Wetland protection faces considerable pressure, and the current state of China's wetlands is not encouraging
Remote sensing monitoring is more accurate and objective, and has gained international recognition
“Compared with traditional monitoring technologies, monitoring using remote sensing satellite technology has obvious advantages such as being macroscopic, dynamic, rapid, real-time and accurate, and in particular it minimizes interference from human factors and ensures independence, transparency and objectivity. It has become an indispensable technical means for dynamic global ecological and environmental monitoring.” Academician Guo Huadong, head of the expert group for global ecological and environmental remote sensing monitoring and director of the Institute of Remote Sensing and Digital Earth of the Chinese Academy of Sciences, told reporters that China's global ecological and environmental monitoring capability has been significantly improved in recent years. “With a global vision, we actively participate in research on global ecological and environmental issues of common concern to the international community, fully demonstrating the positive attitude and unique contribution of China's remote sensing scientific and technological community to serving human society, responding to global climate change and solving global ecological and environmental problems.”
According to researcher Li Jiahong, chief engineer of the National Remote Sensing Center of the Ministry of Science and Technology, over the past three years, China's global ecological and environmental remote sensing monitoring work has not only attracted widespread attention domestically, but has also received high praise from international peers. The total downloads of related dataset products released simultaneously with the report exceeded 600,000.
Building on the work of the 2012 and 2013 annual reports, the National Remote Sensing Center led the organization of the Institute of Remote Sensing and Digital Earth of the Chinese Academy of Sciences, Tsinghua University, the Research Institute of Forest Resource Information Techniques of the Chinese Academy of Forestry, the China Institute of Water Resources and Hydropower Research, the National Satellite Meteorological Center, the China Centre for Resources Satellite Data and Application and other leading domestic scientific and technological forces to complete the compilation of the 2014 Annual Report.
Five internationally important wetlands, including Hubei Chenhu and Jiangsu Yancheng, are greatly affected by economic activities
As newly added content, the “Large Internationally Important Wetlands” special topic for the first time included wetlands, an indicator with extremely high ecological functions and service value, in the annual report. “This is the first time internationally that satellite remote sensing technology has been used to monitor and analyze large internationally important wetlands on a global scale, reflecting China's outstanding contribution to the protection of internationally important wetlands and receiving high praise from international wetland organizations.” said researcher Shi Jiancheng, director of the State Key Laboratory of Remote Sensing Science.
It is reported that using satellite remote sensing data, the report objectively evaluated the status and changes of 100 large internationally important wetlands worldwide and 20 internationally important wetlands in China in 2001 and 2013: from 2001 to 2013, the area of the 100 large internationally important wetlands worldwide remained stable (a decrease of less than 1%), but some wetlands, such as the Danube Delta in Romania, Europe, the Chiquita Lakes in Argentina, South America, Lake Urmia in Iran, Asia, and Lake Chad in Chad, Africa, suffered relatively serious disturbance and degradation.
What is the ecological status of China's wetlands? The 2014 Annual Report points out that although China has made tremendous efforts in wetland protection in recent years, due to pressure from population, resources and the environment, compared with the global average level, China's internationally important wetlands face higher pressure and threats.
⟦NL> As of now, 46 wetlands in China have been included in the List of Wetlands of International Importance, all of which are nature reserves. The Report assessed and analyzed the area changes, overall landscape integrity and degree of disturbance/degradation of 20 of these internationally important wetlands. The results show that from 2001 to 2013, the wetland area in most reserves did not change significantly. However, the wetlands in the Nanweng River Reserve in Heilongjiang decreased by about 8,000 hectares, accounting for about 3.5% of the reserve area; the total area of the Dalai Lake wetland in Inner Mongolia decreased by more than 20,000 hectares overall, accounting for about 3.5% of the reserve area. It is worth noting that due to economic activities such as paddy field cultivation, aquaculture and dam construction within the reserves, five internationally important wetlands, including Hubei Chenhu, Jiangsu Yancheng, Shanghai Chongming Dongtan, Heilongjiang Zhenbaodao and Dongfanghong, are still at a relatively high level of disturbance or degradation.
