上海郊区中心小城镇半城市化特征及其对水环境的影响实例研究

中心小城镇作为上海市都市城镇构造体系的一级,对于区域城市化进程及产业区位调整具有极为重要的意义,同时中心小城镇具有典型的半城市化特征,这是导致中心小城镇成为该区域新的环境污染中心的重要原因。以青浦区为例分析半城市化的具体表现,以枫泾镇镇区内河流水体及沉积物总磷区域及季节特征揭示由半城市化问题所带来的水体污染的严重性。夏季镇区河流所有样点均遭受严重的磷污染,而且区域内差异性大,小城镇河流磷污染严重于其它类型的水体磷污染,这一特征较好地反映了中心小城镇半城市化所带来环境问题的突出性。     

Production of Pearl Millet Irrigated with Different Levels of Brackish Water and Organic Matter

ABSTRACT

The objective is to determine the growth, yield and chemical characteristics of pearl millet irrigated with different levels of brackish water and organic matter in two cultivation cycles. The experimental design was randomized blocks in a 4 × 4 factorial arrangement, composed of 4 levels of brackish irrigation (25, 50, 75 and 100% evapotranspiration), 4 levels of organic matter (0, 15, 30 and 45 t ha^?1) with 3 repetitions. Along two cultivation cycles, pearl millet crop was analyzed for: plant growth variables, fresh and dry mass production, water-use efficiency, and chemical composition. There was significant interaction between applied water levels and organic matter for lignin in the 2nd cut (P < .05). The number of leaves, number of dead leaves and fresh mass production were influenced by the isolated effect of brackish water levels in cut 1 (P < .05). In turn, fresh mass production, dry mass production, plant height, leaves length, panicle length, fresh mass production, crude protein and ether extract were influenced by the isolated effect of saline water levels in the 2nd cut (P < .05). Growth, biomass production and chemical composition variables in second cut are positively influenced by different brackish irrigation levels under low rainfall conditions.     

三峡库区小流域不同生态恢复阶段的水土流失特征

在三峡库区汝溪河小流域,采用“空间代替时间”方法对撂荒地和柏木新造林、幼龄林、中龄林4个恢复阶段的水土流失特征进行研究.结果表明:撂荒地演变为柏木新造林、幼龄林和中龄林后,水土流失明显减少,土壤流失量大小排序为撂荒地＞新造林＞幼龄林＞中龄林;表层(0-20 cm)土壤砂粒含量分别减少2.95％,6.86％和9.51％,而粗粉粒和物理性粘粒含量增加;各层土壤的抗蚀性明显增强,且随土层加深而降低;各层土壤团聚体的稳定性提高,而且土壤团聚体破坏率均需较长时间达到稳定,尤其是幼龄林和中龄林.可见,植被的保持水土、改良土壤作用随生态恢复进程得到增强.但在三峡库区增加森林植被覆盖的同时,还应注重培育和维护合理的林分结构.     

喀斯特小流域不同等级石漠化综合治理生态工程技术集成研究

分析了花江示范区木工和孔落箐两个小流域不同等级石漠化的空间分布特征,采取脆弱生态环境恢复模式,木工小流域的发展方向为发展草食畜牧业,孔落箐小流域为发展区域经济。通过研究两个小流域不同等级石漠化治理生态技术优化组合,提出强度石漠化地区宜采取生态修复与先锋物种恢复技术集成方式,中度石漠化地区采取人促生态恢复与经济林规范种植技术集成方式,轻度石漠化地区采取林草配置与特色经济林果栽植技术集成方式。     

Remediation of Cadmium Pollution in Soils by Different Amendments: A Column Study

