نشریه آب و توسعه پایدار
سال پنجم شماره 2 (پیاپی 11، پاییز و زمستان 1397)

In recent years, the level of groundwater table of Ghahavand plain has been reduced by excessive withdrawal of groundwater resources. Therefore, it is important to apply an appropriate management strategy for the optimal utilization of this resource. The main challenge in the economic management of water resources in the balance between supply and demand. To address this balance, the economic value of water, similar to other items, plays a decisive role. Therefore, water pricing is recommended as an indirect method for the sustainable use of water in the agriculture sector. The aim of this study is determining the economic value of water using the spatial econometric approach. Due to the relationship between the farm wells and groundwater resources, this study aims to answer the question of how this relationship affects the water demand of farmers. The correlation coefficient show that the use of spatial regression is superior to the classic regression method. The required data in this study were collected through field research and a questionnaire completed by farmers in 2016. The results show that the real price of water in wheat production is 2500 Rials per cubic meter. To control water consumption and balance the supply and demand for water, the difference between the real price and the price paid by farmers can be used for water pricing policies.

Due to population growth and increase in the usage of drugs and cosmetics as well as the inability of conventional processes of wastewater treatment to remove emerging contaminants such as PCPs, EDCs, surfactants, pesticides, industrial additives, and pharmaceutical organic pollutants, the effluents discharge in Iran's wastewater refineries may contain significant concentrations of emerging contaminants. The mechanism of biological removal of emerging contaminants from wastewater predominantly includes biodegradation by microorganisms such as bacteria, algae, and fungi into small molecules or water and carbon dioxide. Biological treatment technologies include a variety of conventional and unconventional methods such as activated sludge, MBR, aerobic, anaerobic, microalgae and fungi bioreactors, rotating biological reactor, trickling filter, nitrification and denitrification, biosorption, and constructed wetland. Therefore, wastewater characteristics play a key role in the selection of biological treatments. Based on previous research, the maximum removal efficiency of EDCs, beta blockers, and PCPs was revealed with MBR, surfactants, lipid regulators and anti-inflammatory with activated sludge, antibiotics and pesticides with biological activated carbon, analgesics with the aerobic process and other pharmaceuticals with microalgae. Due to the use of the activated sludge system for biological refinement in most wastewater refinement plants of Iran and the inability of this system to remove emerging contaminants, except surfactant, lipid regulators, and antiinflammatory, a national comprehensive research is needed for the removal of aforementioned contaminants by biological processes in future studies.

Freshwater, which accounts for less than 1% of world water resources, is rapidly decreasing due to extreme levels of withdrawals and the influence of seawater in areas under tension. This decreasing trend has reached a critical level in the Middle East since the water per capita in this area is much lower than the world average. Desalination is an approach for reducing water stress by producing freshwater from seawater, saline groundwater, drainage water, and wastewater in the coastal and inland areas. During these processes, rejected streams with high salinity as a sub-product are produced in which disposing of them is costly. A large amount of concentrated water containing the remaining compounds discharge into the environment and is potentially considered as a serious problem. Inland desalination due to the impossibility of disposing the produced brine is different from the desalination of seawater. In desalination of underground saline waters, fouling occurs with water-soluble salts and sedimentation reduces the production of water with a certain amount of energy during these processes. Therefore, the evolution of desalting technologies makes it cheaper, more reliable, and less productive.

Phenolic compounds are known to be environmentally dangerous pollutants. It is demonstrated that discharging them into environment causes an inhibitory effect on plant seed germination, plant growth, and microbial division. However, antioxidant properties of phenols, has persuaded researchers to recover these compounds from industrial wastes in the recent years. Olive mill wastewater is a rich source of phenolic compounds and its treatment for recovering these compounds is inevitable. It has been investigated that coupling these treatments with recovery of valuable reagents can compensate a large amount of costs. Nowadays, recovery of phenolic compounds from olive mill wastewater has attracted much attention due to its high added-value. Degradation of phenolic compounds can also produce high addedvalue materials. Biogas and compost are products from biological degradation processes. In this study physicochemical, biological, and combined processes for recovery and removal of phenolic compounds from olive mill wastewater are reviewed.

