Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz (UESC), Ilhéus, BA, 45662-900, Brazil.
Departamento de Ciências Agrárias e Ambientais, Universidade Estadual de Santa Cruz (UESC), Ilhéus, BA, Brazil.
Environ Monit Assess. 2019 Dec 23;192(1):65. doi: 10.1007/s10661-019-8020-0.
Changes to land use generate imbalances in the natural dynamics of aquatic ecosystems. These changes can vary according to the specific characteristics of each environment and due to seasonal factors, reinforcing the importance of studies in this area in different regions of the globe. Thus, the aim of this study was to analyze the effects of land use change on the rivers and streams of the Cachoeira River Basin in the Northeast of Brazil. Samples were collected bi-monthly at 16 points along the basin over 1 year and analyzed for physical and chemical parameters (temperature, pH, conductivity, and percentage saturation of dissolved oxygen), inorganic nutrients (NO, NO, NH/NH, PO, SiO) and dissolved major ions (Ca, K, Mg, Na, HCO). The highest concentrations of NO, NO, NH/NH, and PO occurred at the points with the highest percentage of urban areas and population density. The major ions Ca, K, Mg, Na, and HCO were positively correlated with the percentage of pasture coverage; however, the high concentrations of these ions and the strong correlation between them revealed that other factors besides land use, such as soil cover, geological formation, and water deficit, may be jointly contributing to increases in their concentrations. Thus, the results show that urbanization represents the type of land use with the greatest negative effect on water quality since it alters the concentrations of inorganic nutrients dissolved in the Cachoeira River Basin.
土地利用的变化会导致水生生态系统自然动态的失衡。这些变化会根据每个环境的具体特征以及季节性因素而有所不同，这加强了在全球不同地区对该领域研究的重要性。因此，本研究旨在分析土地利用变化对巴西东北部卡舒埃拉河流域河流和溪流的影响。在 1 年的时间里，每月在流域的 16 个点采集两次样本，并对物理和化学参数（温度、pH 值、电导率和溶解氧饱和度）、无机养分（NO、NO、NH/NH、PO、SiO）和溶解的主要离子（Ca、K、Mg、Na、HCO）进行分析。NO、NO、NH/NH 和 PO 的浓度最高出现在城市化程度和人口密度最高的点。Ca、K、Mg、Na 和 HCO 等主要离子与牧场覆盖率呈正相关；然而，这些离子的高浓度以及它们之间的强烈相关性表明，除土地利用外，土壤覆盖、地质形成和水分不足等其他因素可能共同导致它们浓度的增加。因此，研究结果表明，城市化是对水质产生最大负面影响的土地利用类型，因为它改变了卡舒埃拉河流域中溶解的无机养分的浓度。
