Notes HC Sustainable Development 2022 6t/m8
12 okt
HC1 (kennisclips)
First clip
Sustainability Issues in Water management
Water scarcity, floods,
Water science
Hydrologic Cycle and Water balance
Introduction to concepts
- Physical processes in runoff generation
- Water balance
- Flowpaths
- River basin management
Hydrologic cycle
- Renewable freshwater cycle in units of thousands of km3 and thousands of km3/year,
respectively, for pools (white numbers) and fluxes (black numbers)
Submarine groundwater discharge is often a neglected part of cycle
- Direct groundwater outflow across the ocean-land interface into the ocean
SGD= freshwater groundwater + recirculated salt water
Physical processes in Runoff Generation
Precipitation
- Water that falls to the earth
Runoff
- Water that flows across land surface after storm event or snowmelt
Infiltration
- Water that seeps into ground
Groundwater
, - Water contained below the ground surface
Evaporation
- Phase change from liquid to gas
Transpiration
- Plant releasing water vapor through its leaves
Water balance
- The amount of water stored in a particular location at a specific time
Interaction between atmospheric water, soil water, surface water, groundwater
Change in storage = inflow – outflow
Watershed
- Area of land where precipitation collects and drains off into a river (or any body of
water)
Water balance
^S = P – Q – ET + Gin – Gout
S= storage
P= precipitation
Q= discharge
- Water flowing at a point in the river
ET= evapotranspiration
Gin= groundwater input (input from neighboring watersheds)
Gout= groundwater output (our groundwater can rise to surface, become part of Q and leave
our watershed)
Flowpaths-> through gravity
Surface pathways
- Direct precipitation
o Precipitation that falls directly into the stream channel
- Overland flow / surface runoff / surface wash:
o Water moving across the soil surface often in concentrated flows that may cause
rill or gully erosion
Subsurface pathways
, - Subsurface stormflow / interflow / throughflow
o Shallow, slope-parallel (i.e. lateral) flow over an impeding horizon
Groundwater flow
- Water infiltrating through the soil matrix or through preferential pathways to an
unspecified underground depth and is conveyed laterally and/or vertically to the stream
channel along permeable zones (e.g. deep soil or bedrock, fractures in bedrock, or
porous sedimentary strata)
River Basin Management
People, societies, agriculture use watersheds-> it is a system, affected by demand and supply
Issues
- Which water users get priority?
- How large can irrigation area A and/or B grow before exceeding the system’s capacity to
supply these agricultural areas with water?
- What are the other competing, non-irrigation uses for the Virgin dam?
- Many more
Second clip
Sustainability Issues in Water Management 1
Many actors affect water management
- The goal of water management
- Sustainable water resources management
- Why plan? Why manage?
Begin with the end in mind-> the goal of Water Management is water security
- The capacity of a population to safeguard sustainable access to adequate quantities of
acceptable quality water for sustaining livelihoods, human well-being, and socio-
economic development, for ensuring protection against water-borne pollution and
water-related disasters, and for preserving ecosystems in a climate of peace and
political stability
, Sustainable water resources management described
- Water resource systems that are managed to satisfy the changing demands placed on
them, now and on into the future, without system degradation, can be called
sustainable
- Sustainable water resource systems are those designed and managed to fully contribute
to the objectives of society, now and in the future, while maintaining their ecological,
environmental, and hydrological integrity
Differences?
- First emphasizes changing demands
Sustainable water resources management involves three blocks and many disciplines
Overlapping science, management, sustainability
PESTEL analysis through, political, economic, social, technological, environmental, legal
Video Singapore domestic, diverse water supply, instead of relying on Malaysia
Why plan, why manage?
- Too little water (water scarcity)
- Too much water (floods)
- Too polluted (water quality)
- Too expensive/cheap (water pricing)
- Ecosystem too degraded (mitigation)
Two trends/drivers in contemporary Water Resource Management:
- Sustainability concerns
- Need for “grassroots” participatory approach
o Needs to involve as many stakeholders as possible
Water sustainability issues 1
- Too little water (water scarcity)
- Too much water (floods)
Too little water (water scarcity)
We have a lot of water, but only a small proportion 3% is fresh water, most of that is in ice
