Hilly Terrain Research Articles

The influence of locally induced wind systems on the effectiveness of nocturnal dry deposition of ozone

The structure of the planetary boundary layer above a valley of the Swiss Plateau is investigated. The very high night-time loss rates of O 3 observed are mainly attributable to dry deposition at the surface. Although it can be inferred that smog-chemistry plays an important role, homogeneous chemistry accounts on average for only about 20% of the observed O 3 destruction rates. It is concluded that the dry deposition of O 3 at night is much more effective in the hilly terrain around the field site than over horizontally homogeneous terrain. This increase in efficiency is linked with a local wind system. The O 3 destruction due to dry deposition occurs mainly in layers of nocturnal downslope wind where O 3-rich air is brought to the ground during the whole night. Hence the air reaching the bottom of the valley has a very low O 3 content and the upward airflow associated with this local wind system leads to continuous O 3 depletion within the lower part of the boundary layer. It follows that the increased effectiveness of the dry deposition in hilly terrain results in a self-cleaning mechanism of the atmosphere which is not necessarily restricted to O 3.

Productivity Studies of a Large Scale Semi-mechanised Harvesting System for Shortwood in Hilly Terrain

SYNOPSIS Large scale extraction of shortwood E. grandis timber by means of a semi-mechanised system in hilly terrain gives high productivity from clearfellings. The system employs wheeled tractors and manually loaded low-bed trailers for infield shortwood harvesting. Loads of five to six tons are transshipped in bundled form by crane to road-haulage vehicles. Handling times are given for each operation for different categories of pole mass and load size.

Earth Flows Along Henry Creek, Northern Alaska

Many earth flows occurred during the summer of 1979 in the hilly terrain near Umiat, Alaska, particularly along Henry Creek. Most were shallow, involving only the tundra mat and no more than 1.5 m of the underlying mud. The summer of 1979 was the warmest and wettest for the period of record at Umiat, and precipitation was characterized by brief but intense localized rainstorms. Failure probably was triggered by the heavy rains and facilitated by an absorbent tundra mat over a clayey substrate, and perhaps in some cases by a thicker than normal active layer. Flows of this kind have occurred repeatedly in the Uniat area, most likely during summers in which climatic conditions were similar to those of 1979.Key words: earth flows, rainfall, temperature, active layer, bentonitic materials, Alaska

GROUNDWATER EXPLORATION IN HARD‐ROCK TERRAIN—A CASE HISTORY*

AbstractThe utility of electrical resistivity and magnetic measurements to locate suitable wellsites in hard‐rock terrains intruded by dykes is illustrated. The example is taken from a highly hilly terrain of Karnataka State situated in the Western Ghat hills of Peninsular India. Electrical resistivity profiles and soundings, S.P., and total magnetic field measurements are discussed. Of the fifteen recommended sites, nine have been drilled, eight of which are reported to yield between 6–12 m3/hr (1500 to 3000 gals./hr), which is considered satisfactory in this region.

Crop Responses to No‐till Management Practices on Hilly Terrain1

AbstractManagement practices are needed that will permit economic crop production in hilly terrain without excessive soil and water losses. Field studies were conducted over a 3‐year period to determine the effects of two rates of atrazine on yield of corn (Zea mays L.) sod planted in orchardgrass (Dactylis glomerata L.) for 2 years and to determine the residual effect of atrazine on germination and growth of 16 agricultural plant species the third year. Atrazine at 2.2 and 4.5 kg/ha was applied at planting time for sod‐planted corn and compared with two different methods of growing corn using conventional tillage. Regrowth of orchardgrass in sod‐planted treatments was measured following harvest of corn. Temperature and soil water measurements were made in sodplanted and conventionally‐tilled corn over a 2‐year period. Silage and grain yields were significantly higher from sod‐planted corn than from conventionally tilled corn. No soil losses were noted in areas where corn was sod‐planted as compared to heavy losses in conventionally‐tilled corn. Soil temperatures in no‐till corn averaged about 10 C less than under conventional tillage methods, with significantly higher amounts of available soil water present in no‐till plots than in conventionally‐tilled plots throughout the growing season. Residual studies with 16 different plant species indicated very little detrimental effect from residual atrazine after 2 years of application. Growth of many plant species was significantly higher following application of atrazine.

Trace Element Geochemistry of Apollo 16 Soil 68501

THE Apollo 16 lunar samples were obtained from the first site remote from the maria basins (landing site 9° 00′ 01″ S; 15° 30′ 59″ E). The Descartes region is in typical highlands terrain, saturated with large craters. Two separate formations, identified from photographic mapping, were sampled. These were the Descartes Formation, comprising the hilly terrain, and the Cayley Formation, making up the smoother lower lying plains. The sample reported on here is a soil from station 8 of the traverse (EVA 2) located on a ray from South Ray Crater.