Abstract

A column study was conducted to determine the effect of city compost, lime, gypsum, and phosphate on cadmium (Cd) mobility in three well‐recognized benchmark soils of India [viz., (Islamnagar) Vertisol, (Amarpur) Inceptisol, and (Khala) Alfisol]. Columns made of PVC were filled with soil treated with different treatment doses [viz., 0.5% city compost, 1% city compost, 2% city compost, 2.5 t lime/ha, 5 t lime/ha, 2.5 t lime/ha+0.5% city compost, 2.5 t gypsum/ha, 2.5 t gypsum/ha+0.5% city compost, and 100 kg P₂O₅/ha as potassium phosphate (KH₂PO₄). The columns were leached with 100 mg L^?1 Cd under saturated condition. The amount of water moving through the soils was measured as the pore volume. A delayed breakthrough curve (BTC) of Cd in the presence of lime has been observed in all the studied benchmark soil series. Among the treatments, lime application reduced the movement of Cd from surface soil to lower depth of soil to a large extent resulted in 9, 25, and 45% more retention of Cd in surface soil of the Islamnagar, Amarpur, and Khala series respectively. Explanation for reduced Cd mobility in limed soil can be derived from pH changes of soils. In comparison to control soil, phosphate application caused 6, 21, and 30% more retention of Cd in surface soil in the Islamnagar, Amarpur, and Khala series, respectively. Combined application of lime and city compost reduced the movement of Cd in the soil profile. It appears that organic matter controls the sorption of Cd in soils. The amount of Cd sorbed increased with increasing organic carbon content, but gypsum application may leach Cd beyond the root‐zone depth. A rapid breakthrough curve was observed under gypsum‐treated soils. Retardation factor revealed that a somewhat lower degree of Cd retention occurred in the Khala series, which might possibly be attributed to less clay content and low pH. Overall, the column study indicated that total Cd accumulation occurred up to depths of 5–7.5 cm, 7.5–10 cm, and 10–15 cm in soils of Islamnagar, Amarpur, and Khala series, respectively.     

三峡库区王家沟小流域不同坡度土壤氮素流失特征研究

采用野外径流小区观测方法,研究了三峡库区王家沟小流域旱坡地不同坡度土壤氮素的流失特征。结果表明:①旱坡地不同坡度小区土壤氮素流失量总体不大,单场降雨侵蚀泥沙氮素流失量最大值为189.06 mg/m2,而在地表径流中仅为28.12 mg/m2,侵蚀泥沙氮素流失量明显高于地表径流氮素流失量,最大差异达到16.8倍,差值随着坡度的增大有减少的趋势;坡度越大,地表径流氮素和侵蚀泥沙氮素的流失量也越大,呈现出小区17°>9°>4°的趋势;铵态氮流失量明显低于硝态氮流失量,4°、9°、17°小区地表径流硝态氮流失量较铵态氮流失量分别高出3.2、3.6、4.0倍,说明硝态氮较铵态氮更易于流失,且随着坡度的增大差异增大。②不同坡度小区地表径流量、侵蚀泥沙流失量与降雨量均存在显著的线性正相关(P<0.05),且随着坡度的增大地表径流量与降雨量的相关系数在增大,侵蚀泥沙流失量表现则相反,这可能与土壤母质、作物生长等情况有关。     

GIS技术在水土保持初设中的应用--以四川省遂宁市玉丰小流域为例

介绍了在四川省遂宁市市中区玉丰小流域的水土保持初设中 ,运用地理信息系统 (GIS)软件Ar cView进行了流域空间分析、获取水保初计数据、绘制和打印所需图版以及系统演示的应用方法 ,并探讨了地理信息系统与水土保持体系的相互关系     

A Comparative Study of Different Amendments on Amelioration of Saline-Sodic Soils Irrigated with Water Having Different EC: SAR Ratios

