The rural–urban equity nexus of Metro Manila’s water system

ABSTRACT

This article examines equity concerns and inherent conflicts related to rural–urban water supply allocation and use, with focus on Metro Manila. Going beyond the much-discussed difficulty farmers experience from an allocation policy prioritizing urban water requirements, it shows that inequity in raw water allocation is linked to, and further exacerbated by, inequities in urban domestic water provision. Moreover, it highlights the need for broader equity reviews, using the concept of the rural–urban water equity nexus to draw attention to key equity considerations across space and scale that otherwise might remain invisible.     

Drivers of water governance reforms in the Philippines

This paper analyses the enabling conditions for a water governance model responsive to future Philippine water requirements. Using the stage-based approach to institutional reforms, it assesses the outcomes of previous water governance reforms, such as conflicts in customary and formal rules; urban and rural; upstream and downstream; and the contestations in water supply privatization in Metro Manila. The analysis suggests that past water governance reforms were symbolic and procedural, and structural changes to support the legal frameworks were not achieved. Based on the case findings, the authors support the current reform agenda of implementing a decentralized framework of water governance at a watershed scale.     

北三河流域水资源供需平衡对降水变化的敏感性

分析不同区域水资源供需平衡对降水变化的敏感性,并结合考虑云水资源和降水效率的空间分布,有助于常态化人工增雨作业地点的确定,对实现空陆水资源的统筹利用具有重要意义。以北三河流域为研究区域,基于新安江模型和彭曼-蒙特斯公式分析了研究区需水量对降水变化的响应,并探讨了不同计算单元水资源供需平衡对降水变化的敏感性。结果表明:当降水量增加时,流域平水年产水量增加的比例大于枯水年与特枯年,农田灌溉需水量随降水量的增加大致呈线性减小趋势;在不考虑外调水和地下水超采的情况下,自然降水情景的流域资源性缺水量分别为35.46亿m3（降水频率p=50%）、43.17亿m3（p=75%）和46.30亿m3（p=95%）,缺水峰值分别出现在5月、7月和8月;各单元缺水量对降水变化的敏感性主要由产水变化主导,空间上呈由北向南逐渐递减的趋势,当平水年降水量增加20%时,北部地区缺水量相对减少率达到150%以上,中部介于30%~50%,南部则小于15%。     

Dry season water allocation in the Chao Phraya River basin,Thailand

This study examines the recent quantitative characteristics of dry season water allocation in the Chao Phraya River basin, Thailand. Previous studies have focused on inequitable allocation, where the highest priority is given to the domestic water sector and uneven irrigation water variability exists among projects in the delta. This study uses a statistical test and panel data analysis to confirm that the characteristics highlighted in previous studies remain accurate, and it discusses the source of these characteristics in order to understand the issues in water allocation in the Chao Phraya River delta.     

基于四水转化的灌区耗水量计算模型

针对以往灌区耗水量计算方法的不足和灌区水循环机制的特点,本文建立了基于四水(即大气水、地表水、地下水和土壤水)转化的灌区耗水量计算模型。该模型把灌区划分为农田、林草地、荒地、湖泊湿地和城镇用地五类水均衡模块,重点考虑了人类活动对灌区农业、工业、生活和生态耗水量的影响。以宁夏青铜峡引黄灌区为例,详细计算了各种耗水类型的耗水总量和耗用的黄河水总量,并定量分析了各水均衡要素间的相互转化关系。模拟计算结果与试验观测结果对比分析表明,该模型在平原灌区具有较好的模拟精度,能够应用于生产实践。     

各生育期不同灌水下限对茄子生长、产量及水分利用效率的影响

为指导节水灌溉和增产,在茄子苗期、开花结果期和成熟采摘期进行不同灌水下限处理来研究各生育期不同灌水下限对茄子生长、产量及水分利用效率的影响。试验结果表明：株高、茎粗、叶面积、地上部干重、总根长、总根鲜重和干重均随着灌水下限的降低而降低。与正常灌溉相比,苗期和开花结果期适当降低灌水下限对茄子的生长、产量和水分利用效率的影响不明显。而成熟采摘期时对水分最为敏感,此时降低灌水下限对茄子的生长、产量和水分利用率的影响较为显著。综合灌水量、茄子生长、产量、水分利用效率几个方面考虑,苗期灌水下限60豫,开花结果期灌水下限65豫,成熟采摘期灌水下限70豫是最合适的灌水下限。     

