ASSESSING CLIMATE CHANGE LINKAGES RELATED TO WATER QUALITY TRADING EFFECTIVENESS FOR INCORPORATING ANCILLARY BENEFITS

摘要

Climate change effect on water quality performance of lakes, rivers and streams is a significant concern for watershed planning and management. Climate change characteristics may potentially increase the likelihood that waterbodies will fail to meet established water quality standards, often obligating watershed managers to undertake expensive monitoring and load allocation studies for possible remedies against such impairment. One such load allocation study involves the implementation of water quality trading (WQT), which often is proposed as a mechanism for improving surface water quality goals under a socially and economically feasible manner. However, while future growth and land use change is incorporated through a margin of safety, WQT markets do not typically incorporate the characteristics of climate change that have been suggested to exhibit strong linkages against achieving the desired levels of water quality benefit. Consequently, this modelling study evaluates the characteristics of climate change upon the levels of water quality benefit along a river system subject to distinct load removal exercises: a) removal upon point sources only and b) removal based on a point-nonpoint source trading mechanism under a theoretical WQT program. This study applies such assessments upon the load allocation exercises through carbonaceous biochemical oxygen demand reduction for addressing a recognized dissolved oxygen problem along the Jordan River in Utah, conducting such analyses through selected climate change projections described by the representative concentration pathways. For achieving such tasks, separate simulations are conducted through the Water Quality Assessment Simulation Program, evaluating the performance of such trading mechanisms under observed meteorological data against modelled climate data through selected representative concentration pathway projections under a historical period from Water Year 2007 to 2009. This exercise assesses the performance of such load allocation studies subject to climatic characteristics toward suggesting linkages among climate change, water quality benefit and the effectiveness of a theoretical WQT mechanism.