Soil degradation affects soil properties such as structure, water retention, porosity, electrical conductivity (EC), sodium adsorption ratio (SAR), and soil flora and fauna. This study was conducted to evaluate the response of contrasting textured soils irrigated with water having different EC:SAR ratios along with amendments: gypsum (G), farm manure (FM), and mulch (M). Water of different qualities viz. EC 0.6 + SAR 6, EC 1.0 + SAR 12, EC 2.0 + SAR 18, and EC 4.0 + SAR 30 was used in different textured soils with G at 100% soil gypsum requirement, FM at 10 Mg ha^?1, and M as wheat straw was added on surface soil at 10 Mg ha^?1. Results revealed that the applied amendments in soils significantly decreased pH_s and electrical conductivity (EC_e) of saturated paste and SAR. Four pore volumes of applied water with leaching fraction 0.75, 0.77, and 0.78 removed salts 3008, 4965, and 5048 kg ha^?1 in loamy sand, silty clay loam, and sandy clay loam soils, respectively. First four irrigations with LF of 0.82, 0.79, 0.75, and 0.71, removed 5682, 5000, 3967, and 2941 kg ha^?1 salts, respectively. The decreasing order for salt removal with amendments was FM > G > M > C with LF = 0.85, 0.84, 0.71, and 0.68, respectively. This study highlights a potential role of soil textures to initiate any mega program for reclamation of saline-sodic soils in the perspective of national development strategies.     

Mitigation of Diffuse Phosphorus Pollution during Rewetting of Fen Peat Soils: A Trans-European Case Study

Intensive cultivation of fen peat soils (Eutric Histosols) for agricultural purposes, started in Europe about 250 years ago, resulting in decreased soil fertility, increased oxidation of peat and corresponding CO₂-emissions to the atmosphere, nutrient transfer to aquatic ecosystems and losses in the total area of the former native wetlands. To prevent these negative environmental effects set-aside programs and rewetting measures were promoted in recent years. Literature results and practical experiences showed that large scale rewetting of intensively used agricultural Histosols may result in the mobilisation of phosphorus (P), its transport to adjacent surface waters and an accelerated eutrophication risk. The paper summarises results from an international European Community sponsored research project and demonstrates how results obtained at different scales and from different scientific disciplines were compiled to derive a strategy to carry out rewetting measures. A decision support system (DSS) for a hydrologically sensitive area in the Droemling catchment in north-eastern Germany was developed and is presented as a tool to regulate rewetting in order to control P release. It is demonstrated that additional laboratory experiments to identify essential processes of P release during rewetting and the site-specific management of the water table, the involvement of specific knowledge and experience of the stakeholders are necessary to develop an applicable DSS. The presented DSS is practically used to prevent freshwater resources from diffuse P pollution.     

基于制度分析的跨行政区流域水污染治理绩效优化研究

[目的]从制度是博弈的规则角度分析影响跨行政区流域水污染治理绩效的症结,旨在为提高流域水环境质量提供规则建议。[方法]通过对《环境保护法》、《水法》、《水污染防治法》相关法律条款和水资源管理体制进行分析,以及对中国水环境质量状况进行调查。[结果]条块分割,多头管理,缺乏协调机制的流域管理体制及制度安排已难以适应污水排放量急剧增长和解决日渐频繁的跨区域性流域水污染事件的需要,而环境法制执行力的缺失进一步使嵌入经济和政治双重竞争博弈的地方政府容易采取保护污染企业和转嫁污染等恶性竞争手段,使流域陷入公地悲剧的非理性均衡。[结论]提高跨行政区流域水污染治理绩效需要进一步完善博弈规则设计,提高制度执行力以承诺行动的方式提高中央政策的可信性和有效性,建立"河长制",创新流域产权及完善异地开发补偿制度。     

Pollution in a Lowland River System. A Case Study: the Reconquista River (Buenos Aires,Argentina)

The Reconquista river is a lowland watercourse; about three million people and several thousands of industries are settled in its flood plain. It can be considered as one of the most polluted rivers of Argentina. The present work is an attempt to describe the quality of the surface water through 16 physicochemical variables measured monthly in five sites (S₁to S₅) during 1994. Univariate and multivariate analyses of data showed a clear difference of S₁and S₂respect to S₄and S₅for ammonium, ortophosphate, pH, hardness, chloride, phenols, BOD, COD, and DO values. S₃appears to be a transition site. DO content showed a significant negative regression respect to the distance from the mouth. In the multivariate analyses between seasons the concentration of phenols appeared as an important feature. However it can be considered that seasonal variations were difficult to explain because of the river is the receptor of both regular and intermitent pollution pulses. It was concluded that the deterioration of this water body was progressive downriver, the contribution of the Moron creek in S₄determined a sharp adverse change in the physicochemical conditions. In the two downstream sampling stations (S₄and S₅) the values were far from natural conditions.     

