scholarly journals Can on-farm irrigation reservoirs enhance long-term sustainability of large irrigated systems? The case of Riegos del Alto Aragón (Spain)

Author(s):  
David Haro-Monteagudo ◽  
Leticia Palazón ◽  
Santiago Beguería

<p>With a total irrigated area above 127,000 ha divided into 58 sectors, the Riegos del Alto Aragón (RAA) irrigation district is currently the largest irrigated area in Spain and in the European Union. Also, it is the largest water user within the Gallego-Cinca subsystem within the Ebro River Basin, which also supplies water to 588 livestock operations, 10 industrial polygons, and 110 populated areas. Although there are plans to increase the irrigated area by another additional 47,000 ha, the system is currently close to its resource limit and several supply restrictions took place in the last years with consequent impacts on agricultural productivity. Moreover, this expansion of the irrigated area collides with environmental objectives in the region, mostly due to water quality and nature conservancy aspects, as well as with other water uses downstream.</p><p>The forecasted effects of climate change on future water resources produced in the Pyrenees (the major source of water in the system), as well as market prices, national and international trade and agricultural policies, among other variables, are surrounded by a high level of uncertainty that difficult investment decision-making. Some of the adaptation measures initially devised for the system, e.g. construction of new large reservoirs in the Gallego and Cinca rivers, require either confronting further environmental conflicts or large energy expenses, when not both. With the end of the era of large public works, there is a need to identify new and robust strategies for climate change adaptation. One of these strategies is the construction of private on-farm reservoirs within the RAA system that started in recent years.</p><p>The present work evaluates the contribution of on-farm reservoirs to enhancing the long-term sustainability of the RAA system using a multi-model and multi-scenario approach. The Soil and Water Assessment Tool (SWAT) was used to simulate water provisions from the Gallego-Cinca headwater system under an ensemble of downscaled climate models. Afterward, SWAT outputs were fed into a water allocation model built with AQUATOOL to simulate the management of the system's reservoirs, including on-farm reservoirs, and the water supply to the different demands. The performance of agricultural demands and compliance with environmental flow requirements in the system was evaluated for different on-farm reservoir sizes and combined with construction and operational costs to develop sustainability/investment curves. The outcomes have the potential to better inform decision-making from farmers in RAA as well as from managers in the Ebro River Basin Agency, providing further understanding of the system's dynamics under climatic change.</p>

2021 ◽  
Author(s):  
Hanna Bolbot ◽  
Vasyl Grebin

<p>The current patterns estimation of the water regime under climate change is one of the most urgent tasks in Ukraine and the world. Such changes are determined by fluctuations in the main climatic characteristics - precipitation and air temperature, which are defined the value of evaporation. These parameters influence on the annual runoff distribution and long-term runoff fluctuations. In particular, the annual precipitation redistribution is reflected in the corresponding changes in the river runoff.<br>The assessment of the current state and nature of changes in precipitation and river runoff of the Siverskyi Donets River Basin was made by comparing the current period (1991-2018) with the period of the climatological normal (1961-1990).<br>In general, for this area, it was defined the close relationship between the amount of precipitation and the annual runoff. Against the background of insignificant (about 1%) increase of annual precipitation in recent decades, it was revealed their redistribution by seasons and separate months. There is a decrease in precipitation in the cold period (November-February). This causes (along with other factors) a decrease in the amount of snow and, accordingly, the spring flood runoff. There are frequent cases of unexpressed spring floods of the Siverskyi Donets River Basin. The runoff during March-April (the period of spring flood within the Ukrainian part of the basin) decreased by almost a third.<br>The increase of precipitation during May-June causes a corresponding (insignificant) increase in runoff in these months. The shift of the maximum monthly amount of precipitation from May (for the period 1961-1990) to June (in the current period) is observed.<br>There is a certain threat to water supply in the region due to the shift in the minimum monthly amount of precipitation in the warm period from October to August. Compared with October, there is a higher air temperature and, accordingly, higher evaporation in August, which reduces the runoff. Such a situation is solved by rational water resources management of the basin. The possibility of replenishing water resources in the basin through the transfer runoff from the Dnieper (Dnieper-Siverskyi Donets channel) and the annual runoff redistribution in the reservoir system causes some increase in the river runoff of summer months in recent decades. This is also contributed by the activities of the river basin management structures, which control the maintenance water users' of minimum ecological flow downstream the water intakes and hydraulic structures in the rivers of the basin.<br>Therefore, in the period of current climate change, the annual runoff distribution of the Siverskyi Donets River Basin has undergone significant changes, which is related to the annual precipitation redistribution and anthropogenic load on the basin.</p>


Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1498 ◽  
Author(s):  
Solomon Mulugeta ◽  
Clifford Fedler ◽  
Mekonen Ayana

With climate change prevailing around the world, understanding the changes in long-term annual and seasonal rainfall at local scales is very important in planning for required adaptation measures. This is especially true for areas such as the Awash River basin where there is very high dependence on rain- fed agriculture characterized by frequent droughts and subsequent famines. The aim of the study is to analyze long-term trends of annual and seasonal rainfall in the Awash River Basin, Ethiopia. Monthly rainfall data extracted from Climatic Research Unit (CRU 4.01) dataset for 54 grid points representing the entire basin were aggregated to find the respective areal annual and seasonal rainfall time series for the entire basin and its seven sub-basins. The Mann-Kendall (MK) test and Sen Slope estimator were applied to the time series for detecting the trends and for estimating the rate of change, respectively. The Statistical software package R version 3.5.2 was used for data extraction, data analyses, and plotting. Geographic information system (GIS) package was also used for grid making, site selection, and mapping. The results showed that no significant trend (at α = 0.05) was identified in annual rainfall in all sub-basins and over the entire basin in the period (1902 to 2016). However, the results for seasonal rainfall are mixed across the study areas. The summer rainfall (June through September) showed significant decreasing trend (at α ≤ 0.1) over five of the seven sub-basins at a rate varying from 4 to 7.4 mm per decade but it showed no trend over the two sub-basins. The autumn rainfall (October through January) showed no significant trends over four of the seven sub-basins but showed increasing trends over three sub-basins at a rate varying from 2 to 5 mm per decade. The winter rainfall (February through May) showed no significant trends over four sub-basins but showed significant increasing trends (at α ≤ 0.1) over three sub-basins at a rate varying from 0.6 to 2.7 mm per decade. At the basin level, the summer rainfall showed a significant decreasing trend (at α = 0.05) while the autumn and winter rainfall showed no significant trends. In addition, shift in some amount of summer rainfall to winter and autumn season was noticed. It is evident that climate change has shown pronounced effects on the trends and patterns of seasonal rainfall. Thus, the study contribute to better understanding of climate change in the basin and the information from the study can be used in planning for adaptation measures against a changing climate.


2012 ◽  
Vol 43 (1-2) ◽  
pp. 73-90 ◽  
Author(s):  
Fei Yuan ◽  
Liliang Ren ◽  
Zhongbo Yu ◽  
Yonghua Zhu ◽  
Jing Xu ◽  
...  

Vegetation and land-surface hydrology are intrinsically linked under long-term climate change. This paper aims to evaluate the dynamics of potential natural vegetation arising from 21st century climate change and its possible impact on the water budget of the Hanjiang River basin in China. Based on predictions of the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (IPCC-SRES) A1 scenario from the PRECIS (Providing Regional Climates for Impact Studies) regional climate model, changes in plant functional types (PFTs) and leaf area index (LAI) were simulated via the Lund-Potsdam-Jena dynamic global vegetation model. Subsequently, predicted PFTs and LAIs were employed in the Xinanjiang vegetation-hydrology model for rainfall–runoff simulations. Results reveal that future long-term changes in precipitation, air temperature and atmospheric CO2 concentration would remarkably affect the spatiotemporal distribution of PFTs and LAIs. These climate-driven vegetation changes would further influence regional water balance. With the decrease in forest cover in the 21st century, plant transpiration and evaporative loss of intercepted canopy water will tend to fall while soil evaporation may rise considerably. As a result, total evapotranspiration may increase moderately with a slight increase in annual runoff depth. This indicates that, for long-term hydrological prediction, climate-induced changes in terrestrial vegetation cannot be neglected as the terrestrial biosphere plays an important role in land-surface hydrological responses.


