Interbasin Water Transfers and Water Scarcity in a Changing World: A Solution or a Pipedream?

The world is increasingly forced to face the challenge of how to ensure access to adequate water resources for expanding populations and economies, whilst maintaining healthy freshwater ecosystems and the vital services they provide. Now the growing impacts of climate change are exacerbating the problem of water scarcity in key regions of the world. One popular way for governments to distribute water more evenly across the landscape is to transfer it from areas with perceived surpluses, to those with shortages.While there is a long history of water transfers from ancient times, as many societies reach the limits of locally renewable water supplies increasingly large quantities of water are being moved over long distances, from one river basin to another. Since the beginning of dam building that marked the last half of the 1900s more that 364 large-scale interbasin water transfer schemes (IBTs) have been established that transfer around 400 km³ of water per year (Shiklomanov 1999). IBTs are now widely touted as the quick fix solution to meeting escalating water demands. One estimate suggests that the total number of largescale water transfer schemes may rise to between 760 and 1 240 by 2020 to transfer up to 800 km³ of water per year (Shiklomanov 1999).The wide range of IBT projects in place, or proposed, has provoked the preparation of this review, including seven case studies from around the globe. It builds on previous assessments and examines the costs and benefits of large scale IBTs. This report assesses related, emerging issues in sustaining water resources and ecosystems, namely the virtual water trade, expanding use of desalination, and climate change adaptation. It is based on WWF's 2007 publication "Pipedreams? Interbasin water transfers and water shortages".The report concludes that while IBTs can potentially solve water supply issues in regions of water shortage - they come with significant costs. Large scale IBTs are typically very high cost, and thus economically risky, and they usually also come with significant social and environmental costs; usually for both the river basin providing and the river basin receiving the water

Recent changes of water discharge and sediment load in the Yellow River basin, China

The Yellow River basin contributes approximately 6% of the sediment load from all river systems globally, and the annual runoff directly supports 12% of the Chinese population. As a result, describing and understanding recent variations of water discharge and sediment load under global change scenarios are of considerable importance. The present study considers the annual hydrologic series of the water discharge and sediment load of the Yellow River basin obtained from 15 gauging stations (10 mainstream, 5 tributaries). The Mann-Kendall test method was adopted to detect both gradual and abrupt change of hydrological series since the 1950s. With the exception of the area draining to the Upper Tangnaihai station, results indicate that both water discharge and sediment load have decreased significantly (p<0.05). The declining trend is greater with distance downstream, and drainage area has a significant positive effect on the rate of decline. It is suggested that the abrupt change of the water discharge from the late 1980s to the early 1990s arose from human extraction, and that the abrupt change in sediment load was linked to disturbance from reservoir construction.Geography, PhysicalGeosciences, MultidisciplinarySCI(E)43ARTICLE4541-5613

Impacts of, and Vulnerability and Adaptation to, Climate Change in Water Resources and Agricultural Sectors in China

human development, climate change

Chinese agricultural water resource utilisation in the 21st century

With increasing industrialisation and urbanisation, more and more of China’s scarce water resources are being transferred from low-value agricultural use to high-value industrial and domestic uses. The challenge now facing decision makers is how to resolve the conflict between increasing food demand and decreasing water supply without undermining the growth of cities and the industrial sector. Along with water shortages, water use inefficiencies are apparent. An analysis of some causes of these inefficiencies is provided. They include attenuated property rights, artificially low water prices, lack of user participation in irrigation district management, fragmented government management, and lack of a compensating mechanism between upstream and downstream users. It is concluded, against the background of a transitional economy, that the lack of economic incentives in the allocation of water is the principal reason why shortage and waste coexist in Chinese irrigated agriculture. Owing to failures in both markets and governments, it is argued that water resources should be allocated through a quasi-market

Comparative assessment of the vulnerability and resilience of 10 deltas : work document

Background information about: Nile delta (Egypt), Incomati delta (Mozambique), Ganges-Brahmaputra-Meghna (Bangladesh), Yangtze (China), Ciliwung (Indonesia), Mekong (Vietnam), Rhine-Meuse (The Netherlands), Danube (Romania), California Bay-Delta, Mississippi River Delta (USA

Analysis of long-term terrestrial water storage variations in the Yangtze River basin

In this study, we analyze 32 yr of terrestrial water storage (TWS) data obtained from the Interim Reanalysis Data (ERA-Interim) and Noah model from the Global Land Data Assimilation System (GLDAS-Noah) for the period 1979 to 2010. The accuracy of these datasets is validated using 26 yr (1979–2004) of runoff data from the Yichang gauging station and comparing them with 32 yr of independent precipitation data obtained from the Global Precipitation Climatology Centre Full Data Reanalysis Version 6 (GPCC) and NOAA's PRECipitation REConstruction over Land (PREC/L). Spatial and temporal analysis of the TWS data shows that TWS in the Yangtze River basin has decreased significantly since the year 1998. The driest period in the basin occurred between 2005 and 2010, and particularly in the middle and lower Yangtze reaches. The TWS figures changed abruptly to persistently high negative anomalies in the middle and lower Yangtze reaches in 2004. The year 2006 is identified as major inflection point, at which the system starts exhibiting a persistent decrease in TWS. Comparing these TWS trends with independent precipitation datasets shows that the recent decrease in TWS can be attributed mainly to a decrease in the amount of precipitation. Our findings are based on observations and modeling datasets and confirm previous results based on gauging station datasets

