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1. Study on the streamflow compensation characteristics of reservoirs in Luanhe River Basin based on Copula function.

Author

Fang Wan, Lingfeng Xiao, Qihui Chai, and Li Li

Subjects
COPULA functions, WATERSHEDS, STREAMFLOW, WATER supply, WATER security
Abstract

With the rapid development of economy and society, the contradiction between supply and demand of water resources is increasing. Efficient utilization and allocation of limited water resources are one of the main means to solve the above contradictions. In this paper, the multidimensional joint distribution of natural streamflow series in reservoirs is constructed by introducing the mixed Copula function, and the probability of wet and dry encounters between natural streamflow is analyzed. Luan River is located in the northeastern part of Hebei Province, China, taking the group of Panjiakou Reservoir, Douhe Reservoir and Yuqiao Reservoir in the downstream of Luan River Basin as an example, the probabilities of synchronous and asynchronous abundance and depletion of inflow from the reservoirs are calculated. The results show that the probability of natural streamflow series between reservoirs is 61.14% for asynchronous wetness and dryness, which has certain mutual compensation ability. Therefore, it is necessary to minimize the risk of water supply security in Tianjin, Tangshan and other cities, and strengthen the optimal joint water supply scheduling of reservoirs. The research results are reasonable and reliable, which can provide reference for water supply operation of other basins. [ABSTRACT FROM AUTHOR]

Published
2022
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2. São Paulo drought: trends in streamflow and their relationship to climate and human-induced change in Cantareira watershed, Southeast Brazil.

Author

Nicoleti de Freitas, Gabriela

Subjects
*CLIMATE change, *REFORESTATION, *DROUGHTS, *WATER supply, *STREAMFLOW, *LAND use mapping
Abstract

The 2013-2015 drought in the Metropolitan Region of São Paulo exposed the lack of resilience of the regional water supply system, highly dependent on the Cantareira reservoirs. In this paper, inflows to each of the four main Cantareira reservoirs are tested for systematic change. Persistent trends in streamflow, rainfall, temperature and evapotranspiration are first evaluated. Streamflow was also tested for step change. Double-mass curves were employed to assess modification in the precipitation-runoff relationship. Subsequently, we used the climate elasticity method and the ABCD model to quantify the relative contribution of climate and human activities into the detected trends. Only Cachoeira and Atibainha sub-basins showed a significant downward trend in streamflow. The results for step change were also significant, and the year of occurrence coincided with breakpoints in precipitation-runoff relationship. For both Cachoeira and Atibainha, human activities had a more significant impact on streamflow reduction than climate variability. Land use and cover maps suggest that the reduction of pasture/abandoned land parallel to an increase in reforestation/silviculture is behind streamflow reduction. The results highlight the importance of coordinating land-use patterns and water management, as an important contributor beyond any considerations of a changing climate. Implications for better managing regional water resources are discussed. [ABSTRACT FROM AUTHOR]

Published
2020
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3. Baseflow estimation in typical catchments in the Yellow River Basin, China.

Author

Caihong Hu, Dong Zhao, and Shengqi Jian

Subjects
RIVER conservation, STREAMFLOW, WATER supply, ENVIRONMENTAL protection, STANDARD deviations
Abstract

Baseflow is crucial to maintaining river flow during low-rainfall periods. The baseflow estimation is important to water supply and ecological environmental protection in the Yellow River Basin (YRB), China. This paper comprehensively assessed the applicability of four single-parameter digital filtering, recursive digital filtering, and HYSEP (streamflow hydrograph separation) methods across four typical catchments in the Yellow River Basin: the Zuli River Basin, the Kuye River Basin, the Tuwei River Basin, and the Jingle sub-basin. We also investigated annual and monthly variations in baseflow. We found the standard deviation and coefficient of variation of baseflow index through recursive digital filter were relatively small. And the baseflow process line was smoother and more reasonable in typical year and typical storm-flood events, which conformed to the damping and hysteresis effect of the underlying surface. Thus the recursive digital filter method had the best performance, which was recommended for baseflow separation in the YRB. The estimated baseflow index of typical basins were between 0.354 and 0.502. In addition, inter-annual baseflow showed a decreasing trend and intra-annual baseflow was characterized by uneven distribution, which was subject to the characteristics of each basin. [ABSTRACT FROM AUTHOR]

Published
2021
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4. Implications of Climate Change for Water Resources Development in the Ganges Basin

Author

Jorge Jose Escurra, N. Harshadeep, Don Blackmore, Marc Jeuland, and Claudia Sadoff