2010 ◽  
Vol 10 (7) ◽  
pp. 1647-1661 ◽  
Author(s):  
L. Palatella ◽  
M. M. Miglietta ◽  
P. Paradisi ◽  
P. Lionello

Abstract. In this paper we produce projections of seasonal precipitation for four Mediterranean areas: Apulia region (Italy), Ebro river basin (Spain), Po valley (Italy) and Antalya province (Turkey). We performed the statistical downscaling using Canonical Correlation Analysis (CCA) in two versions: in one case Principal Component Analysis (PCA) filter is applied only to predictor and in the other to both predictor and predictand. After performing a validation test, CCA after PCA filter on both predictor and predictand has been chosen. Sea level pressure (SLP) is used as predictor. Downscaling has been carried out for the scenarios A2 and B2 on the basis of three GCM's: the CCCma-GCM2, the Csiro-MK2 and HadCM3. Three consecutive 30-year periods have been considered. For Summer precipitation in Apulia region we also use the 500 hPa temperature (T500) as predictor, obtaining comparable results. Results show different climate change signals in the four areas and confirm the need of an analysis that is capable of resolving internal differences within the Mediterranean region. The most robust signal is the reduction of Summer precipitation in the Ebro river basin. Other significative results are the increase of precipitation over Apulia in Summer, the reduction over the Po-valley in Spring and Autumn and the increase over the Antalya province in Summer and Autumn.


2020 ◽  
Author(s):  
Fabian Drenkhan ◽  
Randy Muñoz ◽  
Christian Huggel ◽  
Holger Frey ◽  
Fernando Valenzuela ◽  
...  

<p>In the Tropical Andes, glaciers play a fundamental role for sustaining human livelihoods and ecosystems in headwater areas and further downstream. However, current rates of glacier shrinkage driven by climate change as well as increasing water demand levels bear a threat to long-term water supply. While a growing number of research has covered impacts of climate change and glacier shrinkage on the terrestrial water cycle and potential disaster risks, the associated potential economic losses have barely been assessed.</p><p>Here we present an integrated surface-groundwater assessment model for multiple water sectors under current conditions (1981-2016) and future scenarios (2050) of glacier shrinkage and growing water demand. As a case, the lumped model has been applied to the Santa river basin (including the Cordillera Blanca, Andes of Peru) within three subcatchments and considers effects from evapotranspiration, environmental flows and backflows of water use. Therefore, coupled greenhouse gas concentration (RCP2.6 and RCP8.5) and socioeconomic scenarios are used, which provide a broad range of the magnitude of glacier and water volume changes and associated economic impacts. Finally, net water volume released on the long term due to deglaciation effects is quantified and by multiple metrics converted into potential economic costs and losses for the agriculture, household and hydropower sectors. Additionally, the potential damages from outburst floods from current and future lakes have been included. Results for the entire Santa river basin show that water availability would diminish by about 11-16% (57-78 10<sup>6</sup> m³) in the dry season (June-August) and by some 7-10% (103-155 10<sup>6</sup> m³) during the wet season (December-February) under selected glacier shrinkage scenarios until 2050. This is a consequence of diminishing glacier contribution to streamflow which until 2050 would reduce from about 45% to 33% for June-August and from 6% to 4% for December-February. A first rough estimate suggests associated economic losses for main water demand sectors (agriculture, hydropower, drinking water) on the order of about 300 10<sup>6</sup> USD/year by 2050. Additionally, with ongoing glacier shrinkage and the formation of new lakes, about 45,000 inhabitants and 30,000 buildings are expected to be exposed to the risk of outburst floods in the 21<sup>st</sup> century.</p><p>The pressure on water resources and interconnected socio-eonvironmental systems in the basin is already challenging and expected to further exacerbate within the next decades. Currently, water demand levels are considerably increasing driven by growing irrigated (export) agriculture, population and energy demand which is in a large part sustained by hydropower. A coupling of potential water scarcity driven by climate change with a lack of water governance and high human vulnerabilities, bears strong conflict potentials with negative feedbacks for socio-economic development in the Santa basin and beyond. In this context, our coupled hydro-glacial economic impact model provides important support for future decision-making and long-term water management planning. However, uncertainties are relatively high (uncertainty range to be estimated) due to a lack of (good) hydro-climatic and socio-economic information at appropriate spatiotemporal scales. The presented model framework is potentially transferable to other high mountain catchments in the Tropical Andean region and beyond.</p>


