Lessons 9 · 1 lessons · Sh. M. Sharipov, V. N. Fedorko, N. I. Safarova, V. A. Rafiqov. Geography (Applied geography), Grade 10, 1st edition. “O‘zbekiston milliy ensiklopediyasi” State Scientific Publishing House, Tashkent, 2017
9
Geosystems and their hierarchy
Textbook: pp. 36–39
GoalExplain the concept of a geosystem, its types and its hierarchical structure (from landscape to facies).
The concept of the geosystem was introduced in 1963 by V. B. Sochava: it is a territorial nature–society system whose components interact and exchange matter and energy. Geosystems are closed (do not exceed the limits of matter and energy exchange, such as the geographic envelope) or open (like a landscape, exchanging with its surroundings). By scale there are planetary, regional and topological (local) levels. The hierarchical order is: geographic envelope – land – continent – physical-geographic country – zone – province – district – region – landscape – mestnost – urochishche – facies; the smaller lie inside the larger. A landscape is a system with uniform geological structure, relief type and climate, made of smaller geosystems. A mestnost is a group of similar urochishche, a urochishche consists of interconnected facies, and a facies is the smallest geosystem with uniform conditions. Human impact is felt first in facies because their links are the most fragile; if the impact stops, a facies gradually tends to return to its former state.
Worked examples
A uniform stretch of floodplain in a river valley is one facies; several similar floodplain patches and hollows together may form a urochishche, the lower terraces of the river a mestnost, and the whole desert valley a landscape: small → large.
Grazing thinned the grass cover in one pasture patch: a change at the facies level. If grazing stops, vegetation begins to recover within a few years, since the rock has not changed.
Class activity
“Nesting dolls”: students write six levels of geosystem on cards and nest them from largest to smallest (paper boxes or a layered drawing). Scissors are used with the teacher.
Practice
1
Who introduced the concept of the geosystem into science and in which year?
Academician V. B. Sochava, in 1963.
2
Order from largest to smallest: facies, landscape, urochishche, mestnost.
Landscape, mestnost, urochishche, facies.
3
Why is a landscape considered an open geosystem?
Because it exchanges matter and energy with neighbouring landscapes (water, air, rock material, heat flows).
4
Why is human impact felt first in facies, and what may happen if it stops?
Because the links between components in a facies are most fragile and change quickly (plants first); if the impact stops, the facies slowly tends to return to its former state.