A dominialidade privada dos recursos hídricos em face do desenvolvimento sustentável

This article presents a brief reflection on the history of the field of water resources in Brazil. The evolution of the legal protection of water resources shows that the effect of the Water Code, the legal protection of waters was limited to neighborhood disputes and power generation, without concern for its preservation. However, the rapid industrialization process has required a greater intake of water resources and to promote the rational use and ensure multiple uses, it required a more effective legal protection and consistent with the new panorama, paper absorbed by the Constitution of the Republic of 1988. Subsequently, the Water Law in 1997, which established the National Water Resources Policy, implemented the constitutional principles, highlighting water as a public good with economic value, whose use planning and management must occur in a sustainable manner. When you assign an economic value to water, asks if the rational has been actually achieved, or through a discourse of scarcity, was being privatized, or even if the instruments of grant and collection of use ensure the sustainable use water resources. It is noted that water is a fundamental right of all and that is what your domain should be oriented. However, there is a tortuous path to tread to ban the private dominion of water resources and promote ethical consumption of water, essential for the implementation of a sustainable water management.

Purpose: The National Water Resources Policy established foundations and instruments for the management of water resources in Brazil. Despite being considered one of the most advanced internationally, its effectiveness is questioned for water management in rural contexts where small users predominate. The article presents elements of water management conducted by rural landowners, seeking to analyze how these elements approach or distance themselves from the foundations and instruments of the National Water Resources Policy. For this purpose, semi-structured interviews were carried out with 151 rural landowners who use water resources in the context of the supply sources of the Cantareira Water Production System. The results indicate that the water sources accessed by users are the central reference that supports decisions on local water management, which distances itself from the watershed as a management unit, as proposed by law. Not based on a scientific conception, users mobilize specific indicators to determine the quality of the water consumed. Perceptions of the private domain and common good surrounding water sources do not fully align with the understanding of water as a public good. Furthermore, the notion of free access to and use of water also distances itself from any intention to charge for water in rural areas. It is concluded that the foundations and instruments of the National Water Resources Policy are not able to promote the management of water resources at the level of small sources and users, and that the perceptions and management practices of these users are far from what is established by law. The objective of the article is to present elements of water management conducted by rural landowners, seeking to analyze how these elements approach or distance themselves from the foundations and instruments of the National Water Resources Policy. Method/design/approach: The research is of a qualitative nature, of a descriptive nature, having been carried out empirical research. For the empirical research, semi-structured interviews were carried out with 151 rural landowners who use water resources in the context of the supply sources of the Cantareira Water Production System. Results and conclusion: The results indicate that the water sources accessed by users are the central reference that supports decisions on local water management, which distances itself from the hydrographic basin as a management unit, as proposed by law. Not based on a scientific conception, users mobilize specific indicators to determine the quality of the water consumed. Perceptions of the private domain and common good surrounding water sources do not fully align with the understanding of water as a public good. Furthermore, the notion of free access to and use of water also distances itself from any intention to charge for water in rural areas. Research implications: From the analysis, it is highlighted that the fundamentals and official instruments of water resources management cannot influence the water management that occurs at the level of small rural users. The main implication of the study is to stimulate reflection on the need to build a policy that takes into account elements of local water management, seeking full management of water resources. Originality/value: The study seeks to contribute to the improvement of water resources management, in terms of local management aspects. The ways of acting of rural landowners need to be recognized, understood and valued, so it will be possible to promote sustainable water management in one of the most critical contexts for water security in the country.

