Quantification of effects of climate variations and human activities on runoff by a monthly water balance model: A case study of the Chaobai River basin in northern China

The Chaobai River basin in northern China consists of two major tributaries, the Chao River and Bai River. Monthly observations of precipitation, streamfiow, and panevaporation data are available for 35 years (1961-1966 and 1973-2001). Using the annual time series of the observed streamfiow, one break point at 1979 is detected and is adopted to divide the data set into two study periods, the "before" and "after" periods marking the onset of significant anthropogenic alteration of the flow (reservoirs and silt retention dams, five times increase in population) and significant changes in land use (conversion to terraced fields versus sloping fields). The distributed time-variant gain model (DTVGM) was used to evaluate the water resources of the area. Furthermore, the Bayesian method used by Engeland et al. (2005) was used in this paper to evaluate two uncertainty sources (i.e., the model parameter and model structure) and for assessing the DTVGM's performance over the Chaobai River basin. Comparing the annual precipitation means over 13 years (1961-1966 and 1973-1979), the means of the second period (1980-2001) decreased by 5.4% and 4.9% in the Chao River and Bai River basins, respectively. However, the related annual runoff decreased by 40.3% and 52.8%, respectively, a much greater decline than exhibited by precipitation. Through the monthly model simulation and the fixing-changing method, it is determined that decreases in runoff between the two periods can be attributed to 35% (31%) from climate variations and 68% (70%) from human activities in the Chao River (Bai River). Thus, human impact exerts a dominant influence upon runoff decline in the Chaobai River basin compared to climate. This study enhances our understanding of the relative roles of climate variations and human activities on runoff. © 2009 by the American Geophysical Union.published_or_final_versio

Modeling the Total Allowable Area for Coastal Reclamation : a case study of Xiamen, China

Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Ocean & Coastal Management 76 (2013):38-44, doi:10.1016/j.ocecoaman.2013.02.015.This paper presents an analytical framework to estimate the Total Allowable Area for Coastal Reclamation (TAACR) to provide scientific support for the implementation of a coastal reclamation restriction mechanism. The logic of the framework is to maximize the net benefits of coastal reclamation subject to a set of constraints. Various benefits and costs, including the ecological and environmental costs of coastal reclamation, are systematically quantified in the framework. Model simulations are developed using data from Tongan Bay of Xiamen. The results suggest that the TAACR in Tongan Bay is 5.67 km2, and the area of the Bay should be maintained at least at 87.52 km2.The study was funded by the National Oceanic Public Welfare Projects (No. 201105006) and the Fujian Natural Science Foundation (No. 2010J01360

Urban, agricultural, and environmental protection practices for sustainable water quality

Sustainable water management often emphasizes water resource quantity, with focus on availability and use practices. However, only a subset of the available water may be usable when also considering water quality. Water quality management is examined within three broad sectors—urban, agriculture, and environmental systems—to investigate how water quality sustainability (WQS) is defined by each and across the three sectors. The definitions determined for both urban and agricultural WQS mention downstream human and ecosystem use; however, regulatory policy does not always support these definitions. This challenge of managing water quality locally and downstream, coupled with interactions across multiple sectors, has led to a fragmented approach to water quality management. Legislation typically divides water quality management into compartments without considering the entire system. Within the United States, there is an uneven distribution of responsibility regarding water quality protection, and notable policies which counteract efforts to improve water quality. The review suggests that despite a growing intention to use a single system approach where water is considered as a limited resource that must supply all competing interests, one does not yet exist and is even hindered by current policies and regulations. Recent policy is signaling a shift toward increasing interagency coordination; however, the basic definitions of WQS remain disconnected across sectors. It is the conclusion of this review that sustainable water quality is not currently practiced in the United States

Data accompanying the article: "Analytical model captures intratidal variation in salinity in a convergent, well-mixed estuary"

Salinity data of the Humen Estuary, Guangdong, China Survey data courtesy of the Guangdong Province Hydrology Bureau and the Pearl Hydrology Bureau from the River Conservancy Commission

Sanmenxia multipurpose hydraulic project

Sanmenxia hydro-junction is the first sizable water conservation project constructed on the Yellow River’s main stream during the socialist revolution and construction period following the foundation of new China. Due to lacking understanding and experience with sediment-laden water rivers, after the project was constructed in 1960, it was reconstructed and/or modified twice. This paper presents the case study of the Sanmenxia project.</p