Comparison of Water Cap between Murray-Darling River and Yellow River.doc

此文档收集于网络，如有侵权，请联系网站删除Comparison of Water Cap between Murray-Darling River and Yellow RiverShuangyan Jin(Hydrology Bureau, YRCC)Abstract: Yellow River and Murray-Darling River, two famous rivers in the world, have undergone similar developing course and been confronted with analogical problem and both have water allocation scheme as the measures to constrain water diversion. After the implementation of the cap, in-stream flow increased to some degree, the trend of river health degrade was choked back. In this paper, the two allocation schemes were compared and sound recommendations were addressed, which can give us some suggestions on river water resources management.Key words: Water Cap, Water Diversion, Murray-Darling River, Yellow RiverLocated in the south-east of Australia, the Murray-Darling Basin (MDB) covers 1,061,469km2, equivalent to 14% of the countrys total area. The Darling (2740km), Murray (2530km) and Murrumbidgee (1690km), major tributaries of Murray-Darling River (MDR), are the three longest rivers in Australia.The Basins extends over three-quarters of New South Wales, more than half of Victoria, significant portions of Queensland and South Australia, and includes the whole of the Australian Capital Territory. Well over half of the Basin is in New South Wales and almost a quarter is in Queensland.Yellow River, the second largest river in China, stretches 5464km, covers 795,000km2, and flows through nine provinces or autonomous region of Qinghai, Sichuan, Gansu, Ningxia, Inner Mongolia, Shanxi, Shaanxi, Henan and Shandong.1 WHY THE WATER CAP?Water resource system is the important part of natural, social and economic coordination system. Water is an important input for economy, water resource and economy has the close and inevitable relation. On the one hand, economic growth will promote the growth of water demand. On the other hand, the shortage of water supply will limit economic growth.The increasing of water demand for different users has led to competition and conflict, as well as inadequate water flows to meet the environment needs (.au/). The durative water diversion out-stream resulted in some symptoms and issues: river systems showing signs of stress, no certainty whether current riverine environment is sustainable with the current water regime, reducing security to existing irrigators, and entironment problems, such as deterioration of water quality like salinity, water ceasing, land desertification, etc.Since the 1990s, with the emergence of sustainable theory of resources and ecology circulation which requires harmonious development of economy, environment and society, a series of noticeable changes appeared for water resources management in theory and in practice.Herein, in order to settle the contradiction between water resource status and economic development needs, implementing water cap is imminent decision-making.2 WATER DIVERSION IN MURRAY-DARLING RIVERThe mean annual runoff in MDB is 23,850GL (MDBC, e-Resources, 2005). Regulated rivers of MDR changed natural flow regimes and reduced outflow from a mean of 13,700 GL/year to 4,900 GL/year (.au/). In December 1996, Water Cap in MDR was confirmed by the Murray-Darling Basin Ministerial Council as a permanent cap effective from 1 July 1997 (Dr Wally Cox, Paul Baxter, 1996).1.1 2.1 Water diversion before water capThe MDB supplies water for agriculture, and a variety of domestic, industrial and environmental purposes. Figure 1 (IAG, 1996) reveals annual diversions in MDB from 1920 to 1994, from which it can be seen that the growing is steadily before the middle 1950s, while after it until 1994 the increasing tendency is dramatically. The diversion data was around 3000GL in 1930, while in 1994 reached 10780 GL (MDBC, Audit, 1995), the growth rate from 1988 (9989 GL) to 1994 was 7.9%.Fig.1: Growth in Water Use in Murray-Darling Basin1.2 2.2 Definition and objectiveThe cap is the water volume that would have been diverted under 1993/94 levels of development (Dr Wally Cox, Paul Baxter, 1996).The primary objective is to maintain and, where appropriate, improve existing flow regimes in the waterways of the MDB to protect and enhance the riparian environment; and to achieve sustainable consumptive use by developing and managing Basin water resources to meet ecological, commercial and social needs (Dr Wally Cox, Paul Baxter, 1996).1.3 2.3 Prediction of water diversionIn order to examine the prospects for diversion growth after 1994 in the Basin, two different scenarios have been analysed and demonstrated.2.3.1 Full Development Scenario:In this scenario it is assumed that there is no change to 1993/94 management rules, which in theory models the maximum diversion with all existing water entitlements. The growth in diversion to this scenario is listed in Table 1, which indicates there is a potential average increase for a further 14.5% above 1994 levels of water usage (MDBC, e-Resources, 2005). Under this scenario, water supplies for original irrigators would become less secure and river health problems would be exacerbated.Table 1: Diversion growth in MDB in different states of two different scenariosStates19881994Full developmentLimited interventionGLGLGL% increaseGL% increaseNSW55505861686817.2%62737.0%Victoria3579381940105.0%39062.3%SA57261083536.9%77727.4%Queensland22542655630.5%53325.1%ACT63657515.0%7515.0%The whole basin9989107811234414.5%115647.3%Note: source from An Audit of Water Use in the Murray-Darling Basin, 19 Limited Intervention Scenario:It includes changes to management rules that have been canvassed as possible options if a decision was made to allow limited expansion. It is not an agreed position of Governments or the Commission but rather an option that provides perspective on the effectiveness of various measures in restricting growth in diversions. The expected diversion growth under this Scenario with 1994 levels is showed in Table 1, there would be 7.3% increase on 1994 levels.1.4 2.4 Water diversion after water capThe annual diversion in total basin and five individual States kept stable or underwent a slight drop after water cap in MDB. Diversion in NSW ranks the first, which occupies 54.1% of the total value, followed by is Victoria of 35.0%. The proportion of the other three is only 6.2%, 4.4% and 0.36% respectively, the order is SA, Qld and ACT, see Table 2.Table 2: Water diversion in MDB after water cap unit: