policies of the City of Portland, Portland State University, Oregon Health Sciences University or the Homestead Neighborhood Association. The report will hopefully foster communication between the Homestead Neighborhood Association, the medical complex and the City of Portland. This is not intended as a final plan but rather as a starting point for further discussion. The next step in this planning process is for the Neighborhood and University to continue a dialog to formulate the goals and objectives of a neighborhood plan. A series of public discussions would follow to determine the contents of the final document. The final step would be to get the plan ratified by the Portland City Council.
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2467. [Article] The Japanese beef market in a disequilibrium econometrics framework : implications for the U.S. - Japan beef market access agreement
The success of the U.S. government in persuading Japan to liberalize the beef market is viewed as a relief to the U.S. beef industry. The economic benefit (to the U.S. beef producers!) of the trade liberalization ...Citation Citation
- Title:
- The Japanese beef market in a disequilibrium econometrics framework : implications for the U.S. - Japan beef market access agreement
- Author:
- Anteneh, Berhanu
The success of the U.S. government in persuading Japan to liberalize the beef market is viewed as a relief to the U.S. beef industry. The economic benefit (to the U.S. beef producers!) of the trade liberalization however is yet to be seen. The size of this benefit is determined, among others, by (a) the net change in Japan's retail price due to the liberalization, (b) the price elasticity of demand for the U.S. beef in Japan, (c) the degree of price rise in the world market, and (d) the export capacity of the domestic sector. Availability of alternative beef sources and the degree of substitutability between the U.S. beef and those alternatives affect factor (b) and factor (d) depends on the extent to which beef and other meat products substitute each other in the domestic market both in production and consumption. Evaluation of the U.S. - Japan Beef Market Access Agreement (BMAA) therefore has become a high policy profile. In the interest of assessing possible policy effects of BMAA, several researchers have attempted to parameterize and quantify the Japanese demand for beef. The fact that this market is (a) semi-isolated from the rest of the world by restrictive import quota, (b) managed domestically by government parastatal, and (c) characterized by multi- and intensely differentiated beef with no parallel historical data has made the choice of economic theory and methodology difficult. While most researchers (Group 1) relied on conventional method [e.g. 55; 125], others (Group 2) [2] contend that managed import market may better be explained by a model of political nature. By assuming the usual competitive market behavior, Group 1 underestimates possible implications of existing market structure for building and estimating conventional econometric models. Group 2, on the other hand, limits itself to normative analysis. Due to the absence of consensus among researchers regarding implications of policy-relevant parameters, the desirability of the BMAA is still an unsettled policy issue. The general purpose of this study has been to generate some further information on Japan's beef market. In pursuant of this objective, an attempt is made to (a) show how significant the beef quality issue is in evaluating that market, (b) test the market equilibrium hypothesis, and (c) upon the acceptance of the alternative (disequilibrium) hypothesis, estimate the structural parameters from a model specified in the light of imperfections in the market. This fills the void in previous studies. Drawing on existing literature, the beef quality categories are shown to have been narrowing and, in fact, converging to the two middle categories, medium and common grades. It is suggested that future market studies may benefit from concentrating on these two grades in assessing competitiveness and substitutability with domestic beef. Understanding the nature of this convergence (i.e whether the shift is attributable to changes in cost or preference structure) may contribute to sound policy making. Based on (a) increased concentration in production and distribution sectors, (b) government intervention in beef and related markets, (c) high degree heterogeneity in beef, and (d) short-run supply inflexibility due to long fattening period and restrictive import policy, the Japanese beef market was hypothesized to have been in disequilibria due to incomplete market information. In testing this hypothesis, two data sets were used -Statistical Yearbook and the Family Income and Expenditure Survey. For reference purposes, they are referred to as Market I and Market II respectively. The equilibrium hypothesis was tested for uniform and upward and downward differential adjustment speeds. The uniform adjustment rate estimated from the reduced form price equation supports the hypothesis in both markets. The structural equations were then adjusted in the light of the imperfections in the market and structural parameters estimated using non-linear three stage least squares. Both upward and downward adjustment speeds in Market I suggest perfect flexibility in prices on annual basis. In Market II, prices are found to have been flexible downward but rigid otherwise. The upward rigidity in prices suggest excess demand. Perfect flexibility in prices on annual basis however may not suggest market equilibrium in a period less than a year. Consumers are found to be more price responsive than in previous studies implying a greater response of the demand for beef imports to changes in prices due to the liberalization than envisaged by previous studies. The demand for beef however is income inelastic suggesting a partial offsetting in the incremental demand for imports. Finally, consumers respond to changes in beef retail prices by consuming less fish and poultry.
