The Economic Impact of Water Evaporation Losses from Water Reservoirs in the Segura Basin,SE Spain

In this paper we assess the economic impact of evaporation losses from great dams (GDs) and on-farm agricultural water reservoirs (AWRs) in the semi-arid Segura River basin, SE Spain. Evaporation losses from water reservoirs reduce the high water use efficiency reached in agriculture by means of other techniques such as well-built water pipes or drip irrigation and have a substantial economic impact. Evaporation losses have been calculated using Class-A pan evaporation data and pan coefficients, whereas their economic impact has been assessed using an economic mathematical programming model that simulates land and water allocation in the different irrigated areas of the basin. Our results show that annual evaporation from GDs and AWRs represents 8.7% of the water currently available for irrigation in the Segura basin. The economic impact of such losses has been estimated in a reduction of 6.3% of the value of agricultural production and 5.4% of the farm net margin. As less water is effectively available for farmers the basin’s irrigated area is reduced in a 7.5%. This impact is greater, in both absolute and relative terms, in the areas accommodating the most intensive and profitable irrigated agriculture. The applied methodology and results could be useful to regional water agencies and collective irrigation schemes for future planning and management, including the assessment of alternatives for reducing evaporation from reservoirs.     

Water and Land Resources Development in Southeastern Turkey

The Southeastern Anatolia Project (GAP), which was initiated in 1976 as a large-scale and multisectoral regional development project in Turkey, is a combination of 13 projects primarily for hydropower generation and irrigation. The project involves the construction of 22 dams and 19 hydroelectric plants with a total capacity of 7500 MW. At full development 27.3 billion kWhr of hydroelectric energy will be generated annually. GAP will also provide irrigation for 1.7 million ha of land corresponding to one-fifth of irrigable land of Turkey. As an integrated development project relating sectors including hydropower,irrigation, industry, transportation and social infrastructure, the Southeastern Anatolia Project has top priority among national projects of Turkey. In this paper, various aspects of hydropower and irrigation planning and development for the Southeastern Anatolia project will be discussed. Water availability, agricultural and other objectives, physical structures, developmentstrategies and scenarios are examined. Some important aspects of international water use are discussed.     

基于光学和雷达遥感信息的灌溉信号分析及灌溉面积提取方法研究-以华北平原灵寿县磁右灌区为例

目前,灌溉面积主要通过调查统计方式获取,时效性和准确性较差,而在灌区用水管理中迫切需要掌握实际灌溉面积及其空间分布和动态变化等信息。为此,本文开展基于雷达遥感信息的灌溉信号探测识别及次灌面积提取方法研究。首先,使用水云模型结合实测土壤水分数据进行模拟,量化灌溉事件导致后向散射系数的变化。然后,提出一种基于时序差值和局部阈值法的实际灌溉面积提取方法,使用高频次的哨兵1号雷达卫星遥感数据开展华北平原灵寿县磁右灌区灌溉面积提取,并结合灌区实地调查资料对提取结果进行验证。结果表明:使用水云模型模拟显示春季小麦地块的灌溉事件可导致C波段的雷达后向散射系数变化超过1 dB,灌溉信号可被绝对辐射精度优于1 dB的雷达卫星探测;基于时序雷达后向散射系数分析显示,灌溉事件导致C波段雷达后向散射系数呈现明显的先增大后减小的时域特征,与降水事件不同,灌溉事件导致雷达后向散射系数呈现明显的局地变化特征。以本文提出的方法提取研究区的灌溉面积,结合实地调查样本检验,结果表明灌溉面积的总体提取精度为76.6%。小麦返青期第一次渠灌面积约为9.20万亩,小麦拔节期第二次渠灌面积约为10.64万亩。此外,由于井灌区和渠灌区存在明显的时差,基于雷达遥感信息可对不同水源的灌溉区进行探测,研究区井灌面积约为3.9万亩。基于高频次的雷达遥感信息可对灌区的灌溉事件进行探测,本文提出的方法可为区域次灌溉面积调查和流域水资源管理等应用提供技术支撑。     

Developing Strategies for Agricultural Water Management of Large Irrigation and Drainage Networks with Fuzzy MCDM

