Abstract
The water-surface areas of the lakes in the mid-lower reaches of the Yangtze River, China, have undergone significant changes under the combined impacts of global climate change and local anthropogenic stress. As a typical lake in this region, the Honghu Lake features water-surface area variations that are documented in this study based on high–resolution remote sensing images from the 1990s to 2013. The impact of human activities is analyzed by a novel method based on land use data. The relative impacts of each driving force are further distinguished by the statistical analysis method. Results show that the water-surface area has significant inter-annual and seasonal variabilities, and the minimum of which generally occurs in spring. The degree to which climate factors and land use structure affect the water-surface area varies between different stages. In the April-May period, the sum of the water demands of paddies and aquaculture has a negative effect that is greater than the positive effect of the difference between the monthly precipitation and monthly evaporation. In the June–October period, the precipitation features a positive impact that is greater than the negative effect of the water demand of agriculture. Meanwhile, climate factors and human activities have no influence on the lake area in the November–March period. With the land use being altered when annual precipitations are close in value, paddy field areas decrease, ponds areas increase, and the water demand of agriculture rises in both flood and drought years. These findings provide scientific foundation for understanding the causes of water-surface area variations and for effectively maintaining the stability of the Honghu Lake area through adjustments in land use structure.
Highlights
Lakes are essential fresh water bodies, which are vital resource for human life and productive activities, and play an important role in the biogeochemical and hydrological cycles
To investigate the process by which these climate factors influence the lake’s water-surface area, we examine the relationship between the water-surface area and the monthly precipitation (P) and monthly evaporation (E), as well as the difference in the monthly precipitation and monthly evaporation (P–E), in the period between the 1990s and 2013
The increase in pond area heightens the water demand of agriculture, which leads to quick reduction of the water-surface area
Summary
Lakes are essential fresh water bodies, which are vital resource for human life and productive activities, and play an important role in the biogeochemical and hydrological cycles. The water inputs and outputs are affected by anthropogenic activities. Agriculture, industry and other human activities mainly affect the water-surface areas of lakes via land use change [1,2]. Due to climate change and anthropogenic activities, many inland lakes in China have undergone dramatic changes in both number and area during the past 30 years. The number of vanished lakes in the middle and lower reaches of the Yangtze River accounts for 40% of total loss of lakes in China, which is mainly attributed to human activities such as exploitation of fisheries, reclamation of land and construction of water conservancy [9].
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have