Aquaticplant in shallow lake has important ecology function and regulatory mechanism. In the theory of Regime Shifts on shallow lakes, what is different from deep lake is that shallow lake may suddenly shift from a state of clear water in which the submergedplant is dominant to a turbid state in which phytoplankton holds the dominant position. At a certain nutritional level, the type of steady state is determined by the existence and cover degree of submerged plants. The major environmental problem of grass-type lake is the growth of the numerous aquaticplants leads to swamping of the lake, while the manifestation of shallow-lake swamping is emerged and floating-leaved plants gradually secure the dominant position. Therefore, acquiring accurately and effectively the spatial and temporal distribution and changes is significant in guiding the lake restoration and management.
The lake environment remote sensing team of Nanjing Institute of Geography & Limnology, CAS led by Luo Ju, with the support by National Foundation Program, has carried out a series of researches on aquaticplants remote sensing. They have built a satellite remote sensing extraction model for aquatic plants using the real-time data measured by satellite remote sensing, making the monitoring precision above 80%; and for the problem that characteristic threshold in the remote sensing extraction model for aquatic plants remain uncertain, they have proposed a threshold algorithm which is not dependent on synchronous measurement sample points, resolving the difficulty in extracting the aquaticplants due to the lack of remote sensing image of real-time measurement sample points. This finding has been carried by Remote Sensing, a mainstream journals of remote sensing category. Based on the new algorithm, the team has also rebuilt the spatial distribution data set of submergedplant and floating-leaved plants in Taihu Lake for the past 30 years, illustrating phenology and seasonal dynamics of floating-leaved plants and submerged plants. They have found that the structural index changes of aquatic plants measured via remote sensing, to some extent, indicate the N,P quantity changes in the lake. This research finding has been recently carried in Ecological indictors. This research has provided a theoretical basis and reference to ecological restoration and management of eutrophic shallow lakes.
Original text link:http://www.mdpi.com/2072-4292/6/8/7442
http://www.rslakes.com/up/document/2016/Ecological%20Indicators.pdf