The need for freshwater can never be over-stressed. Global agencies (including WHO, UNDP, UNICEF etc.) expect that 24 of the least developed countries, many of them along coastal areas without access to water and electricity, need to more than double their current efforts to reach the Millennium Development Goals for basic health, sanitation, and welfare. Desalination of available brackish or seawater sources is an ideal option for freshwater production. However, existing desalination technologies are energy-intensive and cost-prohibitive. Low temperature desalination using waste heat sources or solar collectors is an attractive option. Because the energy demands can be provided at low costs and with minimum environmental pollution. The main objective of this research is to investigate the technical feasibility of a multi-effect low temperature desalination process with higher thermodynamic efficiency and low environmental impact. Principles of operation, theoretical analyzes and experimental studies will be discussed in detail.

Reliable, high-quality water services are a substantial component of a state’s or country’s energy consumption profile. Although the water–energy nexus has received much attention in the past few years, relatively little work has addressed water systems’ energy use, their potential for energy savings, or their empirical results of energy management. This paper surveys the literature on theoretical energy savings in water systems and compares the estimates with the outcomes of numerous case studies where water systems undertook energy efficiency projects and/or programs. The results in practice confirm that the theoretical estimates are indeed achievable; annual energy savings of 10 to 30 percent are typical among water utilities that pursue energy management. These savings come by capital projects, operational changes, and intra-agency inter-agency coordination to deliver water by the most energy-efficient path. Such solutions often help improve hydraulic performance and water quality, showing that energy management is cost-effective, prompt, and synergistic, a critical step in advancing sustainable water supply.

This paper analyses and compares the use of cost-benefit analysis (CBA) for exemptions and disproportionate cost decision according to the implementation of Water Framework Directive Article 4 in groundwater bodies in the Spanish River Basins. Data has been obtained from both, the hydrological plans for the first planning cycle (2009-2015) and for the second one (2015-2021). Results show the evolution in the scope of good chemical and quantitative status of groundwater bodies in both planning cycles, and the different methodologies used to justify economically exemptions to achieve the environmental objectives in such bodies.

This study aims to assess global experience on agricultural water management under different scenarios. The results showed that trend of permanent crops to cultivated area, HDI, irrigation water requirement, and percent of total cultivated area drained is increasing and trend of rural population to total population, total economically active population in agriculture to total economically active population, value added to GDP by agriculture, and the difference between NIR and irrigation water requirement is decreasing. The minimum and maximum values of pressure on renewable water resources by irrigation, are related to the third and first scenarios by 2035 (6.1%) and 2060 (9.2%), respectively.

In this paper, area equipped for irrigation has been estimated in Europe using three different scenarios by 2035 and 2060. The number of 10 indexes (as the main indexes) was selected to assess agricultural water management based on their importance and other indexes were not studied due to lack of adequate data. The changes of the main indexes in the past half of century argued that they had similar values in some regions and had very different values in other regions due to the nature of the indexes and conditions of the regions. The maximum value for area equipped for irrigation is related to Mediterranean Europe; 33.6% and 38.8% by 2035 and 2060, respectively.

Understanding the hydrogeology of aquifers is fundamental to the management of groundwater resources especially in arid and semi-arid regions. However, understanding the responses of hydrogeological processes to climate change is complicated since climate change can affect hydrogeological processes directly and indirectly. This study aims at implementing a physically-based groundwater model to investigate the effects of climate change on groundwater system under fifteen General Circulation Models (GCMs) in a semi-arid region for the period of 2020-2044. A nonparametric method, Probability Density Function (PDF) estimator, was used to quantify the level of uncertainties in the simulations. The methodology was applied in an area of 2073 Km² in south-west Iran, consist of five plains; Western Dez, eastern Dez, Sabili, Deymche and Lor. Results indicate that there is a decline in recharge in April, May, June, and October. The range of changes in recharge were determined between -%10 and +%13 in the Sabili plain, -%6 and +%10 in the Deymche plain, -%4 and +%10 in the western-Dez plain, -%6 and +%26 in the eastern-Dez plain, -%40 and +%100 in the Lor plain. The most significant decline in groundwater level occurs in the Sabili plain in September. The largest uncertainty in simulation of recharge under GCM scenarios was determined in August, September, and December.