Rivalry over river water resources has been a constant theme in the international politics of the South Asian region ever since the British Raj ended in 1947. Indeed, hardly had independence been gained when the competing claims of India and Pakistan to the waters of the Indus river basin helped bring on the first war between them over Kashmir (1947-1949). Nearly a decade of arduous World Bank-facilitated negotiations resulted finally in the 1960 Indus Waters Treaty (IWT), a landmark agreement that succeeded in resolving the question of Indus waters ownership by getting Indian and Pakistani consent to the permanent division of the six rivers of the Indus system. That formula, perhaps suitable enough for then, strikes some as an ill fit for now. After all, much has changed in the sixty-odd years that have passed since independence. The South Asian region has experienced more than a tripling of its population; and it has also undergone the massive social and economic changes that go along with industrialization and urbanization. Inevitably, these things have brought it under vastly increased pressures on water availability for agricultural and other uses. Acute fresh water scarcity now ranks among the most pressing domestic problems faced by Pakistan, and it is scarcely less pressing for large parts of India and Bangladesh as well. Exacerbated by equally acute power shortages in these countries (a development attracting attention to the region’s vast hydroelectric potential), their water resource-related disputes are already among the most nettlesome issues on their bilateral agendas. This is no less true of India-Bangladesh relations, which are bedeviled by the failure of their governments to seal water sharing agreements on any but one of the 54 rivers India and Bangladesh share in common, than it is of India-Pakistan relations. True, the near-term likelihood of war erupting in the region as a direct consequence of these disputes is slight; but that the region’s water rivalries are already fraying tempers, deepening distrust, and, in myriad ways, acting as conflict multipliers cannot be denied. Added to this, of course, is that neighboring China’s own extreme fresh water scarcity and its much-magnified interest in tapping into Tibet’s rich water resources hover threateningly over South Asian water supplies. Tibet’s water resources include the Brahmaputra river, already of unquestionably crucial importance to Bangladesh and India. With China now beginning to weigh in on the scales of South Asia’s water security, the potential for serious confrontation over water resources is heightened still further. Increased basin-wide cooperation over these resources is one possible—and, indeed, highly desirable—outcome of these developments. One highly undesirable—but perhaps no less possible—outcome, of course, is water war.

برای بررسی اثر سطوح شوری آب آبیاری و زمان شروع آبیاری با آب شور و لب‌شور بر خصوصیات کمی خربزه دیررس، آزمایشی با 7 تیمار و 3 تکرار در قالب بلوک‌های کامل تصادفی با استفاده از روش آبیاری قطره‌ای نواری، در مرکز تحقیقات کشاورزی و منابع طبیعی خراسان رضوی انجام شد. تیمارهای آبیاری عبارت بودند از: 1- آبیاری با آب شیرین (6/0 دسی‌زیمنس بر متر) از ابتدای کاشت تا انتهای فصل برداشت، 2- آبیاری با آب با شوری 3 دسی‌زیمنس برمتر از ابتدا تا انتهای فصل داشت، 3-آبیاری با آب با شوری 6 دسی‌زیمنس بر متر از ابتدا تا انتهای فصل، 4- آبیاری با آب با شوری 6 دسی‌زیمنس بر متر از 20 روز بعد از جوانه‌زنی تا انتها، 5- آبیاری با آب با شوری 3 دسی‌زیمنس بر متر از 20 روز بعد از جوانه‌زنی تا انتها، 6- آبیاری با آب با شوری 6 دسی‌زیمنس بر متر از 40 روز بعد از جوانه‌زنی تا انتها و 7- آبیاری با آب با شوری 3 دسی زیمنس بر متر از 40 روز بعد از جوانه‌زنی تا انتهای فصل داشت. نتایج نشان داد که، شوری آب بر عملکرد کل، عملکرد اقتصادی و کارآیی مصرف آب آبیاری تاثیر معنی‌داری داشت. بالاترین عملکرد کل و عملکرد اقتصادی و کارآیی مصرف آب آبیاری از تیمار شاهد بدست آمد که تفاوت آن‌ها با تیمارهای آب شور و لب‌شور معنی‌دار بود. در ضمن تفاوت بین عملکردهای تیمارهای شور و لب‌شور معنی‌دار نبودند. آبیاری با آب شیرین در اوایل دوره رشد باعث افزایش محصول نشده بلکه، باعث وارد شدن تنش بیشتر به گیاه می‌شود.

