Protecting speciality cropland from urban development: the case of the Okanagan Valley,British Columbia

Mapping from air photos reveals coinsiderable urbanization of the Okanagan fruitlands between 1966 and 1981. For a number of years reduced areas of fruitland have been compensated for by increased productivity, but the limit of increased productivity has nearly been reached and there are no significant amounts of new land to be planted to fruit. The British Columbia Land Commission Act, with its Agricultural Land Reserve (ALR) programme was a bold attempt at preventing the urbanization of prime agricultural land in British Columbia. Undoubtedly the urban conversion of the Okanagan Valley fruitlands has been slowed from what would have occurred without the ALR programme. Nevertheless, sequential maps and records of appeal applications indicate that considerable urban conversion of fruitland is still occurring. There is also evidence that the current British Columbia government's commitment to the ALR programme is waning. If the future urban development patterns and political climate continue along recent trends, it is difficult to be optimistic about preserving the Okanagan fruitlands for future generations.     

Remote Sensing and Geophysical Investigations of Glacial Buried Valleys in Northeastern Kansas

Aquifers found in glacial buried valleys are a major source of good-quality ground water in northeastern Kansas. The extent and character of many of these deposits are not precisely known, so a detailed study of the buried valleys was undertaken. Test drilling, Landsat imagery, shallow-earth temperature measurements, seismic refraction, surface electrical resistivity, and gravity data were used to evaluate two sites in Nemaha and Jefferson Counties. Tonal patterns on springtime Landsat imagery and winter/summer anomalies in shallow-earth temperatures were quick and inexpensive methods for locating some glacial buried aquifers and suggested areas for more intensive field studies. Reversed seismic refraction and resistivity surveys were generally reliable indicators of the presence or absence of glacial buried valleys, with most depth determinations being within 25% of test-drilling results. The effectiveness of expensive test-hole drilling was greatly increased by integrating remote sensing, shallow-earth temperature, seismic, and resistivity techniques in the two buried valley test areas. A gravity profile allowed precise definition of the extent of one of the channels after the other techniques had been used for general information.     

OCS,H2S,and CS2 fluxes from a salt water marsh

The diurnal-to-monthly behavior of the fluxes of OCS, H₂S, and CS₂ from a mixed-Spartina grass-covered site in a Wallops Island salt water marsh was determined through a series of experiments in August and September, 1982. Absolute flux values were determined for OCS and H₂S, while only relative values were determined for CS₂. The rates of emission of OCS and H₂S were observed to vary diurnally and to be strongly influenced by tides. The time-averaged flux values show that such mixed-Spartina stands are insignificant ( 1%) global sources of H₂S or CS₂ and insignificant contributors to the global OCS cycle (< 1%). These results demonstrate that some marsh regions play a minor role in the global sulfur budget and, consequently, that the inclusion of such areas in extrapolations of measurements of more productive regions could lead to an overestimate of the role of salt water marshes in the global sulfur budget.     

Seismic responses of deck-type arch bridges

The dynamic responses of three deck-type arch bridges, with main spans of 59,213 and 518m, are presented. The ratios of natural period to arch span were found to be quite close for all three bridges. Artificial ground motions were applied separately in three directions to finite-element models of each bridge. Three acceleration levels were considered—0.09g, 0.22g and 0.50g—corresponding to the AASHTO Seismic Risk Zones I, II and III, respectively. Responses to uniform lateral motion were generally the largest, while the responses to vertical motion were generally lower than those due to lateral or longitudinal motion. In all cases considered, none of the total stresses in the main members exceeded the yield stress. Connection and secondary member responses were also calculated and are presented. In addition, the effects of unequal motions at the supports were sampled by various deterministic inputs. While the effects of such motions in the vertical and lateral directions were less than the responses to uniform motion, the effects of unequal longitudinal motions at the supports were substantial.     

The tsunami model of the origin of ring structures concentric with large lunar craters

The largest lunar craters are normally surrounded by one or more ring anticlines which are accompanied on their inner edges by ring synclines.     

The brightness of a black hole due to gravitational lensing

The influence of a Schwarzschild black hole on the light from stars is examined. The result is, that due to gravitational lensing light comes from the black hole and thus a black hole shines. The effect is very small and numerical calculations suggest that the magnitude of the black hole is smaller than 60 ^m , this means unobservable with present instruments. It is also shown that there is no effect on the cosmic background radiation.