Sustainable water resources management aims at increasing the efficient use of water and achieving food security. This work proposes a generalized novel spatial fuzzy strategic planning (SFSP) in combination with multi-criteria decision making (MCDM) and a conceptual agricultural water use model for determining sustainable agricultural water management strategies. The proposed framework is applied to an irrigation and drainage network in Iran, which constitutes a large-scale water resource system. A spatial strength, weakness, opportunity, and threat (SWOT) analysis of internal and external factors related to agricultural water management is applied in this work. Possible water management strategies were ranked with the MCDM approach that combines the Analytic Hierarchy Process (AHP) and the Fuzzy technique for order-preference by similarity to ideal solution (TOPSIS). The AHP estimates the criteria weights and the TOPSIS model prioritizes the agricultural water management strategies. The results of SWOT analysis show that the final scores of the internal and external factors are equal to 2.9 and 2.73, respectively. Accordingly, the most attractive strategic type is a SO (aggressive) strategy, and a combination of structural and non-structural strategies (SO, ST, and WO strategies) are the top-ranked ones. Proposed strategies for water supply and demand management are the development and rehabilitation of the physical structure of water resources system of irrigation network, improvement of operation management and maintenance of water resources system, wastewater management, and inter-basin water transfer within the irrigation network. The results indicate that the total annual volume of agricultural water under normal conditions is about 1.8 billion cubic meters, of which about 1707 million cubic meters (95%) issue from surface water sources and 90 million cubic meters (5%) from groundwater sources. The proposed model and the calculated results provide viable and effective solutions for the implementation of sustainable management of water resources and consumption in large-scale water resources systems.

     

井灌类型区农业高效用水模式及产业化示范

农业高效用水管理示范工程是国家科技部在“九五”期间批准立项的重大科技产业工程项目。井灌类型区农业是我国重要的灌溉农业类型区一，提高井灌区的灌溉水利用率和单方水的生产效率，对节约用水，提高农业生产水平具有重要的意义。河北省三河市通过提高井灌区水的利用率，创建和发展了相关产业，使该项目成为农业高效用水科技产业示范工程。     

Impact of the Syrian conflict on irrigated agriculture in the Orontes Basin

The impact of conflict on irrigated agriculture and consequently summer crop production within conflict-affected agricultural lands was observed in the Orontes Basin. Water and energy use were reconfigured through a transition from rainfed to irrigated agricultural production over the past 20 years, but have been disrupted as the Syrian war has unfolded since 2011. Remotely sensed vegetation indices were used to determine irrigated summer crop yields during the year 2013. Findings suggest that irrigated agricultural production dropped between 15% and 30% in the Syrian portion of the basin in 2000–2013, with hotspots identifiable in Idleb, Homs, Hama, Daraa and Aleppo. The developed approach demonstrated effectiveness in quantifying and geolocating hotspots where conflicts have the strongest impact on agricultural water use, agricultural production, and eventually support relief and regional agricultural reconstruction in this and other conflict regions.     

Satellite Remote Sensing for Estimating Productivities of Land and Water

Satellite remote sensing offers the capability of objectively measuring spatiotemporalland surface parametersthat can provide information critical to irrigation performance studies. This study demonstrates the use of satellite remote sensing to identify the spatially distributed patterns of wheat yield and crop evapotranspirationfor the Bhakra command area (1.2 million ha), in the Haryana State of north-west India. For the first time, satellite remote sensing has been used to obtain estimates of productivity per unit of water consumed by crop evapotranspiration,a key indicator of the performance of irrigated agriculture. It is shown that areas with the highest grain yield correspond to the areas having the highest evapotranspiration.Consequently, the spatial variations in crop production per unit evapotranspiration are less (cv = 0.10) than spatial variations in productivity of land (cv = 0.17). Whereas head- and tail-end differences in three major branch canals were found for productivity of land, this trend was not detected for the productivity of water consumed. Causal factors for the spatial patterns of productivity need to be more thoroughly investigated. While calculation approaches are suggested to estimate productivity of land and water using satellite remote sensing, further research is required to refine these techniques. Better estimations of the productivity of land and water will allow for more detailed and objective performance studies at a range of scales from individual farm fields to entire irrigation schemes. It will help scientists understand productivity issues better, and enable water managers and policy makers to support improvements in the utilization of land and water resources.     

Innovative Approaches in Water Resources Development in the Southeastern Anatolia Project (GAP)

In the Southeastern Anatolia Project, 13 major groups of water resources development projects-primarilyfor irrigation and hydropower-areplanned to develop and manage soil and water resources in the south-eastern part of Turkey. In this paper, the innovative approaches which are being implemented for sustainable water resources development in the Southeastern Anatolia Project are described.     