Rapid industrialization has led to global climate change, raising attention to environmental issues. The problem of water resource shortage shown in various statistical data indicates the government should convey to consumers the idea of water management in order to retard expansion of water scarcity. “Water footprint” is an indicator for measuring scarcity of fresh water. It is a focus gradually concerned by businesses, and many of them use it as a tool for disclosing water resource and enhancing their green image. There are blue, green and grey water footprints. The former two are used to indicate water consumed by production. The last considers the amount of diluted fresh water required for maximum tolerable concentration of discharging pollutants to nearby waters; its calculation, compared to traditional water usage, must include intangible degree of water pollution in production of product or service. The location and standard of pollutants discharged to nearby waters must be acquired for conducting water footprint assessment by combining calculations of life cycle and water footprint. This is a critical point in calculating grey water footprint. However, the information cannot be easily accessed. Its range is often only within the focal firm of the business, and single water quality criterion beneficial to the business is mostly adopted for assessing the entire water footprint. The purpose of this study is to apply GaBi 5 LCA software in establishment of an integrated and operable water footprint calculation model. This model will be included in the fourteen criteria for life environment and human health protection stipulated by EPA, and its range will extend to raw material production. A DVD of cradle-to-gate will be used as an example in this study for considering the uncertainty water environment where up-stream material supplier is located, settling the situation of the supplier’s uncertain water grade, exercising analysis, excluding uncertainties, and assessing the range between optimal and worse water footprint. Current LCA software is without built-in calculation model of water footprint indicator. The Gabi 5 model developed by this study requires only input of water grade, total emission stipulated by EPA, and natural concentration of the water. We must include phases from raw material exploitation, transportation and manufacture to in-firm recycling. For a 4.7 G DVD, of which supplier is located at highest land surface water grade, the water footprint is 235.5735 kg. The method of uncertain water grade is then applied, and analysis of optimal and worse results narrows the range to 117.1178 kg.