GLYearNSWVicSAQldACTTotal19945860381961042665107801995646248236381763212131199661393662574246631068419977115410658046730122981998657839306317414411924199963503730669608231138020005035331762254127954220017148349166268834120232002673538346213413611567200341322993751212408128200441053217611805288766200536663137623392277845200650383267590316329243(Source: Water Audit Monitoring Report, from the year 1993/94 to 2005/06)The Cap limits or ensures the long term average diversion equals the value of this trend line in 1993/94 of 10780 GL, shown as in Figure 2. Due to 90% of the water in the basin is used for irrigation, and irrigation demand varies with seasonal conditions, the diversions permitted under the Cap fluctuate nearby the diversion cap from 1994 to 2006.Fig.2: The Operation of the Cap on Murray-Darling Basin Diversions3 WATER ALLOCATION IN YELLOW RIVERYellow River is the import water resources of Northwest and Northern China, whose natural annual mean runoff is 58,000 GL, among them 21,000 GL is set specially for environmental use, account for 36.2%, the remainder 37,000 GL is available for water cap.1.5 3.1 Out-stream water supply of Yellow RiverFrom 1950s, with the national economy development, out-stream water supply underwent a keeping increase, from 12,000 GL, amount to 50,000 GL in current, which mainly is agricultural water consumption. Out-stream water supply from 1980 to 2006 was shown in Figure 3.Fig.3: Out-stream water supply increase in Yellow River1.6 3.2 Scheme and objective of Yellow River water diversionThe Yellow River Available Water Regulation Scheme ratified by the State Council in 1987, but has not been implemented. The YR Water Regulation Management Stipulation approved by the State Council, and issued by the State Development and Planning Committee and Ministry of Water Resources in December 1998, which involved 9 provinces or autonomous within the Basin, and Hebei province and Tianjin city outside of the Basin. Then YRCC was mandated to conduct the unified water resources regulation in YR basin, the detailed annual water allocation is seen in Table 3.The primary objective of unified water regulation is to prevent the YR from drying up and to alleviate the conflict between water demand and supply in the basin. The ultimate objective is to realize the optimal water regulation and keeping Yellow River healthy waterway.Table 3: The annual distributed quota of 1987 water allocation scheme in YR basin unit: GLProvinceQinghaiSchGansuNingxiaMongoliaShaanxiShanxiHenanShdHbTjTotalQuota14,100403,0404,0005,8603,8004,3105,5407,0002,00037,0001.7 3.3 Remarkable achievementsl Water depletion amount decreased.After the integrated water regulation mode, the amount of outflow to the sea rises distinctly. According to the hydrology data, the annual average observed runoff in Lijin station increased 552 GL, equivalent to 31.5%, from the period 19992006 to 19901998.l Drying up situation is prevented.Yellow River experienced continuous drought after 1999, the tendency of runoff in Huayuankou station is decreasing, particularly from 1999 to 2002, simultaneously the change of water consumption fluctuates slightly (in Figure 4). However, through the improved and appropriate water regulation, the drying up situation is prevented.l Ecology ecosystem and environment is improved.Due to preventing the dry up for 11 consecutive years, the ecological deterioration trend was controlled, and the relationship between human being and nature become gradually harmonious.The water diversions have changed temporal and spatial distribution of water resources in the main stream of the YR, and improved the water quality of the important reaches, the function of water body became better than before.4 DISTINCTION OF WATER CAP BETWEEN THE TWO RIVERSBy comparison with water cap in MDR, water allocation of the YR has some virtues:l Ascertained environmental water volume.According to ecological function, based on the scientific calculation and analysis, an unambiguous environmental water volume was ascertained. It materializes the principle of ecological priorities for the river, keeping river health and ecological harmony. The YR water allocation scheme is carried out under the principle of controlling total amount and determining water supply based on availability after the ecological water.l More operable character for water resources regulation and management.YR water allocation scheme is not a simple water volume quota, but consists of the process of water allocation. Based on the predication of next year, water regulation scheme is established, which is regarded as the guideline of water allocation in a year. During the yearly regulation, monthly, ten days and real-time scenario are also established and repaired under guideline. The water regulation balanced water supply among provinces and regions, between upstream and downstream as well as both banks, thus security rate of water supply in different regions tend to be same, the water withdrawal of provinces and regions which have exceeded their quotas have effectively reduced.Fig.4: The drying up days in Lijin, runoff and water consumption in Huayuankou of past years5 CONCLUSIONS AND RECOMMENDATIONSAs the twins living in the river, diversion and in-stream flow share the total water volume in the river, the more diversion the less flow left in-stream, and vice versa. When diversion was controlled, the higher security guarantee to the in-stream flow, which is beneficial to the sustainability of environment and river health.After cap implementation, there is no doubt that it has halted diversions growth and therefore protecting water quality, water supply reliability and environmental health.From the above analysis and statements, we can get the following conclusion and suggestions.l Water cap restricted water diversion rather than development.The growth rate of water diversion was 7.9% from 1988 to 1994, if without cap there is a potential for a further 14.5% increase. Under the cap, the percentage of rising is 7.3%.l Ratification of the appropriate environmental flows is necessary to maintain river health.Water diversion increasing has an adverse impact on river health. Making certain that environment has a right which is prior to consumptive uses of water and it is essential to have sound science environmental flows on the negotiating table (Angela, 2002).l Measures should be implemented to halt the environmental degradation as a result of unsustainable consumptive water uses.Participatory approach and the water saving awareness of the whole society should be further improved. At the same time, government should encourage communities to vol