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1.

Purpose  

The management of natural resources over large spatial scales is inherently complex due to numerous biophysical and socioeconomic factors and the uncertainty associated with environmental systems and human behavior. Numerous approaches have been put forward to facilitate the decision-making process, including adaptive management (AM) which was developed in the 1960s and 1970s as an alternative to more rigid management frameworks. In recent years, it has been utilized for the management of water and river basin resources, particularly in North America. Its use for sediment resources is less well developed. This paper presents a review of the AM approach, including its characteristics, steps, and barriers to implementation. It also gives some recent examples where the AM approach has been used for sediment quantity and quality issues. Finally, it considers the potential of the AM approach for sediment resource management given Water Framework Directive and other legislative requirements.  相似文献   

2.
基于生态水文学的新疆绿洲生态用水若干问题   总被引:8,自引:0,他引:8  
新疆是中国西部干旱区的典型地区,基于水资源可持续发展战略,生态用水的理论与方法亟需解决。以新疆为代表的干旱区生态用水具有一系列规律与特征。生态用水的水质与水量具有较大的变幅范围,用水的方式比较灵活,水分的供给状况影响生物的生产力。生态用水受制于GSPAC中水分循环与转化的效率,并与植被特征、土壤理化性状、地形特点、水资源利用水平具有密切的相关性。生态用水量的估算有许多参数与模型需要率定;干旱区生态用水观念的确立,对于完善生态水文学的学科体系,指导水资源的科学管理和生态实践,促进生态产业可持续发展具有理论价值和现实意义。  相似文献   

3.
华北低平原区有着巨大的粮食增产潜力,同时也是粮食生产和农业水资源矛盾突出的地区。外来调水与浅层微咸水的联合利用是解决区域水资源问题的有效途径之一,同时也将引起区域水循环和水环境的改变。为明确外来调水对华北低平原区地表水和地下水水化学特征的影响,本研究在华北低平原区河北省南皮县域内对调水后不同季节地表水和地下水进行调查和采样,利用水文地球化学和氢氧(d~2H、d~(18)O)稳定同位素相结合的方法,研究外来调水对地表水和地下水转化及其水化学特征的影响。研究结果表明,11月至翌年7月,受蒸发作用的影响,地表水电导率(EC)和钠吸附比(SAR)增加,d2H、d18O同位素不断富集;由于地表水和周围土壤的交换吸附作用使其水化学类型向Na~+、Cl~-和SO_4~(2-)增加、HCO_3~-减少的咸水转变。调水改变了地表水和浅层地下水之间的补给关系,11月至翌年3月,沟渠附近浅层地下水受外来调水直接或者灌溉补给,使得3月浅层地下水EC降低,埋深变浅,部分采样点分布在外来调水的SAR-EC区域。受调水影响,3月沟渠附近浅层地下水水化学类型为Na·Mg·Ca-Cl·SO_4、Na·Mg-Cl·SO_4·HCO_3、Na·Mg-SO_4·Cl·HCO_3等,是11月调水(Na·Mg·CaSO_4·HCO_3·Cl)和浅层地下水(Na·Mg-Cl·SO_4)的过渡类型。3月至7月浅层地下水补给沟渠水,地下水埋深变深,7月浅层地下水水化学类型与3月相似。调水可以季节性地改善区域内沟渠水及其附近的浅层地下水水质,而对深层地下水和坑塘水的水质无改善作用。调水对沟渠水水质的改善体现在调水季节,对浅层地下水水质的改善存在滞后性,2014年11月调水之后,2015年3月浅层地下水的水质得到改善。因此,采用调水和浅层地下水、坑塘水混合灌溉,对合理开发利用区域咸淡水资源以及深层地下水压采,恢复地下水位意义重大。  相似文献   

4.
水安全与粮食安全   总被引:11,自引:2,他引:9  
水安全是粮食安全的基础,实现农业水资源的高效利用是保障水安全和粮食安全的根本途径。本文阐述了水安全与粮食安全的概念;分析了全球及我国水安全与粮食安全现状和未来形势;辨析了粮食安全的水资源保障战略的构成要素及我国节水农业的发展重点;并就粮食生产的水资源高效利用、水资源高效配置与调控、农业水资源消耗的生态环境效应以及应对旱涝极端气候等进行了讨论,进而对主要科学问题进行了归纳,包括作物理想耗水与多过程协同调控机制、强人类活动下灌区多尺度水循环与伴生过程、粮食生产-水资源-生态过程的互馈机制以及农业旱涝致灾机理与预警机制。  相似文献   

