ENVS10001 Lecture Notes - Lecture 13: Drainage Basin, Water Scarcity, In Essence
26 May 2018
School
Department
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ENVS10001 – Putri Shafira 2018
169
WEEK 7 – HYDROLOGICAL PROCESSES AND MANAGEMENT
Tuesday, April 17th 2018
From Lecture 13: Catchment Management and Water Resources by Alexis Pang
Catchment management and water resources are essential for landscape management and
agricultural systems and more broadly for survival of the human society.
Water scarcity has been an international issue are occurring, translate into geopolitical conflict
(e.g. India and China, not just Australia). The variability and the vulnerability of the changes in
Australia’s climate and rainfall will also cause risks.
Questions
1. Why are we having/ going to have water crises?
2. How can we deal with problems and conflicts over water?
3. How does the natural water (hydrological) system work? – This is essential! à water
crisis, conflicts, and policy, therefore we need to understand the hydrological system
works in various scale
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4. How can we best manage water resources to balance multiple needs of:
- Economy?
- Ecology?
- Society?
- … in a sustainable manner?
Scope
1. The hydrological cycle
2. Catchments and catchment processes à the way of we organize and understanding the
ecological cycle in smaller scale
3. Water resources in catchments
4. Principles and examples of integrated catchment management
Global Hydrological Cycle – closed system
The global hydrological cycle at the global scale is a closed system in the addition of loss
water and gain of water to the Earth.
The water is at the same amount, it is just in different form and different location.
Basically, most of the water that we’re mostly experience as rain or maybe snow (86% is
evaporated from the ocean cause most of the Earth’s surface is covered with ocean). Essential for
of what we do we here on land, is the horizontal advection of transfer of water vapour, forms
cloud with or without wind, over the land from the ocean. And that water forms condenses and
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falls as precipitation (snow ice or rain or liquid water) over land that actually gives us the water
that we require that we use and for the terrestrial environment uses.
The terms flow back to the ocean to runoff, there is some storage on the Earth surface,
but also there is a return flow in terms of ground water. So ground water also acts as a storage
(like a sponge that absorb water) and there is also a slow flow back towards the ocean (of course
there is abstraction as well).
Major loses of the Earth surface are through the evaporation (physical change of the water
from the liquid stage into the gaseous stage), but also equally important for transpiration, which
plants take water from the soil and then transpire as part of the photosynthesis process and the
transpiration processes.
But, there is the operation of the 6-cell model. There is the global atmospheric circulation
that actually causes the high and low pressure in different parts of the Earth’s surface and also
impacts on the existing of different biomes, the movement of the ITCZ and so on which causes
an uneven spatial and temporal distribution towards the Earth’s surface.
Generally, when there is ITCZ and the converging winds, a lot of uplift of air and
condensation of water vapour and then rain occurring. And the other parts of the world, unless
there is descending air and very stable, so there is pretty little uplift, you have pretty dry
conditions. In essence, you have different combinations of those climatic/ atmospheric
parameters, giving different ways and which hydrological cycle operates in different parts of the
world/ different regions of the world (e.g. Maritime locations – near to the sea; continental – far
inland). All pretty closely interrelated.
Document Summary
From lecture 13: catchment management and water resources by alexis pang. Catchment management and water resources are essential for landscape management and agricultural systems and more broadly for survival of the human society. Water scarcity has been an international issue are occurring, translate into geopolitical conflict (e. g. india and china, not just australia). The variability and the vulnerability of the changes in. Australia"s climate and rainfall will also cause risks. Water crisis, conflicts, and policy, therefore we need to understand the hydrological system works in various scale. Envs10001 putri shafira 2018: how can we best manage water resources to balance multiple needs of: Scope: the hydrological cycle, catchments and catchment processes the way of we organize and understanding the ecological cycle in smaller scale, water resources in catchments, principles and examples of integrated catchment management. The global hydrological cycle at the global scale is a closed system in the addition of loss water and gain of water to the earth.
