Potenzialabschätzung von technischen Wasserspeicheroptionen, Bewässerungsansätzen und ihrer Umsetzbarkeit

Irrigation is one of the most effective measures to avoid or reduce yield losses caused by droughts. When water resources are limited, the main challenge relates to the issue of increasing water availability for crop production without causing or exacerbating conflicts of interest with other water-consuming sectors. Considering the already observed change of rainfall patterns in Germany, water storage reservoirs could be part of the solution to agricultural producers. Such reservoirs can be filled in autumn or winter months either with surface water run-off in case of persistent or heavy precipitations, or with abstractions from surface waters when water levels and discharges are high. The stored water can then be used for irrigation in case of spring or summer droughts, thus improving water availability and increasing the reliability of water provision for agricultural producers as well as reducing the conflicts of interest regarding groundwater extractions. This working paper presents the results of a comprehensive literature review carried out in order to identify research needs in the field of agricultural water management and to provide orientation for the research project LAWAMAD – Agricultural Water Management in Germany. In the first step the available technical water storage options and the criteria which are of importance when deciding on their implementation are reviewed. Subsequently, the feasibility of these options for German agriculture is being discussed and the four most suitable ones – water storage basin, rainwater retention basin, infiltration facility and dams are identified. The choice of a technical water storage option and the decision about its size and volume depends among other things with the already available or envisioned irrigation infrastructure and farm strategies to optimize irrigation. Respectively, we discuss the existent irrigation methods, their advantages and disadvantages, as well as chances and risks of irrigation from the agronomic and the economic efficiency perspectives. In the final step of our literature review we provide an overview of the current state of scientific discussion on the barriers to investments in irrigation and water storage infrastructure from three theoretical perspectives.

灌溉是规避或减轻干旱引发作物减产损失的最有效手段之一。在水资源有限的背景下，核心挑战在于如何提升农业生产可用水量，同时不会引发或加剧与其他用水部门的利益冲突。鉴于德国已观测到的降雨格局变化，储水水库可成为解决农业生产者用水问题的方案之一。这类水库可在秋、冬两季充水：若遭遇持续或强降雨，可通过收集地表径流蓄水；若地表水水位与径流量较高时，亦可通过抽取地表水完成蓄水。储存的水源可在春、夏季干旱时段用于灌溉，由此提升农业生产可用水量，增强农业生产者的供水可靠性，同时减少因抽取地下水引发的利益冲突。本工作论文梳理了一项全面文献综述的研究成果，该综述旨在明确农业水管理领域的研究需求，并为研究项目「LAWAMAD——德国农业水管理」提供研究方向。研究首先梳理了现有各类工程储水方案，以及决策是否采用此类方案时需考量的关键评判标准。随后，本研究探讨了各类方案在德国农业场景下的可行性，并筛选出四种最适配的方案：储水池、雨水滞留池、渗滤设施与水坝。工程储水方案的选型，以及其库容规模的决策，需综合考量现有或规划中的灌溉基础设施，以及农场优化灌溉的经营策略等多重因素。本研究分别从农艺学与经济效率视角，探讨了现有灌溉技术的优劣势，以及灌溉实践所面临的机遇与风险。在本次文献综述的最终环节，本研究从三大理论视角，梳理了当前学界关于灌溉与储水基础设施投资障碍的讨论现状。