城市化,农业,气候变化影响湖泊水质和水葫芦生长。本研究考察了湖泊地表水温度的时空变化,浊度,塔纳湖的叶绿素a(Chl-a)及其与水葫芦生物量的关系。MODIS陆地/湖泊地表水温度(LSWT),前哨2MSI图像,并使用了原位水质数据。验证结果表明,MODISLSWT与现场实测水温(R=0.90)有很强的正相关关系。原位浊度和归一化差异浊度指数(NDTI)(R=0.92),和原位Chl-a和归一化差异叶绿素指数(NDCI)(R=0.84)。整个湖泊的LSWT趋势各不相同,随着东北地区趋势的增加,西北,西南地区和西部地区的下降趋势,南方,和中部地区(2001-2022年)。雨前空间平均LSWT趋势显著下降(0.01℃/年),多雨(0.02℃/年),雨季和雨季后(0.01℃/年),而旱季(0.00℃/年)无显着增加(2001-2022年,P<0.05)。各季节空间平均浊度显著下降,除了雨季前(2016-2022年)。同样,雨前和雨季空间平均Chl-a显著下降,而在旱季和雨季后(2016-2022年),它表现出不显著的增加趋势。水葫芦生物量与LSWT(R=0.18)呈正相关,而与浊度(R=-0.33)和Chl-a(R=-0.35)呈负相关。在LSWT中观察到高时空变异性,浊度,Chl-a,随着整体下降趋势。研究结果提出了综合管理策略,以平衡水葫芦的根除及其在水净化中的作用。这些结果对于决策支持系统和制定可持续水资源管理战略计划至关重要,环境保护,和污染预防。
Urbanization, agriculture, and climate change affect water quality and water hyacinth growth in lakes. This study examines the spatiotemporal variability of lake surface water temperature, turbidity, and chlorophyll-a (Chl-a) and their association with water hyacinth biomass in Lake Tana. MODIS Land/ Lake surface water temperature (LSWT), Sentinel 2 MSI Imagery, and in-situ water quality data were used. Validation results revealed strong positive correlations between MODIS LSWT and on-site measured water temperature (R = 0.90), in-situ turbidity and normalized difference turbidity index (NDTI) (R = 0.92), and in-situ Chl-a and normalized difference chlorophyll index (NDCI) (R = 0.84). LSWT trends varied across the lake, with increasing trends in the northeastern, northwestern, and southwestern regions and decreasing trends in the western, southern, and central areas (2001-2022). The spatial average LSWT trend decreased significantly in pre-rainy (0.01 ℃/year), rainy (0.02 ℃/year), and post-rainy seasons (0.01℃/year) but increased non-significantly in the dry season (0.00 ℃/year) (2001-2022, P < 0.05). Spatial average turbidity decreased significantly in all seasons, except in the pre-rainy season (2016-2022). Likewise, spatial average Chl-a decreased significantly in pre-rainy and rainy seasons, whereas it showed a non-significant increasing trend in the dry and post-rainy seasons (2016-2022). Water hyacinth biomass was positively correlated with LSWT (R = 0.18) but negatively with turbidity (R = -0.33) and Chl-a (R = -0.35). High spatiotemporal variability was observed in LSWT, turbidity, and Chl-a, along with overall decreasing trends. The findings suggest integrated management strategies to balance water hyacinth eradication and its role in water purification. The results will be vital in decision support systems and preparing strategic plans for sustainable water resource management, environmental protection, and pollution prevention.