流域土壤侵蚀对椒江口悬浮泥沙时空分布的影响

利用通用土壤流失方程，对椒江流域1995年、2000年、2005年、2010年及2015年土壤侵蚀模数进行估算，椒江流域1995年、2000年、2005年、2010年及2015年均达到中等土壤侵蚀的强度，其中，1995年至2010年土壤侵蚀有逐年恶化的趋势，而2010年至2015年有所缓解.基于椒江及河口、近岸的野外实测数据，构建椒江及近岸水体悬浮泥沙浓度遥感定量反演模型，对椒江及近岸水体1995年、2000年、2005年、2010年及2015年悬浮泥沙浓度进行估算，对水体悬浮泥沙的空间分布进行分析，椒江口水体悬浮泥沙浓度表现出较强的空间分布规律及高时空动态性，其中，椒江悬浮泥沙浓度明显高于河口和台州湾；椒江中游累年悬浮泥沙浓度平均值最大，时空动态性最低，受陆相及海相输沙综合影响，易形成悬浮泥沙的最大浑浊带.流域土壤侵蚀量越大，水体悬浮泥沙浓度越高.最后，定量分析了降雨，日照时间和人类活动等因素对河口悬浮泥沙格局影响.降雨作为椒江地表径流的主要来源，对悬浮泥沙也起到一定的“稀释”作用.年内日照时长的增加，加剧了水体水量的损失，削弱水体的“稀释”作用.若以流域内居民地面积表征人类活动强度，其与水体年均悬浮泥沙浓度之间相关性较弱，但其年际变化表现出较高的相关性.

Impact assessment of watershed soil erosion on spatiotemporal distribution of suspended sediment in Jiaojiang Estuary

The intensity of soil erosion in Jiaojiang Estuary was reached at moderate level at 1995， 2000,2005， 2010 and 2015. From 1995 to 2010， soil erosion tended to deteriorate year by year， but eased from 2010 to 2015. The measured data and model simulation results shows that the suspended sediment concentration in Jiaojiang and Taizhou Bay shows strong spatial distribution and high spatial and temporal dynamics. The suspended sediment concentration in Jiaojiang is significantly higher than that in Taizhou Bay. The average concentration of suspended sediment concentration in the middle reaches of Jiaojiang River is the highest， with the lowest temporal and spatial dynamics， and the maximum turbidity zone of suspended sediment is easy to be formed by land and sea sediment transport. The higher the soil erosion amount is， the higher the sediment concentration is. Rainfall is one of the main driving factors of soil erosion. Rainfall is not only the main driving factor for the production of suspended sediment in the water， but also the main source and recharge of the effective carrier of sediment， as a role of “dilution”. Therefore， rainfall has a double effect on the change of suspended sediment concentration. During the year， the increase of sunshine duration aggravated the loss of water flow and weakened the dilution of water. If the area of building land is used to characterize the intensity of human activities， the correlation between it and annual suspended sediment concentration is weak， while the inter-annual variability of the two species showed a high correlation.