Presentation is loading. Please wait.

Presentation is loading. Please wait.

1 Resource Flow Analysis ScottMatthews 12-712 / 19-622 Lecture 8.

Similar presentations


Presentation on theme: "1 Resource Flow Analysis ScottMatthews 12-712 / 19-622 Lecture 8."— Presentation transcript:

1 1 Resource Flow Analysis ScottMatthews / Lecture 8

2 Administrative Issues  HW 3 Graded (avg 45)  HW 4 Due Wednesday  Project Updates  Only 5 groups submitted plans last week 2

3 Recap of Last Time  Ecological footprint  Relevant metric (equiv land use)  Concerns/issues about data and assumptions  Gallery show 3

4 Mass Balance  Fundamental principle of engineering / environmental engineering (law of conservation of mass)  Commoner: “everything must go somewhere”  Physical quantities  Energy  Calories, etc.  Relevant: stocks and flows, ins and outs 4

5 5 Source: USGS

6 Material (Resource) Flow Analysis  Has existed for 100 years, but formalized as a modeling technique more recently  Tool to link impacts with material uses  Simple: materials book-keeping  Complex: dynamic flow analyses  Inevitably an IN=OUT issue  Is this trivial? Is it relevant? Do others realize?  We tend to underestimate complexity – i.e. simple materials in fact very complex flows 6

7 MFA – Definition (Brunner)  A systematic assessment of stocks and flows of a material at a given space/time  Connects sources and pathways with sinks, intermediate flows 7

8 Basic Plan for an MFA  Begin building a simple IN=OUT model  Start assembling IN, OUT flow data  Are there many more relevant IN, OUT flows?  Is there a substantial stock or sink?  Do we have sufficient data to quantify them?  Continue iterating as data and time allow  When done, summarize as many disaggregate stocks and flows as possible  Typically express results “over life cycle” 8

9 9 Source: Brunner

10 10 Source: USGS “MFA and Sustainability”

11 11

12 12 Source: Yale STAF Project

13 13

14 Cadmium USGS Report 14

15 Postel (1996) - Water 15

16 Computers  What Data do we have?  What data do we need?  Can we do a “good enough” job? 16

17 Group exercise  Split into groups  Try to do computer MFA for

18 18 Source: USGS, Obsolete Computers, “Gold Mine,” or High-Tech Trash? Resource Recovery from Recycling

19 Policy Relevance of MFA  Can we track natural versus anthropogenic flows?  JIE paper – Cadmium – only way to reduce is to eliminate inflow  But inflow is byproduct of Zinc; either need to eliminate zinc production or cut off co-product  Structure of such studies – and construction of the stock/flow models – yields insights  Can we learn more about connections between stocks and flows, our activities? 19

20 MFA Issues  Data / methods are largest barriers (conceptually simple otherwise)  What about uncertainty? 20

21 Sankey Diagrams  Generally used for Energy flow analyses  Implicit assumptions  The diagrams concern quantity sizes that are related to a period in time or to a functional unit, such as a product unit.  The quantity scale is proportional (i.e., twice the quantity is represented by an arrow that is twice as wide).  Inventories are not taken into account (i.e., there is no stock formation).  An energy or mass balance is maintained. 21

22 22

23 23 Source: WRI,

24 24

25 Lead Flows 1970 (USGS) 25

26 Lead Flows

27 To Dos  HW 5 coming Wednesday.  Start tracking your expenses AND your general “material/resource” flow starting tomorrow am. Will need to for HW. 27


Download ppt "1 Resource Flow Analysis ScottMatthews 12-712 / 19-622 Lecture 8."

Similar presentations


Ads by Google