Urban wastewater treatment is one of the most important challenges in villages of southern Spain. This is especially outstanding in arid and semiarid regions in which wastewater are discharged to temporary streams or wetlands. The treatment plant of the Fuente de Piedra village discharges its wastewater, passing previously through four semi-natural wetlands, into Fuente de Piedra Lake, a RAMSAR wetland. In summer 2016, a very dry year, water affluent to Fuente de Piedra was limited to wastewater plant effluents without dilution. In order to study the natural assimilation capacity of the wetland system, four key points were sampled. Physico-chemical and biological indicators were analyzed (temperature, pH, conductivity, total phosphorous, total nitrogen, bacteria, phytoplankton and zooplankton). The results show very high chlorophyll a concentration (>500 mg/l) at the water inlet, which decreased to concentration lower than <20 mg/l before discharging into the RAMSAR wetland. Zooplankton, dominated by cladocerans (Daphnia sp.),was lowest in the inlet wetland and highest in the last wetland. Total nitrogen and phosphorus concentration was (14 mg/l and 5mg/l respectively) at the wastewater inlet point and decreased in the first wetland (7 mg/l and 2mg/l respectively). Fecal streptococci was highest at the inlet point (1033 ± 351 ufc/100 mL) and decreased to 1 ± 1 ufc/100 mL before entering in the RAMSAR wetland. In conclusion, during the wetlands circuit (i) phytoplankton reduce the total phosphorous and nitrogen concentration, (ii) then phytoplankton is controlled by zooplankton decreasing drastically the input of nutrient and biomass into the RAMSAR wetland, (iii) fecal bacteria decreases three orders of magnitude. Thus, the negative impact from wastewater treatment plant is reduced. The waterbirds, one of the major tourists attractive of this wetland, benefit from food and water supply in dry years, guaranteeing the possibility of bird watching during high season.

Coffee producers in Mesoamerica are already facing some of the expected challenges arising from pressures derived by climate change, principally lowered water supply. Some farmers have implemented strategies of adaptation based on crop diversification, being the introduction of cocoa one of the main alternatives. The focus of this research is to analyse coffee producers’ perceptions on changing from coffee to cocoa as an adaptation strategy. This research tries to find the factors that smallholders take into account when facing the decision of introducing cocoa. Here we simulate the farmers’ response to climate factors and water needs, also considering its relationship with humankind, specially through variables related to economic and social development. Farmers’ perceptions were extracted via a specifically designed questionnaire applied to 219 small coffee producers in the departments of Esteli and Jinotega in Nicaragua. A Multivariate probit econometric model was estimated to analyse diversification through three simultaneous equations—for climatic, economic and social development drivers.  Marginal effects of these drivers were calculated and used to simulate farmers’ response to global change scenarios. Regional distribution of crop diversification probability was mapped considering different global change scenarios. The importance of climatic factors over the decision process is, as data shows, higher than social and economic issues. The environmental implications of this change, such as deforestation, have also been discussed.

As pointed out by Field and Field [1] there is a natural tendency among people to think that enacting a law automatically leads to the rectification of the problem to which it is addressed.

The implementation and effectiveness of a groundwater use limit as well as pricing policy crucially depends on enforcement capacity, sanctioning systems, and the need for the generation of information and its management. Key issue in groundwater management is the size of the groundwater user community. Groundwater aquifers can be very small, with only tens or hundreds of users, but generally there is a large extent of individual users. Enforcement ultimately requires energy and resources thus it turns into a costly activities. 

Implementing an on-farm monitoring and control system typically involves a fixed component such as installing measuring devices, setting up administration and facilities, and a variable component that increases with the water proceeds (i.e. monitoring and collection activities). Monitoring/detection, may include both measuring the performance of water users and monitoring their compliance with regulation, as well as the development of monitoring technologies [2].

The aim of this research is to define a framework analysis of groundwater monitoring and control in agriculture in order to assess its cost. In Mediterranean region, irrigation water accounts for the largest volume of groundwater withdraw by many individual small users. The magnitude of cost for an individual monitoring may oversize the expected economic return of groundwater control.  The case of Capitanata irrigation basin (Apulia region, South of Italy) is used to carry out the cost assessment of at-farm-gate monitoring and control systems on irrigation groundwater.   

Reference

1. Field, B.C.; Field, M.K. Environmental economics: An introduction. McGraw-Hill: New York, 2002.
2. McCann, L.; Colby, B.; Easter, K.W.; Kasterine, A.; Kuperan, K.V. Transaction cost measurement for evaluating environmental policies. Ecological Economics 2005, 52, 527-542.

Capturing the variation of lake-water area using remotely sensed imagery is an essential topic in many related fields. There are a variety of remote sensing data that can serve this purpose. Generally speaking, higher spatial resolution data are able to derive better results. However, most high spatial resolution data are sometimes defective because of their low temporal resolution and limited scene coverage. Visible Infrared Imaging Radiometer Suite onboard Suomi National Polar-orbiting Partnership (Suomi NPP-VIIRS) provides a newly-available and appropriate manner for monitoring large lakes because of its frequent revisit and wide breadth. But its spatial resolution is relatively low, from 375m to 750m. This study introduces a two-step method that integrates spectral unmixing and sub-pixel mapping to map lake-water area at sub-pixel scale from NPP-VIIRS imagery. Accuracy was assessed by employing corresponding Landsat images as the reference. Five plateau lakes in Yunnan province, China, were selected as the case study areas. Results suggest that the proposed method is able to derive finer resolution lake maps that show more details of the shoreline. The accuracy was significantly improved comparing to traditional classification method. Analysis also reveals that errors and uncertainties also exist in this method. Most of them come from the spectral unmixing procedure that retrieve water fraction from NPP-VIIRS data. Therefore, in order to achieve better lake mapping result, future work should concentrate more on improving this part to produce a better water fraction map first.