Presentation from the 2013 World Water Week in Stockholm

Transcription

1 Presentation from the 2013 World Water Week in Stockholm The Author(s), all rights reserved

2 Restoration of ecosystem by reallocation of water resources in Shiyanghe River Basin Qiang Zhu & Yuanhong Li Gansu Research Institute for Water Conservancy,

3 Basic information of Shiyanghe River Basin Location: western part of Gansu, on the ancient silk road, inland river basin Area: 41,600km 2, plain area: 30,000km 2 Population: 2.27M, in which, rural 1.34M Food production: 1.13M t, 500kg per capita, one of commodity food production bases in Gansu Income per rural capita: 390 USD Main industry: Nickel finery factory, 2 nd largest in the world Gansu Province Shiyanghe River Basin

4 Basic information of Shiyanghe River Basin Climate: arid area in the plain, semi-arid in the mountain Annual precipitation: plain area: mm, mountain: mm Evaporation: plain area: mm, mountain: mm River system: 8 tributaries originate from Qilian Range in the south, converge to the main River in the plain Water resources: 1.66B m 3, surface WR: 1.56B m 3, subsurface WR: 0.1B m 3. Water quality: 8 tributaries and GW in upper and mid stream: Class I-II, main river and GW in downstream: Class III-V and worse Cultivated land: 317,000ha, irrigated 300,000ha, agriculture relies on irrigation: no irrigation, no agriculture

5 Vulnerability of the ecological and environmental system Downstream Minqin Basin is surrounded by the deserts on the east, west and north boundaries, always threatened by sand invasion Trees (Oleaster, Elm, etc.) and shrubs (Tamarisk, Salix, etc) survive by abstracting ground water. Water table should be kept in an appropriate range. The terminal lake acts as the barrier to resist sand dune invasion. It is an indicator of the ecosystem in the Basin. However, it dried up in the 1950 s.

6 Social and economy development of the Shiyanghe River Basin in the past 50 years Construction of water resources projects: Up to 2003, 20 reservoirs with total capacity of 450M m 3 built, 7 tributaries were dammed 109 irrigation canals with total length of 4000 km most lined and field canal networks 15,600 well among which 10,100 wells in downstream basin One of the most prosperous irrigated agriculture systems and one of the commodity grain bases in the province Support the water use of the world 2 nd largest nickel industry

7 Problems of water resources development in the Basin Water use far exceeded the carrying capacity of water resources system: water exploitation amounted to 2.88B m 3 (173% of WR); consumption amounted to 2.08B m 3 (125% of WR); Irrigation occupied 86.3% and 70.7% of water exploitation and water consumption respectively. In the past 50 years, irrigation area increased by 50%+. Unbalance use between upper & down streams: 5 4 In past 50 years, consumed water and irrigation area in the upper stream basin increased by 76.4% and 70%, respectively. Yearly inflow into downstream decreased from 0.46B m 3 in 1950 s to 0.1B m 3 in Down stream surface inflow

8 Problems of water resources development in the Basin Over-exploitation of WR can only from groundwater: the over-draft amounted to 0.43B m 3, 26% of the WR, mainly in the downstream basin Groundwater over-draft caused water table drop by 5-14m in the past 20 years in mid and down stream basins. Trees and shrubs withered/died out due to descending of water table Sand dunes invasion, desertification and land degrading sped up Groundwater quality deteriorated by salty water invasion.. Land & houses buried by sand Withered trees Dried well

9 Evolution of terminal lake Time Population Cultivated land ha Prehistory 2000 None 200 BC 130,000 80, AC 160, , AC 190, , AC 310, ,000 Pre-history 200 BC AC AC Present

10 Serious water crisis threatened stability of Shiyanghe oasis The terminal lake and the trees/shrubs are two barrier for resistance of sand invasion from deserts on east, west and north sides of Minqin Basin. Loss of them means loss of stability of Minqin Oasis and will eventually effect the stability of whole oasis of Shiyanhe River Basin and continuity of the Hexi corridor, the ancient silk road. If following the business in usual, an ancient tragedy of Lop Nor might recommitted. Lop Nor was an ancient 2 nd largest salty water lake in China with maximum area of more than 10,000 km 2. It s water had supported the Loulan (Kroraina) Kingdom from 176 BC to 630 AC with population of 41,000. Owing to the climate change and over-use of WR, the Kingdom became ruins and the lake dried up in the 1970 s. Present Lop Nor Ruins of Loulan kingdom

