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Figure 1 shows the Tejo/Tajo basin and the principal flow stations. |
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Figure 2 River Tajo at Alcantara - Spain - artificial influences on flow |
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Figure 3 Simulated and naturalised flow - River Tajo at Alcantara - Spain |
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Figure 4 Simulated and naturalised flow - River Tejo at Almoural - Portugal |
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Figure 5 Flow duration curve - observed and project flow - River Tajo at Alcantara |
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Figure 5 Average monthly observed, naturalised and projected flow - River Tejo at Almourol |
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Figure 1 Great Lakes of Africa |
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Figure 2 Example of infilled lake temperature data |
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Figure 1 Mekong River Basin |
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Figure 2 Monthly average temperature - Mekong River Basin |
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Figure 5 Projection change in monthly average flow - River Mekong at Stung Treng |
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Figure 6 Projected (2050) and observed (1987) flow - Stung Treng |
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Figure 1 - Tonle Sap Lake and Cambodia |
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Figure 2 - Water levels in Tonle Sap Lake and the Mekong at Kampong Cham |
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Figure 3- Simulated and observed levels in Tonle Sap Lake |
Item | Description | Score |
Road segment identification | Coordinates and brief description | For cross-referencing only. |
Road category | MRD categories from 1 to 4 | Score in inverse order. Class 1 has 4 points, class 4 has 1 point. |
Length | Kilometres | Logarithm of the road length in metres. For example, a segment 10,000 metres long world have a score of 4 |
Category of road joined to | e.g. National Road, MRD 3 | As for road categories. If connected to a national road then 5 points. Points are given for both ends. |
Population in communes adjoining road | This is the total population of all the communes the road passes through. | Score is based on the logarithm of the population. For example, if the population is 30,000 the score is 4.5 |
Schools | The presence or otherwise of a school | Score is 1 or 0 |
Wat/Church/Mosque | The presence or otherwise of a Wat (Pagoda) | Score is 3 or 0. Higher than a school as it relates to the whole community and often provides a refuge during a flood. |
Clinic or health centre | The presence or otherwise of a clinic. | Score is 2 or 0. Higher than a school as it relates to the whole community. |
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Figure 1 Map of project area |
Data source | Data |
National Climatic Data Centre (part of the National Oceanographic and Atmospheric Administration of the USA) | Daily values of rainfall, maximum and minimum temperature. |
Climate Explorer, a site run by the Netherland Meteorological Service. | Monthly values of temperature and rainfall. |
TuTiempo, a weather site run by a Spanish company. | Daily values of temperature, rainfall, wind speed, atmospheric pressure, relative humidity. |
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Figure 2 Observed and projected monthly temperature |
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Figure 4 Observed and projected annul precipitation |
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Figure 4 Projection of monthly temperature in 2050 |
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Figure 5 Projection of annual rainfall |
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Figure 6 Projection of annual maximum daily rainfall |
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Figure 7 Projection of unsatisfied crop water demand |
Area (m2) of the 5 islands which have disappeared | |||||
Island | 1947 | 1962 | 2002 | 2011 | 2014 |
Kale | 48,890 | 43,070 | 12,572 | 509 | 0 |
Rapita | 45,700 | 21,250 | 0 | 0 | 0 |
Rehana | 38,330 | 21,800 | 0 | 0 | 0 |
Kakatina | 15,150 | 3,580 | nd | 0 | 0 |
Zollies | 12,240 | 4,980 | 0 | 0 | 0 |
Total | 160,310 | 94,680 | 12,572 | 509 | 0 |
The above chart gives just one rate of sea level rise - the one for the whole period. So what if we look at year-on-year sea level change.
Year-on-year rate of sea level rise
The next chart plots the difference between the value of sea level in the given year and the value in previous year, for each year from 1981 to 2013. So, the first value is the difference between sea level in 1881 and in 1880, and so on. Looking at the chart there is a lot of year-to-year variation, from minus 17 mm/year to plus 21 mm/year. A trend line through the data shows that the rate of sea level rise has increased, by 0.0141 mm/year/year. That means the underlying rate of sea level rise was 1.9 mm/year higher in 2015 than it was in 1880. In other words, the rate of sea level rise is increasing.
Smoothed rate of sea level rise
One way of observing underlying trends more clearly when the data have a lot of year-on-year variation is to use a moving average. This takes the average of the values of the data for a number of years before and after each point plotted. As the data are so variable a long period has been used for averaging, 31 years. The first point plotted is for 1896 and is the average of the sea level from 1881 to 1911, the next is the average from 1882 to 1912 and so on.
This chart confirms that the rate of sea level rise is increasing but not in a uniform way. From a peak of 1.66 mm/year in 1900 to fell to minimum of 0.51 mm/year in 1920. It then rose to another peak of 2.2 mm/year in 1946 before falling to to a minimum of 1.33 mm/year in 1978. The rate of sea level rise then increased again to another peak of 2.84 mm/year 1997.
The trend line on the chart gives a slightly different value for the rate at which the rate of sea level rise in increasing, 0.0117 mm/year/year, to that in the chart above. This is due to effect of the averaging.
Cyclical component to sea level rise
The final chart plots the difference between the rate of sea level rise and the trend line. This is described as the detrended rate of sea level rise. For example, the peak in 1946 was 2.20 mm/year, the value on the trend line for that year was 1.63 mm/year so the value plotted was the difference between them 0.57 mm/year.
This chart shows that the rate of sea level rise has two components. The first is the underlying increase in the rate of sea level rise, this is 0.0141 mm/year/year as seen in the first chart. The second is a cyclical component with an amplitude of plus or minus 0.6 mm/year and a periodicity of around 50 years.
And the orange line? Climate scientists have detected a number of cycles in observed climate data. One of these is called the Atlantic Multidecadal Oscillation (AMO). It is based on sea temperatures in the northern part of the Atlantic Ocean. When the values of this oscillation are plotted along with the detrended rate of sea level rise they show a high degree of synchronicity. It cannot be argued that the AMO causes the variation in the rate of sea level rise. On other hand, it could be argued that both phenomena share an unknown forcing agent.
Island | Mean Sea Temperature - °C |
Cook Islands | 26.0 |
Fiji | 28.4 |
Kiribati | 29.6 |
Marshall Islands | 28.7 |
Nauru | 28.1 |
Papua New Guinea | 30.5 |
Solomon Islands | 29.4 |
Samoa | 29.1 |
Tonga | 25.4 |
Tuvalu | 29.4 |
Vanuatu | 27.2 |
Federated States of Micronesia | 29.9 |
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Figure 4 - Water levels in Tonle Sap Lake and the Mekong at Kampong Cham |
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Figure 11 - Observed and projected water levels in Tonle Sap Lake |
Return period (years) | Current conditions | Projected 2045 |
1-in-2 | 8.60 | 9.43 |
1-in-5 | 9.20 | 10.13 |
1-in-10 | 9.60 | 10.60 |
1-in-25 | 10.11 | 11.18 |
1-in-100 | 10.48 | 11.62 |
1-in-100 | 10.85 | 12.05 |