“Wetlands have multiple ecological functions, such as protecting biodiversity, storing and regulating floods, purifying water quality, regulating climate and maintaining ecological balance; the economic benefits brought by artificial wetlands come at the cost of sacrificing ecological value.” Shi Jiancheng gave an example, saying that natural wetlands are usually migration habitats for birds. After they become paddy fields, due to reasons such as reduced biodiversity, birds can no longer inhabit them. “Compared with economic benefits, ecological benefits are hidden and long-term. Once lost, they are difficult to restore, and their negative impacts and losses are difficult to estimate. Therefore, before developing wetlands, a comprehensive assessment of their long-term impacts must be carried out, and we must not focus only on short-term economic interests.”
Professor Gong Peng, director of the Center for Earth System Science at Tsinghua University, believes that “China has developed to the point today where it is time to protect wetlands and restore wetlands. Lucid waters and lush mountains are also invaluable assets. In particular, as people's living standards improve and demand for tourism and entertainment increases, protecting wetlands well can also generate economic benefits —— Hangzhou's Xixi Wetland is a typical example.”
Global winter wheat growth was good in 2014—2015, and China's winter wheat is expected to increase production
According to Guo Huadong, following the previous year's focus on the production situation of major grain and oil crops, this year's monitoring covered the planting status of four major grain and oil crops in major global producing areas in 2014: corn, rice, wheat and soybeans.
The 2014 Annual Report shows that in 2014 the total output of the four major grain and oil crops worldwide — corn, rice, wheat and soybeans — reached 2.764 billion tonnes, an increase of 1.2% year on year, among which corn and rice output remained basically flat, while wheat and soybean output was better than the previous year; in 2014 China's total output of major grain and oil crops was basically flat compared with 2013; in 2014 the global supply situation for major grain and oil crops was good, the production situation in China's soybean import source countries was optimistic, and output in the import source countries for corn, rice and wheat declined slightly.
At the same time, global winter wheat growth was good in 2014—2015, with only Ukraine and parts of neighbouring Russia showing poor crop growth; crop growth in China's main winter wheat producing areas was better than last year and the average level of the past 5 years, while the planted area increased slightly. If agrometeorological conditions are normal before the winter wheat harvest, winter wheat is expected to increase production.
China conducted remote sensing monitoring of Africa for the first time, and for the first time internationally conducted remote sensing monitoring of the ecological and environmental status of the China—ASEAN region
According to Gong Peng, the 2014 Annual Report, based on multiple types of satellite remote sensing data, established the most up-to-date African land cover database so far.
The monitoring results show that among African land cover types, the four with the largest area proportions are bare land, shrubland, grassland and forest. During 2000—2014, the farmland area in Egypt's Nile River basin increased by a net 11.19%; around Lake Victoria, as the population continued to grow, the area of urban-dominated artificial surface cover increased by 143.97%; grassland vegetation showed an increasing trend in most areas of the Sahel region.
“Africa is a region with relatively rapid future population growth and economic development, and balancing economic development and ecological protection is very important.” Gong Peng said he hopes China's monitoring results can help them better achieve sustainable development.
Remote sensing monitoring of the ecology of the China—ASEAN region shows that the spatial distribution of ecological and environmental factors in the region differs significantly; ASEAN countries have a good ecological and environmental status and the region is rich in ecological resources, but per capita availability varies greatly. The region is rich in forest resources, and the country with the highest total forest biomass is China, accounting for 41% of the regional total. The annual carbon sequestration capacity of forests in the entire region is nearly 2 billion tonnes, and deforestation and forest fires have a significant impact on forest carbon sequestration capacity; agricultural production intensity is generally high, with the proportion of cultivated land planted in most areas exceeding 95%.