This paper reviews from a historical perspective the various methods for treating and simulating turbulence. After highlighting the main characteristic features of turbulence and its role in hydraulics, a necessary brief overview is given of the main methods used in hydraulic flow calculations for dealing with turbulence and its effects. These are 1) empirical relations, 2) solution methods for the Reynolds- Averaged Navier-Stokes (RANS), 3) Direct Numerical Simulations (DNS), and 4) Large-Eddy Simulations (LES). Brief comments are made on the historical development of different methods. Moreover, some application examples are presented for RANS, DNS, and LES methods.

Agriculture uses a significant portion of water consumption. Therefore, the policy of optimal management of water consumption is essential. To achieve this, it is necessary to improve the design and use of advanced technologies and management. Precision irrigation creates coordination between advanced irrigation management, monitoring and investigation of data, modeling, and control. The purpose of this system is to automatically and continuously adjust the irrigation application system to a desired performance, and account for any variability (temporal or spatial) in crop water requirements or water intake across the field. This article describes the latest hardware and software technologies for precision irrigation on both farm-scale and larger regional scales, such as soil moisture mapping, wireless sensor networks, and precision irrigation management. Finally, trends for advanced irrigation technologies are presented.

There are numerous mathematical models that predict and analyze the movement of water and pollutants in saturated and unsaturated zones beneath the soil. The usefulness and accuracy of these models severely depend on the reliable characterization of the soil hydraulic properties, i.e. water retention and hydraulic conductivity of the unsaturated zone. The accurate measurements of these properties are highly cumbersome and are not feasible for many applications including issues concerning soil contamination. UNSODA is a soil database containing unsaturated soil hydraulic properties (water retention, hydraulic conductivity, and soil water diffusivity), basic soil properties (particle-size distribution, bulk density, organic matter content, etc.), which are used for indirect prediction of the unsaturated soil hydraulic functions. This paper introduces this database, explains its applications, and shows how it can be used in soil and water research.

The hydrological sector is one of the most important and fundamental natural sectors in catchments. In order to evaluate the behavior of this sector under different conditions, it is essential to model hydrological processes. One of the aims of conducting hydrological studies is to determine the relationships between rainfall and runoff. Since it is not possible to measure all quantities required for the runoff analysis in the catchments, it is necessary to select a model which has a simple structure and a reduced number of parameters that can accurately simulate the runoff caused by rainfall. In this study, classification of hydrological models and the results of several models used in different case studies have initially been investigated. Furthermore, some of the information associated with several rainfall-runoff models have been noted. In the next step the model evaluation criteria and comparison of the selected models according to these criteria for the final model selection has been offered. Finally, the choice of the best model has been provided. According to the capabilities and limitations of each model, by considering the necessities and objectives of the considered rainfall-runoff model in each catchment, the appreciate model can be selected. Although it is better to select the lumped models because of their simplicity of structure and minimal required data and ease of use, it is better to select the semi-distributed models. Since semi-distributed models are in a position between the high simplicity of lumped models and the extensive required data by distributed models.

Urban runoff problems are comprised of two distinct but interdependent types. To control the quantity and quality, volume and the peak flow of runoff, downstream flooding and the flooding potential in the downstream must be reduced. These problems are subject to conducted flood control systems and methods. Nowadays, the protection of receiving waters is one of the engineers' concerns which cannot be simply achieved due to its reliance on the complexity and fluctuation of the flood. This needs comprehensive planning, design, and management of such systems which can be obtained through an efficient method and by use of urban runoff calculation and control models. In this research, the runoff simulation of district 9 of Mashhad municipality is carried out using the SWMM model. To calibrate and evaluate the model, 4 and 2 rainfall occurrences were measured at the basin outlet. The model calibration results showed a good agreement between the simulations of the four incidents with a NS higher than 0.5. The evaluation results confirm the SWMM model’s performance and accuracy for NS values above 0.5. For simulated incidents derived from the calibration and validation of the SWMM model, the Kling Gupta (KGE) index values was higher than 0.5. These values confirm the model results. Therefore, there is a good agreement between the simulated and observed runoff volumes which is an indication of the good performance of the SWMM model in predicting urban flood and this model can then be used in urban flood management projects and drainage network planning in Mashhad.

