A serious look at the hydrology of Chinese Rivers and manmade global warming's threat.

We depend on glaciers for much more than direct drinking supply,
it’s also the critical reserve drinking supply for millions,
it ought to remain locked up for many direct and indirect benefits to the current regional ecology and future water needs.
It’s disingenuous to try and isolate glaciers from the rest of the eco-system.
All of which are under attack by global warming.

Climate Change and Adaptation for Water Resources in Yellow River Basin, China IHP VII Technical Document in Hydrology UNESCO Office in Beijing, 2010 http://unesdoc.unesco.org/images/0018/001879/187933E.pdf p. 13) Yellow River is a world famous sediment-laden river. {dams love lots of silt} According to 1956 to 2000 series statistics, the average years of measured sediment runoff in Sanmenxia Station is 1.14 billion t, and the average sediment concentration over 31.6kg/m3, YR is in the top of the list of major rivers at domestic and abroad. ... p.14) (4) Serious issues on water for ecological environment and sediment transport YR has high sediment transport capacity, high sediment, which causing the rivers serious. To reduce intensity of the lower Yellow River silting, it is needed to maintain necessary water sediment transport and ecological base flow. According to the average years of 21 billion m3 of water to transport sediment to the sea and sustain the ecosystem, the runoff utilization rate of the YR should not exceed 60%. … 1.2 Changes and trends of the YR water resources 1.2.1 Factors related to changes in the YR water resources (2) Precipitation According to data analysis, the Yellow River Basin in general was decreasing trend in precipitation (Figure 2). From 1956 to 2005, the annual precipitation of the YR over Huangkou is about 450.5mm, which reduced rainfall since 1986 nearly 7%. (3) Runoff According to the calculations of the natural runoff (Huayuankou hydrological station) from 1956 to 2000, is 53.28 billion m3. In recent years, the natural runoff of the YR Basin greatly reduced (see Figure 3), natural runoff since 1986 has a decrease of nearly 20% (compared to before 1986). Runoff and precipitation trends broadly consistent with the trend, showing that climate influence the runoff. p17.) (5) Ecosystem and environment changes in the headwater region of the Yellow River Due to warmer resulted from climate change, the glacier area of Animaqing Mountain in Headwater region of the Yellow River decreased 17% in recent 35 years from 1966 to 2000, the glacier line rose nearly 30m, many lakes shrank and even disappeared, the ecosystem and environment deteriorated. The area of swamp and lake decreased 3000 km2 from 1976 to 2000. The increase in temperature has probably led to the melt of permafrost, increase in evaporation, and runoff reduction. At mean time, the climate change and over-grazing has resulted in degradation of grassland and serious rat hazard. The headwater region is the main water sources region of the Yellow River , its runoff amount accounts 40% of that of the total basin. Thus, it is regarded as the water tower of the basin, the deterioration of the eco- environment in the headwater region has adversely effected the runoff volume of the whole basin. p. 20) 2.3 Water Shortage Situation The contradiction between supply and demand of water will become more acute. According to the analysis, under the current situation, the available water supply of Yellow River basin is 40.6 billion m3, and however national economy water demand is 48 billion m3, the gap is 7.4 billion m3. In consideration of the water saving by 2030, national economy water demand will reach 54.7 billion m3, and the gap will reach 10.4 billion m3. At the same time, the water into the sea is only 18.3 billion m3 which can not meet the need of river ecological water demand. Therefore, the shortage of water resources will become the main restraining factor of future economic and social sustainable development and ecological environment benign maintenance.
Also see:
How China Is Dealing With Its Water Crisis BY RENEE CHO|MAY 5, 2011 http://blogs.ei.columbia.edu/2011/05/05/how-china-is-dealing-with-its-water-crisis/
Impending Water Crisis in China Nina Brooks http://www.arlingtoninstitute.org/wbp/global-water-crisis/457 Water Supply China’s water supply comes from glaciers, surface water, and groundwater. However, it is not the lack of water, but the uneven distribution of water that makes China’s current situation so dire. China is in the unique position of being both water rich and water poor. Water is extremely scarce in the North but abundant in the South. 1.1 Glaciers The Qinghai-Tibetan Plateau, located in Western China, is comprised of over 35,000 glaciers with an area of approximately 50,000 km2.[6] Seasonal melting typically keeps China’s rivers flowing during the dry season. This seasonal behavior is unfortunately being disrupted by warming due to climate change (to be discussed later). The Qinghai-Tibetan plateau is the origin of two of China’s most important rivers, the Yangtze and Mekong, as well as rivers that run through other countries such as the Indus, Mekong, Salween, and Tarim Rivers. 3.4 Climate Change Climate change poses a serious threat to ecosystems around the world. Many aspects of climate change and its role in the water scarcity issue for China are still ambiguous and being studied. However, global warming has had an undeniable effect on the Qinghai-Tibetan Plateau, which is the source of water for the Yangtze and Yellow Rivers. MSNBC reported in 2006 that, “glaciers covering China’s Qinghai-Tibet plateau are shrinking by 7 % a year due to global warming and the environmental consequences may be dire."[44] According to the IPCC, global temperatures have warmed by .76 Celsius over the last 100 years.[45] The glacier’s seasonal melting keeps the rivers flowing during the dry season, but as the glacier retreats by more and more every year, there will be less water during the dry season. In addition, the melting could cause massive flooding, followed by severe drought and an ultimate long-term decrease in water supply that is irreplaceable. This warming has not only caused glacial retreat but also the drying up of numerous lakes that feed the region’s rivers. ... Lake shrinkage mainly occurred in the Yangtze River source region, a total decrease of 114.81 km2, accounting for 10.64% of the total lake area in the Yangtze River source region and for 58.4% of the total decreased area in the combined region. The source lake for the Yellow River source lake has decreased by 5.28 %."[46] The decrease in rainfall is also causing desertification across China, increasing the percentage of land that is unusable for agriculture. It is still unclear whether global warming will increase or decrease precipitation in the long run for China, but the past several years have seen significant drops in rainfall across several provinces. ... Consequences of Water Scarcity Possible Water Management Solutions 5.1 Three Gorges Dam 5.2 South-North Water Diversion Project
Conclusion ... The Yangtze and Yellow Rivers have been drying up earlier than ever and now rarely reach the Pacific Ocean during the dry season. All of China’s water sources are becoming scarcer, while sources of demand are increasing. Rivers and lakes are drying up, what water is left is increasingly polluted, glaciers are melting, groundwater is being over-pumped beyond recharging limits, and precipitation has been dwindling. Global climate change has already had a recorded impact on China’s water resources and threatens to worsen the plight. All of these problems overlap and amplify the effects of each other, putting even greater stress on water resources. ...