IRRIGATION PLANNING BASED ON WATER DEFICITS1

ABSTRACT: The deliberate underwatering of a larger land area, as practiced in Southern Asia, has provided impetus for a systematic investigation into the effects of designing projects for crop water deficits on Benefit-Cost performance. The study began with the derivation, from published experimental results, of functions relating ultimate crop yield to the magnitude and timing of water deficits, i.e., of the productivity of irrigation water. To obtain the net benefit of the project, the relation between the harvested area and output and the on-farm production costs was then suggested. The cost of supplying the irrigation water to the proposed area and of distributing and applying it to the field was determined, thus completing the Benefit-Cost equation. A computer simulation model was then established to search for the irrigation project design capacity and area to maximize the net present value in the Benefit-Cost analysis for the development proposed.     

PRIORITIZING WATER MANAGEMENT PROJECTS IN SOUTHEAST ASIA: AN EXPERIMENTAL METHODOLOGY

ABSTRACT: Southeast Asian nations with extensive water management systems have numerous candidate and ongoing programs and projects. They cannot possibly all be funded and implemented simultaneously in any serious way. Choices must be made. But how to select? What criteria can assist with the screening in an acceptable manner, particularly in the near absence of useful technical and economic information across them all. This paper suggests a methodology by which assessment criteria can be constructed which conforms to any given national information base and development needs. Criteria can be weighted one against the other in their relative importance. For each criterion a ranking scale puts the “best” (most, highest) at one end and the “worst” (least, lowest) at the other. Each candidate project is then subjected to these consistent assessment methods for a weighted “score.” Key criteria normally have surrogate measures depending on information available. Criteria are of three sorts: sheer volume, e.g., of a specific use, a benefit; ratios and relations, e.g., A as percent of B; and other more subjective criteria, e.g., regional or income distribution impacts. The basic criteria include, for example, time to full benefits (minimize), OM & R as percent of investment (minimize), and permanent rural jobs created (maximize).     

灰色模型在确定关键污染因子中的应用

将灰色模型引入水环境质量评价中，通过对某个时间段内污染物原始监测数据的灰色处理，从动态演变中找出关键因子，客观地判定各污染因子所起的作用，并对各因子在下一个时间段的发展趋势作出判断，增加了评价的准确性。经过实例运用分析表明，该方法物理意义明确，简便易用。     

西湖引水治理后的底栖动物群落

１９９５年１月－１９９６年１２月对西湖底栖大型无脊椎动物群落进行了连续监测与研究,共发现大型底栖无脊椎动物２６种,其中寡毛类６种,多毛类１种,水生昆虫９种,蛭类,线虫和无节蠕虫各１种。     

密切值法在污水土地处理工程选址中的应用

本文对密切值法在污水土地处理工程选址中的应用进行了探讨，通过实例分分析看出该方法科学可行且简易。     

国家环保模范城市创建中监测类指标操作要点

国家环境保护模范城市考核指标体系共28项考核指标(集中供热率仅考核北方城市),其中11项指标以环境监测为基础。环境监测类指标是环保模范城市考核中定量考核的主要方面,也是在创模过程中容易出现问题的方面。笔者根据多年参与环保模范城市考核的体会,提出了各项指标的操作要点。     

建设项目环保设施竣工验收监测的规范化管理

为保证建设项目环保设施竣工验收监测质量，加快竣工验收监测的规范化管理进程，本文介绍了建设项目环保设施竣工验收的意义、验收监测的程序、监测方案的制定、监测报告的编写要求等内容，供同行参考。     

玄武湖引水工程的环境效益分析

从现有引水工程环境实施效果入手，通过小试试验，响应模型计算及投资效益分析，提出了引水工程的改进方案。     

不同光照强度下香溪河浮游植物演替过程研究

为丰富三峡水库浮游植物演替机制,为三峡水库“潮汐式”调度提供理论依据和基础数据,基于前期香溪河水华易发区现场监测结果,其水下光照强度变化范围为1 800~17 000 lx,据此开展不同梯度恒定光照条件下香溪河源水混合浮游植物群落演替过程的室内控制试验.结果表明:①按照R*法则和关键光强假说,在其他环境条件适宜的情况下,光照为4 500 lx时,香溪河源水中混合浮游植物的生物量和多样性最高.②CSR理论（Competitor-Stress Tolerator-Ruderals Theory）中的浮游植物环境适应机制及生长策略不能准确解释不同梯度恒定光照控制条件下浮游植物的演替规律.光照条件是影响浮游植物群落演替方向的关键要素,而演替方向由群落发生演替时的光照条件与该群落中藻种关键光强的匹配程度决定.③香溪河源水中混合藻种的不同梯度恒定光照控制试验结果显示,小球藻（Chlorella sp.）、衣藻（Chlamydomonas sp.）、栅藻（Scenedesmus sp.）、肾形藻（Nephrocytium sp.）、微囊藻（Microcystis sp.）、色球藻（Chroococcus sp.）、隐藻（Cryptomonas sp.）和小环藻（Cyclotella sp.）的最适光强分别为3 000、8 000、13 000、6 000、6 000、13 000、13 000和6 000 lx.研究显示,将光照控制在合适的阈值范围,有助于维持浮游植物的多样性,对水华防治具有重要意义.      

2019年5月上海复合污染过程中挥发性有机物的污染特征及来源

本研究基于2019年5月上海市臭氧（O₃）和细颗粒物（PM_2.5）复合污染期间获得的城区大气中挥发性有机物（VOCs）的观测结果,分析了大气中VOCs的污染特征及其与二次生成的关系,同时解析了气团的潜在来源及VOCs的人为源贡献.结果表明,2019年5月上海市O₃与PM_2.5共出现4次污染过程,在平均气温约26℃,相对湿度约40%左右的气象条件下,发生了PM_2.5和O₃同步超标的复合污染现象.VOCs光化学消耗程度与O₃最大净增长量呈现明显的正相关,二次有机气溶胶生成潜势（SOA_P）与PM_2.5日均值呈现明显的正相关.VOCs物种中对臭氧生成有重要贡献的关键活性组分为：间/对-二甲苯、乙烯、甲苯、丙烯和邻-二甲苯等,在臭氧污染日,乙烯和丙烯等关键活性组分的臭氧生成潜势（OFP）百分比贡献进一步加强;对二次有机气溶胶（SOA）有重要贡献的关键活性组分为：甲苯、间/对二甲苯、乙苯、邻-二甲苯和1,2,3-三甲苯,在PM_2.5污染日,甲苯、乙苯、邻-二甲苯和1,3,5-三甲苯等关键活性组分的SOA_P的百分比贡献会进一步加强.