Uzbekistan experience in V&A assessments for water resources
Transcript
Slide 1
Uzbekistan experience in V&A assessments for water
resources
Slide 2
Current status of work Regional climate scenarios construction
on the base of the GCM outputs Selection of appropriate scenarios
with taking into account the high level of their uncertainty
Analysis of previous results in the field of water resources
assessment and evaluation of priorities 1. Climate change impact on
the hydrological regime of the Amudarya and Syrdarya rivers 2.
Climate change impact on the irrigation regime and water supply
Adaptation and calibration of the methodologies for water resources
assessment (baseline period) Carrying out the assessments using
adopted models
Slide 3
To construct the regional climate scenarios the outputs of GCMs
collected in database SCENGEN were used with application of the
MAGICC (Model for the Assessment of Greenhouse-gas Induced Climate
Change). Outputs in grid points of six GCMs have been averaged for
the purpose of uncertainty reduction. Regional climate scenarios
Downscaling method based on the multiple linear regression has been
applied. Grid points SCENGEN and reference stations of Uzbekistan
Reference stations of nearby mountain territory........
Slide 4
Observed and expected changes of annual air temperature in
Uzbekistan (averaging of six models, mid climate sensitivity).
Observation data Conclusion: it is possible to consider only two
scenarios ( A2 and B2 )
Slide 5
5 Uzbekistan belongs to the semi-arid and arid zones, which are
under natural water deficit. Intensive water use for irrigation
needs is the main cause of the Aral Sea crisis. Different nature of
the runoff processes in the mountains and in the plains has led to
the division of the territory into the - zone of runoff formation
situated in uplands and - water dispersal area where the runoff is
withdrawn for irrigation purposes and evaporates. Irrigated areas.
Tashkent y u S r d a y y r r a a a m A d
Slide 6
At present water of rivers in the Aral Sea Basin are completely
regulated and distributed among water users. According to
interstate agreements Uzbekistan receives from 43 to 52km3 of water
annually. The main consumer of water resources is irrigated
farming, which uses over 90 % of the available water. Water
resources formation Kirgizstan Tajikistan Turkmenistan Afghanistan
Uzbekistan
Slide 7
Main river basins in the runoff formation zone River basins are
divided into hydrological sub-regions Chircik-Ahangaran Rivers of
Chatcal ridge Rivers of Chatcal ridge Rivers of Fegana ridge Rivers
of Fegana ridge Rivers of Alay ridge Rivers of Alay ridge Zeravshan
river basin Zeravshan river basin Panj river basin Panj river basin
Kafirnigan river basin Kafirnigan river basin
Slide 8
To assess climate change impact on water resources the model of
river runoff formation developed at the Central Asian Research
Hydro- meteorological Institute has been selected. The model
permits to take into account the main regularities of surface water
formation under climate factors. Challenges Assessment of spatial
distribution of precipitation and other meteorological parameters
considering altitude and orographic features Adaptation of each
model to conditions of information deficiency Adaptation of the
software Model of snow cover formation Model of melted and rain
water entering Model of glacier runoff formation. Model of runoff
transformation Models blocks
Slide 9
Changes in number of snow measurement points in Uzbekistan To
describe precipitation and temperature fields in the mountain area
adequate network of observation is required. Our main challenge is
significant reduction of observation points in mountain territory.
Other challenges are caused by occurred climate change Snow storage
reduction Degradation of glaciation
Slide 10
Example of precipitation data restoring Comparison of measured
and restored precipitation mm mm MeasuredRestored
Slide 11
Model simulation of the snow storage at the end of March Snow
cover in the mountains is an important feeding source for the
rivers of Uzbekistan. At present the snow contribution in river
runoff amounts to 60-75%. Model simulation of the integrated snow
storage shows their decrease in all spring months Ugam -Hodjikent
mln.m 3 Years
Slide 12
Glaciological observations have been organized in runoff
formation zone since 1957. In the past 10-15 years the
glaciological observations practically have been stopped. Currently
only the separate glacial areas are estimated on the base of
satellite information. km 2 ? ? ? ? Reduction of the glacier area
in the separate river basins
Slide 13
Updating of base 1990-2005 Data recovering Estimating quality
Parameters of Transformations model Estimating quality Adaptation
of Models Data base Updating parameters of models Adaptation of
models is necessary due to: 1. Information deficit 2. Changing snow
storage 3. Changing glaciation Addressing these problems allows
starting an estimation of water resources components under
realization of climate scenarios. Adaptation of software Spatial
generalization of different components Gathering and analysis of
available data Estimating quality
Slide 14
Pskem river Results of adaptation and parametrization of the
models: Real description of runoff formation during the year
Measured runoff Calculated Calculated snow contribution glacier
contribution rain contribution
Slide 15
Assessment of inflow to Charvak water reservoir Pskem + Chatkal
rivers B2 scenario, 2030 Current norm
Slide 16
Climate change impact on the irrigation regime and water supply
The CROPWAT and ISAREG (The Irrigation Scheduling Simulation Model
by the Institute of Agronomy, Technical University of Lisbon)
models were selected. Depending on data availability, various time
step computations can be used. Input data include: Meteorological
data - precipitation and reference evapotranspiration or weather
data to compute evapotranspiration; Crop data - crop coefficients
and soil water depletion for crop growth stages, root depths and
the water-yield response factor; Soil data - available soil water,
soil water content at planting, potential groundwater contribution.
The ISAREG model permits to simulate alternative irrigation
schedules for different levels of admissible crop water stress and
various water constraints.
Slide 17
Calibration and validation (not only in the framework of SNC
preparation). The calibration and validation of ISAREG were
performed by comparing observed and simulated soil water content on
the base of field observations. The crop coefficients, water-yield
response factor, parameters for estimating the groundwater
contribution and others factors were adjusted for local conditions.
Obtained results have shown a good agreement between field
observations and model simulation, which allow the use of the model
to assess climate change impact and selection of adaptation
options. Changes in number of evaporation measurement points in
Uzbekistan Currently the evaporation measurement network in
Uzbekistan is insufficient. Average difference between measured and
calculated evaporation is about 10% at separate points.
Slide 18
20080 . 2 2 20080 . 2 2 The most significant growth of
evaporation will be occurred at the cold period of the year.
Example of estimated potential evaporation Annual water demand for
irrigation, m 3 /ha (baseline period) RegionCottonWinter wheat
Bukhara74504700 Tashkent56003200 Fergana58003490 Sherabad81004550
At present, the water demand for irrigation needs is very high. The
expected increase in evaporation will reduce water
availability.
Slide 19
Assessment of future water demand using CROPWAT and ISAREG
models. Integration of sectoral impact assessments on water
resources and agriculture and for analyzing adaptation options with
application of the WEAP model. On the most territory of Uzbekistan
water withdrawal varies from 60 to 100% of the total volume of
renewable water resources. The current problem of water supply may
become more severe due to climate change and population growth.
Selection and implementation of adaptation measures are necessary
for countrys sustainable development. According to the estimation
of runoff formation regime, climate change will lead to increase of
runoff variability and probability of extreme phenomena (droughts,
intensive freshets, mudflows). Planning work: Assessment of
possible extreme values (quantiles of 10 and 90% probability within
of climate scenarios)