NECO 2019 Geography Practical Physical answers
(1a)Old side = 1:50,000
New side = 1:150,000
Old scale/New scale = 50,000/150,000 = 1/3
This implies that the map will be reduced by 3
Old length = 27cm
New length = 27/3= 9.0cm
Old breadth = 29cm
New breath = 29/3= 9.6cm
(1c) RELIEF AND DRAINAGE OF THE MAPPED AREA
The drainage pattern of the mapped area is dendritic. There is an irregular branching of the tributaries in many directions like the branches of a tree. The south western part of the mapped area is marshy, poorly drained and liable to flooding.
The highest point on the map is on 900ft while the lowest point is on 600ft. There is a pressure of the conical hill on the south western part of the mapped area.
(i)Outwash Plain; Also called a sandur, an outwash plain is formed by glaciers. Such a plain is formed when a glacier deposits sediments at its terminus. As a glacier moves, it erodes the bedrock and carries the eroded sediments downstream.
(ii)Till Plain; A till plain is also a plain formed by glacial action. Such plains are formed by the deposition of glacial till (unsorted glacial sediment). When a sheet of glacial ice gets detached from the main glacier and melts in place, the sediments are deposited on the ground to result in the formation of a till plain.
(iii)Lava Field; A lava field can also be referred to as a lava plain. Such a plain is formed by the accumulation of layers of lava. The lava plains can stretch for miles and are easily visible from the air or in satellite images where they appear darker in color than the surrounding landscape.
(i)Plains has alluvial soil which make it fertile
(ii)Many rivers flows through plains which provide water.
(iii)Plains are also important in economic conditions.
(iv)Plains are flat therefore they used for human settlement.
-Unloading; This is the release of stress in a rock that produces expansion joints can cause exfoliation. In other words reduction in stress occurs when rocks previously buried deeply are exposed due to erosion of overlying rocks, or when ice sheets that bury rocks melt.
-Exfoliation; is the term used to describe the peeling away of sheets of rock millimeters to m eters in thickness from a rock’s surface due a range of physical and chemical processest during exhumation and weathering.
Action of Plants and animals; can be agents of mechanical weathering. In other words the seed of a tree may sprout in soil that has collected in a cracked rock. As the roots grow, they widen the cracks, eventually breaking the rock into pieces.
Environmental hazard simply refers to disasters which affect lives and properties within environment as a result of the action of man and other natural phenomena
(i)Deforestation exposes the land surface to erosion
(ii)It leads to deterioration of environment
(iii)It increase evaporation and lowers the water table
(iv)It leads to reduction of soil nutrient
(i)Drought threats plant life which leads to crop failure
(ii)It leads to high loss of crops and livestock
(iii)it causes reduction in agricultural productivity
(iv)it causes conflicts between farmers and pastoralists
(v)It can lead to scarcity of food and also lead to desertification
Map digitization involves the extraction of data values from graph. It involves importing the graph from a file, defining the axis system and digitizing it automatically or manually
(i) Land surveying : This is the process by which measurement of the land is made and then represent such measurement by tables,places or layout for specific purposes.
(ii) Map scanning : Exiting maps of various scales containing different types of information about the area of interest are scanned. The information of these maps can be fed into a G I S
(iii) Tabular data : This involves the use of speed data arranged in tables and such data are analyzed and processed by computer in order to generate useful information
(iv) Field investigation : Computerized information systems for data management may be needed during emergencies.
A data base is operational in this case
(i)Corrasion: This refers to wearing away of sides and floor of a river valley by the load.This load includes sand,pebbles,boulders and silts which are being transported
(ii)Attrition: This is the wearing down of the loaf as they collide with one another and the floor and sides of the valley Large boulders therefore are broken down into small pieces like pebbles
(iii) Hydraulic Action: This refers to the force of moving water which is able to remove loose materials such as gravel ,sand and silt and which is also able to weaken solid rock by surging into cracks in the rock
(ii) River cliff and slip off slopes
(iii) Wider valleys
(iv) Shallower valleys