5.
Water quality degradation in the Selangor River will still be present in the years to come since pollutant loads from poultry farms, municipal wastewaters, and industrial wastewaters are not envisaged to be handled effectively. This will be facing the problems of water quality status to use for multiple purposes and to provide its aquatic environment continuously. The water quality evaluation system is used to assess the water quality condition in the river. This system distinguishes two categories of water condition i.e., the water quality index and water quality aptitude. The assessment of water quality for the Selangor River from nine stations along the main stream, which concludes that water has been highly polluted (index 5) immediately downstream of station 02 Selangor River before confluence with Kubu River due to high concentration of microorganisms and immediately downstream of station 06 Selangor River before confluence with Batang Kali River due to high concentrations of microorganisms and suspended particles, was verified. Mineral micropollutants were found to gradually pollute the stream water, ranging from the unpolluted water (index 1) in the upstream to the bad quality (index 4) in the downstream area.  相似文献   

6.
As a result of convenants between the Port of Rotterdam and the German Chemical Industry, the emissions in the Rhine between Basle (Switzerland) and the Dutch boarder have fallen by more than half in the past fifteen years. Recent studies have concluded that people are nowadays polluting the Rhine more than industry. This places Rotterdam’s involvement with the quality of water and the sediment of the Rhine, port and North Sea in a different perspective. As a medium-sized European municipality, Rotterdam doesn’t want to take on too much, certainly not when cross-border issues such as the quality of the North Sea and the Rhine water are concerned. Rotterdam is now trying to get other organisations to co-operate in solving this problem. A cleaner Rhine, after the success on point sources, can be achieved primarily by reducing the contamination from diffuse sources, over which the port itself has absolutely no control. Rotterdam is the homeport of Mrs. Els Kuijper. She gave a keynote lecture during the SedNet Inaugural Conference, April 22–23, 2002, which forms the basis of this article. Mrs. Kuijper is the vice-mayor and environmental alderman of Rotterdam.  相似文献   

7.
Abstract

Ground water wells from unfertilized Florida rangelands were sampled to monitor water quality parameters. Ground water was collected (1990–92) monthly from three range sites (south Florida flatwoods, slough, and freshwater pond) at the Southwest Florida Research and Education Center near lmmokalee, Florida. Water samples were analyzed for pH, electrical conductivity, total phosphorus (P), potassium (K), and ammonium‐nitrogen (NH4‐N); and water table depth was monitored monthly. Levels of nutrients were highly variable during the sampling period. Levels of P at all three sites exceeded the South Florida Water Management District's (SFWMD) maximum allowed level (0.18 mg P/L) in surface water runoff from rangeland. Time series models were useful for predicting (p<0.15) future events for all nutrients and water table depth. Variation in water quality, related to its N, P, and K content, was minimized by excavating the ground water wells three times before sampling. Water samples continue to be collected from each range site to develop a longterm water quality database from unfertilized rangeland.  相似文献   

8.
Water scarcity is one of the most prominent issues worldwide in relation to sustainable development, especially in arid areas. To gain a better understanding of the trade‐off between improving agricultural productivity and maintaining the stability of an oasis ecosystem in these areas, this study took the Heihe River Basin in northwestern China as a case to explore the changes in oasis dynamics and their human driving forces. The results showed that along with the 11·0% expansion of agricultural land, the total water demand for irrigation increased by 6·3% during 2000–2010. Although tremendous economic incentives for farmers spurred the oasis expansion and cropping system changes, the key driving force behind the oasis expansion in the study area was closely related to sufficient irrigation water guaranteed by new water sources (excessive consumption of groundwater and surface water) and water conservation efforts that were the results of the “water‐saving society” project (cropping system adjustments and technological improvements in irrigation). This loose regulation of water resource management can be considered to be partially attributable to the ignorance of the ecological value of water resources. Sustainable land use in the study area can only be achieved through the strict regulation of the management of surface water and groundwater resources throughout the basin and the invisible water provided by the water conservation measures. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

9.
BP神经网络在渭河水环境质量评价中的应用   总被引:4,自引:0,他引:4  
为准确和客观地评价渭河水环境质量状况,将改进算法的BP神经网络引入地表水环境质量评价领域,采用渭河2010年(9月7日至10月11日)水质指标监测数据,构建了渭河水环境质量评价模型。通过3个水质监测项目(氨氮、高锰酸盐指数、溶解氧)对渭河水质进行了评价,评价结果与环境保护部公布结果完全一致。结果表明,BP神经网络应用于水环境质量评价具有客观性、通用性和实用性,可以很好地解决评价因子与水质等级间复杂的非线性关系,评价方法简便可靠,预测精度高。  相似文献   

