The low-lying coastal basins of Ravenna (Italy) are at or below mean sea level and currently undergoing land subsidence, which exposes the basins to frequent inundation and groundwater and soil salinization. The surface water drainage becomes necessary to lower the water table head and further prevent flooding and waterlogging. The study examines the evolution of drainage apropos to climate change and land subsidence in the three main Ravenna coastal basins. Our findings show that the evolution of drainage is influenced by land subsidence, climate change variability, droughts, vertical seepage, and local water management. Land subsidence causes an increase in upward-directed vertical seepage of saline water through the shallow unconfined aquifer into the drainage channels of the coastal basins, thus leading to an increase in drainage through time. At a seasonal timescale, the rate of pumping depends on antecedent rainfall and soil–water storage. The warming extremes indices, specifically drought indices, show to be more significant than rainfall indices trends to monitor drainage evolution. Drought indices permit easy comparison of dryness or wetness severity with drainage evolution along their time scale. The co-occurring anthropogenic and natural factors involving in the increasing drainage rate will affect decadal and seasonal water management policies in the area. The implications of increasing drainage rates, long periods of drought with limited rainfall, and increasing temperature will further worsen freshwater availability in this coastal area already experiencing soil and water salinization. However, drainage of this low-lying territory has effectively mitigated rising water tables and avoided flooding. Our study has shown that each coastal basin behaves differently in terms of sensitivity to land subsidence and climate extremes. Therefore, when using drainage data time series for water management purposes, one should account for past management practices and for the specific sensitivity of each basin to external factors.

拉文纳（意大利）的低洼沿海盆地处于或低于平均海平面，目前正在发生地面沉降，这使得这些盆地经常被淹没以及地下水和土壤盐碱化。为了降低地下水位并进一步防止洪水和内涝，地表排水变得必要。该研究考察了拉文纳三个主要沿海盆地的排水系统与气候变化和地面沉降相关的演变。我们的研究结果表明，排水系统的演变受地面沉降、气候变化变异、干旱、垂直渗漏和当地水资源管理的影响。地面沉降导致盐水通过浅层无承压含水层向上垂直渗入沿海盆地的排水通道，从而导致随时间推移排水量增加。在季节性时间尺度上，抽水速率取决于先前的降雨量和土壤-蓄水量。在监测排水演变方面，极端变暖指数，特别是干旱指数，显示出比降雨指数趋势更显着。干旱指数可以很容易地将干旱或潮湿的严重程度与沿其时间尺度的排水演变进行比较。涉及增加排水率的同时发生的人为和自然因素将影响该地区的十年和季节性水资源管理政策。排水率增加、降雨量有限的长期干旱以及温度升高的影响将进一步恶化已经经历土壤和水盐渍化的沿海地区的淡水供应。然而，这片低洼地区的排水有效地缓解了地下水位上升并避免了洪水。我们的研究表明，每个沿海盆地在对地面沉降和气候极端事件的敏感性方面表现不同。因此，在将排水数据时间序列用于水管理目的时，应考虑过去的管理实践以及每个流域对外部因素的特定敏感性。