2017 ◽  
Author(s):  
Rachel Schattman

climate forecasts suggest farmers in the northeast will be faced with both challenges and opportunities as the climate changes. currently farmers and other land stewards manage the risks created by changing weather patterns in many different ways.


2021 ◽  
Author(s):  
◽  
Judith Helen Lawrence

<p>The ability of decision makers to respond to climate change impacts such as sea-level rise and increased flood frequency is challenged by uncertainty about scale, timing, dynamic changes that could lead to regime shifts, and by societal changes. Climate change adaptation decision making needs to be robust and flexible across a range of possible futures, to provide sufficient certainty for investment decisions in the present, without creating undue risks and liabilities for the near and long-term futures. A country’s governance and regulatory institutions set parameters for such decisions. The decision-making challenge is, therefore, a function of the uncertainty and dynamic characteristics of climate change, a country’s institutional framework, and the ways in which actual decision-making practice delivers on the intention of the framework.  My research asks if the current decision-making framework, at national and sub-national scales, and practices under it are adequate to enable decision makers to make climate change adaptation decisions that sufficiently address the constraints posed by climate change uncertainty and dynamic change. The focus is on New Zealand’s multi-scale governance and institutional framework with its high level of devolution to the local level, the level assumed as the most appropriate for climate change adaptation decisions. Empirical information was collected from a sample of agencies and actors, at multiple governance scales reflecting the range of geographical characteristics, governance types, organisational functions and actor disciplines. Data were collected using a mix of workshops, interviews and document analyses. The adequacy of the institutional framework and practice was examined using 12 criteria derived from the risk-based concepts of precaution, risk management, adaptive management and transformational change, with respect to; a) understanding and representing uncertainty and dynamic climate change; b) governance and regulations; and c) organisations and actors.  The research found that the current decision-making framework has many elements that could, in principle, address uncertainty and dynamic climate change. It enables long-term considerations and emphasises precaution and risk-based decision making. However, adaptive and transformational objectives are largely absent, coordination across multiple levels of government is constrained and timeframes are inconsistent across statutes. Practice shows that climate risk has been entrenched by misrepresentation of climate change characteristics. The resulting ambiguity is compounded at different governance scales, by gaps in the use of national and regional instruments and consequent differences in judicial decisions. Practitioners rely heavily upon static, time-bound treatments of risk, which reinforce unrealistic community expectations of ongoing protections, even as the climate continues to change, and makes it difficult to introduce transformational measures. Some efforts to reflect changing risk were observed but are, at best, transitional measures. Some experimentation was found in local government practice and boundary organisations were used as change-agents. Any potential improvements to both the institutional framework and to practices that could enable flexible and robust adaptation to climate change, would require supporting policies and adaptive governance to leverage them and to sustain decision making through time.  This thesis contributes to understanding how uncertainty and dynamic climate change characteristics matter for adaptation decision making by examining both a country-level institutional framework and practice under it. The adequacy analysis offers a new way of identifying institutional barriers, enablers and entry points for change in the context of decision making under conditions of uncertainty and dynamic climate change.</p>


2015 ◽  
Vol 6 (2) ◽  
pp. 447-460 ◽  
Author(s):  
K. Frieler ◽  
A. Levermann ◽  
J. Elliott ◽  
J. Heinke ◽  
A. Arneth ◽  
...  

