Research on Comprehensive Evaluation and Coordinated Development of Water Resources Carrying Capacity in Qingjiang River Basin, China

The protection of a water resource’s ecological environment is one of the most important tasks in the watershed in China. The evaluation of water resources carrying capacity (WRCC) is the foundation for the suitability of territorial space development. It is necessary to further analyze the weaknesses of the coordinated development of various dimensions of WRCC and explore the basis of territorial space development and optimization. This paper considers Chinese unique policy tasks, namely, “three water management together”, the types of main function areas, “red lines” control, and national spatial suitability evaluation, to construct the evaluation index system of WRCC. Monomial evaluation, integrated evaluation, and coupling coordination analysis methods are used separately to evaluate the carrying index, comprehensive carrying index, and coupling coordination degree of WRCC in the Qingjiang River Basin. The results show that: (1) As far as monomial evaluation is concerned, water resource supplies are often overloaded on the overall economy, industrial, and agricultural development; (2) The comprehensive indices of WRCC of the counties in the southwest are obviously better than that of the counties in the northeast; (3) The degree of coupling coordination of WRCC in the Qingjiang River Basin is not high, and is essentially in the primary or barely coordinated level; (4) the short board of WRCC in the Qingjiang River Basin presents obvious spatial characteristics, which from west to east are water environment, water resources and water ecology lagging, respectively. This paper measures WRCC for industry, agriculture, life, and ecology, which is helpful in promoting the suitability evaluation of land space development. Meanwhile, the case study of the Qingjiang River Basin provides reference for other regions to implement the “double evaluation”.

Longitudinal variation characteristics of stable isotope ratios of suspended particulate organic matter in the headwaters of the Qingjiang River, China

To determine the sources and characteristics of suspended particulate organic matter (SPOM), the spatial distribution of carbon and nitrogen and their isotopic values (δ13C and δ15N) were measured from upstreamto downstream (i.e. site 1 to site 4) in the head waters of the Qingjiang River in central China. The mean annual SPOM δ15N and δ13C values varied between sites but exhibited a unimodal pattern. The mean annual δ15N increased from site 1 (2.5‰) to 3 (5.3‰), followed by a major decrease to 2.2‰ at site 4. Furthermore, the mean annual δ13C varied unimodally, being the most positiveat sites 1 (−21.6‰) and 4 (−22.8‰) followed by sites 2 (−24.5‰) and 3 (−26.4‰). In particular, the mean SPOM δ15N and δ13C in the tailwaters from a domestic wastewater treatment plant, which was located approximately 0.3 km upstream of site 4, were 2.2‰ and −25.6‰, respectively. The SPOM C/N values from stream water at site 4 (8.5 ± 1.5) and tailwater (6.2 ± 0.9) were similar. Collectively, the results suggested that wastewater treatment plant tailwater influenced the stable isotope values of SPOM in the stream and affected the variation trendfrom upstream to downstream.

Research on Various Operation Modes of Geheyan Hydropower Station Reservoir in the Qingjiang River

According to the characteristics and main task of the Geheyan hydropower station reservoir in the Qingjiang River, the problem of how to use reservoir storage capacity to cope with the contradictions between the flood control and power generation, reliability and economy of hydropower station, the supply and demand of power when runoff cannot be accurately forecasted. Aiming at these problems, various operation modes of Geheyan hydropower station are presented in this paper. In order to pursue maximizing generation benefit, considering both hydro condition and adjust peak requirement of power system, the expected benefit as the objective function is presented. Comparisons are conducted for three various operation modes. The results show that dynamic programming successive approximations (DPSA) is better than other algorithms, whose average annual generation and generating guarantee rate increase obviously compared to the effects of other algorithms.