Surface water (SW) and groundwater (GW) are connected components of the hydrologic system with a dynamic interaction at different local or regional scales. In the first part of this study, the review of principles and general concepts of GW-SW, including the importance of interaction between these two water components is carried out. In the second part, a review of the scientific studies on the interaction of GW-SW at different spatial scales ranging from the point scale to the regional scale is presented. In each of these scales, the differences between the mechanisms of interaction with other scales are investigated and then regional modeling is specifically studied. Regional GW-SW is rarely examined in experimental field studies, which almost exclusively cover small areas. There are various modeling approaches and a few of them can be used in the regional scale but there are still uncertainties about using them. If GW-SW at the regional scale is essentially regarded as the sum of all hydrological processes in a region/catchment, then the most appropriate way to address this seems to be the use of fully coupled, physics-based models. These models attempt to acquire a holistic description of the hydrological cycle and have an ability to connect various processes over a range of spatial and temporal scales. Most authors agree that regional scale integrated modeling is constrained by data availability. Therefore, despite the attractiveness of fully complex schemes, coupling relatively simple models may still provide a suitable approach even if this means an oversimplification in the regional systems.

Water scarcity is one of the greatest human challenges in this century which can cause many limitations in the world. Demand for freshwater is also increasing due to economic and population growth. Therefore, suitable planning for the limited water resources for storage, allocation, return flow, and environmental services is critical in order to optimize resources. Nowadays, an efficient water accounting system based on measuring, reporting, planning, and monitoring water resources in the world is needed. This system provides the possibility of processing and interpreting information in order to establish a comprehensive and integrated management of water resources through the organization of various data from different hydrological, environmental, and economic sectors. The water accounting system is an approach to standardize the way that data and information is organized. The purpose of this study is to introduce the WA+ water accounting framework as a simple and standard method that describes the state of water and land management in complex watersheds. This method is based on the water balance approach. Its feature is the use of satellite data to access the hydrological base data and surface ground processes. In general, the input data required for this framework can be derived from satellite measurements, hydrological models, and ground data. At present, WA+ contains 8 sheets which summarize water management situation and results are also presented as tables and maps. WA+ has a set of performance indicators that are used in the assessment and analysis of water resources and water consumption situations. WA+ has limitations that need to be resolved in the future and be edited for wider use.

Groundwater plays an important role in water supply for domestic, industrial, and agricultural demands. In many countries, the irresponsible and excessive use of groundwater has led to serious problems and depletion and destructions of aquifers. In some regions, as a result of pollution, groundwater resources are gradually becoming unusable. Due to climate change and the changing patterns of rainfall, river flows have decreased, therefore decreasing the groundwater recharge rate. This ultimately leads to increased pressure on groundwater resources. Inefficiency and non-effectiveness of current unsustainable practices are often the biggest challenges in water management in arid and semi-arid regions. Ground water governance is essential to tackle the identified challenges. Governance has been adopted to control the sudden rise of groundwater withdrawals. “Water governance” means rules and practices for decision-making about water policy and their implementation, i.e. the range of political, institutional, and administrative processes through which stakeholders articulate their interests. Therefore, concerns are considered, decisions are taken and implemented, and decision-makers are held accountable in the development and management of water resources and delivery of water services. Governance should be seen as a context where integrated water resources management can be implemented.

