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<article language="en">
	<journal>
		<journal_title>Hydrology and Earth System Sciences</journal_title>
		<journal_url>www.hydrol-earth-syst-sci.net</journal_url>
		<issn>1027-5606</issn>
		<eissn>1607-7938</eissn>
		<volume_number>10</volume_number>
		<issue_number>5</issue_number>
		<publication_year>2006</publication_year>
	</journal>
	<doi>10.5194/hess-10-619-2006</doi>
	<article_url>http://www.hydrol-earth-syst-sci.net/10/619/2006/</article_url>
	<abstract_html>http://www.hydrol-earth-syst-sci.net/10/619/2006/hess-10-619-2006.html</abstract_html>
	<fulltext_pdf>http://www.hydrol-earth-syst-sci.net/10/619/2006/hess-10-619-2006.pdf</fulltext_pdf>
	<start_page>619</start_page>
	<end_page>644</end_page>
	<publication_date>2006-09-13</publication_date>
	<article_title content_type="html">Extension of the Representative Elementary Watershed approach for cold regions via explicit treatment of energy related processes</article_title>
	<authors>
		<author numeration="1" affiliations="1,2">
			<name>F. Tian</name>
			<email>tianfq@tsinghua.edu.cn</email>
		</author>
		<author numeration="2" affiliations="1,2">
			<name>H. Hu</name>
		</author>
		<author numeration="3" affiliations="1,2">
			<name>Z. Lei</name>
		</author>
		<author numeration="4" affiliations="3">
			<name>M. Sivapalan</name>
		</author>
	</authors>
	<affiliations>
		<affiliation numeration="1" content_type="html">Department of Hydraulic Engineering, Tsinghua University, Beijing, 100084, China</affiliation>
		<affiliation numeration="2" content_type="html">State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing, 100084, China</affiliation>
		<affiliation numeration="3" content_type="html">Department of Geography, University of Illinois at Urbana-Champaign 220 Davenport Hall, MC-150, 607 South Mathews Avenue, Urbana, IL 61801, USA</affiliation>
	</affiliations>
	<abstract content_type="html">The paper extends the Representative Elementary Watershed (REW)
theory for cold regions through explicit treatment of energy balance
equations to include associated processes and process descriptions.
A new definition of REW is presented which subdivides the REW into
six surface sub-regions and two subsurface sub-regions. Vegetation,
snow, soil ice, and glacier ice are included in the system so that
such phenomena as evaporation/transpiration, melting, freezing, and
thawing can be modeled in a physically reasonable way. The
sub-stream-network is separated from other sub-regions so that the
sub-REW-scale runoff routing function can be modeled explicitly. The
final system of 24 ordinary differential equations (ODEs) can meet
the requirements of most hydrological modeling applications, and the
formulation procedure is re-arranged so that further inclusion of
sub-regions and substances could be done more easily. The number of
unknowns is more than the number of equations, which leads to the
indeterminate system. Complementary equations are provided based on
geometric relationships and constitutive relationships that
represent geomorphological and hydrological characteristics of a
watershed. Reggiani et al. (1999, 2000, 2001) and Lee et al. (2005b)
have previously proposed sets of closure relationships for unknown
mass and momentum exchange fluxes. Tian (2006) has applied Lee&apos;s
procedures and formulas and Monte Carlo simulation method, and has
come up with a determinate system based on the equations, though
precluding energy balance ones, proposed in this paper. The
additional geometric and constitutive relationships required to
close the new set of balance equations will be pursued in a
subsequent paper.</abstract>
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</article>

