Climate, Climatic Change, and Water Supply (1977) / Chapter Skim
Currently Skimming:
2. Interpretation of Past Climatic Variability from Paleoenvironmental Indicators
2. Interpretation of Past Climatic Variability from Paleoenvironmental Indicators
Pages 34-46
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 34... ...
There seems to be disagreement even among experts as to the need for understanding climatic variability in relation to water supply. There are those who believe that, since most projects in water resources have an economic life of from 40 to 100 years, and since there appears to have been little or no obvious climatic change over the past 200 years, the chance for natural climatic change in the next 200 years is minimal, and, therefore, the question is academic.
|
From page 35... ...
showed that Markov and more persistent generating mechanisms could lead to very different estimates of reservoir firm yield for 50-year design lives even when the generating mechanisms used yielded samples with identical expected values for the mean, variance, and lag-one correlation. They concluded that it was essential that hydrologists and water-resource planners understand the nature of climatic variability and persistence.
|
From page 36... ...
The X and C used to derive the transfer function are the calibration data set. The X to which the transfer functions are applied is the climatic reconstruction data set.
|
From page 37... ...
8000 (rare) 1000 + 1 1 10,000 + — Varied Temperature, precipitation, soil moisture Surface temperature, global ice volume; bottom temperature and bottom-water flux; bottom-water chemistry Temperature, accumulation Temperature, precipitation, soil moisture Temperature, runoff, precipitation, soil moisture Varied Varied
|
From page 38... ...
Comparison of two or more independently derived biologically based transfer functions: In ocean-sediment analysis this could mean comparing results obtained by using radiolaria to those obtained by using foraminifera. In continental regions, the results obtained by pollen analysis can be compared with those obtained by treering analysis, or results based on tree-ring data from one site can be compared with those from another location.
|
From page 39... ...
o 15 30 45 60 75 I ~ I ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 1 1 5 8 11 14 0 30 60 90 11 -38 -32 -28 0.5 ~.2 ~.9 -1.6 FAUNAL INDEX ARBOREAL ICE CORE 6180 IN POLLEN 6180 PLANKTON SHELL FIGURE 2.3 Comparison of paleoenvironmental indicators of climatic records for the past 135,000 years (modified from Figure A.13, U.S. Committee for the Global Atmospheric Research Program, 1975~.
|
From page 40... ...
These were periods of retracted ice sheets, high sea levels, and relative warmth. The amplitude of the climatic variations associated with the glacial cycles seems remarkably constant.
|
From page 41... ...
present plots of frequency versus percentage of variation in different climatic records.-One of these is reproduced as Figure 2.8. From this diagram it is apparent that, based on well-dated temperature records from Central England and Iceland and an isotope record from Greenland, the data in the intermediate zone (500 to 1000 years)
|
From page 42... ...
Their study provides detailed reconstructions of total annual runoff for several subbasins within the Upper Colorado River Basin. In addition, it suggests that, within a larger basin, the tributary systems can show varying degrees of persistence.
|
From page 43... ...
From the foregoing evidence, it appears that within the southwestern United States climatic change has occurred during the past 500 or so years, that it has occurred over a fairly short time span, and that it has been reflected in the annual runoff, at least for the Upper Colorado River Basin. Northeastern United States The only currently existing detailed regional analysis using historical data for the northeastern United States is
|
From page 44... ...
By increasing our knowledge of past climate, we gain a valuable perspective to our view of climate of the present and future. There exist, at present, isolated time series that indeed suggest important climatic changes at all time scales.
|
From page 45... ...
. Long-term surface water supply and streamflow levels in the upper Colorado River basin, Lake Powell Research Project Bull.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.