Socio-Economic Impact of Evaporation Losses from Reservoirs Under Past, Current and Future Water Availability Scenarios in the Semi-Arid Segura Basin

This study assesses evaporation losses from water reservoirs in the semi-arid Segura basin (south-east Spain), one of the most water stressed European catchments. These losses are evaluated from both the hydrologic and economic perspectives under different water availability scenarios that are based on water policy trends and climate change predictions. We take a multidisciplinary approach to the analysis, combining energy balance models to assess the effect of climate change on evaporation from water bodies, Class-A pan data and pan coefficients to determine evaporation loss on a regional scale, and non-linear mathematical programming modelling to simulate the economic impact of water use and allocation in the basin. Our results indicate that water availability could be reduced by up to 40 % in the worst-case scenario, with an economic impact in the 32–36 % range, depending on the indicator in question. The total annual evaporation loss from reservoirs ranges from 6.5 % to 11.7 % of the water resources available for irrigation in the basin, where evaporation from small reservoirs is more than twice that from large dams. The economic impact of such losses increases with water scarcity, ranging from 4.3 % to 12.3 % of the value of agricultural production, 4.0 % to 12.0 % of net margin, 5.8 % to 10.7 % of the irrigated area, and 5.4 % to 13.5 % of agricultural employment. Results illustrate the importance of evaporation losses from reservoirs in this region and the marked upward trend for future scenarios. Besides, they highlight the extent of the impact of climate change on future water resources availability and use in southern Europe.     

Improvement of Field Water Distribution and Irrigation Techniques: The Southeastern Anatolia Project-GAP

ABSTRACT

The Southeastern Anatolia Project-GAP is an integrated regional development project implemented in southeast Turkey. The project cows all development-related sectors such as agriculture, industry, health care, education. tourism, transportation, and telecommunications.

Water resources development is one most important component of the project. Rational use of water is the goal in every aspect of development, be it hydropower, irrigation, or flood control. To complement the efforts to optimize water use in irrigated agriculture, a project has been carried out in regard to on-farm equipment and management of water. This paper describes several equipment and management combinations, applied to a very large irrigation area. ranging from gravity to sprinkler irrigation, and from upstream to downstream control of water.

Five different applications are analyzed in this study along with their technical, economic, and operational merits and disadvantages.

The project area is selected in the Sanliurfa-Harran Plains, the largest one-piece scheme to be opened to irrigation in GAP It is owned and cultivated by private farmers, and as such, it is expected to act as a large-scale, real-world laboratory to test different irrigation practices in actual conditions.     

近40年可鲁克湖-托素湖面积变化及影响因素分析

以位于青海省德令哈市境内的可鲁克湖-托素湖为研究对象,利用美国地质调查局自1973年-2013年的多年遥感影像,运用目视解译和改进的归一化差异水体指数方法提取可鲁克湖和托素湖的面积值,分析其变化特征,结合德令哈市的降水、气温、蒸发、径流、农业灌溉耗水资料,对影响湖泊面积变化的因素进行初步探讨。结果表明,可鲁克湖的面积大致保持不变,托素湖的面积自1973年以来呈现先减小又增大的趋势,降水量呈增加趋势,可以认为湖泊面积变化受降水的影响较小,可鲁克湖的面积主要受蒸发、气温和上游巴音河径流量的影响,但其影响存在明显的滞后性。上游农业耗水量是间接影响托素湖面积变化的主要因素,气温的变化通过影响蒸发量和上游冰雪融水间接影响托素湖的面积。     

