Climate impacts on European agriculture and water management in the context of adaptation and mitigation—The importance of an integrated approach

We review and qualitatively assess the importance of interactions and feedbacks in assessing climate change impacts on water and agriculture in Europe. We focus particularly on the impact of future hydrological changes on agricultural greenhouse gas (GHG) mitigation and adaptation options. Future projected trends in European agriculture include northward movement of crop suitability zones and increasing crop productivity in Northern Europe, but declining productivity and suitability in Southern Europe. This may be accompanied by a widening of water resource differences between the North and South, and an increase in extreme rainfall events and droughts. Changes in future hydrology and water management practices will influence agricultural adaptation measures and alter the effectiveness of agricultural mitigation strategies. These interactions are often highly complex and influenced by a number of factors which are themselves influenced by climate. Mainly positive impacts may be anticipated for Northern Europe, where agricultural adaptation may be shaped by reduced vulnerability of production, increased water supply and reduced water demand. However, increasing flood hazards may present challenges for agriculture, and summer irrigation shortages may result from earlier spring runoff peaks in some regions. Conversely, the need for effective adaptation will be greatest in Southern Europe as a result of increased production vulnerability, reduced water supply and increased demands for irrigation. Increasing flood and drought risks will further contribute to the need for robust management practices.The impacts of future hydrological changes on agricultural mitigation in Europe will depend on the balance between changes in productivity and rates of decomposition and GHG emission, both of which depend on climatic, land and management factors. Small increases in European soil organic carbon (SOC) stocks per unit land area are anticipated considering changes in climate, management and land use, although an overall reduction in the total stock may result from a smaller agricultural land area. Adaptation in the water sector could potentially provide additional benefits to agricultural production such as reduced flood risk and increased drought resilience.The two main sources of uncertainty in climate impacts on European agriculture and water management are projections of future climate and their resulting impacts on water and agriculture. Since changes in climate, agricultural ecosystems and hydrometeorology depend on complex interactions between the atmosphere, biosphere and hydrological cycle there is a need for more integrated approaches to climate impacts assessments. Methods for assessing options which “moderate” the impact of agriculture in the wider sense will also need to consider cross-sectoral impacts and socio-economic aspects.     

The Impact of Dry Years on Crop Water Requirements in Eastern England

Agricultural water demand is weather and climate driven. Irrigated crop production which makes the largest agricultural demands is highly seasonal, water only being required in a few summer months. A 'droughtiness'factor which is based on crop type and potential soil moisture deficit indicates large differences in the amount and timing of water demand for different crops. Soils with low water retention capacity are shown to be marginal for the potato crop unless irrigation is available in these areas. Economic data are presented which indicate that potato production realizes a considerable benefit from investment in irrigation, but this leads to inertia in the relocation of agricultural production centres in dry years. It is concluded that investment in on-farm winter water storage for irrigation should be a priority investment in eastern England.     

Agro-Pelago: Foodscapes for the Future

What if landscape architects could cultivate the sea to produce food? In the future, rising populations and the demand on resource consumption alongside the crisis of climate change leave agricultural land in coastal areas facing extinction. Across the globe, rising sea levels causes farmland flooded by salt water, unsustainable farming depletes soils, pollinators and crop varieties increase, and as land transforms from arable to urbanized, food security disappears. These worldwide threats present opportunities for landscape architecture to re-envision food landscapes for the future. Presented through an animated and narrated film, Agro-Pelago addresses global food security challenges while implementing local solutions.     

Moderating effects of the geometry of reservoirs on the relation between urban land use and water quality

Edges mediate the material flux between adjacent systems. This mediating effect of edges is strongly tied to the complexity of the adjacent shapes. Land use within a watershed has a direct impact on the water quality of adjacent aquatic systems. Hydrological processes carry material produced by land-use activities into aquatic ecosystems through the edges of the ecosystem. Therefore, the geometry of aquatic ecosystems theoretically affects the relationship between land use and water quality. This study investigates whether the shape complexity of reservoirs moderates the direct impact of land use on the water quality of adjacent reservoirs. A moderation model was adopted to measure the shape effects, and 153 reservoirs were randomly sampled with a consideration of reservoir size (surface area), geographic location, and data availability. With a focus on urban land use, we used GIS to measure land-use types within a 1 km buffer of reservoir boundaries. The shape complexity of sampled reservoirs was measured using fractal dimensions. Land uses and shape complexity were then regressed to measure water quality parameters such as chemical oxygen demand (COD), biological oxygen demand (BOD), total nitrogen (TN) and total phosphorus (TP). Correlation analysis revealed that the shapes of reservoirs are likely to be simple where urban land use dominates the areas close to reservoirs. Use of the standard regression model indicated that the increasing shape complexity of reservoirs significantly reduces the concentration of BOD, COD, and TP within reservoir water. Moderation models for BOD, COD, TN, and TP suggest that shape complexity can considerably relieve the negative impacts on water quality of urban land use in areas adjacent to reservoirs. The results of this study highlight the need to focus on shoreline management in order to mitigate the adverse impacts of land use on lakes and reservoirs.     