灌溉水中盐分对土壤结构性质及水流运动特征的影响

再生水和微咸水等用于农田灌溉对缓解农业用水紧缺、保证粮食稳产高产方面作用显著。但这些非常规灌溉水中的盐分进入受灌农田土壤会引起土壤结构性质的改变,进而引起入渗水流运动特征的变化,增大了农业灌水和施肥的管理难度及地下水受污染的风险。本文通过室内灌水入渗试验,研究了灌溉水盐分浓度(0、1.0、3.0和5.0 g/L)、灌水频率(1天1次、2天1次、4天1次)、含盐灌溉水-清水交替灌溉模式(纯清水灌溉、纯含盐灌溉水灌溉、含盐灌溉水-清水交替灌溉)对受灌土壤容重、团聚体结构稳定性、孔隙结构特征、地表入渗性能以及入渗水流运动非均匀特征的影响。结果表明,适度的盐分浓度、较低的灌水频率但较大的灌水定额、含盐灌溉水-清水交替灌溉均有利于提升土壤团聚体的稳定性、抑制土壤板结、改善受灌土壤的地表入渗性能、降低入渗水流运动的非均匀性。研究成果对再生水和微咸水农田灌溉制度设计具有参考价值。     

Application of Integrated Hydrologic and River Basin Management Modeling for the Optimal Development of a Multi-Purpose Reservoir Project

Multi-purpose reservoir development have been always a big challenge for the management of water resources. This paper describes an integrated approach for investigating catchment hydrology in the development of a hydropower and a canal irrigation system based on model analyses. The investigation aims to adequately determine an optimal domestic and irrigation water resources allocation scheme based on an assessment of the reservoir water balance and capacity for hydropower. The soil and water assessment tool (SWAT) which characterizes basin hydrology and the water management and planning model MODSIM which provides a decision support system for water allocation optimization, were used in this study. The integrated approach was applied to Prek Te River basin in Cambodia. The water demand aspect was examined based on domestic water use, irrigation water, environmental flow, and water losses. An operational rule curve was developed for hydropower operation with respect to a power potential of 13 MW. Hydrologic modeling revealed 90 % dependable water of about 2.7 m³/s during the dry season and 214.3 m³/s during the wet season, indicative of a wet-season dependent reservoir for storage. Results from the 26-years simulation period also showed that diversions for domestic water and irrigation water supply were 92.3 % dependable for a 13 MW capacity hydropower development. The integrated approach was shown to be a valuable decision support tool for water resources management with the determination of an optimum policy for multi-purpose reservoir operation based on available basin water supply.     

引嫩入白供水工程对嫩江鱼类影响分析

引嫩入白供水工程从嫩江引水为白城提供农业灌溉用水、城市饮用水和生态用水.引水时间为4月-10月,枯水期不引水.工程取水对取水前后白沙滩断面水位变化主要集中在5月-7月农业用水期,水位下降将对鱼类的产卵造成一定的不利影响,同时工程取水对下游水生生态环境产生的影响.     

辽宁省玉米水分生产率时空变化规律及影响因素

基于 2005- 2017 年辽宁省 14 个地级市玉米种植数据、灌溉用水量及气象数据等资料, 运用线性倾向估计及全局空间自相关分析等方法, 从不同地区、不同降水年型( 枯、平、丰) 角度出发, 分析不同玉米水分生产率指标的时空变化规律及其影响因素, 结果表明: 在时间尺度上, 全省玉米灌溉水分生产率多年平均值为 11 63 kg / m3 , 玉米水分生产率总体每 10 a 以 01 04 kg/ m3 的速率波动上升; 在空间尺度上, 全省玉米灌溉水分生产率均值呈现出西北 高、东南低的空间分异, 玉米水分生产率在枯水年( 2006) 和平水年( 2007) 总体均表现为东北高、西南低, 而丰水年 ( 2012) 则表现为西北高、东南低; 玉米单产量是影响各水分生产率指标最显著的因素。该研究成果可为提高辽宁省农业用水效率、缓解水资源压力提供一定参考。     