Subjects
STREAMFLOW, GENERAL CIRCULATION MODEL, RIVERS, WATER CONSUMPTION, COASTS, FLOW, CANALS, EMISSIONS TRENDS, Geography, Planning and Development, RIVER BASINS, EMISSIONS SCENARIOS, GASES, GROUNDWATER RESOURCES, WATER MANAGEMENT SYSTEMS, LARGE DAMS, CONVERGENCE, WATER, Water cycle, RAINFALL, LAND USE, MONSOONS, EMISSIONS, Water Science and Technology, MUNICIPAL WATER, EVAPOTRANSPIRATION, EMISSIONS SCENARIO, SEAWATER, ANNUAL RAINFALL, WATER AVAILABILITY, WATER RESOURCE, TEMPERATURE CHANGE, CATCHMENTS, EVAPORATION, WATER DEMAND, WATER POLICY, SURFACE RUNOFF, AVAILABLE WATER, CRU, Downscaling, FLOW AUGMENTATION, GROUNDWATER IRRIGATION, HYDROPOWER POTENTIAL, WATER USES, CRYOSPHERE, POWER PLANTS, WATER MANAGEMENT, HYDROLOGIC REGIME, AQUIFER, Management, Monitoring, Policy and Law, COVERING, IRRIGATION SYSTEMS, WATERS, HYDROPOWER PRODUCTION, Water scarcity, CAPACITY, WATER USE PATTERNS, REMOTE SENSING, LEAD, HYDROLOGY, CATCHMENT, GLACIERS, SURFACE WATER, SALINE INTRUSION, GLOBAL WARMING, WATER CYCLE, WATER SHORTAGE, METERS, WATER RESOURCES DEVELOPMENT, RAIN, AQUIFERS, ATMOSPHERE, GCM, WATER ALLOCATION, CLIMATIC VARIABILITY, ENVIRONMENTAL ISSUES, SNOW, CLIMATE DATA, Water resource management, GREENHOUSE, HYDROLOGICAL RESPONSE, HYDROLOGICAL DATA, HYDROLOGICAL MODEL, DOMESTIC WATER, GROUNDWATER, CLIMATE RESEARCH UNIT, CLIMATE CHANGE, ENERGY PRODUCTION, FLOODING, ENGINEERING, WATER STORAGE, RIVER BASIN, WATER MANAGERS, HYDRODYNAMICS, ENERGY, Water balance, WATER TOWERS, CLIMATE VARIABILITY, FORESTS, SURFACE WATER IRRIGATION, IRRIGATION, LESS, RUNOFF, INDIRECT RECHARGE, TEMPERATURE, DROUGHT, IPCC, ALTERNATIVE ENERGY, STORAGE CAPACITY, PRECIPITATION, GROUNDWATER RECHARGE, WATER SYSTEMS, IRRIGATORS, SEDIMENT LOAD, CLIMATOLOGY, GREENHOUSE GASES, CLEAN ENERGY, WATER YIELD, Climate change, WATER REQUIREMENTS, HYDROLOGIC CYCLE, FLOOD DAMAGE, BASINS, BENEFITS, RIVER DELTAS, SNOW MELT, DAMS, Hydrology, WATER ALLOCATIONS, FLOODS, Global warming, WATER SUPPLY, WATER USE, NATURAL RESOURCES, Water resources, CLIMATE, CLEAN ENERGY TECHNOLOGY, COASTAL AREAS, INTERNATIONAL WATERS, WATER RESOURCES, Environmental science, ECOSYSTEM, Climate model, RESERVOIRS, EMISSION
Abstract

This paper presents the first basin-wide assessment of the potential impact of climate change on the hydrology and production of the Ganges system, undertaken as part of the World Bank’s Ganges Strategic Basin Assessment. A series of modeling efforts, downscaling of climate projections, water balance calculations, hydrological simulation and economic optimization, inform the assessment. The authors find that projections of precipitation across the basin, obtained from 16 Intergovernmental Panel on Climate Change-recognized General Circulation Models are highly variable, and lead to considerable differences in predictions of mean flows in the main stem of the Ganges and its tributaries. Despite uncertainties in predicted future flows, they are not, however, outside the range of natural variability in this basin, except perhaps at the tributary or sub-catchment levels. The authors also find that the hydropower potential associated with a set of 23 large dams in Nepal remains high across climate models, largely because annual flow in the tributary rivers greatly exceeds the storage capacities of these projects even in dry scenarios. The additional storage and smoothing of flows provided by these infrastructures translates into enhanced water availability in the dry season, but the relative value of this water for the purposes of irrigation in the Gangetic plain, and for low flow augmentation to Bangladesh under climate change, is unclear.

Published
2013