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2468. [Article] White-breasted nuthatch density and nesting ecology in oak woodlands of the Willamette Valley, Oregon
Habitat loss causes a reduction in available resources for wildlife, alters the configuration of remaining habitat, and may isolate wildlife populations. White-breasted nuthatches (Sitta carolinensis) ...Citation Citation
- Title:
- White-breasted nuthatch density and nesting ecology in oak woodlands of the Willamette Valley, Oregon
- Author:
- Viste-Sparkman, Karen
Habitat loss causes a reduction in available resources for wildlife, alters the configuration of remaining habitat, and may isolate wildlife populations. White-breasted nuthatches (Sitta carolinensis) are experiencing long-term population declines in the Willamette Valley of Oregon, where they are historically associated with oak woodlands. As secondary cavity-nesters, white-breasted nuthatches may be limited by the availability of existing cavities for nesting and roosting. Oak vegetation in the Willamette Valley has changed since European-American settlement times from vast areas of open oak savanna to isolated closed-canopy stands separated by agricultural fields. We examined nuthatch density, nest cavity selection, and nest success in relation to oak woodland structure and landscape context. We conducted point transect surveys in 3 strata: woodland interiors, large woodland edges, and small woodlands. We located and monitored nuthatch nests and sampled vegetation at nest locations and matching random locations around each nest. Woodland structure and edge density were measured at a 178-m radius (home range) scale, and landscape context was measured using vegetation cover within a 1-km radius around point transects and nests. We used program DISTANCE to fit detection functions and calculate nuthatch densities. We used conditional logistic regression to compare nest locations with random locations, and analyzed nest success with Mayfield logistic regression. White-breasted nuthatch density was significantly higher in small woodlands than in edges of large woodlands, which had higher nuthatch density than woodland interiors. Density of nuthatches increased with a combination of oak cover within a 1-km radius of the point, edge density within a 178-m radius, and number of oak trees >50 cm diameter at breast height (dbh) within a 100-m radius. Nest cavities were situated in oak trees containing more cavities than random oak trees that had cavities, and oak trees used as nest trees had a larger dbh than oak trees within random plots. Local woodland structure at nest locations was characterized by larger trees, measured by greater mean dbh, canopy cover, and basal area of oaks than random locations within the home range. Nest success in natural cavities was 71% and was not predicted by attributes of nest cavities, nest trees, local woodland structure at nests, woodland structure at the home range scale, or landscape context. These results suggest that the most suitable habitat for white-breasted nuthatches in the Willamette Valley includes oak woodlands in close proximity to one another with a high proportion of edge and mature oak trees. Managers should preserve trees containing cavities and large oak trees whenever possible. Thinning of small oaks and removal of conifers in oak woodlands to create more open, savanna-like conditions may also promote the development of larger oaks with more spreading branches, providing more opportunities for cavities to form and more foraging surface area for nuthatches.
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Streamflow forecasts are essential to the optimal operation of hydroelectric and irrigation reservoirs in the Pacific Northwest. Satellite snow cover observations would aid in these streamflow forecasts by ...
Citation Citation
- Title:
- An investigation into modeling snow cover elements at Crater Lake National Park and surrounding environs as an improved "ground truth" method for satellite snow observations
- Author:
- Hamilton, William L.
Streamflow forecasts are essential to the optimal operation of hydroelectric and irrigation reservoirs in the Pacific Northwest. Satellite snow cover observations would aid in these streamflow forecasts by providing snow cover data at regular time intervals. Unfortunately, satellite capability to remotely sense mountain snow cover conditions is indeterminate due to lack of "ground truth." This study focuses on the development of a mountain snow cover model capable of generating snow cover data at a scale useful as "ground truth" for operational satellite snow cover observations. The study area used to develop the snow cover model was Crater Lake National Park and its surrounding environs. Both the physiography (topography and vegetation) and snow climate of the study area were analyzed and found to be quite dynamic. In order to take into account the affects of the dynamic snow climate and physiography upon snow cover conditions, multiple regression analysis was used to create the Crater Lake Snow Model. Forty-five snow core sites were located within the study area. Snow depth and snow water equivalent values were recorded at each site. Eighteen sites located within Crater Lake National Park were sampled on a weekly basis for the 1977-1978 snow year. An additional 16 sites were sampled at high elevations in the Park on a weekly basis from April through June, 1978. The remaining 11 sites comprised the historical snow core data set collected by Soil Conservation Service (S.C.S.) on a monthly basis, January through June, 1948 through 1978. These data sets were statistically reduced using the quasi-constant ratio theory to synthesize values for missing data to temporally unify the data sets. Also the physiographic elements of slope, aspect, elevation, percentage of forest canopy cover, and regional aspect were recorded for each snow core site. The physiographic elements (independent variables) were regressed against the snow core data (dependent variables) to produce snow model equations. Three different Temporal-Spatial Situations (T.S.S. 1, 2, 3) of data were entered into regression analysis. T.S.S. 1 and 2 models were generated from the 11 S.C.S. snow core sites, T.S.S. 1 from 1978 data and T.S.S. 2 for 1948 -1978 data. The T.S.S. 3 model was generated from the 45 snow core site data for 1978. Using the theory of the quasiconstant ratio it was possible to combine the T.S.S. 1, 2, and 3 sets of regression equations to produce a T.S.S. 4 snow model ( a model based upon the 45 sites for the 1948-1978 snow seasons). Subsequently the T.S.S. 1 and 2 snow models were utilized with this derived T.S.S. 4 snow model to produce T.S.S. 3 snow cover models for any month of any year for the 1948 through 1978 period. Validity testing of the model indicates that it has an average error of ± 15.7" for modeled snow depth values and ± 8.2" for modeled snow water equivalent values. The Crater Lake Snow Model has a combined spatial, annual, and long term resolution unequaled in previous snow cover models. The Model's combined high resolving properties give it capabilities of generating mountain snow cover "ground truth." Current studies are being conducted to couple dynamic snow meteorology and LANDSAT digital data to the Model to increase its accuracy and reduce its dependency on snow core data. Also, output of the Model can be used for studies on snow cover affect upon wildlife movement and survival and the determination of source regions of relative runoff from snow melt.
