Reviewer: Rick Lawford

Chapter: Water Management

Question 8 comments:

1\. Page 91, lines 2017-2020: In terms of building reservoirs, canals,
etc,

it would be appropriate to also mention the role of the US Army Corp of
Engineers.

2\. Page 91, line 2036--2038: It would be useful to also list the fact
that

the high visibility of a bad decision's outcome tends to encourage
reservoir operators and other water managers to be very conservative in
their decision making.

3\. Some parts of the description of RiverWare sound a bit like a
summary

from a sales document or something written by the provider.

4\. The text on 2b and 2d should be moved to a point later in the

Prospectus because it takes away from the focus on global change data.

For the purposes of this discussion it would be helpful to have some
discussion about what role CCSP sees for the private sector,
intellectual property rights, open source code, etc. The issue of
putting in costs of licensing in Section 2d (p. 94) does not seem
appropriate for this Prospectus. An internet address that links
interested readers with the supplier would be more appropriate. Also,
the description of who is likely to have the capability of using
RiverWare could be placed near the end of the discussion after the
description of the combined use of climate data and the software.

5\. The last two paragraphs of 2c also deal with the specific details
and

simulation capabilities of RiverWare. It would be helpful for the
description to highlight the use of climate data and Earth Observation
inputs which are clear when one looks at RiverWare in the context of the
ET Toolbox.

6\. The scenario description on p. 96 (lines 2155 to 2160) is very
helpful

in terms of an application. What climate data were used in developing
this scenario? This would be a good example to elaborate and build on as
a case study related to the application of climate data and the use of
RiverWare.

7\. Page 96 (lines 2174,2175): These lines do not give credit to the

extensive use that has been made of ET Toolbox which uses the Land Data
Assimilation System outputs derived from observations and hydrological
models to process conditions in the western US for the Bureau of
Reclamation. The work of Houser et al. and others should be referenced
here.

8\. Page 97, lines 2183 -- 2186 and 2190-2192: As noted earlier it would
be

good to clarify very early in this chapter that independent hydrologic
models are needed to provide RiverWare with streamflow at all time
scales not just at mid-range.

9\. Page 97, line 2196 to 2198: It is a little confusing to have AMSR,

ICESAT etc listed if none of them are used in conjunction with
RiverWare.

Perhaps when the discussion of the ET toolbox is included there can be
more clarification of what remote sensing data is actually used in the
model so the write-up can be clearer.

10\. Page 97, line 2203: I wholeheartedly agree with this statement.
Given

that natural flows are so difficult to calculate and do not represent
what is happening in the river or what is measured at hydrologic gauges,
the reader will be left wondering why they are used at all. Could the
rationale for the use of these hypothetical variables in these days of
sophisticated hydrologic models be given in more detail.

11\. Page 98. lines 2212 to 2218: This example holds the seed of a
helpful

approach example for this chapter. Could the author take an example of
an event and track it through the hydrologic modeling and RiverWare
system.

Can an example be given where an event from a longer term record event
(say one in 50 years or one in a 100 years event) was passed through the
system? Could this be presented in a way that would exemplify the types
of uncertainties that may be introduced or amplified by RiverWare.

12\. Page 98, lines 2227 to 2231: It would be good to provide references
to

several reports that discuss how the uncertainties in the streamflow
estimates derived from precipitation inputs are amplified by hydrologic
models.

13\. Page 98, line 2235: "poor radar coverage" might be more precisely

described as "beam blockage by mountains"

14\. Page 99, line 2245: replace "smaller extent" by "smaller domains"

15\. Page 99, lines 2253 to 2256: These descriptions of non-stationarity

are very important -- can they be expanded by including a description of
the "percentage of non-stationarity per decade" or some such measure?.

Also, could a description be provided of the consequences of different
types of non-stationarity. (e.g., non-stationarity in means versus
non-stationarity in variances). A description of ways in which RiverWare
could be used to elaborate the impacts of these changes would also be
helpful.

16\. Page 99., lines 2260 to 2262: The description of naturalized flows

seems repetitive with what was given earlier. (There is a general need
to reorganize this chapter to deal with issues only once).

17\. Section 3c: These discussions could deal with both uncertainties in

the magnitudes and timings of flows and their consequences.
Uncertainties in timing are not emphasized here although they are likely
to be the major impact arising from a warming climate .

18\. Page 101, first paragraph: It would be important to mention the

uncertainties due to vegetation cover when using satellites to estimate
snow water equivalent. The Walker and Goodison reference is quite old,
are there no references to their more up to date work? (I think the more
common term than "snow water volume" is "snow water equivalent").

19\. Page 101, Paragraph 3: This would be a good place to introduce the

concept of ensemble forecasts and the HEPEX project (Reference John
Schaake and colleagues).

20\. Page 102, line 2324: What is meant by "proper identification of a

predictive model" (What is "proper"?)

21\. Page 102, line 2329: refer to precipitation rather than rainfall
(snow

should be included)

22\. Page 102, lines 2332-2333 These comments are very useful and could
be

used to highlight the potential applications of RiverWare.

23\. Page 102, line 2342: I think this statement sells RiverWare and the

community that has been working with RiverWare and climate information
short. There is a lot more that has been done than this statement
suggests. Could the author change this statement from a negative one to
a positive one in order to better achieve the purposes of this report.

(Conclusions about this chapter reported in other parts of the
Prospectus should also be modified based on these revisions).

24\. Page 103, last line: "Hydrologic risk" should be defined.

25\. Page 104, lines 2380 to 2382: Given all these successful studies
that

have provided information when should RiverWare be used? If the purpose
of this Prospectus is to show successful examples should the chapter be
rewritten with some other system that has been used more successfully
with climate data? (I think the answer to my question is "no" but then
more should be added on RiverWare as part of the ET Toolbox).

26\. Page 105, line 2414: Do we really think that every time there is an

application of the system that a full scientific explanation should be
given? If predictions are made with a well known system on a routine
basis this approach seems like "overkill." A caveat should be given for
the application of this principal.

27\. Page 105, lines 2418 to 2419: How good do forecasts have to be
before

they are useful for water resource management? How can forecast utility
be defined (with and without RiverWare)?

28\. Page 105, lines 2403-2411: This looks like an interesting and

appropriate example. Can more information be provided on the
uncertainties of the interactions between the components of the system
and how these affected the final outcome?

29\. General: Some discussion should be added about the robustness of

forecasts, trends and scenarios to reflect the fact that the level of
confidence in some products and variables (e.g., temperature) is higher
than others (e.g., precipitation). This affects the uncertainties and
utility for forecasts and systems that rely extensively on precipitation
inputs.