Dilemmas of integrated water resources management implementation in the Awash River Basin,Ethiopia: irrigation development versus environmental flows

Environmental flows allocation is an intrinsic part of Integrated Water Resources Management (IWRM). This paper analyses socio‐political issues and effects of environmental flows integration on water availability under the context of increased agricultural intensification in an effort to tackle food insecurity. Lack of appropriate framework comprising the procedural requirements and strategic directions as well as prevalence of politically motivated ad hoc development programmes are among major challenges identified. Introducing environmental flows to a perceived satisfactory level would result in a significant increase of unmet irrigation water demand, yet, “productivity first” norm overtakes. This is presumed to be due to skewed focus on irrigation expansion and low awareness on the possible consequences. The particular challenges highlighted generally unveil the inherent contradictions in the IWRM concept putting its claim that the set of principles and entire course stand universally accepted as a means to balance socio‐economic and environmental outcomes under question.     

Estimating economic value of agricultural water under changing conditions and the effects of spatial aggregation

Given the high proportion of water used for agriculture in certain regions, the economic value of agricultural water can be an important tool for water management and policy development. This value is quantified using economic demand curves for irrigation water. Such demand functions show the incremental contribution of water to agricultural production. Water demand curves are estimated using econometric or optimisation techniques. Calibrated agricultural optimisation models allow the derivation of demand curves using smaller datasets than econometric models. This paper introduces these subject areas then explores the effect of spatial aggregation (upscaling) on the valuation of water for irrigated agriculture. A case study from the Rio Grande-Rio Bravo Basin in North Mexico investigates differences in valuation at farm and regional aggregated levels under four scenarios: technological change, warm-dry climate change, changes in agricultural commodity prices, and water costs for agriculture. The scenarios consider changes due to external shocks or new policies. Positive mathematical programming (PMP), a calibrated optimisation method, is the deductive valuation method used. An exponential cost function is compared to the quadratic cost functions typically used in PMP. Results indicate that the economic value of water at the farm level and the regionally aggregated level are similar, but that the variability and distributional effects of each scenario are affected by aggregation. Moderately aggregated agricultural production models are effective at capturing average-farm adaptation to policy changes and external shocks. Farm-level models best reveal the distribution of scenario impacts.     

A multi-scale, multi-model approach for analyzing the future dynamics of European land use

Europe’s rural areas are expected to witness massive and rapid changes in land use due to changes in demography, global trade, technology and enlargement of the European Union. Changes in demand for agricultural products and agrarian production structure are likely to have a large impact on landscape quality and the value of natural areas. Most studies address these changes either from a macro-economic perspective focusing on changes in the agricultural sector or from a local perspective by analyzing recent changes in landscapes for small case studies. This paper describes a methodology in which a series of models has been used to link global level developments influencing land use to local level impacts. It is argued that such an approach is needed to properly address the processes at different scales that give rise to the land use dynamics in Europe. An extended version of the global economic model (GTAP) and an integrated assessment model (IMAGE) are used to calculate changes in demand for agricultural areas at the country level while a spatially explicit land use change model (CLUE-s) was used to translate these demands to land use patterns at 1 km² resolution. The global economic model ensures an appropriate treatment of macro-economic, demographic and technology developments and changes in agricultural and trade policies influencing the demand and supply for land use related products while the integrated assessment model accounts for changes in productivity as result of climate change and global land allocation. The land use change simulations at a high spatial resolution make use of country specific driving factors that influence the spatial patterns of land use, accounting for the spatial variation in the biophysical and socio-economic environment. Results indicate the large impact abandonment of agricultural land and urbanization may have on future European landscapes. Such results have the potential to support discussions on the future of the rural area and identify hot-spots of landscape change that need specific consideration. The high spatial and thematic resolution of the results allows the assessment of impacts of these changes on different environmental indicators, such as carbon sequestration and biodiversity. The global assessment allows, at the same time, to account for the tradeoffs between impacts in Europe and effects outside Europe.     

