The Australian Murray–Darling Basin Plan: challenges in its implementation (part 1)

The latest in a set of major water reforms in the Australian Murray–Darling Basin occurred in November 2012 with completion of a new integrated water resources plan for the region (the Basin Plan). This occurred over a four-year period (2009–12) and was not without controversy. However, perhaps the most challenging part of this reform is occurring now with the implementation of the Basin Plan between 2012 and 2024. This paper discusses the key tasks to be undertaken by June 2016 and the main challenges in their implementation. A companion paper discusses the challenges in implementing the other tasks that need to be settled by 2024.     

嫩江、松花江洪水遭遇情况

洪涝灾害是松花江流域的主要自然灾害之一, 尤其是嫩江、松花江( 以下称为两江) 交汇处时常出现洪水遭遇 而造成的大洪水现象。以两江洪水在三岔河口附近的遭遇现象作为工程背景, 基于两江历史洪水资料分别采用统 计学方法及 Copula 函数 2 种方法从定性和定量的角度综合分析两江洪水的洪峰遭遇及洪水过程遭遇情况, 为提高 两江的防洪能力提供有力帮助。通过研究发现: 两江洪水以小量级洪水遭遇居多, 且遭遇发生在 8 月 7 日左右的概率最大; 通过计算还得到两江在同频率洪水下每日的遭遇风险以及遭遇概率最大时两江在不同频率洪水组合下的遭遇概率。采用 2 种方法所得的遭遇规律相同, 结论可信。洪水遭遇可通过上游水量调节等方式予以避免。     

黄河流域干旱时空演变的空间格局研究

干旱因子是突变性和连续性并存的复杂地理要素(即空间异质性和相似性并存),理清其空间分布格局,对于深入认识流域水资源演变规律具有重要意义。本文以黄河流域为例,采用标准化降水指数(SPI)分析流域干旱时空演变规律,基于此,运用游程理论方法从标准化降水指数中识别出干旱发生次数、历时和烈度三种属性变量,并分析季尺度干旱因子的空间分布规律;最后,利用全局和局部Moran’s I指数探究了不同特征变量的全局和局部空间自相关性,确立了流域季尺度干旱因子的空间聚集(离散)位置及其空间分布格局。结果表明:(1)黄河流域四季干旱化程度加剧,下游干旱化程度高于上游,随着季节的变化,同一响应单元存在由湿转干再转湿的变化规律;(2)不同季节,流域旱情空间分布格局差异明显,春季西安及周边区域存在区域性干旱现象(干旱次数少、历时长、烈度大);夏季黄河源区旱情严重(历时长、烈度大);秋季黄河下游三门峡、孟津和运城区域存在区域性干旱现象(干旱次数少、历时长、烈度大);冬季宁蒙河段旱情严重,而兰州断面干旱历时和干旱烈度呈现"低高异常"的空间分布格局,旱情可能会加剧。掌握旱情空间分布类型,重点布控"高高聚集"格局区域,可以有效提高旱灾决策的准确度。     

Riparian Vegetation Communities of the American Pacific Northwest are Tied to Multi‐Scale Environmental Filters

Riparia surrounding low‐order streams are dynamic environments that often support distinct biodiversity. Because of their connection to nearby uplands, riparian vegetation communities at these streams respond to many environmental filters—climatic, physical, chemical or biotic factors—that restrict what species can occur at a given location from within larger regional species pools. In this study, we examined how environmental filters originating at the landscape, watershed and reach scales correspond to riparian plant community composition across the interior Columbia and upper Missouri River basins, USA. We correlated riparian vegetation to environmental filters, identified unique communities and partitioned the variance within riparian vegetation data among filters originating at different scales. Riparian vegetation composition was strongly correlated to landscape‐scale filters including elevation, precipitation and temperature. Watershed‐scale filters such as grazing and reach filters indicative of fluvial setting were also correlated to vegetation composition, often differentiating communities with similar landscape settings. We identified 10 distinct vegetation communities. Forested communities occurred at higher elevation, moderate gradient reaches with high mean annual precipitation. Shrub–forb systems corresponded to fluvial and watershed disturbances and occurred within climates that could preclude forest establishment. Meadows corresponded to high water tables and/or high grazing activity. Variance partitioning showed that landscape‐scale filters explained the most variance within vegetation communities. Global change will alter many of the environmental filters that drive vegetation. Vegetation change may occur rapidly if local filters (e.g. fluvial process) change rapidly or may occur more slowly if larger‐order filters (e.g. climate) change slowly and without influencing local hydrogeomorphic filters. By identifying filter–vegetation relationships at large spatial scales, hypotheses can be constructed on how riparian vegetation communities may change under future environmental conditions. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.     