滇东南岩溶地区三种退耕还林模式的水土保持效应研究

对滇东南岩溶地区3种退耕还林模式和坡耕地的径流和植被、土壤测定分析,结果表明：退耕地还林恢复植被后,能取到明显的固土保水增肥作用。营造纯林、乔草混交林或经济林与牧草复合经营,均具有较好的水土保持效果,综合考虑保水、保土和保肥能力,由大到小依次是：川滇桤木：红三叶〉墨西哥柏〉花椒：大百脉根。与坡耕地相比,川滇桤木与红三叶混交林能减少37．23％的径流和99．40％的土壤流失,固体养分流失量中有机质、全氮、全磷、全钾、速效氮、速效磷和速效钾分别减少99．37％,99．43％,98．68％,98．86％,99．34%,99．35％和99．58％,液体养分流失中氮、磷、钾分别减少32．45％,19．80％和21．57％。不仅减少了水土和养分的流失,同时枯枝落叶等有机质对土壤的改良和营养补充,使土壤养分有所提高,而坡耕地的土壤养分则有所下降。     

黄土丘陵沟壑区三种不同植被土壤水分动态及蒸散耗水规律研究

通过连续5a定点观测流域土壤水分、气象要素等资料,利用水量供耗平衡原理,分析了该区域3种不同植被类型阶段储水量、耗水量和耗水规律.结果表明:天然次生林年耗水量最少,为487.8 mm,玉米次之,为519.65mm;苹果最大,为540.7 mm;从不同类型土壤储水量分析表明:在阴坡生长的天然次生林处于充分供水状态,年耗水量稳定在500 mm左右;而玉米和苹果树全生育期内大部分月份都处在土壤水分亏缺状态,耗水量年变差较大,其年最大耗水量之差分别达240 mm和140.7 mm,当作物在土壤水分亏缺状态下生长时耗水量较小;年耗水量与当年降雨量关系不显著,而与降雨时间分布较为密切.     

岔路河流域水资源合理配置研究

水资源合理配置是实现水资源可持续利用的有效调控措施之一。以岔路河流域为研究对象,对该流域的水资源特征进行了分析,采用多目标规划建立流域水资源配置模型,以2007年为规划水平年,以经济效益最大和用水量最小为规划目标,对水资源进行配置。结果表明：在保证生活及生态用水的前提下,节约农业灌溉用水,以发展乡镇工业,从而实现可利用水资源量效益的最大化。     

三树种P－V曲线水分参数的比较研究

应用Ｐ－Ｖ技术研究了野外条件下海红、山杏和沙枣三个树种的水分参数（ψｓ＾ｓａｔ，ψｓ＾ｔｌｐ，ＲＯＷＣｔｌｐ，ＲＷＣｔｌｐ和ＡＷＣ）及其季节变化规律。探讨了树种对干旱胁迫的适应性反应。结果表明：树木各水分参数的季节变化规律与气候条件，尤其是水分条件相关，并与树木长期适应当地气候条件而形成的物候节律有关。嫩枝生长阶段是树木抗旱性最弱的时期，随着干旱锻炼过程的进行及小枝木质化程度的提高，树木的抗旱性不     

广东高州水库库区不同开发类型小流域的水土流失比较分析

本文通过面上调查和定点取样分析,对粤西高州水库库区三个不同农业开发类型小流域的水土流失进行了比较分析。结果表明，格苍小流域地势陡削，比良垌、军屯两小流域更不利于保持水土。由于该流域以热带亚热带竹林和针阔叶混交林为主的植被保护较好，能因地制宜发展立体林业、建立林农复合农业生态系统，故水土流失远小于良垌和军屯，农业经济效益也优于良垌和军屯。     

Sugar Cane Industry as a Source of Water Pollution – Case Study on the Situation in Ipojuca River, Pernambuco, Brazil