Crop and irrigation management strategies for saline-sodic soils and waters aimed at environmentally sustainable agriculture

Irrigation has long played a key role in feeding the expanding world population and is expected to play a still greater role in the future. As supplies of good-quality irrigation water are expected to decrease in several regions due to increased municipal-industrial-agricultural competition, available freshwater supplies need to be used more efficiently. In addition, reliance on the use and reuse of saline and/or sodic drainage waters, generated by irrigated agriculture, seems inevitable for irrigation. The same applies to salt-affected soils, which occupy more than 20% of the irrigated lands, and warrant attention for efficient, inexpensive and environmentally acceptable management. Technologically and from a management perspective, a couple of strategies have shown the potential to improve crop production under irrigated agriculture while minimizing the adverse environmental impacts. The first strategy, vegetative bioremediation--a plant-assisted reclamation approach--relies on growing appropriate plant species that can tolerate ambient soil salinity and sodicity levels during reclamation of salt-affected soils. A variety of plant species of agricultural significance have been found to be effective in sustainable reclamation of calcareous and moderately sodic and saline-sodic soils. The second strategy fosters dedicating soils to crop production systems where saline and/or sodic waters predominate and their disposal options are limited. Production systems based on salt-tolerant plant species using drainage waters may be sustainable with the potential of transforming such waters from an environmental burden into an economic asset. Such a strategy would encourage the disposal of drainage waters within the irrigated regions where they are generated rather than exporting these waters to other regions via discharge into main irrigation canals, local streams, or rivers. Being economically and environmentally sustainable, these strategies could be the key to future agricultural and economic growth and social wealth in regions where salt-affected soils exist and/or where saline-sodic drainage waters are generated.     

Sustainable Landscapes in an Enlarged Europe—the Landscape Research Group/Institute for Landscape Ecology symposium

This study focuses on the visual perception of agricultural cultivated landscapes by examining the role of five specific landscape components as predictors of visual preferences: field size, lot shape, land texture, crop texture and built elements. The Lower Galilee in northern Israel was chosen as the study area. The landscape was viewed by 90 participants using a photographic representation. Overall, the preference ratings indicated a relatively positive judgment of the agricultural cultivated landscapes. More specifically, the findings suggest that visual preferences regarding agricultural cultivated landscapes may be explained to a large extent by land textures, crop textures and lot shapes that are associated with complexity and fertility. Despite these findings, the intensification of agriculture over the last decades in many agricultural areas is still characterised by the removal of boundaries and the reduction of crop types. Increasing knowledge related to the visual perception of these landscapes may encourage the managers of agricultural areas to begin taking into account several crucial factors that influence the aesthetic quality of cultivated lands.     

关于发展节水型园林绿地的思考

针对北方城市水资源紧缺、城市园林绿地灌溉用水量逐年增加、城市生态环境用水供需矛盾突出的现实,分析了园林绿地灌溉的特点,指出当前园林绿地灌溉普遍存在方法落后、用水浪费的现象.提出应调整植物种植结构,发展节水、抗旱型绿地,积极推广先进适用的节水灌溉新技术、改善和提高绿地灌溉条件,严格规范灌溉系统的规划设计与施工,研究探索废污水回收利用和收集汛期降雨、灌溉城市绿地的新途径,以加强城市水资源综合利用,缓解北方城市用水紧张局面.     

从土地整理到综合规划 荷兰乡村景观整治规划及其启示

荷兰具有深厚的乡村规划传统,千年的圩田开垦形成了美丽、丰产、耐用的乡村景观,20世纪以来农业机械化、集约化和专业化迫使乡村景观在改善水管理、优化土地划分和完善道路基础设施建设3方面加以整治。在20世纪荷兰政府陆续颁布了主要的4个相关法规,乡村景观规划经历了从早期的农业优先到1970年代以后关注历史性和生态敏感性景观的保护,再到目前景观保护的多元化和任务的综合性。荷兰的乡村景观整治提高了农业生产,但也对传统乡村景观结构也造成了巨大的冲击,相关的经验和教训值得我们借鉴。     

Agriculture: Sustainable Business – Sustainable Environment?