Abstract. Climate change and its impacts already pose considerable challenges for societies that will further increase with global warming (IPCC, 2014a, b). Uncertainties of the climatic response to greenhouse gas emissions include the potential passing of large-scale tipping points (e.g. Lenton et al., 2008; Levermann et al., 2012; Schellnhuber, 2010) and changes in extreme meteorological events (Field et al., 2012) with complex impacts on societies (Hallegatte et al., 2013). Thus climate change mitigation is considered a necessary societal response for avoiding uncontrollable impacts (Conference of the Parties, 2010). On the other hand, large-scale climate change mitigation itself implies fundamental changes in, for example, the global energy system. The associated challenges come on top of others that derive from equally important ethical imperatives like the fulfilment of increasing food demand that may draw on the same resources. For example, ensuring food security for a growing population may require an expansion of cropland, thereby reducing natural carbon sinks or the area available for bio-energy production. So far, available studies addressing this problem have relied on individual impact models, ignoring uncertainty in crop model and biome model projections. Here, we propose a probabilistic decision framework that allows for an evaluation of agricultural management and mitigation options in a multi-impact-model setting. Based on simulations generated within the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP), we outline how cross-sectorally consistent multi-model impact simulations could be used to generate the information required for robust decision making. Using an illustrative future land use pattern, we discuss the trade-off between potential gains in crop production and associated losses in natural carbon sinks in the new multiple crop- and biome-model setting. In addition, crop and water model simulations are combined to explore irrigation increases as one possible measure of agricultural intensification that could limit the expansion of cropland required in response to climate change and growing food demand. This example shows that current impact model uncertainties pose an important challenge to long-term mitigation planning and must not be ignored in long-term strategic decision making.


Atmosphere ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 883 ◽  
Author(s):  
Mahtsente Tadese ◽  
Lalit Kumar ◽  
Richard Koech

Understanding the hydrological processes of a watershed in response to climate change is vital to the establishment of sustainable environmental management strategies. This study aimed to evaluate the variability of potential evapotranspiration (PET) and water availability in the Awash River Basin (ARB) under different climate change scenarios and to relate these with long-term drought occurrences in the area. The PET and water availability of the ARB was estimated during the period of 1995–2009 and two future scenarios (2050s and 2070s). The representative concentration pathways (RCP4.5 and RCP8.5) simulations showed an increase in the monthly mean PET from March to August in the 2050s, and all the months in the 2070s. The study also identified a shortage of net water availability in the majority of the months investigated and the occurrence of mild to extreme drought in about 40–50% of the analysed years at the three study locations (Holetta, Koka Dam, and Metehara). The decrease in water availability and an increase in PET, combined with population growth, will aggravate the drought occurrence and food insecurity in the ARB. Therefore, integrated watershed management systems and rehabilitation of forests, as well as water bodies, should be addressed in the ARB to mitigate climate change and water shortage in the area.


Author(s):  
Elisabeth Johann

Austrian landscapes range from plains at approximately 100 metres above sea-level to the Alps with peaks at almost 4,000 m. With a share of 47% the forest surface is an important element.One can assume that forests have been used intensively in the course of time and have been impacted by an increasing industry and population, but also by climate change. In some areas the utilization caused the modification of forest stands in particular with regard to the density, composition of tree species and age structure and reduced the extent of the forest area. However, despite these long-term interventions in the forest ecosystem the forests have never been cleared totally and about 30% of the territory remained wooded even in times of heavy exploitation. This is the reason why the share of natural forests is still relatively high. Today, some of these forests now form important assets of the Austrian network of protected forest areas. In this study I want to highlight the socioeconomic and ecological factors in the past which were responsible for this development. It will be illustrated by two case studies from different geographical regions. This examination can contribute to improving the knowledge base for decision making at the internodes of energy, biodiversity and forest policy as well as in forest resource management.


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