This study conducts a comprehensive analysis of the various research with a focus on biophysical, socioeconomic, and geopolitical impacts of dams through a systematic literature review for the period of 2000 to 2016. The major research databases were searched and 110 papers were identified. 24 papers were selected thematically and based on the period that the research was undertaken. Based on this, the effects of dams can be categorized into socio-economic, biophysical, and geopolitical. Results revealed that dam construction has both positive and negative impacts on the aforementioned three categories. The positive effects of dams include improving livelihoods, life expectancy, social cohesion, infrastructure development, sustainability of areas, preventing flood damage, creating new landscapes, and building local institutions. The negative effects include the displacement of indigenous populations, destruction of life/landscapes, community conflicts, cultural damage, or anthropological artifacts. Two strategies were recommended for managing the pros and cons of dams: 1) implementing sustainable impact assessment, and 2) corporate social responsibility.

The lack of precipitation data has always been one of the major constraints on water engineering and climatology studies. Hence, researchers and engineers are always investigating alternatives to fill the gap of data scarcity for ungauged areas. Nowadays, one of the options for the researchers in this area is applying global gridded precipitation datasets. These datasets provide a gridded regional or global precipitation data by collecting data from various sources including gauges, remote sensing information, and numerical models. The first step to use the datasets is being aware of different sources of these datasets. The second step is to select the most suitable dataset for a given region. This selection is carried out by comparing the extracted precipitation data from different datasets with the existing gauged information. Given the necessity of using the global precipitation datasets, a brief description of the method of obtaining precipitation data in each dataset is presented in the current paper. Moreover, the characteristics of each database, including the spatial-temporal resolution, and time period of the information of databases has been explained.

Increasing population and the ever-growing needs cause over exploitation and unprincipled utilization of natural resources. This has led to more extensive and irreparable consequences particularly in arid and semi-arid regions due to their high susceptibility and fragility. Therefore, consequence assessment of the aforementioned issues is essential for integrated management of the watersheds. Although the concepts of watershed health and sustainability are close to each other but there are some differences in between which are not clear to everyone. Hence, the present research aims to identify, clarify, and compare the concepts of watershed health and sustainability. The conducted investigations indicate that the watershed health refers to the ability of the watershed to selfmaintain and recover its potentials after the stresses. This concept is a temporary process closely linked to watershed services. Thus, biophysical criteria are used to assess watershed health and the results obtained from this health assessment can provide an early warning system for managers and policy-makers. Furthermore, the reason behind the problems and stresses in watershed systems can be diagnosed. Watershed sustainability is the ability of a watershed to provide services in the future. Watershed sustainability is a permanent process for which the social, economic, and environmental components are used in the assessment. The proper assessment of watershed health and sustainability provide a proper basis for comprehensive management in the scale of the catchment area. A comprehensive understanding of these concepts helps managers and policy-makers for better management of the resources.

Considering the severe water shortage crisis for producing agricultural products, the concept of real water saving in agriculture has been introduced recently. The reason behind this is that many researchers have realized that many approaches which are used for water saving in agriculture (e.g., improving irrigation efficiency, and even improving agricultural water productivity-WP) rely on the development of modern water-saving irrigation methods such as pressurized irrigation. These systems, when required conditions or relevant context are not fulfilled, may not lead to real water savings and may even cause an increase in water consumption. Examples of these arguments, discussion, and pieces of evidence are provided in the latest book published by FAO. In this analytical paper following explanation of the concepts, terms, the visions on real water saving, and effectiveness of modern irrigation technologies in this regard, all the activities relevant to improving WP, with the objective of water saving in agriculture, are elaborated and discussed. The paper concludes that for the purpose of recognition and selection of technical and economical approaches effective on water demand and use, water accounting framework should be set in a specific basin. Also in parallel to the attention to the development of pressurized irrigation systems in Iran, other approaches and measures, such as agronomic practices for reducing ET in agriculture (e.g. use of mulches, conservation agriculture, and proper crop rotation, etc.) should be selected. Finally, for achieving real water saving, the WP index should be evaluated based on ET and not based on applied water to the field. This should be the necessary criteria in selecting irrigation systems and other measures in regards to their effectiveness on real water savings in agriculture.

A summary of measures to overcome the water crisis
Report of the Second National Water Technology Festival
Section of the festival
Professional meetings
Statement of specialized meetings
Conclusion