Critical analysis of water governance challenges of Songkhla Lake Basin,Thailand

The present study examines water governance challenges in the Songkhla Lake Basin (SLB) with the aim of evaluating and analysing policies, legislations, regulations, institutions and actors responsible for the current state of the basin. The present study adopted three methodological approaches, including literature reviews, face‐to‐face expert interviews and field survey to investigate governance challenges confronting the SLB. It identified six major governance challenges that combined to produce current barriers to sustainable governance, resulting in depletion and deterioration of the SLB resource system. Moving forward will require pursuit of better resource management and governance systems, which will require strengthening of the Songkhla Lake Basin Committee to play a much needed coordinating and policy harmonization role to promote coherent actions among the formal and informal actors in the basin. Review of existing water resources and related governance instruments to make them appropriate, adequate and relevant for the sustainability of the SLB also is essential.     

怒江源区那曲干流河水稳定同位素沿程变化特征

为了识别那曲流域的水循环过程,基于2016年8月,2017年1月、7月、8月、12月那曲流域采集的河水和湖水样品δ_D和δ_(18O)的测试结果,运用最小二乘法得到那曲流域夏季和冬季地表水线(surface water line,SWL)(夏季:δ_D=6.29δ_(18O)-18.01,冬季:δ_D=5.39δ_(18O)-33.54),分析了研究区河水和湖水稳定同位素时空分布特征。结果表明,河水中氢氧稳定同位素的变化具有显著的季节性差异,这可能是由河水的水源补给和蒸发作用引起的。错那湖湖水中,δ_(18O)值最大,其平均值为-9.28‰,受到不同程度蒸发分馏作用的影响,导致湖水富集重同位素。湖水对于河水中同位素和过量氘的分布具有重要的调节作用。干流河水中δ_(18O)平均值为-12.70‰,支流河水中δ_(18O)平均值为-14.88‰。以错那湖为分界点,干流河水中δ_(18O)值呈现为先增大后减小的变化趋势;过量氘(D-excess)值则呈现为先减小后增大的变化趋势。     

基于Mike Basin的复杂水库群联合调度模型研究

重庆涪陵区龙潭水利工程为由并联、串联水库组成的复杂水库群,水资源配置难度较大,有必要借助数值模拟软件来完成。在Mike Basin水资源配置模型的基础上进行编程计算,提出了用Mike Basin模型计算多功能复杂水库群联合调度的方法,并计算了4种工况下工程运行对下游发电的影响。通过验证发现,该模型可以很好地模拟龙潭水利工程水库群调度现状。对Mike Basin水资源配置模型存在的不足进行了分析,并提出了可行的解决方法,相关结论可为今后运用Mike Basin解决水库群联合调度问题提供参考。     

On Goodness of Fit for Operational Risk

The Advanced Measurement Approach (AMA) to operational risk, as described by the Basel Committee on Banking Supervision ( 2011 ), provides a framework meant to be used by banks for establishing the capital required to be set aside to cover worst‐case operational loss scenarios. The problems raised by an AMA approach are primarily statistical in nature, and many lie at the frontier of statistical research. The aim of this paper is to contribute to one of the more pressing challenges of an AMA, namely that of testing the goodness of fit (GoF) of a distributional family to operational loss data. Our focus is on extending certain classically known tests, such as that of Anderson–Darling, with particular emphasis on the right tails of the distributions. The nature of such GoF tests is examined in detail, and computational efficiency of the procedures is taken into account. We also propose a novel saddlepoint approximation method for assessing the asymptotic null distributions of the test statistics based on the eigenvalues of covariance kernels estimated via a jackknife and influence function‐based approach.     

从生活环境主义的立场解读琵琶湖流域的河川管理

为了解决伴随城市化发展、过度开发产生的河川环境污染问题,使人与河川和谐相处,以日本琵琶湖河川管理为实例,从社会学理论之一,即"生活环境主义"的立场出发,提出水利工程应该在考虑与河川生态系统共生的前提下进行可持续利用;在河川与流域管理中,注重恢复河川生物多样性,增加河川活力,实行管理部门与当地居民共同参与的方针。     

泾河流域土地利用/覆被变化对径流情势的影响

通过建立泾河流域SWAT分布式水文模型,重点模拟分析了河流径流情势对土地利用/覆被变化的响应,对比了不同气候条件及人类活动综合影响下研究区水文过程的变化。结果表明:1996年以前土地利用/覆被变化是影响水文过程的主要人类活动影响源,径流量年际变化平稳,属有小幅增加的正偏;年内影响以枯水季节为主,年内分配更趋均匀,径流集中度降低,集中期略有滞后,且趋于平稳;土地利用/覆被变化导致流域蒸散发量、冠层和落叶层截留量减小,入渗量增加,河川基流量和地表径流量相应增大,并在时域上耦合形成了水文过程的新变化;1996年以后,气候条件驱动下泾河年径流量呈现明显的增大趋势,人类活动亦从以土地利用/覆被变化为主转变为以人类水事活动为主的综合影响模式,且人类水事活动超过气候变化和土地利用/覆被变化成为影响水文过程变化的主因。