Introduction: Agricultural activity in Varamin plain has been faced with many challenges in recent years, due to vicinity to Tehran the capital of Iran (competition for Latian dam reservoir), and competition with Tehran south network in allocation of Mamlou dam reservoir and treated wastewater of south wastewater treatment plant. Mamlou and Latian dam reservoirs, due to increase of population and industry sectors, allocated to urban utilization of Tehran. Based on national policy, the treated wastewater should be replaced with Latian dam reservoir water to supply water demand of agricultural sector. High volume transmission of wastewater to Varamin plain, will be have economical, environmental, and social effects. Several factors effect on wastewater management and success of utilization plans and any change in these factors may have various feedbacks on the other elements of wastewater use system. Hence, development of a model with capability of simulation of all factors, aspects and interactions that affect wastewater utilization is very necessary. The main objective of present study was development of water integrated model to study long-term effects of irrigation with Tehran treated wastewater, using system dynamics modeling (SD) approach. Materials and Methods: Varamin Plain is one of the most important agricultural production centers of the country due to nearness to the large consumer market of Tehran and having fertile soil and knowledge of agriculture. The total agricultural irrigated land in Varamin Plain is 53486 hectares containing 17274 hectares of barley, 16926 hectares of wheat, 3866 hectares of tomato, 3521 hectares of vegetables, 3556 hectares of alfalfa, 2518 hectares of silage maize, 1771 hectares of melon, 1642 hectares of cotton, 1121 hectares of cucumber and 1291 hectares of other crops. In 2006 the irrigation requirement of the crop pattern was about 690 MCM and the actual agriculture water consumption was about 620 MCM (supplying 90 percent of the demand), 368 MCM of which was supplied through groundwater and 252 MCM was supplied by surface water. In recent years supplying water from Latyan Dam to the agriculture in Varamin Plain due to water supply of Tehran and the recent droughts has been reduced to lower than half (the average 68.8 MCM). On the other hand, shortage of surface water resources has caused an additional pressure to the groundwater resources of the Plain. Excessive groundwater withdrawal and use of brackish reused waters in the southern parts of the plain has caused the quality loss in groundwater resources, so that groundwater salinity has increased about 0.5 dS/m from the year 2000 to 2011. Obviously, by continuing the present situation, in less than two decades the groundwater resources in Varamin will be either quite destroyed or unable to be used due to inappropriate quality. Another source of surface water is allocated to the Varamin Plain is treated wastewater produced from Tehran Wastewater Treatment Plant. Utilizing the phases 1 to 4 of this treatment plant, about 80 MCM (2.5 up to 4 m3/s) of wastewater is annually transferred to Varamin Plain. According to the projections, it is assumed that wastewater will be used in near future as the most important water resource to Varamin Plain. In this study, SD was applied as the system analysis method for the Varamin wastewater management. The spatial boundary of the SD model for Varamin model was the whole Varamin area, which is 1584 km2. The historical review period was from 2001 to 2011, the simulated period was from 2011 to 2036, and the simulation time interval was one year. The most important scenarios evaluated consisted of four wastewater allocation scenarios [(i) keeping the excising condition, (ii) complete allocation of Latian dam reservoir water to Tehran domestic use, allocation of 200 MCM treated wastewater during growing season to agricultural sector and 40 MCM to artificial aquifer recharge during non-growing season starting year 2016, (iii) similar to scenario number two w/o artificial aquifer recharge and (iv) similar to scenario number two plus allocating 50 MCM starting year 2021]. Mass flow or convection method by considering surface adsorption of solute was used to survey movement and adsorption of elements in soil. Adsorption isotherms delineated and determined by field and experimental measurement. Results and Discussion: The result indicated that if raw wastewater be used till 2031, Cadmium and Copeer concentration will be outstanding and will have harmful effects on farmer’s health. Utilization of treated wastewater will be safe and will have not harmful effects on farmer’s health by heavy metals, to about 150 future years. Also, simulating result showed that Nitrate concentration in groundwater will exceed from allowable limitation for potable water in all scenarios to 2031. Application of scenarios (iv) and (iii) lead to the lowest and the highest Nitrate concentration, respectively. Conclusion: In this model a systems system dynamics approach was applied to understand how various factors related to operation of wastewater and water sustainability interrelate. The developed model is capable to simulation of all factors, aspects and interactions that affect wastewater utilization. Result of this study demonstrated that SD is a useful decision support tool for sustainable wastewater management. By considering severe water shortage problems in the study area, and safe utilization of treated wastewater, treated wastewater transmission of Tehran plant to Varamin Plain can help to solve water shortage problems. Increase of treated wastewater allocation lead to decrease of raw sewage and hereby decreasing hygienic harmful effects.

The Water Framework Directive (WFD) sets an efficient and sustainable framework on water resources where the environmental objectives are the core of it; achieving a good water status should be pursued for each river basin. Thus, it is necessary to undertake analyses of the characteristics of each singular position and to evaluate the impacts of human activity, as well as economic analyses of the water usage. With respect to the environmental protection, there is a need for a greater integration of qualitative and quantitative aspects regarding both surface waters and ground waters. The WFD suggests the use of economic instruments by Member States to achieve these goals. In particular, it sets that Member States must introduce selected pricing policies by 2010. The principle of the recovery of the costs of water services, including environmental and resource costs associated with damage or negative impact on the aquatic environment, should be taken into account in accordance with the Polluter Pays Principle - PPP, also in order to internalize the environmental costs. Thus, the economic analysis of water services (contained in the river Basin Management Plans) assumes a crucial role in order to achieve the WFD sustainable goals. This paper aims at analyzing the PPP application to the Italian case, assessing the adopted criteria in the economic analysis of water services in the light to evaluate methods suggested in the current literature.