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2470. [Article] Emergency contraceptive pills and college women : factors influencing intention and use
Approximately half of the 6.4 million pregnancies occurring each year in the United States are unintended (Finer & Henshaw, 2006). Unintended pregnancies, defined as pregnancies not wanted at the time ...Citation Citation
- Title:
- Emergency contraceptive pills and college women : factors influencing intention and use
- Author:
- Nelson, Heather A.
Approximately half of the 6.4 million pregnancies occurring each year in the United States are unintended (Finer & Henshaw, 2006). Unintended pregnancies, defined as pregnancies not wanted at the time conception occurs, regardless of contraceptive use (Chandra, Martinez, Mosher, Abma, & Jones, 2005) can have serious repercussions on women, children, and society. For decades, women facing the possibility of an unintended pregnancy following unprotected intercourse, birth control method failure, or sexual assault, have had no choices outside of abortion. Since 1997 however, another option has become available to American women making unintended pregnancy decisions – emergency contraceptive pills (ECPs). Research has indicated that widespread use of ECPs has the potential to prevent 1.5 million of the approximate 3 million unintended pregnancies occurring each year in the US, including as many as 700,000 pregnancies that now result in abortion (Trussell, Stewart, Guest, & Hatcher, 1992). Although 84% of American women have heard of ECPs, only 6% claim to have ever used them (Hoff, Miller, Barefoot, & Greene, 2003). Despite their effectiveness and the public’s awareness of them, ECPs still remain underutilized in many high-risk populations. Explanations for this discrepancy are not readily available. In particular, young adult women attending college are at risk for unintended pregnancy yet we know little about their relationship with ECPs. Although extensive ECP use could have a profound effect on unintended pregnancy rates, we have limited information about the factors that influence a woman's decision to use ECPs. Furthermore, with the US Food and Drug Administration's approval of behind the counter status for the emergency contraceptive Plan B on August 24, 2006, one of the last major external hurdles for women accessing emergency contraceptive pills appears to have been removed. However, it is unknown whether prescription-free availability will be the final factor in women's predisposition to use ECPs or if other intrinsic factors, may in fact, override use. The purpose of this study was to determine the nature and extent of college women's knowledge, self-efficacy, attitudes, perceived social norms, and use related to emergency contraceptive pills. Additional goals included: using a conceptual framework to determine which social and behavioral constructs suggested by the contraceptive literature best predict intention to use ECPs and ECP use. Data were collected via an online survey designed by the lead author. A sample of 4,219 female students was drawn from a directory list of students enrolled at Oregon State University during the Spring Quarter of 2004. A total of 1718 women returned usable questionnaires. Key findings were that the majority of sexually active participants (68%, n = 871) had experienced a pregnancy scare in the past yet only 28.3% (n = 362) had ever used ECPs. Further, women had insufficient knowledge about ECPs in order to make informed decisions. Male partners were the most influential social reference in ECP decision-making. Although prescription-free access to ECPs is an historical milestone for reproductive health in the US, this policy change may not be the final step in ensuring that women access and use ECPs when they need them. Intrinsic factors including: knowledge that ECPs prevent pregnancy by interfering with ovulation, knowledge that ECPs are not a form of abortion, and confidence in accessing ECPs in time if needed seem to influence ECP use. In order for ECPs to impact unintended pregnancy rates to the extent research has demonstrated, strategies addressing these internal factors are warranted and must target both women and men.