Drastic change in China's lakes and reservoirs over the past decades

Abstract

Using remote sensing images, we provided the first complete picture of freshwater bodies in mainland China. We mapped 89,700 reservoirs, covering about 26,870 km2 and approximately 185,000 lakes with a surface area of about 82,232 km2. Despite relatively small surface area, the total estimated storage capacity of reservoirs (794 km3) is triple that of lakes (268 km3). Further analysis indicates that reservoir construction has made the river systems strongly regulated: only 6% of the assessed river basins are free-flowing; 20% of assessed river basins have enough cumulative reservoir capacity to store more than the entire annual river flow. Despite the existence of 2,721 lakes greater than 1 km2, we found that about 50 lakes greater than km2 have formed on the Tibetan Plateau resulting from climate change. More than 350 lakes of ≥1 km2 vanished in four other major lake regions. Although the disappearance of lakes happened in the context of global climate change, it principally reflects the severe anthropogenic impacts on natural lakes, such as, the excessive plundering of water resources on the Inner Mongolia-Xinjiang Plateau and serious destruction (land reclamation and urbanization) on the eastern plains.

Periphyton: an important regulator in optimizing soil phosphorus bioavailability in paddy fields

“…Currently, the control of excessive nutrients from agricultural runoff to surface waters is an urgent matter (Yang and Lu 2014). This study demonstrated that the inclusion of periphyton benefited to reduce P content in the runoff of paddy systems and thus cut down the P loading discharged into natural waters.…”

MODIS-Derived Spatiotemporal Changes of Major Lake Surface Areas in Arid Xinjiang, China, 2000–2014

“…Water extents were found to have decreased significantly due to anthropogenic impacts, such as agricultural water consumption and damming in this region [24]. The Ebinur Lake, the largest salt lake in the XUAR, exhibited a significant inter-annual and inter-seasonal variation based on SPOT VEGETATION data [25]. However, due to the large area of XUAR, previous studies have mainly focused on selected water bodies and annual or seasonal temporal intervals.…”

“…Several studies have examined changes of lakes in the XUAR using satellite imagery, such as Landsat [22][23][24], SPOT VEGETATION [25], and MODIS [12,26] data. Landsat TM imagery has been used to interpret changes in area of inland lakes in Xinjiang over the period 1975-2007, but only selected lakes in spring and autumn seasons were analyzed [22].…”

Mechanisms of enhanced inorganic phosphorus accumulation by periphyton in paddy fields as affected by calcium and ferrous ions

“…Then, during the critical flowering and maturation stages of high P demand, plant-available P to rice is low. Consequently, P use efficiency is low in paddy fields, and these fields are an important nonpoint source of P runoff (MacDonald et al, 2011;Yang and Lu, 2014;Zhou and Zhu, 2003). Better management strategies based on a mechanistic understanding of P biogeochemical processes are needed to improve P use efficiency and reduce P discharged from paddy fields.…”