基于多源遥感数据和水量平衡原理的灌溉用水量分析

农业灌溉水量估算和区域农业用水的校核是用水统计、监管的难点。现行基于典型调查和定额推算的方法依赖统计人员经验,易受人为因素干扰,准确性难以控制;采用基于水量平衡的灌溉用水推算方法时,区域蓄水变量和耗水量等要素仅依靠传统地面监测条件难以获取。遥感技术能够解决水量平衡方程中区域蓄水变量和蒸散发的估算问题,可以提高水量平衡方法在计算灌溉用水中应用的可行性,但大多数遥感产品存在区域适用性和精度的问题,需要将多种产品结合,通过相互校验和组合控制误差;此外,遥感产品与水量平衡要素之间还存在一定程度的概念差异,需要进行匹配与转换。本文构建了一种基于多源遥感数据和水量平衡原理的灌溉用水分析方法,利用区域水量平衡方程检验多源遥感数据的一致性和可靠性,建立遥感数据与水量平衡要素的对应关系,选取合理的区域蒸散发数据,再利用田间水量平衡将总蒸散发分解为降水蒸散发和灌溉蒸散发,推算得到灌溉耗水量和灌溉用水量的合理范围。应用本文提出的方法进行山东省济南市2012—2015年灌溉用水分析,并与济南市水资源公报统计的农业用水进行对比,结果表明:在降水量接近多年平均的2012、2013、2015年,二者结果较为接近;在干旱的2014年,本文的分析结果与公报结果相差较大。结合同期农田作物长势、区域地下水位变化分析,认为该年份存在较大的灌溉用水,本文结果比较合理。本文方法可为校核区域灌溉用水统计数据的合理性提供技术支撑。     

Agricultural Water Use in Turkey

Abstract

Agriculture is the largest user of water in Turkey with 75 percent of the total consumption. Turkey has developed 50 percent of total irrigable land so far. Water is a limiting factor for agriculture throughout much of Turkey. The amount and distribution of precipitation is quite uneven. Turkey, like many countries today, faces challenges in efficiently developing and managing its agricultural water resources while trying to protect water quality and the environment. However, Turkey has some difficulties and problems on water use for agriculture. Current institutional framework and legal regulation, monitoring and evaluation activities are investigated, and agricultural water use and irrigation development are studied. Problems with the lack of data on environmental effects of irrigation and water pricing are underlined. Evaluation of the current situation ends in the conclusion that Turkey needs a comprehensive monitoring and evaluation system both at basin and scheme level, and rehabilitation of irrigation systems for efficient water use in agriculture.     

Second Asian Conference on Water and Wastewater Management

Abstract

This paper analyzes the impacts of the Southeastern Anatolia Project (Turkey) on the hydrological regime of the Tigris and Euphrates rivers. The Southeastern Anatolia Project, commonly called GAP, is a Turkish multi-dimensional development project involving primarily irrigation and hydropower generation in the Euphrates and Tigris river basins. For the last two decades, the GAP has been a source of tension between Turkey and the two riparian countries, Syria and Iraq, which are concerned by the modification of the hydrological regime of the Euphrates and Tigris rivers. The quantification of the hydrological risk faced by Syria and Iraq can be comprehended by an integrated management model that simultaneously considers the dispatch of the hydropower plants and the irrigation water withdrawals. The model assumes that the GAP hydroelectric reservoirs are dispatched so as to minimize the operating costs of the Turkish hydrothermal electrical system while meeting irrigation water demands. This optimization problem is solved by a stochastic dual dynamic programming (SDDP) formulation which allows a detailed representation of the Turkish hydrothermal electrical system including the GAP. Scenarios of future irrigation water demands in the GAP are constructed based on projected irrigation areas and on the main crops. Simulation results show that if the project is completed as planned, Euphrates and Tigris outflows will be reduced by 32% and 25% respectively, while the average production of hydroelectricity would reach 27 TWh. In addition, Turkey' commitment to deliver a minimum flow of 500 m³/s in the Euphrates could only be guaranteed 75% of the time. This percentage increases substantially (up to 95%) if only half of the irrigation projects are implemented.     

A GIS Framework for Changing Cropping Pattern Under Different Climate Conditions and Irrigation Availability Scenarios

Irrigation water availability is a main driver which determines cropping patterns for an irrigation area. Irrigation water availability will potentially reduce due to changes in climate and irrigation extraction limits. Cropping patterns should be adjusted to meet this challenge. This study presents a new approach for assessing future cropping patterns using GIS in combination with an Irrigation Water Availability Simulation model (IWAS) at irrigation area scale. The IWAS-GIS framework was developed for analysis of cropping pattern options based on the forecast of irrigation water availability in 2030 for the Murrumbidgee Irrigation Area (MIA) which is one of the most important irrigation areas in Australia. Six scenarios considering climatic conditions and the irrigation availabilities were input into the IWAS-GIS framework to simulate cropping pattern changes corresponding to predicted monthly irrigation water availability. Cropping patterns were designed by integration of soil type and irrigation water availability to improve irrigation sustainability. Simulations results indicate that the total irrigated areas will likely decrease with drier climate and less irrigation availability. Rice and pasture areas change significantly when climate and irrigation availability varies. Under the same climate condition, horticulture area increases when irrigation availability decrease. The percentage of lands which are unsuitable for cropping has reduced with the drying climate and shrinking irrigation availability. The IWAS-GIS is simple to implement and provides an easy way for assessing spatial cropping pattern changes based on irrigation water availability. This framework was developed to help irrigators plan cropping patterns corresponding to irrigation water availability. It is flexible to be adopted for similar applications in other irrigation areas.     

