Based On RS Time-space Changes In Lunan-Subei Offshore Primary Productivity

Marine primary productivity can reflect the production,distribution and variation of marine primary organic matter.By studying the primary productivity of the oceans,we can understand the production and distribution of marine organic matter in a certain period of time,analyze the characteristics of the ecological environment of the aquaculture,evaluate the reserves of biological resources and production potential,and make a reasonable development and utilization of marine living resources and implement fishery production.And so on to provide basic information.Southern Shandong and Northern Jiangsu are densely populated in the middle of the coastal economic belt of China.The primary productivity of the coastal waters of Southern Shandong and Northern Jiangsu is evaluated.It is important to evaluate the ecological environment of the coastal waters and the surrounding waters closely related to human activities.Based on the characteristics of large spatial scale and long time scale of RS data and the VGPM model,this paper estimates the primary productivity of coastal waters in Southern Shandong and Northern Jiangsu in 2005,2007,2009,2011 and 2013.The results of the primary productivity of the southern part of Shandong and the northern part of Jiangsu each year are obtained,and the temporal and spatial characteristics of the primary productivity of the sea area are displayed and expounded in the form of thematic maps.The analysis of the temporal characteristics of the primary productivity in the study area shows that the highest productivity of the coastal waters in southern part of Shandong and in northern Jiangsu appears in June or September,and the lowest value appears in the winter.In2005,there was a maximum value of primary productivity in the study area,and the minimum value of primary productivity in the study area occurred in 2007.The primary productivity is slightly declining over the same period of the year,but the overall trend of this interannual change is not significant.An analysis of the spatial characteristics of the primary productivity of the coastal waters of Southern Shandong and Northern Jiangsu was realized by using the gravity method.The study of spatial characteristics shows that the highest value of primary productivity in the coastal waters of southern Shandong is always in the coastal waters,where the surface runoff is injected and the Gulf area is obvious.The focus of the primary productivity concentration in the four seasons of the year is generally shifted from northwest to southeast,and the focus of the inter-annual primary productivity concentration is more frequent and the trend is not obvious.The analysis of the controlling factors of primary productivity in the coastal waters ofSouthern Shandong and Northern Jiangsu shows that the level of primary productivity is affected by multiple factors,which is influenced by temperature and precipitation.Moderate year of primary productivity is generally higher,the temperature is too high or too low will inhibit the growth of marine phytoplankton,resulting in reduced primary productivity.River water dilution and terrestrial nutrient injection is affected by precipitation,precipitation is more of the year,the river dilution effect is strengthened,landed nutrient injection increased.Chlorophyll a concentration is an important character of primary productivity,which is positively related to primary productivity.Upward flow and water mass mainly affect the concentration of primary productivity concentration center,ie spatial distribution.Red tide and green tide will also have an impact on primary productivity,especially in the month when red tide outbreaks,the primary productivity of the coastal waters of Southern Shandong and Northern Jiangsu is generally higher.