Water, agriculture and ecosystem services in climate change vulnerable agricultural regions of Spain and Jordan

Irrigated agricultural landscapes generate a valuable set of ecosystem services, which are threatened by water scarcity in many aridand semi‐arid regions of the world. In the Mediterranean region, climate change is expected to decrease water availability through reduced precipitation and more frequent drought spells. At the same time, climate change, demographic and economic development and an agricultural sector highly dependent on irrigation, will raise water demand, increasing experienced water scarcity and affecting the provision of ecosystem services from water resources and agro-ecosystems. In this context, policy makers face the challenge of balancing the provision of different ecosystem services, including agricultural income and production and also water ecosystem protection.

Beyond megaprojects?. Water alternatives for mass tourism in coastal Mediterranean Spain

Water availability in adequate quantities and qualities is a fundamental requirement for tourism. In the Mediterranean, one of the world’s leading tourist destinations, water availability is subject to modest and erratic precipitation figures which may decline with climate change. The tourist industry therefore may have to assure future supplies by either recurring to new technologies such as desalination or increasing efficiency in water use. A third and yet little explored alternative would be to seek for complementary of uses with irrigation, the traditional user in many coastal Mediterranean areas and holder of substantial amounts of water. In this paper we present the example of the Consorcio de Aguas de la Marina Baja to show how Benidorm, in Mediterranean Spain and one of the most important tourist centers of the Mediterranean, obtains part of its water through agreements with farmers by which these trade their water with Benidorm and other towns’ treated wastewater of enough quality to be used for irrigation, and obtain several compensations in return. The advantages and disadvantages of the water trade between farmers and tourist interests in the Benidorm area are discussed and we argue that solutions to the pending water crisis of many coastal Mediterranean tourist areas may not need to rely uniquely on expensive technologies to generate new resources but may attempt other alternatives.

Sugarcane water use from shallow water tables: implications for improving irrigation water use efficiency

The resource potential of shallow water tables for cropping systems has been investigated using the Australian sugar industry as a case study. Literature concerning shallow water table contributions to sugarcane crops has been summarised, and an assessment of required irrigation for water tables to depths of 2 m investigated using the SWIMv2.1 soil water balance model for three different soils. The study was undertaken because water availability is a major limitation for sugarcane and other crop production systems in Australia and knowledge on how best to incorporate upflow from water tables in irrigation scheduling is limited. Our results showed that for the three soils studied (representing a range of permeabilities as defined by near-saturated hydraulic conductivities), no irrigation would be required for static water tables within 1 m of the soil surface. Irrigation requirements when static water tables exceeded 1 m depth were dependent on the soil type and rooting characteristics (root depth and density). Our results also show that the near-saturated hydraulic conductivities are a better indicator of the ability of water tables below 1 m to supply sufficient upflow as opposed to soil textural classifications. We conclude that there is potential for reductions in irrigation and hence improvements in irrigation water use efficiency in areas where shallow water tables are a low salinity risk: either fresh, or the local hydrology results in net recharge. (C) 2003 Elsevier B.V. All rights reserved.

Estimating percolation and lateral water flow on sloping land in rainfed lowland rice ecosystem

Quantifying water losses in paddy fields assists estimation of water availability in rainfed lowland rice ecosystem. Little information is available on water balance in different toposequence positions of sloped rainfed lowland. Therefore, the aim of this work was to quantify percolation and the lateral water flow with special reference to the toposequential variation. Data used for the analysis was collected in Laos and northeast Thailand. Percolation and water tables were measured on a daily basis using a steel cylindrical tube with a lid and perforated PVC tubes, respectively. Percolation rate was determined using linear regression analysis of cumulative percolation. Assuming that the total amount of evaporation and transpiration was equivalent to potential evapotranspiration, the lateral water flow was estimated using the water balance equation. Separate perched water and groundwater tables were observed in paddy fields on coarse-textured soils. The percolation rate varied between 0 and 3 mm/day across locations, and the maximum water loss by lateral movement was more than 20 mm/day. Our results are in agreement with the previously reported findings, and the methodology of estimating water balance components appears reasonably acceptable. With regard to the toposequential variation, the higher the position in the topoesquence, the greater potential for water loss because of higher percolation and lateral flow rates.