11 Measures for restoration of the ecosystem in Shiyanghe River Basin Reduce water exploitation from current 2.88B m 3 (173% of WR) to 1.94B m 3 (117% of WR) by: Reduce irrigation scale from present 300,000ha to 200,000ha in Irrigation area per rural capita is planned based on the long negotiation with water users in the Basins Irrigation area per rural capita, ha Mid stream Down stream Present 0.1~ ~0.35 Planned 0.1~ ~0.17 Implementation of water conservation program in the whole Basin, including adoption of water saving irrigation technique, capacity and awareness building for the farmers, reducing industry water supply quota.

12 Measures for restoration of the ecosystem in Shiyanghe River Basin Reallocate water use between upper and down stream: To ensure an inflow into down stream basin amounting to 0.3B m 3 in 2020 by: restricting the water use in the upper stream diverting water from upper stream and from a pumping station on the Yellow river to Minqin Basin total 0.27B m 3 every year. Stop groundwater over-draft and water table descending by: controlling the whole water use in the basin adopting strict monitoring and management for the groundwater exploitation

13 Measures for restoration of the ecosystem in Shiyanghe River Basin Institutional measure: At the State level, the Premier Mr. Wen Jiabao concerned this project personally. He instructs: Never have the tragedy of Lop Nor happen again in Shiyanghe River Basin An integrated WR Management Authority was set up, responsible for formulating and implementing water allocation plan for the Basin. The Governor of the province chairs the Committee and leadership at relevant levels chairs the sub-committees. Water users associations in various irrigation districts were established. They have the right to participate in formulating, implementing and monitoring the water use plan. Awareness and capacity building among the whole Basin are strengthened.

14 Measures for restoration of the ecosystem in Shiyanghe River Basin -- to improve the population living standard when the irrigation scale reduced Re-structure the industries in the whole Basin by increasing the 2 nd and 3 rd industry to promote the urbanization and to release pressure on agriculture and water resources As an integrated parts of Basin harnessing plan, farmers are encouraged to find temporary job in the cities by providing information, strengthening organizing work and services for rural areas. Change agriculture structure: the Basin is no longer taken as the commodity grain base; support farmers to grow less water consuming but higher beneficial plants, to build greenhouse for cash crops, etc.

15 Current changes of the Shiyanghe River Inflow to the downstream basin increased: inflow in 2010 and 2011 was 0.262B m 3 and 0.28B m 3, respectively Water appeared in the Qintuhu in 2010, first appearance since 1959 According to monitoring, in the year 2011, groundwater table has been raised by 6mm in Minqin County and 42cm around Qingtuhu Lake, indicating that water table descending stopped. Based on a State-wide investigation project for desertification, the forest coverage in Minqin increased from 7.8% to 11.8% in the period of 2006 to 2010.

16 Current preliminary changes of the Shiyanghe River The dune resistance project has started implementation in the north boundary of Shiyanghe River Basin. They use cotton straw and polymer to form grids on the dune and grow shrub (Chinese tamarisk) for sand fixation. Water diversion into Minqing Basin

17 Final remarks Changes in Shiyanghe Basin is first due to change of the guiding ideology on the State policy and also water resources management. Ecosystem has been put the same importance with the economy development. This change now happens from the highest authority, to the authorities at different levels and to the grass roots. In the water scarce area, water reallocation is actually the reallocation of benefit between upper and down stream, between different sectors, and between the benefits of current and of the future. It should be done under an integrated authority empowered by the authorities and all the water users. The change in Shiyanghe is toward the direction of IWRM but how to make the water use more efficient in promoting the social, economy and ecological-environment in an integrate way needs further study.

18 Thank you!