Lake Inflow Simulation Using the Coupled Water Balance Method and Xin’anjiang Model in an Ungauged Stream of Chaohu Lake Basin, China

Water resources are crucial for maintaining daily life and a healthy ecological environment. In order to gain a harmonious development among water resources and economic development in Lake Watershed, it is urgent to quantify the lake inflow. However, the calculation of inflow simulations is severely limited by the lack of information regarding river runoff. This paper attempts calculated inflow in an ungauged stream through use of the coupling water balance method and the Xin’anjiang model, applying it to calculate the inflow in the Chaohu Lake Basin, China. Results show that the coupled model has been proved to be robust in determining inflow in an ungauged stream. The error of daily inflow calculated by the water balance method is between 1.4 and −19.5%, which is within the standard error range (±20%). The calibration and verification results of the coupled model suggest that the simulation results are best in the high inflow year (2016), followed by the normal inflow year (2007) and the low inflow year (1978). The Nash-Sutcliffe efficiencies for high inflow year, normal inflow year, and low inflow year are 0.82, 0.72, and 0.63, respectively, all of which have reached a satisfactory level. Further, the annual lake inflow simulation in the normal inflow year is 19.4 × 108 m3, while the annual average land surface runoff of the study area is 18.9 × 108 m3, and the relative error is −2.6% by the two ways. These results of the coupled model offer a new way to calculate the inflow in lake/reservoir basins.

Assessment of Land Ecological Security and Analysis of Influencing Factors in Chaohu Lake Basin, China from 1998–2018

The land ecosystem provides essential natural resources for the survival and development of human beings. Therefore, land ecological security (LES) acts as a vital part of the sustainable development of human society and economy. This study included a dynamic analysis of land use change in Chaohu Lake Basin (CLB) in China from 1998 to 2018, evaluating the spatiotemporal patterns of LES at both the administrative district scale and grid scale (200 m × 200 m). Then, geographic detector was applied to analyze the influence of the assessment index on LES. The results show that in the 2008–2018 period, land use changed more significantly compared to the 1998–2008 period. The continuous extension of urban land led to a decrease in the areas of other land use types. In the CLB (administrative district scale), the LES levels varied throughout the study period. In Changfeng, Feixi, and the other three regions, the LES has been significantly improved. However, the LES in six other regions showed different degrees of decline, particularly in Hexian and Urban Hefei. Simultaneously, the LES showed a gradual improvement at a 200 m × 200 m grid scale level. The influence of anthropogenic factors on the LES was stronger than natural factors. Findings from this study provide reliable guidance for improving the ecosystem environment in ecologically fragile areas.

Evaluation of Sustainable Regional Development Combining Remote Sensing Data and Ecological Constraints: A Case Study of Chaohu Basin, China

The maintenance of sustainable development in light of climate change is presenting society with a serious challenge. This study analyzes the spatial environment and its coupled relationship with socio-economic and food security in the Chaohu Lake Basin in central Anhui Province, China. Previous studies have shown that this study area has good environmental conditions. However, the ecological security, economic development, and food security in the Chaohu Lake Basin was generally poor and poorly coordinated in 2018, especially in the center of local cities and surrounding areas. Nevertheless, many towns are in a well-organized state, meaning sustainable and coordinated regional development can be achieved through resource optimization. Generally, the economic conditions in the Chaohu Lake Basin should be improved in a way that ensures that the environment is not significantly degraded. The main functional zoning requirements of the counties’ land management planning designate most of the counties as parts of ecological conservation areas. The present study provides monitoring of important basin ecosystems and serves as a guide to future sustainable regional development by providing directions and paths to follow; it can also provide a reference for eco-functional zoning that is applicable to various natural basins worldwide.