Evaluation of the sustainability of water withdrawals in the United States, 1995 to 2025

To evaluate the long term sustainability of water withdrawals in the United States, a county level analysis of the availability of renewable water resources was conducted, and the magnitudes of human withdrawals from surface water and ground water sources and the stored water requirements during the warmest months of the year were evaluated. Estimates of growth in population and electricity generation were then used to estimate the change in withdrawals assuming that the rates of water use either remain at their current levels (the business as usual scenario) or that they exhibit improvements in efficiency at the same rate as observed over 1975 to 1995 (the improved efficiency scenario). The estimates show several areas, notably the Southwest and major metropolitan areas throughout the United States, as being likely to have significant new storage requirements with the business-as-usual scenario, under the condition of average water availability. These new requirements could be substantially eliminated under the improved efficiency scenario, thus indicating the importance of water use efficiency in meeting future requirements. The national assessment identified regions of potential water sustainability concern; these regions can be the subject of more targeted data collection and analyses in the future.

Some like it wet - biological characteristics underpinning tolerance of extreme water stress events in Antarctic bryophytes

Antarctic bryophyte communities presently tolerate physiological extremes in water availability, surviving both desiccation and submergence events. We investigated the relative ability of three Antarctic moss species to tolerate physiological extremes in water availability and identified physiological, morphological, and biochemical characteristics that assist species performance under such conditions. Tolerance of desiccation and submergence was investigated using chlorophyll fluorescence during a series of field- and laboratory-based water stress events. Turf water retention and degree of natural habitat submergence were determined from gametophyte shoot size and density, and delta C-13 signatures, respectively. Finally, compounds likely to assist membrane structure and function during desiccation events (fatty acids and soluble carbohydrates) were determined. The results of this study show significant differences in the performance of the three study species under contrasting water stress events. The results indicate that the three study species occupy distinctly different ecological niches with respect to water relations, and provide a physiological explanation for present species distributions. The poor tolerance of submergence seen in Ceratodon purpureus helps explain its restriction to drier sites and conversely, the low tolerance of desiccation and high tolerance of submergence displayed by the endemic Grimmia antarctici is consistent with its restriction to wet habitats. Finally the flexible response observed for Bryum pseudotriquetrum is consistent with its co-occurrence with the other two species across the bryophyte habitat spectrum. The likely effects of future climate change induced shifts in water availability are discussed with respect to future community dynamics.

The water balance on sloping land in rainfed lowland rice ecosystem

Quantifying water losses in paddy fields assists estimation of water availability in rainfed lowland rice ecosystem. There is, however, no definite method for determining the water losses, and little information is available on water balance in different toposequence positions of a sloped rainfed lowland. Therefore, the aim of this work was to quantify percolation and the lateral water flow with special reference to the toposequential variation. Data used for the analysis was collected in Laos and northeast Thailand. Percolation and water tables were measured on a daily basis. The percolator is a steel cylindrical tube with a lid to prevent water loss from evapotranspiration. The water table meter is a short PVC tube for determination of perched water table and a long PVC tube for groundwater table, and the side is perforated with 5-mm diameter holes at 20-mm distance. Percolation rate was determined using linear regression analysis of cumulative percolation. Assuming that the total amount of evaporation and transpiration was equivalent to potential evapotranspiration, the lateral water flow was estimated using the water balance equation. Our results are in agreement with the previously reported findings, and the methodology of estimating water balance components appears reasonably acceptable. With regard to the toposequential variation, the higher position in the topoesquence, the greater potential of the water losses because of higher percolation and lateral flow rates.

The agricultural water supply challenge - the need for improved water use efficiency

This paper examines the challenges of water supply in agriculture, with particular emphasis on requirements of field crops, including maize. It places the issue of water supply to agriculture in the context of increasing demands for water from alternatives users, declining quality water, pressure of increasing population, all of which are placing stresses on water availability at local, regional and national levels. The paper also examines existing freshwater resources and the potential impact of climate change on water supply and distribution and consequential impact on water stress incidence in various parts of the globe. It examines competition for water in both industrialized and developing countries, with particular emphasis on the impacts on agriculture and food supplies. The challenge of water use efficiency (WUE) in agriculture is explored with discussion of agronomic, economic and physiological WUE concepts, with specific reference to maize.