Irrigation is a small but important part of UK agriculture, accounting for about 150 000 ha of land and 160 000 Ml of water in a 'dry'year. By the year 2021, the irrigated area is predicted to increase by 14% and the volume applied by 50%. Irrigation is of significant economic importance to (a) farmers, (b) growers, (c) the food industry – improving crop yields, quality, consistency and reliability.
The environmental impacts of irrigation on river flows and wetland biodiversity are now receiving more attention. Irrigators are given advice on environmental impacts, voluntary agreements are secured between groups of irrigators and the Environment Agency, and on-farm reservoirs are constructed to reduce summer abstraction and provide more secure and flexible supplies. Better long-term planning and short-term management are essential.     

Nitrogen, land and water inputs in changing cattle farming systems.: A historical comparison for France, 19th-21st centuries

This paper provides an original account of the long-term regional metabolism in relation to the cattle rearing in western France starting by the precise formulation of animal diets at three key dates of the 19th, 20th and 21st centuries. We established links between the demand in fodder of the meat and dairy sectors and the necessary inputs of nitrogen, water and land as well as the land cover changes occurring on the affected local and remote cattle acreage. The average agricultural productivity for fodder supply is estimated at about 50 kg N/ha in the mid-19th, 54 kg N/ha in the early 20th and 150 kg N/ha at the turning of the 21st century. Jointly for the dairy and meat productions, the potential efficiency in the conversion of the vegetal into animal protein more than doubled over the studied period, passing from less than 9% in the 19th to 20% in the 21st century. The current cattle sector is sustained for about 25% by land situated beyond the regional frontiers and uses water at intensities that approach or exceed the availability of renewable water. The nitrogen pollution is expressed in terms of the Net Anthropogenic Nitrogen Inputs (NANI) and, by comparison to the N recovered in products, is used to define the N-Environmental Efficiency of the farming. We discuss the historical succession of the factors that contributed to the growth of the meat and milk production and make a comparison of the impacts and policy between the local and distant resources.     

Changes in land cover and vegetation carbon stocks in Andalusia, Southern Spain (1956-2007)

Land use has significantly changed during the recent decades at global and local scale, while the importance of ecosystems as sources/sinks of C has been highlighted, emphasizing the global impact of land use changes. Land use changes can increase C loss rates which are extremely difficult to reverse, in the short term, opposite to organic carbon (OC) which accumulates in soil in the long-term. The aim of this research is to improve and test methodologies to assess land cover change (LCC) dynamics and temporal and spatial variability in C stored in vegetation at a wide scale. LCCs between 1956 and 2007 in Andalusia (Southern Spain) were selected for this pilot study, assessed by comparison of spatial data from 1956 to 2007 and were reclassified following land cover flows (LCFs) reported in major areas in Europe. Carbon vegetation densities were related to land cover, and C vegetation stocks for 1956 and 2007 were calculated by multiplying C density for each land cover class with land cover areas. The study area has supported important changes during the studied period with significant consequences for vegetation C stocks, mainly due to afforestation and intensification of agriculture, resulting in a total vegetation C stock of 156.08 Tg in 2007, with an increase of 17.24 Tg since 1956. This study demonstrates the importance of LCC for C sequestration in vegetation from Mediterranean areas, highlighting possible directions for management policies in order to mitigate climate change as well as promoting land conservation. The methodologies and information generated in this project will be a useful basis for designing land management strategies helpful for decision makers.     

A review of water quality concerns in livestock farming areas

Post-war changes in farming systems and especially the move from mixed arable-livestock farming towards greater specialisation, together with the general intensification of food production have had adverse affects on the environment. Livestock systems have largely become separated into pasture-based (cattle and sheep) and indoor systems (pigs and poultry). This paper reviews water quality issues in livestock farming areas of the UK. The increased losses of nutrients, farm effluents (particularly livestock wastes), pesticides such as sheep-dipping chemicals, bacterial and protozoan contamination of soil and water are some of the main concerns regarding water quality degradation. There has been a general uncoupling of nutrient cycles, and problems relating to nutrient loss are either short-term direct losses or long-term, related to accumulated nutrient surpluses. Results from several field studies indicate that a rational use of manure and mineral fertilisers can help reduce the pollution problems arising from livestock farming practices. Several best management practices are suggested for the control of nutrient loss and minimising release of pathogen and sheep-dip chemicals into agricultural runoff.     

