16 research outputs found
Choosing the proper spatial and temporal resolution for water management: Don’t forget the ‘Invisible’ factors
In the search for the proper spatial
and temporal resolution at which
to manage natural resources, we
are generally guided by the flows and
stocks of water that we can ‘see’ – rainfall,
flowing water, reservoirs, dams,
etc. We use what we observe to identify
the socially optimal flows/stocks
of water, and then suggest the public
policy action required to achieve
these results. However, there are also
some ‘invisible’ factors that need to be
included in policy discussions related
to water management; one important
invisible factor is groundwater (the
focus of this brief).
The bad news is that groundwater
is ‘invisible,’ hence stocks and flows of
it are more difficult to measure. The
good news is that we are discovering
ways to more cheaply measure
groundwater stocks/flows and to predict
the spatial and temporal effects
of groundwater extraction. The SFRB
research team has developed a demonstration
model capable of examining
these effects, and what follows is
derived from simulation experiments
using that model in the Buriti Vermelho
sub-catchment area located
near Brasilia.
The Buriti Vermelho
Sub-Catchment Area
The Buriti Vermelho (BV) sub-catchment
area is a small watershed
comprised of several
types and spatial extents
of farming activities.
Figure 1 depicts the BV
site; the precise boundaries
of the sub-catchment
area are given
by the thin black line.
Water emerges from
about the south-central
part of the site, just
outside the green patch
of cerrado típico (savanna
forest) and flows from
south to north. Blue
circles identify the
location and size of
capital-intensive centerpivot
irrigation schemes,
while yellow rectangles
identify small farms. Large patches of
rainfed agriculture remain in th
Water productivity at basin level: Methods, benefits, and shortcomings
This research program is part of the CGIAR Challenge Program on Water & Food and is supported by the International
Water Management Institute, the Brazilian Enterprise for Agricultural Research (Embrapa), and the Department of
Land, Air and Water Resources, the Department of Agricultural and Resource Economics, and the Center for Natural Resources Policy Analysis,
all at the University of California, Davis. The views expressed in this research brief need not reflect those of the sponsors
Poverty and water management in the Sao Francisco river basin: Preliminary assessments and issues to consider
Of the approximately 17 million
who inhabited the SFRB
in 2003, about 3.7 million
(approximately 21%) were poor by
Brazilian standards (living on about
one minimum salary or less). Just over
four million people lived in rural areas
of the SFRB and nearly one-third of
them (about 1.2 million) were poor.
But the rural poor were not distributed
evenly across the SFRB (see
Figure 1). The proportion of the rural
poor tended to be lower in the southern
portion of the SFRB, primarily in
the state of Minas Gerais, the mountainous
zone where the São Francisco
River begins. Rural poverty, by this
measure, tended to be higher in the
central and northern zones, with some
municípios registering proportional
rates of poverty well in excess of 50%
of the rural population.
The depth of poverty matters
greatly; Figure 2 depicts the spatial
distribution within the SFRB of
the extreme poverty, i.e., individuals
belonging to households living on
less than one-third of the Brazilian
monthly minimum salary per person.
These extremely poor households are
located almost exclusively in the central
and northern zones of the SFRB.
While poverty is central to our
research, training, and outreach
mandates, it is also interesting to
focus attention on municípios that
are less poor, in part because we may
learn something from these less-poor
municípios that may be useful to their
more-poor counterparts. Reviewing
Figures 1 and 2, it is easy to identify
less-poor municípios in the central
and northern zones of the SFRB
where rural poverty was especially
concentrated. One has to wonder
what factors might cause neighboring
municípios to have such different rural
poverty rates; might water availability
have something to do with this?
Water Availability in the SFRB
While water availability is difficult to
define and even more challenging to
measure, at any resolution, Figure 3
depicts estimated water availability for
the SFRB, by município. Our measure
of water availability considers annual
precipitation, base evapotranspiration,
catchment area upstream,
and slope (how likely is rainfall or
run-on likely to ‘stay’ on the receiving
farm); municípios that appear
in darker blue have more available
water than those in green or
yellow. No seasonal or other water
storage, or artificial conveyance of
water, is included in this measure
of water availability; this measure
of water availability may be most
useful in areas where irrigated
agriculture relies on precipitation
as well as on local diversions of
direct runoff from the upstream
catchment.
Two important patterns emerge,
one that we have been long
familiar with and another that is
somewhat surprising. The familiar
pattern is that of generally higher
measures of water availability in the
southern and central zones of the
SFRB than in the northern zone; this
corresponds to known variations in
annual rainfall, which ranges from a
high of about 1,500 mm/year in the
southern zone to a low of about 500
mm/year in some areas of the northern
zone.
The surprising pattern is the presence
of relatively water-scarce municípios
in the high-rainfall southern
zone, and some relatively water-rich
municípios in the arid northern zone.
Other variables in the water availability
measure as well as scale of analysis
(resolution) explain these differences
Economic Analysis of the Treatment of Malaria: A Case Study
government ; policy making ; health economics ; income
Challenges to managing ecosystems sustainably for poverty alleviation: securing well-being in the Andes/Amazon: final report
Population, Land Use and Deforestation in the Pan Amazon Basin: a Comparison of Brazil, Bolivia, Colombia, Ecuador, Perú and Venezuela
This paper discusses the linkages between population change, land use, and deforestation in the Amazon regions of Brazil, Bolivia, Colombia, Ecuador, Perú, and Venezuela. We begin with a brief discussion of theories of population–environment linkages, and then focus on the case of deforestation in the PanAmazon. The core of the paper reviews available data on deforestation, population growth, migration and land use in order to see how well land cover change reflects demographic and agricultural change. The data indicate that population dynamics and net migration exhibit to deforestation in some states of the basin but not others. We then discuss other explanatory factors for deforestation, and find a close correspondence between land use and deforestation, which suggests that land use is loosely tied to demographic dynamics and mediates the influence of population on deforestation. We also consider national political economic contexts of Amazon change in the six countries, and find contrasting contexts, which also helps to explain the limited demographic-deforestation correspondence. The paper closes by noting general conclusions based on the data, topics in need of further research and recent policy proposals.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42720/1/10668_2003_Article_6977.pd