China
Africa
Explore chapters and articles related to this topic
Origin and recharge rates of alluvial ground waters, Eastern Desert, Egypt
Published in M.M. Sherif, V.P. Singh, M. Al-Rashed, Hydrology and Water Resources, 2020
Mohamed Sultan, Hazem Gheith, Neil C. Sturchio, Zeinhom El Alfy, Shuhab Danishwar
The subject of this study is the ground waters in the shallow (< 150 m) alluvial and limestone aquifers of Wadi El-Tarfa (Fig. 1) and the surrounding valleys, namely Asyuti, Wadi Qena, and Wadi Hammamat. Here, Quaternary deposits comprise wadi and floodplain deposits. The alluvial deposits were eroded from the dissected plateau, and the Red Sea hills and were deposited within the valleys. The floodplain deposits of the Nile Valley are made up of relatively thin (7 m) Holocene units of fine mud and silt deposited by repeated seasonal floods during the past 8,000 y. The sediments are underlain by thicker deposits of middle Pleistocene sand and gravel under the Nile Valley proper. The Quaternary deposits rest on karstified carbonates of Eocene and Upper Cretaceous ages. The carbonates are underlain by Paleozoic-Mesozoic Nubian sandstones that host nonrenewable fossil waters under high pressure (Fig. 2).
2
Published in Eric W. Harmsen, Megh R. Goyal, Flood Assessment, 2017
According to Flood Insurance Study by Federal Emergency Management Agency [23], the land use on the Río Grande de Añasco watershed are distributed as follows: 278 km2 are cropland; 114 km2 are pasture; 85 km2 are forest and woodland; 33 km2 are idle, and 13 km2 are urban development and other uses. The vegetation in the floodplain was primary sugar cane. Soils in the floodplain are clay loams. The entire Rio Grande de Añasco watershed is in the humid, mountainous physiographic area of Puerto Rico. The Atalaya Mountains extend from the coastline eastward along the north side of the floodplain, merging with dissected plateau remnants at slightly lower elevations, north of the City of Añasco [23].
Groundwater Targeting Using Remote Sensing
Published in Prasad S. Thenkabail, Remote Sensing Handbook, 2015
The dissection pattern is easily recognizable on the satellite imagery that helps in geomorphic zonation of the different plateau. In the highly dissected plateau, the stream channels are easily recognizable and are controlled by fracture systems. The soil formation is least and therefore, the tone is lighter. In the undissected plateau, the thickness of the weathered material is more and is darker in tone. The stream channels in the basaltic terrain are normally lineament controlled and are easily mappable on satellite imagery. Very good groundwater potential is also observed in the alluvial plains of major rivers in the basaltic region. Buried channels/old river courses are also identifiable.
The tectonic history of Adelaide’s scarp-forming faults
Published in Australian Journal of Earth Sciences, 2019
The maximum areal extent of preservation of summit surfaces is on Kangaroo Island. At the western end of the island, the surface has an elevation of 200 m; extending in an easterly direction from there it rises to a maximum height of 300 m before descending back to its lowest elevation of 150 m at the eastern end of the island. Thereafter the continuity of the summit surface is interrupted by the Quaternary partial exhumation of a large Carboniferous–Permian glacial valley to form Backstairs Passage, and the surface re-appears east of Cape Jervis on Fleurieu Peninsula at an elevation of 340 m, then rising gradually to 370 m just south of Inman Valley, the next major partially exhumed glacial valley. North of this valley, the dissected plateau lies at 420 m, dropping to 390 m in small remnants 5 km southwest of Mount Compass. In the highest parts of the Kangarilla Block, east of Kangarilla, the summit surface is so intensely dissected that it is reduced to a series of roughly concordant summits at about 430 m elevation. From there it is difficult to recognise any remnants of the summit surface on the Kangarilla Block.
Overview of hydrological and climatic studies in Africa: The case of Ghana
Published in Cogent Engineering, 2021
Generally, the physical relief of Ghana is low (i.e. up to about 450 m above sea level) with topography which is predominantly undulating except the Akwapim-Togo mountain ranges which is located in the eastern part of the country. Mount Afadjato which is the highest altitude of the country (i.e. 880 m above sea level) is situated within this area. The relief of the country has been categorized into five physiographic regions namely: coastal plain, forest dissected plateau, savanna high plains, Voltain sandstone basin and the ridges and escarpment bordering the Voltain sandstone basin (Dickson & Benneh, 1988).