Optimization of inter-sectorial water reallocation for arid-zone megacity-dominated area

Current water demand management of megacity-dominated areas in arid-zones should be revised to optimize water allocation for sustainable development. A novel hierarchical optimization model is proposed and examined for such an area in the arid zone of Iran. The model can significantly increase water economic efficiency, reduce unsatisfied demand, and maintain necessary agricultural production. Model sub-optimization provides the cropping pattern and transient four-phenological-stage deficit-irrigation strategy that maximizes economic benefit per unit agricultural allocation. The model employs a nonlinear benefit function for industry, a linear benefit function for service, and a cubic benefit function for deficit-irrigated agriculture. If available water is unchanged, optimal economic benefit increases 283 percent from the current situation. This requires decreasing agricultural water allocation, changing cropping patterns, using deficit irrigation, and increasing development of industrial and service sectors. If annual available water decreases by 25%, or by 40%, net economic benefit can increase 101% and 19%, respectively.     

The impact of urbanization policy on land use change: A scenario analysis

The rapid urbanization has led to extensive land use change particularly in those developing countries. In line with the development of urbanization, arable land is decreasing dramatically, which presents the threat to the food security for human being. It is therefore essential to understand the level of impacts of urbanization on the land use change. This paper introduces a dynamic systems based method for assessing the impacts of urbanization policy on land use change with reference to the urbanization practice in China. Four typical policy scenarios are identified in implementing urbanization in China, including balanced development driven by planning, uneven development driven by planning, balanced development driven by market and uneven development driven by market and their impacts on land use change are analyzed through a dynamic system model. Land use change is considered as a dynamic system model composing five subsystems: urbanization, social, economic, environmental and land use subsystems. The key attributes in these five subsystems are interactive and they are dynamic variables. The assessment on the impacts of urbanization policy to land use change is demonstrated through employing the software iThink to the land use change dynamic model, using the data collected from the Jinyun County in China. The findings suggest that the urban construction land will continue to increase in the foreseeable future in China, whilst the agricultural land will gradually decrease. Nevertheless, different policy scenarios will have different impacts on these land changes. Thus decision makers can adopt different policies to control the rate of land use change.     

Water balance estimation via SESOIL: Pinios River Basin, Greece

The mathematical modelling of a river basin water balance is a complex process which requires extensive calibration and the use of data that are frequently not available. The seasonal soil compartment model, SESOIL, of the USEPA, is an international tool well suited for this purpose. Knowledge of the water balance on an annual or a monthly basis is particularly important in regions with increased water demand and limited resources. SESOIL has been applied to the Pinios River Basin in Central Greece. Observed input and simulated output are discussed. The model behaved well. The study extends the use of SESOIL which can be run with limited calibration compared to other models in the literature and with data readily available in Europe such as the Corine land cover. Simulations can be used for water allocation practices, water related impacts due to climatic changes and other human activities indicated in the new EC Water Framework Directive EC/2000/60.     

Screening of 47 organic microcontaminants in agricultural irrigation waters and their soil loading

Reclaimed water usage for crop irrigation is viewed both as an excellent sustainable water source and as a potential entrance for emerging organics into the food chain. This concern is backed by the already documented pollutant crop uptake potential. In the present study, irrigation waters used in agricultural fields (Torroella de Montgri, NE Spain) were screened for 47 analytes in a two year study (2007-2008). A total of 26 contaminants belonging to different chemical classes namely, pesticides, pharmaceuticals, personal care products, phenolic estrogens, antioxidants and disinfection by-products, were detected. Marked differences in concentration trends for the different chemical classes were evidenced from 2007 to 2008, and attributed to a persistent drought endured by the region in 2008. Also, loading mass rates of chemical classes were estimated based on crop irrigation regimes and they ranged from 0.8 to 121.3 g ha⁻¹ per crop cycle. These values were contrasted with those obtained for other water sources from countries where crop irrigation is commonly practiced. Finally, crops grown under these irrigation regimes, namely alfalfa and apple, were analyzed and 5 anthropogenic compounds were identified and quantitated, whose concentrations ranged from 13.9 to 532 ng g⁻¹ (fresh weight).     

Subsurface water quality and quantity from the standpoint of irrigation and livestock

Field studies were undertaken at the Oyo North Agricultural Development Project (ONADEP), Shaki, Nigeria in 1988 and 1989 to evaluate the reliability and quality of subsurface water sources in relation to irrigation and livestock usage. Based on data from 22 water samples, 15 soil types, seasonal consumption of water for 10 major crops and extensive hydrogeological records, it was established that (i) alkalinity and salinity hazards are low, hence the groundwater of the study area is suitable for irrigation, (ii) excessive boron levels might restrict the usage of the groundwater of the study area for livestock, (iii) subsurface water sources, estimated at about 31,000 ML per annum is capable of satisfying only 12% of agricultural and livestock water demand of the study area, and (iv) the area under consideration is not endowed with abundant surface and subsurface water as shown by previous studies.