Geology (from the Greek γῆ, gê, "earth" and λόγος, logos, "study") is the science and study of the solid Earth and the processes by which it is shaped and changed. Geology provides primary evidence for plate tectonics, the history of life and evolution, and past climates. In modern times, geology is commercially important for mineral and hydrocarbon exploration, evaluating water resources, is publicly important for predicting and understanding natural hazards, understanding and remediating environmental problems, and understanding past climate change, plays an essential role in geotechnical engineering, and is a major academic discipline.
Engineering Geology is the applied field which deals with the application of geological knowledge in the field of engineering. Engineering geology gives the idea of site selection, proper investigation and eligibility of the area for particular type of engineering project. It is devoted to the investigation, proper site selection and engineering solutions of environmental problems which may arise as result of interaction between geology and human activities as well as the prediction and reduction of geological hazards. Engineering geology has much more scope over the civil engineering as the geology governs the proper selection of site, cost estimation and designs of the structures. Also if various geological structures like fault, folds, unconformity, etc. are not considered then it not only increases cost but also cause the failure of the whole project.
As a student of civil engineering we studied the theoretical parts of engineering geology but it was hard for us to understand those theories. These theories would be understood through field works and study. The field study helps to acquire the actual field condition such as topography, bedding conditions and so on. Without field study the study of geology remains incomplete. So seeing the need to understand this subject properly a tour of three days was organized by the college. The tour was mainly focused to provide practical knowledge about various types of geological structures like landslides, planar features, river channel morphology, types and nature of rocks identification, rocks bedding, etc.
The study area is linked with the Prithvi Highway, which is considered as a channel linking Kathmandu with Pokhara & other major cities of the country. It have peculiar geological features within a small range of area. The Malekhu V.D.C. of Dhading district lies about 70 Km south west of Kathmandu valley and is located at latitude of 27o 50' 38'' to 27o 45' 50'' and longitude of 24o49'5'' to 84o50' 50’’. Malekhu Bazaar is therefore accessible by motor able and graveled roads. The northern part of the study area is accessible through Malekhu – Dhading road. The remaining parts can be reached by narrow foot trails around the Malekhu and Thopal Khola.
1.3 TOPOGRAPHY AND DRAINAGE
The topography of Malekhu is very rugged. It includes hills, river valleys, escarpments, spurs, saddles, river plain and terrace etc. The lowest altitude of this area is about 340m at the Trishuli river valley and the highest altitude of this area is about 1525 m at the north of the Dharapani village.
Malekhu lies on lesser Himalayan unit of Nepal It is situated on the bank of Trishuli and Malekhu river. The Trishuli river is running from the eastern direction to the western direction and the Malekhu river from south to north which mingles into the Trishuli river. Also, the Malekhu river has a tributary namely the Apakhola which meets the Malekhu river at a distance about 3 kms from the Malekhu bazzar. Climatically Malekhu is a sub-tropical zone. The Trishuli River, a snow fed river of the Central Nepal, is the main drainage of Malekhu and its surrounding areas. It flows through the east to the west, more or less parallel to the structure strike. Because of the variation in altitude, ranging from 350 m from sea-level (at the bank of Trishuli Nadi) to 1000m (neighboring hills), the local climate varies throughout the year. There is tropical to sub-tropical climate in valleys and temperate climate at higher areas. Physiographic condition, monsoon winds, altitude & vegetation controls the climate of the area.
Temperature ranges from 250c to 380c in summer and 100c to 200c during winter season. Valley area is relatively warmer than higher areas. Rainy season brings difficulties in habitation. Various disasters like floods, landslides etc. cause the damage to the highway bridges, agriculture lands, houses etc.