Rapid aquaporin translocation regulates cellular water flow:the mechanism of hypotonicity-induced sub-cellular localization of the aquaporin 1 water channel

The control of cellular water flow is mediated by the aquaporin (AQP) family of membrane proteins. The family's structural features and the mechanism of selective water passage through the AQP pore are established, but there remains a gap in our knowledge of how water transport is regulated. Two broad possibilities exist. One is controlling the passage of water through the AQP pore, but this has only been observed as a phenomenon in some plant and microbial AQPs. An alternative is controlling the number of AQPs in the cell membrane. Here we describe a novel pathway in mammalian cells whereby a hypotonic stimulus directly induces intracellular calcium elevations, through transient receptor potential channels, that trigger AQP1 translocation. This translocation, which has a direct role in cell volume regulation, occurs within 30s and is dependent on calmodulin activation and phosphorylation of AQP1 at two threonine residues by protein kinase C. This direct mechanism provides a rationale for the changes in water transport that are required in response to constantly-changing local cellular water availability. Moreover, since calcium is a pluripotent and ubiquitous second messenger in biological systems, the discovery of its role in the regulation of AQP translocation has ramifications for diverse physiological and pathophysiological processes, as well as providing an explanation for the rapid regulation of water flow that is necessary for cell homeostasis.

Aplications of Neural Networks to Find the Impact of Water in Different Berry Components in Grapes

Grape juice composition during the different stages of berry growth was compared. The analytical data collected were used to investigate the relationships between some of the different components studied in these berries during the ripening period. Our goal is to study, with neural networks, the impact of water availability on Vitis vinifera L. cv. Tempranillo grape yields and juice composition over a three-year period.

Water Governance in Haiti: An Assessment of Laws and Institutional Capacities

The Republic of Haiti struggles to sustainably manage its water resources. Public health is compromised by low levels of water supply, sanitation, and hygiene, and water resources are often contaminated and unsustainably allocated. While poor governance is often blamed for these shortcomings, the laws and institutions regulating water resources in Haiti are poorly understood, especially by the international community. This study brings together and analyzes Haitian water laws, assesses institutional capacities, and provides a case study of water management in northern Haiti in order to provide a more complete picture of the sector. Funded by the Inter-American Development Bank as part of the Water Availability, Quality and Integrated Water Resources Management in Northern Haiti (HA-T1179) Project, this study took place from January-July 2015, with the help of local experts and participating stakeholders. The results indicate that Haiti’s water law framework is highly fragmented, with overlapping mandates and little coordination between ministries at the national level, and ambiguous but unrealistic roles for subnational governments. A capacity assessment of institutions in northern Haiti illustrates that while local stakeholders are engaged, human and financial resources are insufficient to carry out statutory responsibilities. The findings suggest that water resources management planning should engage local governments and community fixtures while supplementing capacities with national or international support.

WATER RESOURCES, HEALTH, AND THE SUSTAINABILITY OF INTERVENTIONS TO ACHIEVE WATER AND SANITATION TARGETS OF THE MILLENNIUM DEVELOPMENT GOALS IN A CHANGING WORLD

This dissertation addresses sustainability of rapid provision of safe water and sanitation required to meet the Millennium Development Goals. Review of health-related literature and global statistics demonstrates engineers' role in achieving the MDGs. This review is followed by analyses relating to social, environmental, and health aspects of meeting MDG targets. Analysis of national indicators showed that inadequate investment, poor or nonexistent policies and governance are challenges to global sanitation coverage in addition to lack of financial resources and gender disparity. Although water availability was not found to be a challenge globally, geospatial analysis demonstrated that water availability is a potentially significant barrier for up to 46 million people living in urban areas and relying on already degraded water resources for environmental income. A daily water balance model incorporating the National Resources Conservation Services curve number method in Bolivian watersheds showed that local water stress is linked to climate change because of reduced recharge. Agricultural expansion in the region slightly exacerbates recharge reductions. Although runoff changes will range from -17% to 14%, recharge rates will decrease under all climate scenarios evaluated (-14% to -27%). Increasing sewer coverage may place stress on the readily accessible natural springs, but increased demand can be sustained if other sources of water supply are developed. This analysis provides a method for hydrological analysis in data scarce regions. Data required for the model were either obtained from publicly available data products or by conducting field work using low-cost methods feasible for local participants. Lastly, a methodology was developed to evaluate public health impacts of increased household water access resulting from domestic rainwater harvesting, incorporating knowledge of water requirements of sanitation and hygiene technologies. In 37 West African cities, domestic rainwater harvesting has the potential to reduce diarrheal disease burden by 9%, if implemented alone with 400 L storage. If implemented in conjunction with point of use treatment, this reduction could increase to 16%. The methodology will contribute to cost-effectiveness evaluations of interventions as well as evaluations of potential disease burden resulting from reduced water supply, such as reductions observed in the Bolivian communities.