The Mekong River is the dominant geo-hydrological structure in mainland Southeast Asia, originating in China and flowing through or bordering Myanmar, Laos, Thailand, Cambodia, and Vietnam. Whereas water resources in the wet season are more than adequate to fulfill basin needs, there are regional water shortages during the dry season, when only 1-2% of the annual flow reaches the Delta. Recent rapid agricultural and economic development in the basin has led to increasing competition among the riparian countries for Mekong waters. This development calls for a structured approach to the management of the basin, including efficient, equitable, and environmentally sustainable water allocation mechanisms that support the socioeconomic development in the region. Institutional mechanisms for Mekong cooperation among the riparians in the lower basin have been in place since 1957, and were revived in 1995. However, comprehensive water allocation mechanisms for the (lower) basin have not been developed to date. In this study, multi-country and intersectoral analyses of water allocation and use are carried out for the Mekong River Basin with the objective to determine tradeoffs and complementarities in water usage and strategies for the efficient allocation of water resources. An aggregate economic-hydrologic model for the basin is developed that allows for the analysis of water allocation and use under alternative policy scenarios. Results from the analytical framework indicate that although competition for Mekong water still appears to be very low, there are substantial tradeoffs between instream and off-stream water uses. An analysis of alternative water allocation mechanisms shows that to achieve both equitable and large benefits from water uses across countries and sectors, the ideal strategy would be to strive for optimal basin water use benefits and then to redistribute these benefits instead of the water resource. The development of such an integrated framework of analysis can be a critical first step to overcome some of the obstacles to effective management and joint cooperation in the Mekong River Basin. It could also facilitate the upcoming negotiations of water allocation rules in the lower basin and thus contribute to the reasonable and equitable utilization of Mekong River waters, as envisioned in the 1995 Mekong Agreement.

Contamination of water resources by pesticide toxins is considered as one of environmental issues which is because of plant pest diversity and subsequently use of various toxicants. In previous decades all over the world, the usage of organophosphorus toxins in order to preservation of agriculture products expanded. In Gilan province (Iran) there are numerous agriculture lands and gardens which are sprayed intermittently and since drinking water of the region residents is rather supplied by underground waters, then penetration of toxicants into the wells is possible. For this reason pesticide toxicants use could be a treat for drinking water supplying resources of this state. In the paper, samples of water from ten wells were collected and for measuring the quantities of toxicants, experiments were carried out during 4 seasons of year. Toxicant residues in samples were analyzed according to Gas Chromatography–Electron Capture Detector (GC-ECD) method. Due to phosphorous toxicant analyze results; it is revealed that in some cases precipitation amount has a great effect on toxicant concentration inside well water because of leaching higher layers. Also it is indicated that clay presence in soil due to toxicant holding and rain or flood occurrence cause to decrease and increase toxicant leak into the underground water respectively. Finally in order to Hinosan toxicant removal from water resources, active carbon has been utilized. The results indicated that adsorption by active carbon was of Langmuir type and this adsorbent effective cause to eliminate Hinosan toxin from water resources.

Beneath the great state of Texas, there is water. Texas has nine major aquifers and 21 minor aquifers underlying the state. These aquifers are a vital water supply source in Texas, providing approximately 60 percent of the 16.1 million acre-feet of water used in the state annually.[2] These underground waters also sustain surface water flow in rivers across Texas; thus, they are integral to the health of watersheds throughout the state and the economies that depend on this water. When W.H. Auden wrote, “Water is the soul of the Earth,” he must have been referring to groundwater.
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\nIn Texas, groundwater is regulated on the local level by groundwater conservation districts (GCDs), whose regulatory authority over subsurface aquifers is generally confined by county boundary lines rather than hydrogeological ones. In 1917 after devastating drought, voters approved the Conservation Amendment to the Texas Constitution, which provided the authority for the Texas Legislature to establish GCDs to conserve the state’s groundwater resources.[3] Chapter 36 of the Texas Water Code governs the powers and duties of GCDs in Texas.
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\nTexas landowners own the groundwater beneath their land as private property.[4] While a landowner is entitled to drill for and produce groundwater below the surface of his property, the Texas Supreme Court has held that he is subject to reasonable regulation through GCDs.[5] In GCD-managed areas, a landowner’s right to pump groundwater is tempered by the Water Code’s goals of protecting property rights in groundwater and the groundwater resource. Groundwater regulation ideally prevents one landowner from pumping to such an extent that nearby wells are impacted.
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\nNot all areas of Texas, however, are controlled by a GCD. Approximately one-third of the surface area of Texas is not regulated by a GCD. These areas where a GCD does not exist are depicted on the map below as areas without color. Out of the 254 counties in the state, 174 counties are either fully or partially within a confirmed or unconfirmed GCD.[6] In unprotected areas, there is no regulatory authority to monitor the rate and amount of groundwater withdrawal, and the rule of capture permits landowners to pump unlimited amounts of groundwater, even if doing so dries up neighboring landowners’ wells. Unregulated areas in Texas are the final frontier — the last remaining, lawless parts of the state where groundwater protection is nonexistent.
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\nDuring a time of unparalleled pressure on groundwater resources across the state, the lack of groundwater protection in some areas of Texas is undermining important areas of law and policy — from property rights and natural resource protection, to groundwater management and regional water planning.