10.
The Wet Tropics region of north Queensland has outstanding environmental values, contains the highest biological diversity in Australia, and borders the Great Barrier Reef. Comparable to other tropical areas worldwide, increasing urban and agricultural development in the Wet Tropics has caused concerns with respect to ecosystem degradation due to poor water quality in freshwater reaches and marine environments. Key issues currently identified in the Wet Tropics include erosion and subsequent stream turbidity and sedimentation, nutrients from erosion and fertiliser use and pesticide residue contamination. Issues such as reduced dissolved oxygen, acid sulfate soil runoff, and biological factors such as weed infestation, reduced and degraded riparian vegetation condition, and flow modification have also been identified. These issues mainly arise from agricultural activities with lesser effects from urban development. Management of pollution to improve in-stream water quality requires a long-term monitoring program to characterize water quality conditions over different flows and seasons. This type of monitoring program is underway; however, the focus is on the Great Barrier Reef and does not fully consider freshwater ecosystem health. Another major issue is the lack of a fully developed conceptual framework that links changed land use to water quality and subsequently to aquatic ecosystem health. In this paper, we establish the current level of water quality knowledge in the Wet Tropics while outlining a conceptual framework connecting changing land management practices and their effects to water quality and to ecosystem health.  相似文献   

11.
Soil properties varied in water retention; due to soil texture and organic matter content. Variations of texture in many soils are effected mostly to soil forming factors of parent materials of the soil; biological activities; climactic variation; and duration of soil reaction. While the organic matter contents are affected totally by the environmental conditions of the soils. Water holding capacity of different soils influences' plant growth and development in diverse soil characteristics of the world and determines soil productivity. Water resources for agricultural activities are limited, particularly in arid environment and soil water-holding capacity of arid soil is very low. Kuwait can be good example of arid environment with limited water resources for agriculture activities and possess soil of coarse texture with very low organic matter content (Anonymous, 1997). Agricultural development in Kuwait meets many problems for crop production and urban landscaping. Water resources are limited and the quality is deteriorating at the same time soil water holding capacity is very low. Enormous amount of water, particularly desalinated expensive water is wasted for agricultural activities. This paper will study various parts of Kuwaiti soils water holding capacity and develop water retention data for efficient water irrigation and improvement of plant growth.  相似文献   

12.
以浑太河流域为研究对象,选取流域88个监测站点,在2009,2010,2012年对河流高锰酸盐指数、总氮、氨氮、总磷等9项指标进行监测,并对河流水质的时空异质性进行了分析。选择高锰酸盐指数、总氮、氨氮和总磷作为主要评价因子,采用单因子和综合水质标识指数法对该地区主要河流水污染特征进行分析及评价。结果表明,水质因子具有明显的时空异质性。单因子评价结果表明,非汛期总氮和氨氮为主要污染物,汛期总磷和总氮为主要污染物,非汛期的水质状况较汛期好,说明非点源是造成其污染的主要原因。河流水质综合评价中,小汤河上游、太子河南支、太子河北支所有点位的水质评价结果均为最好。所有站点中,海城河的支流(五道里河、运梁河、南沙河下游)区域的水质最差,达到劣Ⅴ类水质,且出现黑臭现象。研究结果对指导浑太河流域水污染防治及水资源管理具有重要意义。  相似文献   

13.
Water, Air, & Soil Pollution - Decentralized tap water systems are an important drinking water source worldwide. A good quality, high-pressure continuous water supply (CWS) is always the target...  相似文献   

14.
夏玉米水肥异区交替灌溉施肥的产量与环境效应研究进展   总被引:1,自引:0,他引:1  
水资源缺乏、污染严重、肥料利用率不高是我国农业和农村面临的重要且亟待解决的问题。发展节水施肥技术是解决这些问题的关键环节。交替灌溉施肥技术是在亏缺灌溉或部分根区干燥灌溉技术的基础上发展起来的一种节水施肥技术,可有效减少灌水量,提高灌水利用效率,防止灌溉过程中氮素淋失。在适宜的水氮配合条件下,还可以减少氨挥发和氧化亚氮等气态氮损失,增加作物产量。但是该技术的应用效果与环境条件、灌水定额、施肥量、种植密度等密切相关,在应用过程中应该根据环境条件进行微调。另外水肥异区交替灌溉施肥条件下,水分、养分在农田的时空分布规律,转化特征,以及植物对养分、水分吸收利用和调控机制等还有待于深入研究。  相似文献   