Sugarcane Water Productivity Assessments in the São Paulo state, Brazil.

São Paulo state, Brazil, has been highlighted by the sugarcane crop expansion. The actual scenario of climate and land use changes, bring attention for the large-scale water productivity (WP) analyses. MODIS images were used together with gridded weather data for these analyses. A generalized sugarcane growing cycle inside a crop land mask, from September 2011 to October 2012, was considered in the main growing regions of the state. Actual evapotranspiration (ET) is quantified by the SAFER (Simple Algorithm for Evapotranspiration Retrieving) algorithm, the biomass production (BIO) by the RUE (Radiation Use Efficiency) Monteith?s model and WP is considered as the ratio of BIO to ET. During the four generalized sugarcane crop phases, the mean ET values ranged from 0.6 to 4.0 mm day-1; BIO rates were between 20 and 200 kg ha-1 day-1, resulting in WP ranging from 2.8 to 6.0 kg m-3. Soil moisture indicators are applied, indicating benefits from supplementary irrigation during the grand growth phase, wherever there is water availability for this practice. The quantification of the large-scale water variables may subsidize the rational water resources management under the sugarcane expansion and water scarcity scenarios.

Ecological and social characterization of key resource areas in Kenyan rangelands

Key resource areas (KRAs), defined as dry season foraging zones for herbivores, were studied relative to the more extensive outlying rangeland areas (non-KRAs) in Kenya. Field surveys with pastoralists, ranchers, scientists and government officials delineated KRAs on the ground. Identified KRAs were mapped based on global positioning and local experts' information on KRAs accessibility and ecological attributes. Using the map of known KRAs and non-KRAs, we examined characteristics of soils, climate, topography, land use/cover attributes at KRAs relative to non-KRAs. How and why do some areas (KRAs) support herbivores during droughts when forage is scarce in other areas of the landscape? We hypothesized that KRAs have fundamental ecological and socially determined attributes that enable them to provide forage during critical times and we sought to characterize some of those attributes in this study. At the landscape level, KRAs took different forms based on forage availability during the dry season but generally occurred in locations of the landscape with aseasonal water availability and/or difficult to access areas during wet season forage abundance. Greenness trends for KRAs versus non-KRAs were evaluated with a 22-year dataset of Normalized Difference Vegetation Index (NDVI). Field surveys of KRAs provided qualitative information on KRAs as dry season foraging zones. At the scale of the study, soil attributes did not significantly differ for KRAs compared to non-KRAs. Slopes of KRA were generally steeper compared to non-KRAs and elevation was higher at KRAs. Field survey respondents indicated that animals and humans generally avoid difficult to access hilly areas using them only when all other easily accessible rangeland is depleted of forage during droughts. Understanding the nature of KRAs will support identification, protection and restoration of critical forage hotspots for herbivores by strengthening rangeland inventory, monitoring, policy formulation, and conservation efforts to improve habitats and human welfare. (c) 2007 Elsevier Ltd. All rights reserved.

Shijiazhuang ecological landscape planning and design comprehensive improvement program for the Hutuo River

International practice-led design research in landscape architecture has identified water quality and water availability as two of the most important environmental issues in developing countries. China is particularly focused on improving water supplies for its rural and urban populations. However a significant gap in knowledge exists between urban planning and environmental engineering in China as to how to design Chinese public open spaces to reduce water pollution in urban rivers. This project responded to traditional zoning methods in Shijiazhuang City, Hebei Province, by proposing a range of water sensitive design innovations from lake construction to planting design to modify standardised engineering solutions in a Chinese context.