Throughout the world, pressures on water resources are increasing, mainly as a result of human activity. Because of their accessibility, groundwater and surface water are the most used reservoirs. The evaluation of the water quality requires the identification of the interconnections among the water reservoirs, natural landscape features, human activities and aquatic health. This study focuses on the estimation of the water pollution linked to two different environmental issues: salt water intrusion and acid mine drainage related to the exploitation of natural resources. Effects of salt water intrusion occurring in the shallow aquifer north of Ravenna (Italy) was analysed through the study of ion- exchange occurring in the area and its variance throughout the year, applying a depth-specific sampling method. In the study area were identified ion exchange, calcite and dolomite precipitation, and gypsum dissolution and sulphate reduction as the main processes controlling the groundwater composition. High concentrations of arsenic detected only at specific depth indicate its connexion with the organic matter. Acid mine drainage effects related to the tin extraction in the Bolivian Altiplano was studied, on water and sediment matrix. Water contamination results strictly dependent on the seasonal variation, on pH and redox conditions. During the dry season the strong evaporation and scarce water flow lead to low pH values, high concentrations of heavy metals in surface waters and precipitation of secondary minerals along the river, which could be released in oxidizing conditions as demonstrated through the sequential extraction analysis. The increase of the water flow during the wet season lead to an increase of pH values and a decrease in heavy metal concentrations, due to dilution effect and, as e.g. for the iron, to precipitation.

Water resources are constantly under threat from pollution, overexploitation and urbanisation. The European Innovation Partnership on Water (EIP) has identified specific actions to meet the relevant needs which have been codified into 8 priority areas. Focussing on two of the five thematic priorities (water and waste water treatment, including recovery of resources; and water and energy integration, this paper amplifies Blue Economy models aiming to shift society from scarcity to abundance through these new and novel ways. Inland and coastal waters are looked upon as ‘water resources’ that can contribute to the production of sustainable energies. In water reuse, the energy contained in wastewater is also examined in order to contribute to the understanding of the water/energy relationship. Energy is needed for water cycle management; water is needed for energy production and water reuse can help to save both. Biogas production, being an important green energy issue is also examined under the scope of wastewater treatment. Significant energy savings and recovery of nutrients can be achieved on major components of an ‘efficient’ wastewater treatment plant by applying novel blue economy principles. Zones where energy efficiency can be improved, as well as phosphorous recovery is explained always under a holistic water cycle management. Marine based renewable energies are also outlined based on coastal blue potentials and future world energy needs-provided that conventional energy sources are approaching exhaustion. Other general quality issues in coastal environments are presented and examined within the framework of the blue economy principle and thus suggesting actual novel sustainable management techniques.

