Tropical regions cover approximately 36% of the Earth’s landmass. These regions are home to 40% of the world’s population, which is projected to increase to over 50% by 2030 under a remarkable climate variability scenario often exacerbated by El Niño Southern Oscillation (ENSO) and other climate teleconnections. In the tropics, ecohydrological conditions are typically under the influence of complex land-ocean-atmosphere interactions that produce a dynamic cycling of mass and energy reflected in a clear partition of water fluxes. Here, we present a review of 7 years of a concerted and continuous water stable isotope monitoring across Costa Rica, including key insights learned, main methodological advances and limitations (both in experimental designs and data analysis), potential data gaps, and future research opportunities with a humid tropical perspective. The uniqueness of the geographic location of Costa Rica within the mountainous Central America Isthmus, receiving moisture inputs from the Caribbean Sea (windward) and the Pacific Ocean (complex leeward topography), and experiencing strong ENSO events, poses a clear advantage for the use of isotopic variations to underpin key drivers in ecohydrological responses. In a sequential approach, isotopic variations are analyzed from moisture transport, rainfall generation, and groundwater/surface connectivity to Bayesian and rainfall-runoff modeling. The overarching goal of this review is to provide a robust humid tropical example with a progressive escalation from common water isotope observations to more complex modeling outputs and applications to enhance water resource management in the tropics.

热带地区约占地球陆地的36％。这些地区拥有全球40％的人口，到2030年，在厄尔尼诺南方涛动（ENSO）和其他气候遥相关常加剧的显着气候多变情况下，预计到2030年将增长到50％以上。在热带地区，生态水文条件通常受复杂的陆-海-大气相互作用的影响，这些相互作用会在水通量的明确分配中反映出质量和能量的动态循环。在此，我们将对哥斯达黎加7年来连续不断的水稳定同位素同位素监测进行回顾，包括所学的主要见解，主要的方法学进展和局限性（包括实验设计和数据分析），潜在的数据缺口，和未来的研究机会，以及潮湿的热带风光。哥斯达黎加的地理位置在中美洲地峡山区内具有独特性，它从加勒比海（迎风）和太平洋（背风地形复杂）接收水分输入，并且经历了强烈的ENSO事件，为使用同位素变化为生态水文学响应的主要驱动力提供了基础。在一种循序渐进的方法中，分析了同位素的变化，从水分输送，降雨产生，地下水/地表连通性到贝叶斯和降雨径流模型。