Seminar on Water and Energy,Stockholm, Sweden,August 21, 2005

Abstract

In Europe the implementation of the Water Framework Directive (WFD) will have major implications for water resources management. Part of the Directive requires Member States to implement a comprehensive system of controls (licences) on the allocation and abstraction (withdrawal) of surface and groundwater resources. This paper describes the development of a procedure to help assess and set abstraction licences for agricultural irrigation. The methodology is described with reference to Scotland, a country with limited abstraction control previously and where irrigation is supplemental to rainfall. The methodology combines spatial climatic information using a Geographical Information System (GIS) with data derived from a water balance computer model. The procedure enables the volumetric irrigation demand in a ‘design’ dry year for a given site to be estimated, taking into account local variations in climate, soil type, land use and irrigation practices. The approach provides a scientifically robust framework to allow the regulatory authority to assess the ‘reasonable’ water requirements of individual irrigators and hence develop allocations to satisfy the range of competing demands (e.g. agriculture, industry, and environment) on water resources. The methodology is applicable in other temperate countries where water abstraction controls are required and where appropriate datasets are available. The application of the procedure and its methodological limitations are described.     

Characteristics of indicator microorganisms in paddy rice plots after reclaimed water irrigation.

A study was performed to examine the effects of reclaimed-water irrigation on microorganism concentration in the ponded-water of paddy rice plots. Several treatments were used and each one was triplicated to evaluate the change of indicator microorganisms (total coliforms (TC), faecal coliforms (FC), and E. coli) concentrations in 2003 and 2004 growing seasons. Their concentrations increased significantly after irrigation, but decreased by approximately 45% in 24 h. It implies that agricultural activities such as ploughing and fertilising need to be practiced one or two days after irrigation, considering health risks. Treatments with UV-disinfected water irrigation, demonstrated significantly lower concentrations than others, including control plots where natural water was irrigated. The monitoring result from actual paddy rice fields and experimental paddy plots showed that concentrations of indicator microorganisms ranged from 10(2) to 10(5) MPN/100 mL. The field scale water reuse research project is in progress and national guidelines for reclaimed-water irrigation are under preparation in Korea. A comprehensive assessment of existing agricultural practices and a thorough monitoring in the fields as well as treatment plots are recommended to make national guidelines more representative.     

Knowledge,context and problemsheds: a critical realist method for interdisciplinary water studies

ABSTRACT

Understanding water issues as problemsheds addresses the narrowly water-centred framing of watershed and basin-focused water research and policy. In a critical realist approach problemshed also serves to identify the context-specificity of water knowledge, by navigating between the extremes of positivist generalization and interpretivist local specificity and bridging the divide between academic and applied research by identifying the structural similarity in their problem framing. Problemshed is operationalized by situating it in critical realism’s structures-mechanisms-events ontology, and by drawing on realist evaluation’s context-mechanism-outcome configurations. I use large-scale canal irrigation in India to illustrate how this is done.     

Temporal dynamics and drivers of lake ecosystem metabolism using high resolution observations in a shallow,tropical, eutrophic lake (Laguna Lake,Philippines)

The physical, chemical, and biological dynamics under changing atmospheric conditions of Laguna Lake, Philippines were analyzed from intensive observations. Diel measurements were conducted for 48 continuous hours for both dry and wet tropical seasons in addition to fine resolution long-term monitoring. Results revealed significant vertical and diel variations of lake variables in spite of a shallow water depth (2.5 m) caused by the intense surface heating from solar irradiance (~800 W m^?2) and accentuated by the lake's high turbidity (16–32 ftu). Late afternoon land-lake breeze (~5–7 m s^?1) regularly breaks daytime thermal stratification, and convective cooling at night maintains isothermal condition until dawn of the next day. The stratified condition demonstrated a wind-driven, density-induced 2-layer current pattern with a windward moving epilimnion (~4 folds faster) and a compensating hypolimnetic flow in the general lake circulation direction. Laguna Lake was observed to have a dominating diel cycle but also undergoes significant seasonal limnological variations brought primarily by climate, hydrology, and its interaction with the adjacent sea. Significantly correlated variations of pH, chlorophyll-a and DO in the dry season were indicative of the higher biological activity associated with the intrusion of polluted waters from Metro Manila. The non-occurrence of thermal over-turn was observed to be regularly followed by bottom hypoxic conditions (2–4 mg L^?1), indicative of the eutrophic condition of the lake and the importance of diel wind-induced mixing in the bottom supply of DO. Laguna Lake was found to be predominantly net heterotrophic (GPP:R < 1, NEP < 0).     

