37. Wrap Up (rivers, sugar)

Here's world's top 20 longest rivers. A better infographic:

And yet, one has to remember:

"(It's not so easy to define how long a river is. If a number of tributaries merge to form a larger river, how would you define where the river actually begins? Here is how we are defining river length:

River lengths or river-length data are affected not only by some of the natural and artificial causes noted in the preceding paragraph, but also by the precision of various techniques of measurement, by the scale of available maps or aerial photographs, and by somewhat arbitrary decisions. For example, the length may be considered to be the distance from the mouth to the most distant headwater source (irrespective of stream name) or from the mouth to the headwaters of the stream commonly identified as the source stream. "

Following are the river basins:

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Here perhaps a look at dams across these rivers.

"In order to meet the needs of a growing population, a number of infrastructure projects (e.g., dams) were built to increase water withdrawals from rivers and groundwater for much of the 20th century. Specifically, during the second half of the 20th century, construction of dams was regarded as the main measure of river basin management for generating hydropower, controlling flood, storing water storage, and reducing risks from natural disasters"

By the year 2010, a total of 32,473 large dams had been constructed all over the world [27]. The number of large dams (as well as related reservoirs and hydropower stations) for each country is calculated and the result is shown in Figure 1 (see the blue circles). At the continental scale, there were 14,719, 9241, 5163, 1799, 988, and 563 large dams in Asia, North America, Europe, Africa, South America, and Oceania, respectively. It is worth noting that nearly 90% (i.e., (14,719 + 9241+5163)/32,473) of the large dams were built in Asia, North America, and Europe, which are the three continents with more developed countries than other continents. In terms of the locations, most large dams have been constructed in the basins of the great rivers, such as the Yangtze River, the Yellow River, and the Ganges River in Asia, the Mississippi River in North America, and the Rhine River and Danube River in Europe. Furthermore, at the national scale, it is observed that United States has built the most large dams with the number of 7968, followed by China (with the number of 4928) and India (with the number of 4104). Among them, the United States is the most-developed country in the world, while China and India are the two fastest developing countries. Therefore, such results can preliminary indicate the close relationship between large dams and economic development.

Moreover, based on the main use of a large dam given by Global Reservoir and Dam database [28], it is observed that 29% of the large dams were built for hydroelectricity, 34% for irrigation, 10% for flood control, 16% for water supply, and 11% for other uses (e.g., navigation and recreation). It is observed that hydroelectricity and irrigation are the two most important considerations for large dam construction for the purposes of energy production and food production, respectively.

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Wrapping up - Sugar

Sugar subsidies have driven market costs for sugar well below the cost of production. As of 2019, 3/4 of world sugar production is never traded on the open market. Brazil controls half the global market, paying the most ($2.5 billion per year) in subsidies to its sugar industry

Following is slightly dated data on Sweetners.

 Since Sugar became expensive, ... Coke replaced it with corn related

In terms of end use, following is an indicative mix of direct-indirect sugar usage, and then details in one particular country, Germany.  (It is 20 year old data, directional reference only)

Different kinds of sugars: