Adaptation of Cascade Hydropower Station Scheduling on A Headwater Stream of the Yangtze River under Changing Climate Conditions

Abstract

Abstract:Cascade hydropower stations are effective in water resource utilization, regional water allocation, and flood risk management. Under changing climate conditions, water resources would experience complex temporal and spatial changes, which may lead to various issues relating to flood control and water resource management, and challenge the existing optimal scheduling of cascade hydropower stations. It is thus important to conduct a study on cascade hydropower station scheduling under changing climate conditions. In this study, the Jinsha River rainfall-discharge statistical model is developed based on the statistical relationship between meteorological and runoff indicators. Validation results indicate that the developed model is capable of generating satisfactory simulation results and thus can be used for future Jinsha River runoff projection under climate change. Meanwhile, the Providing Regional Climates for Impacts Studies (PRECIS) is run to project future rainfall in the Jinsha River basin under two General Circulation Models (ECHAM5 and HadAM3P), two scenarios (A1B and B2), and four periods (1961-1990, 1991-2020, 2021-2050, and 2051-2099). The regional climate modeling data are analyzed and then fed into the Jinsha hydrological model to analyze the trends of future discharge at Xiangjiaba Hydro Station. Adaptive scheduling strategies for cascade hydropower stations are discussed based on the future inflow trend analysis and current flood scheduling mode. It is suggested that cascade hydropower stations could be operated at flood limited water level (FLWL) during 2021-2099. In addition, the impoundment of cascade hydropower stations should be properly delayed during the post-flood season in response to the possible occurrence of increased and extended inflow in wet seasons.

Adaptation Strategies for Water Resources: Criteria for Research

“…Furthermore, when studies investigating future adaptation scenarios do not provide elements to manage the uncertainty specifically related to the proposed adaptation solution, exploring uncertainty related to the climatic and impact scenarios (using different IPCC emission scenarios) is strongly recommended. Two examples of complete development of adaptation scenarios, at least as regards the climatic and impact scenarios, are provided by Guyennon et al (2017) and Zhai et al (2017).…”

“…In particular, the discussion of uncertainty of the provision of implementation guidance to adaptation actions has never been faced. Only two studies [9,11] identify, propose, discuss, and develop an adaptation scenario. Five other studies [10,14,[16][17][18] belong more properly to the category "Climate change impact studies".…”

“…The parties affirmed that "adaptation must be addressed with the same priority as mitigation" [1,2]. Under this framework, the COP invited "all Parties to enhance action on adaptation" [1][2][3][4][5][6][7][8][9][10][11][12][13][14] by "planning, prioritizing and implementing adaptation actions, including projects and programs" [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. The Paris agreement (COP21) provided numerous indications and details about adaptation, mainly in Article 7 [2].…”

Floodwater Utilization Based on Reservoir Pre-Release Strategy Considering the Worst-Case Scenario

“…The main tributaries in the upper reaches are the Yanzi River, Songjia River, and Jiangjia River. The reservoir basin covers a drainage area of 1400 km 2 , the average annual rainfall in the reservoir area is 1497 mm, the average annual runoff depth is 777 mm, and the annual runoff volume is 1.088 billion m 3 , approximately 20% of which occurs in July. Xianghongdian Reservoir suffered 30 large and small floods from 1998 to 2006; the statistics are shown in Table 1.…”

“…Together with the unreasonable exploitation and utilization of water resources, many countries and regions suffer from water shortage in varying degrees, which may substantially restrict their economic and social development. The utilization of floodwater resources in the flood season is an important way to alleviate regional water resource shortages [1][2][3]. As a common component of a watershed system, reservoirs play an important role in utilizing floodwater resources.…”