苏北地区灌溉农业水质监测分析

为掌握农业灌溉过程中水环境的变化情况,对苏北地区地表水、地下水水质进行了连续五年监测。结果表明:地表灌溉水、地下灌溉水水质综合污染指数均小于1,但有升高的趋势;灌溉退水中部分污染物浓度较灌溉水上升,个别单项指标超标,但不构成综合污染。提出解决制约农业可持续发展重要因素———灌溉农业用水问题的几点建议。     

Assessing Crop Water Demand by Remote Sensing and GIS for the Pontina Plain, Central Italy

An estimation of the crop water requirements for the Pontina Plain, Central Italy, was carried out through the use of remote sensing land classification and application of a simple water balance scheme in a GIS environment. The overall crop water demand for the 700 km² area was estimated at about 70 Mm³ year^− 1, i.e. 100 Mm³ year^− 1 irrigation requirements when considering an average irrigation application efficiency of 70%. The simplest and least demanding available methodology, in terms of data and resources, was chosen. The methodology, based on remote sensing and GIS, employed only 4 Landsat ETM+ images and a few meteorological and geographical vectorial layers. The procedure allowed the elaboration of monthly maps of crop evapotranspiration. The application of a spatially distributed simple water balance model, lead to the estimation of temporal and spatial variation of crop water requirements in the study area. This study contributes to fill a gap in the knowledge on agricultural use of water resources in the area, which is essential for the implementation of a sustainable and sound water policy as required in the region for the application of the EU Water Framework Directive.     

Irrigation Management in GAP

The multisectoral Southeastern Anatolia Project (GAP) is the largest regional developmentplan for one of the less developed parts of Turkey. The GAP project includes the irrigation of 1.7 million ha of land and generation of 27 billion kWh of hydroelectric power with an installed capacity of 7500 MW. In order to optimize the benefits to be obtained from irrigation and to ensure sustainable irrigation in the GAP area, the Government of Turkey has commissioned the GAP Management, and Operation Maintenance study (GAP MOM). The overall MOM model provides an institutional and organizational framework that promotes the most effective development of irrigated agriculture in the GAP region. This goal can be expressed as three major objectives: maximize net benefits, ensure sustainability and be implementable and flexible.     

充分灌与调亏灌溉条件下桃树滴灌的耗水量研究

本文研究了充分灌与调亏灌溉条件下桃树滴灌的耗水量。在田间设置有两个处理，其一是在整个生育期以蒸发量的80%进行充分灌溉；其二是在果实生长缓慢期以蒸发量的20%进行亏缺灌溉，而在其它季节以蒸发量的80%进行充分灌溉。利用石膏块土壤水分传感器和中子仪分别测量了根区土壤水势和土壤含水量的变化，并实测了果实生长量、枝条生长量和产量。利用水量平衡法得出了在上述两种滴灌条件下桃树不同生育期的日均耗水量与蒸发皿系数。与充分灌比较，调亏灌溉对产量没有影响，灌水量减少了32%，并有效抑制了枝条生长。     

冀中山前平原农灌用水与地下水承载力适应性状况

针对冀中太行山前平原浅层地下水严重超采与农林灌溉用水之间关系问题,应用地学的模数理念、水量均衡理论方法和MapGIS空间特征分析技术,建立了农灌用水与地下水承载力之间适应性状况评价方法及指标体系,以0.49km2剖分单元精度识别了冀中山前平原农林灌溉用水强度及其与浅层地下水可采资源量之间适应性状况。结果表明,冀中山前平原农林灌溉导致的"极严重不适应"或"严重不适应"状态是浅层地下水超采的主要原因,其中小麦等夏粮作物灌溉用水主导了这些农灌区地下水超采,蔬菜作物和耗水型果林灌溉开采对地下水的影响呈显著增加趋势,应重视这种非理性加剧影响因素。