Centennial- to decadal-scale monsoon precipitation variations in the upper Hanjiang River region, China over the past 6650 years

The upper Hanjiang River region is the recharge area of the middle route of South-to-North Water Transfer Project. The region is under construction of the Hanjiang-Weihe River Water Transfer Project in China. Monsoon precipitation variations in this region are critical to water resource and security of China. In this study, high-resolution monsoon precipitation variations were reconstructed in the upper Hanjiang River region over the past 6650 years from delta O-18 and delta C-13 records of four stalagmites in Xianglong cave. The long term increasing trend of stalagmite delta O-18 record since the middle Holocene is consistent with other speleothem records from monsoonal China. This trend follows the gradually decreasing Northern Hemisphere summer insolation, which indicates that solar insolation may control the orbital-scale East Asian summer monsoon (EASM) variations. Despite the declined EASM intensity since the middle Holocene, local precipitation may not have decreased remarkably, as revealed by the delta C-13 records. A series of centennial- to decadal-scale cyclicity was observed, with quasi-millennium-, quasi-century-, 57-, 36- and 22-year cycles by removing the long-term trend of stalagmite delta O-18 record. Increased monsoon precipitation during periods of 4390-3800 a BP, 3590-2960 a BP, 2050-1670 a BP and 1110-790 a BP had caused four super-floods in the upper reach of Hanjiang River. Dramatically dry climate existed in this region during the 5.0 ka and 2.8 ka events, coinciding with notable droughts in other regions of monsoonal China. Remarkably intensified and southward Westerly jet, together with weakened summer monsoon, may delay the onset of rainy seasons, resulting in synchronous decreasing of monsoon precipitation in China during the two events. During the 4.2 ka event and the Little Ice Age, the upper Hanjiang River region was wet, which was similar to the climate conditions in central and southern China, but was the opposite of drought observed in northern China. We propose that weakened summer monsoon and less strengthened or normal Westerly jet may cause rain belt stay longer in the southward region, which reduced rainfall in northern China but enhanced it in central and southern China. (C) 2017 Elsevier B.V. All rights reserved

Flood Management in China: The Huaihe River Basin as a Case Study

The Huaihe River Basin (HRB) is a transitional river located in the transitional climate zone in China, and it has been frequently hit by big floods and suffered from flood disasters. Flood control and management of the areas are of vital importance of the Huaihe River Basin in its social and economic development. In this chapter, pioneer works of summarizing the flood management have been done for the Huaihe River in China. It first introduces flood and flood disasters of the River basin. In addition, this chapter summarizes achievements in flood control and management. Furthermore, it discusses experiences and enlightenment in flood control and management and draws conclusions for the research

Little impact of Three Gorges Dam on recent decadal lake decline across China's Yangtze Plain

The ubiquitous lakes across China's Yangtze Plain (YP) are indispensable freshwater resources sustaining ecosystems and socioeconomics for nearly half a billion people. Our recent survey revealed a widespread net decline in the total YP lake inundation area during 2000–2011 (a cumulative decrease of ∼10%), yet its mechanism remains contentious. Here, we uncover the impacts of climate variability and anthropogenic activities including i) Yangtze flow and sediment alterations by the Three Gorges Dam (TGD) and ii) human water consumption in agricultural, industrial, and domestic sectors throughout the downstream Yangtze Basin. Results suggest that climate variability is the dominant driver of this decadal lake decline, whereas studied human activities, despite varying seasonal impacts that peak in fall, contribute marginal fraction (∼10–20% or less) to the interannual lake area decrease. Given that the TGD impacts on the total YP lake area and its seasonal variation are both under ∼5%, we also dismiss the speculation that the TGD might be responsible for evident downstream climate change by altering lake surface extent and thus open water evaporation. Nevertheless, anthropogenic impacts exhibited a strengthening trend during the past decade. Although the TGD has reached its full-capacity water regulation, the negative impacts of human water consumption and TGD-related net channel erosion are already comparable to that of TGD's flow regulation, and may continue to grow as crucial anthropogenic factors to future YP lake conservation

International Experiences of Water Transfers: Relevance to India

Water transfer has and continues to be a complementary water management strategy for promoting socioeconomic development in water-scarce regions. Over 2,500 years ago, the Babylonians, the Roman Empire and the Chinese constructed extensive canal networks, famous aqueducts and the Grand Canal, respectively to support human settlement in water- scarce areas. The Anuradhapura Kingdom of Sri Lanka too, developed major water transfers as far back as 100 AD to support the irrigation civilization needed to feed a growing population (de Silva 2005). In the twentieth century, the phenomenal population growth, economic activities and human settlement in water-scarce regions, advances in science and technology, political will and availability of resources led to the development of many water transfer projects. The global inter-basin water transfer increased from 22 to 56, from 56 to 257 and from 257 to 364 km3 yr-1 during the periods 1900-1940, 1940-1980 and 1980-1986, respectively, and is estimated to increase to 760-1,240 km3 yr-1 by 2020 (Shiklomanov 1999). Most of these transfers took place in Canada, the former USSR, India and the United States of America