沿海缺水灌区水资源优化调配耦合模型

本文研究了一种基于含水层海水入侵模拟模型(子模型)和作物优化配水模型(子模型)的沿海缺水灌区水资源优化调配耦合模型，用数值方法求解了含水层海水入侵模拟子模型，并首次将基于分解协调的人工鱼群算法应用于作物优化配水的计算，通过地下水抽水量实现了子模型的耦合，利用Visual Basic6.0软件编制了耦合模型的计算程序。将模型应用于威海市节水灌溉示范区，得出其平水年(50％)、一般干旱年(75％)两种水文年型的水资源联合调配方案。结果表明基于分解协调的人工鱼群算法收敛性好，提高了计算速率，较好的解决了作物优化配水大系统中常见的变量维数高、约束方程多等问题；示范区平水年增加有效供水量997.05m3／hm2，一般干旱年增加有效供水量863.1m3／hm2，能高效利用水资源并能有效控制含水层海水入侵，经济效益和生态效益明显。     

Smooth flows? Hydrosocial communities,water governance and infrastructural discord in Peru’s southern highlands

ABSTRACT

The article examines how the design and governance of Peru’s water infrastructure shape the social practices and cultural values stakeholders engage in and draw on when negotiating water rights in a year of drought. Reviewing ethnographic data on a large irrigation project in south-western Peru, we discuss how the project both perpetuates power relations between water experts, authorities and users and creates room to challenge its hierarchical organization. The project’s infrastructural assemblage of state and community canals offers an interesting case to explore how the stakeholder cooperation encouraged by Peru’s water law produces hydrosocial communities.     

悬臂式掘进机在复杂环境与地质条件 供水隧洞中的应用与发展

本文介绍了悬臂式掘进机在菲律宾大马尼拉供水隧洞施工中的应用，包括为保证隧洞施工的安全、质量、进度，针对不同的地质条件、施工环境下采取的一系列施工措施；特别是针对施工中存在的不足提出的解决办法和改进思路，旨在供扩大此类掘进机的使用范围及同类工程施工参考。     

浅析大中型农田水利基础设施

通过定性和定量的分析，探讨了大中型农田水利基础设施各自发展中出现问题的原因。对于大中型农田水刺基础设施来说，阻碍其发展的因素包括政府投入不足、单位管理效率低下和水费收取困难等。最后，给出了解决大中弄农田水利基础设施建设和管理问题的对策建议。     

再生水灌溉研究进展

从再生水灌溉对土壤、作物、地下水和土壤斥水性4个方面简述国内外再生水灌溉的发展概况和研究进展。已有研究表明：再生水灌溉对土壤肥力和土壤酶活性的影响尚未有定论;再生水对农作物生长的影响尚有分歧;再生水灌溉对地下水水质具有一定的影响,并显著影响地下水水环境;长期的再生水灌溉会引发土壤斥水性的产生,且土壤斥水持续时间与土壤有机质质量分数呈正相关。目前存在的问题有：再生水灌溉对土壤和农作物的影响研究不一致,如何消除再生水灌水对地下水和土壤斥水性的影响。认为由于再生水中含有作物正常生长的必要营养元素,若能克服再生水灌溉存在的问题,可缓解淡水资源的压力和减少化肥的使用,避免环境的污染。     

鄱阳湖流域主要旱作物需水规律研究

应用大田试验和小型旱作物需水测坑相结合的方法,采用喷/滴灌、沟灌、不灌三种不同灌溉方式,针对鄱阳湖流域主要旱作物需水量变化规律进行研究,找出其缺水敏感期,为灌好关键水提供理论依据,同时分析其作物需水系数,提出不同灌溉方式下作物水分利用率.