This work focuses on the characterization of a typical coastal karst watershed by addressing its physico-chemical parameters. The concentrations of the main ions clearly indicate the dominance of Ca²⁺ and HCO₃⁻ with a carbonate weathering rate equivalent to 230t/Km²/year; that is a typical weathering of karst watersheds. The spatio-temporal variability of dissolved organic matter (DOM) is also assessed in the watershed. Many samples were collected under different hydrological conditions from three representative sites. The evolution of OM composition along an urbanization gradient from upstream to downstream Kadisha watershed reveals the very strong impact of urban discharges on the receiving waters. Substantial differences in DOC results are highlighted in relation to the urban or natural origin of the DOM. Upstream OM flux is quantified and compared to downstream OM flux showing that, during the low flow period, the downstream flux is 29 times higher than the upstream. Also, a large fraction of non-humic substances, including hydrophilic organic matter HPI, is detected in the downstream section impacted by urban discharges. The higher values of SUVA noticed for DOM at upstream compared to downstream, reflects the low aromaticity and non-humic character of DOM in downstream. These outcomes show the impact of the Tripoli urban discharges on the quality and quantity of OM in the receiving waters downstream of the Kadisha catchment. This is typical at low water period when the dilution factor of urban discharges in the receiving waters is the least.

这项工作的重点是通过解决典型沿海喀斯特流域的物理化学参数来表征其特征。主要离子浓度清楚地表明Ca ²⁺和HCO ₃ ^-占主导地位，碳酸盐风化速率相当于230t/Km ² /年；这是典型的喀斯特流域风化作用。还评估了流域中溶解有机物 (DOM) 的时空变化。许多样品是在三个代表性地点的不同水文条件下采集的。有机质成分沿着卡迪沙流域上游到下游城市化梯度的演变揭示了城市排放对受纳水域的强烈影响。 DOC 结果与 DOM 的城市或自然起源相关，存在显着差异。对上游 OM 通量进行量化并与下游 OM 通量进行比较，结果表明，在低流量期间，下游通量比上游高 29 倍。此外，在受城市排放影响的下游部分检测到很大一部分非腐殖质，包括亲水性有机物 HPI。与下游相比，上游 DOM 的 SUVA 值较高，反映了下游 DOM 的低芳香性和非腐殖质特征。这些结果显示了的黎波里城市排放对卡迪沙流域下游受纳水域有机物质质量和数量的影响。这是典型的枯水期，此时受纳水域的城市排放稀释系数最小。