چکیده مدیریت منابع آب در ایران با تقاضای فزاینده برای منابع آب، افزایش قابل توجه در هزینه‌های عرضه آب و برداشت بی‌رویه از منابع آب زیرزمینی مواجه می‌باشد. برای بهبود کارایی استفاده از آب، اقتصاد‌دانان افزایش قیمت نهاده آب را پیشنهاد می‌کنند ولی سیاستگذاران به دلیل نگرانی‌های اقتصاد‌ی، فرهنگی و سیاسی این پیشنهاد را رد می‌کنند. در این تحقیق از تکنیک برنامه‌ریزی ریاضی مثبت (PMP) در سطح مزرعه برای تحلیل اثرات مختلف کاربرد سیاست‌های قیمت‌گذاری آب و همچنین سیاست‌های جایگزین آن در دشت مشهد (استان خراسان رضوی) بهره گرفته شد. سناریوهای شبیه‌سازی‌شده شامل افزایش قیمت نهاده آب، مالیات بر نهاده‌های مکمل نهاده آب و مالیات بر محصول می‌باشد. اثر سیاست‌های جایگزین بسته به گروه بهره‌بردار نماینده متفاوت بوده و اثرات آن بر درآمد، تقاضای آب و الگوی کشت هر گروه از بهره‌برداران گسترده‌ می‌باشد. سیاست قیمت‌گذاری آب و مالیات بر محصول در مقایسه با سیاست مالیات بر نهاده مکمل، مؤثرتر و مناسب‌تر می‌باشند. دو سیاست مالیات بر نهاده و محصول در نرخ‌های معینی می‌توانند به عنوان جایگزین سیاست قیمت‌گذاری آب بکار روند. واژه‌های کلیدی: آب، برنامه‌ریزی ریاضی مثبت، دشت مشهد، سیاست جایگزین

The rapid population growth increases water demand and affects water allocation systems as well as water resources management plans to satisfy the basic water needs for both human and nature. This has called upon the adoption of the integrated water resources management (IWRM) approach which promotes the coordination and management of water, land and related resources to maximize the economic and social welfare in an equitable manner without compromising the ecosystem. Water management and the implementation of IWRM approach cannot be achieved without proper working institutions that can coordinate and manage the implementation strategies. The aim of this paper is to establish a national water resources management authority in Rwanda that will manage and coordinate the national water resources in a sustainable way taking the water resources management bodies in Rwanda, in comparison with the Kenyan water resources management bodies as a good example. An extensive review was conducted using governmental documents, and key institutional elements were analyzed by evaluating their performance in comparing with the Kenyan institutions. The paper revealed that Rwandan water resources management is a fragmented way and the level of control is sophisticated without taking into consideration the management of water resources at a catchment level, which affects the coordination, management and the implementation of water policies. The results show that most of the water laws and policies in Rwanda should be changed and establish the Rwandan water resources management Authority that has the power to control and coordinate the water resources implementation policies.

پاکسازی آب‌های سطحی آلوده به نیترات و فسفات پیش از انتشار آنها در محیط و ایجاد اوتریفیکاسیون باتوجهبهاهمیتسلامتآبوبادرنظرگرفتن پیامدهایناشیازنیترات وفسفات ضروری به نظر می‌رسد. از اینرو این پژوهش برای شناسایی توانمندی دو گیاه علف چشمه و پونه در پالایش آب های آلوده به نیترات و فسفات شامل دو آزمایش فاکتوریل در قالب طرح پایه کاملا تصادفی در شرایط هیدروپونیک انجام شد. فاکتور اول شامل نوع گیاه (پونه و علف چشمه) و فاکتور دوم در آزمایش اول و دوم به ترتیب عبارت از نیترات (50، 100 و 150 میلی گرم در لیتر) و فسفات (5، 10 و 15 میلی-گرم در لیتر) بود. دو گیاه از نظر انباشت فسفات در ریشه و اندام های هوایی با یکدیگر اختلاف داشتند. با اینحال روند تغییرات شاخص غلظت زیستی فسفر در اندام هوایی بین دو گیاه مشابه بود. به نحوی که افزایش غلظت فسفات در محلول کاهش معنی دار این شاخص را در هردو گیاه در پی داشت. علف چشمه و پونه غلظت بالایی از نیترات و فسفر را در خود انباشت داده اند و انباشت این عناصر در اندام هوایی نسبت به ریشه ها بیشتر بود. بطوریکه فاکتور انتقال نیترات در علف چشمه و پونه به ترتیب 3/1 و 07/1 و فاکتور انتقال فسفر نیز به ترتیب 07/1 و 94/0 به دست آمد.