15.
Water scarcity and nitrate contamination have caused considerable attention to environmental matters. Water and nitrogen interactions have critical impacts on their use efficiency, plant growth, and quality. In a field experiment, a combination of three water treatments and three nitrogen rates was applied to determine their interactive effects on the growth of spinach. Soil water supply that was too low [W3N1 (the combination of water treatment 3 and nitrogen treatment 1), W3N2] could cause an increase in nitrate content. Oxalate contents would increase when water and nitrogen were either inadequate (W3N0, W3N1) or too high (W2N2). The most profit from spinach was obtained in plots that received water treatment 2 and nitrogen fertilizer 78 kg N ha?1. However, considering nitrogen treatments could affect the nitrate and oxalic acid, application of water treatment 2 and 39 kg N ha?1 nitrogen fertilizer could get better spinach quality.  相似文献   

16.
ABSTRACT

Most composters in the United States use open-windrows. During high intensity precipitation events, uncontained water running off of the surface of the compost piles can potentially contaminate surface waters with nutrients and metals. Water that is absorbed poses no runoff concern but may threaten groundwater quality. To gain insight into these processes, stormwater runoff fractions and water holding capacity of compost piles have been characterized for greenwaste (GW) and biosolids (BS) materials. Laboratory scale experiments were conducted using days 1, 7, and 14 materials representing three different stages of composting. This study also evaluated sloped and flat-top as different pile geometries and surfactant use for promoting infiltration. Results indicate that fresh materials were most hydrophobic and the infiltration rates increased with increased composting times. The water storage capacity of the compost pile increased with the age of the compost pile. Compost water storage capacities could not be reliably estimated as the difference between field capacity and as-received water contents.  相似文献   

17.
The Loxahatchee National Wildlife Refuge (Refuge) is impacted by inflows containing elevated contaminant concentrations originating from agricultural and urban areas. Water quality was analyzed using the Enhanced Refuge (ERN), the four-part test (FPTN), and the Consent Decree (CDN) monitoring networks within four zones in the Refuge. The zones were defined as the canal surrounding the marsh, the perimeter, the transition, and the interior zones. Although regression coefficients for ALK and SpC, and Ca, Cl, and SO4 concentrations with distance from the canal were lower using the FPTN than when using the ERN, using the FPTN to measure water quality parameters in the Refuge would give similar results as the ERN. Most of the ERN and FPTN sites are located in the northern and central areas of the Refuge. Water is deeper in the southern Refuge, and on an area basis contains a greater volume of water than the northern and central Refuge and therefore, water flow from the canal into the marsh in the northern and southern Refuge may differ. Numerous water quality monitoring sites must be added to the ERN and FPTN in the southern area to characterize water quality in the southern Refuge with confidence.  相似文献   

18.
以津春四号黄瓜为试验材料,研究了不同栽培方式﹝日光温室(G),遮雨棚(S)﹞及土壤水分条件﹝土壤含水率分别为田间持水量的60%~70%(W1)和90%~100%(W2)﹞对黄瓜产量、品质和水分利用效率(WUE)的影响。结果表明:(1)低水条件下,植株根冠比较大,但生物量、产量较低。耗水量随土壤含水率上升而增加,含水率较低的土壤有利于WUE提高幅度较大;日光温室内植株根冠比较小,生物量和产量高于遮雨棚;(2)较低的土壤含水率利于果实品质提高,其维生素C(Vc)、可溶性糖、可溶性蛋白质和可溶性固形物含量较高;遮雨棚内黄瓜营养品质优于日光温室内的黄瓜。  相似文献   

19.
抗旱节水剂在葡萄栽培上的应用试验研究   总被引:19,自引:1,他引:19  
通过保水剂、旱地龙、BGA土壤激活剂3种抗旱节水剂在葡萄种植上的田间试验,分析多种抗旱节水剂集成应用对土壤含水率、葡萄产量、葡萄品质(主要指可溶性固形物)的影响。结果表明,保水剂、旱地龙、BGA土壤激活剂在旱地果园的抗旱保墒中均有一定的效果,对于提高葡萄的品质和产量起着积极作用。  相似文献   

20.
水资源评价进展与存在的几个问题   总被引:5,自引:0,他引:5  
水资源评价是水资源利用基础。综述了水资源评价研究进展,提出了水资源评价中存在的问题,并对水资源评价中的干流区间水资源计算、水质水量联合评价、人类活动对水资源的影响以及生态需水等4个问题进行讨论,以推进水资源评价工作进展。  相似文献   

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