The Ipojuca river, a river in Northeast Brazil extending from west to east, is situated in the semiarid interior and rainy coastal zone of Pernambuco state. The river basin covers an area of 3,514 km², with a total river length of 215 km. The water flow regime is characterized by the annual change from dry to rainy season as well as periodically occurring dry cycles. Mean flow rates vary between 2 and 35 m³ s^?1. The dominant impacts on water quality of the river are domestic sewage input in the upper catchment and sugar cane cultivation and processing in the lower catchment. Long-term monitoring data used to demonstrate the impact of sewage discharge on the river’s self-purification capacity indicated a severe change to the worse in the lower course. One reason is the use of stillage (wastewater from cane processing) for fertilization and irrigation (fertigation). Pathways of contamination have been identified by evaluating cultivation and processing techniques of a bio-alcohol factory with annexed sugar cane cultivation. The river’s main ecological problems are water heating, acidification, increased turbidity, oxygen imbalance, and increased coliform bacteria levels. Precipitation-related wash-off and wash-out causes significant contamination within one to two days after rainfall. The increase in coliform bacteria is a consequence of secondary contamination. To determine the impact of the sugar cane industry on the river, the Brazilian bio-alcohol program must be subject to a critical evaluation. Environmentally friendly sugar cane cultivation methods need to be developed, and sugar cane factories must use waste-reducing technologies and water cycling processes in order to protect the region’s water resources.     

不同修复植被类型的三峡库区消落带土壤细菌群落分析

为了探究三峡库区消落带不同修复植被对土壤细菌群落结构的影响,以纯草地(A₁)、纯林地(A₂)和覆草林地(A₃)3种不同样地土壤为研究对象,采用土壤理化因子检测及扩增子测序的研究方法,分析了不同修复植被对三峡库区消落带土壤细菌群落的影响。结果表明:不同样地的pH值、全氮(TN)和全磷(TP)含量无显著性差异,A₁和A₃的土壤有机碳(SOC)含量之间无显著性差异,但均显著高于A₂(p<0.05); 相关分析显示样地土壤细菌群落ACE指数和Shannon指数与土壤SOC和TN含量显著正相关(p<0.05),Chao1指数与土壤SOC含量显著正相关(p<0.05); 不同样地土壤的细菌优势种群无明显区别; 属水平上6个优势种群的相对丰度与土壤SOC和TN含量显著相关(p<0.05); 冗余分析显示SOC是影响三峡库区消落带不同修复植被样地细菌群落的主要显著性因子(p<0.05)。由此可以得出,不同修复植被类型的消落带土壤的细菌优势种群无明显差异,土壤细菌群落结构主要受土壤SOC的影响。     

The Case of Pollution of Lake Maggiore: a 12-Year Study with the Bioindicator Mussel Dreissena polymorpha

In 1996, dichlorodiphenyltrichloroethane (DDT) pollution of industrial origin was discovered in Lake Maggiore. It was caused by industrial effluents on a tributary of the River Toce, one of the major affluents of the lake in correspondence of Pallanza Bay. This event is the worst case of environmental pollution that has occurred in Western countries in the last 25 years, not due to agricultural use of DDT, but because of an accidental industrial discharge. Heavy polychlorinated biphenyls (PCBs) pollution was also noticed in 2002, with concentration levels three to seven times higher than those measured in other Italian subalpine lakes. In this study, the current DDT and PCBs contamination levels were assessed according to their presence in zebra mussel (Dreissena polymorpha) specimens sampled in the last 5 years (2003–2008) in eight sampling stations of Lake Maggiore, chosen to cover the entire perimeter of the basin. Moreover, for two stations (Baveno and Pallanza-Villa Taranto) located inside and outside Pallanza Bay, respectively, it is possible to make comparisons starting from 1996. The results obtained show how Lake Maggiore is still an ecosystem with a severe environmental risk, more than 10 years after the original insecticide discharge. DDT contamination continues to evolve, and natural events, like lake overturn, floods, and heavy rains, can have a great influence on the insecticide levels in the lake. By contrast, PCB contamination is absolutely negligible, even if the peak of pollution revealed in 2002 seems to indicate that these pollutants are still present in large quantities in the Lake Maggiore watershed.