Department of Geomatics, National Cheng-Kung University, Tainan City 701, Taiwan.
Int J Environ Res Public Health. 2013 Jan 28;10(2):478-89. doi: 10.3390/ijerph10020478.
The effects on water quality of land use and land cover changes, which are associated with human activities and natural factors, are poorly identified. Fine resolution satellite imagery provides opportunities for land cover monitoring and assessment. The multiple satellite images after typhoon events collected from 2001 to 2010 covering land areas and land cover conditions are evaluated by the Normalized Difference Vegetation Index (NDVI). The relationship between land cover and observed water quality, such as suspended solids (SS) and nitrate-nitrogens (NO(3)-N), are explored in the study area. Results show that the long-term variations in water quality are explained by NDVI data in the reservoir buffer zones. Suspended solid and nitrate concentrations are related to average NDVI values on multiple spatial scales. Annual NO(3)-N concentrations are positively correlated with an average NDVI with a 1 km reservoir buffer area, and the SS after typhoon events associated with landslides are negatively correlated with the average NDVI in the entire watershed. This study provides an approach for assessing the influences of land cover on variations in water quality.
土地利用和土地覆被变化对水质的影响与人类活动和自然因素有关，但这些影响还没有得到充分的认识。高分辨率卫星图像为土地覆被监测和评估提供了机会。利用归一化植被指数（NDVI）对 2001 年至 2010 年台风事件后采集的覆盖陆地面积和土地覆被状况的多幅卫星图像进行了评估。本研究探讨了土地覆被与观测水质（如悬浮物（SS）和硝酸盐氮（NO3-N））之间的关系。结果表明，水库缓冲区的 NDVI 数据可以解释水质的长期变化。悬浮物和硝酸盐浓度与多个空间尺度上的平均 NDVI 值有关。年度 NO3-N 浓度与 1 公里水库缓冲区的平均 NDVI 呈正相关，而与滑坡有关的台风事件后的 SS 与整个流域的平均 NDVI 呈负相关。本研究提供了一种评估土地覆被对水质变化影响的方法。
