Proposed methods report for the Fitzroy catchment

Agricultural Land Planning

CSIRO

DOI  :  10.4225/08/58518a831c564
RP-ID  :  EP164619

学科分类：地球科学(综合)

澳大利亚|英语

来源: CSIRO Research Publications Repository

【 摘 要 】

The Northern Australia Water Resource Assessment will provide a comprehensive and integrated evaluation of the feasibility, economic viability and sustainability of water resource development in three priority areas in northern Australia: the Fitzroy catchment (Western Australia), the Darwin catchments (Northern Territory) and the Mitchell catchment (Queensland). Each Assessment seeks to:- evaluate the climate, soil and water resources- identify and evaluate water capture and storage options- identify and test the commercial viability of irrigated agricultural, forestry and aquaculture opportunities- assess potential environmental, social and economic impacts and risks of water resource and irrigation development.In addition, each Assessment is designed to:- address explicitly the needs and aspirations for local development- meet the information needs of governments as they assess sustainable and equitable management of public resources, with due consideration of environmental and cultural issues- meet the due diligence requirements of private investors, by exploring questions of profitability and income reliability of agricultural and other developments.The objective of this report is to broadly outline the methods proposed for the Assessment in the Fitzroy catchment. The purpose is to openly communicate the scope of the Assessment and the proposed methods to a wide range of stakeholders, to allow them to provide feedback and engage with the Assessment team. The report also provides a mechanism for the Assessment team to acquire feedback on the proposed methods, to ensure that they are fit-for-purpose. The actual methods that the Assessment will use may differ as more information becomes available and local nuances are better understood. The final methods will be documented in technical detail in the final technical reports.The Assessment comprises the following interrelated activities, which are discussed below.Climate opportunities and constraintsThe climate activity (Chapter 3) will seek to characterise the opportunities for water resource development, and agriculture and aquaculture production, in the context of current and future climates. The activity will generate several variants of 125 years of daily climate series representative of a 2.2°C temperature rise relative to 1990, guided by global climate models (GCMs) from the Intergovernmental Panel on Climate Change Fifth Assessment Report (AR5) for an RCP8.5 emissions scenario. Pattern scaling will be used to transform the broad-scale GCM outputs into catchment-scale variables that can be used by hydrological and agricultural simulation models.Availability of suitable soilThe land suitability activity (Chapter 4) will develop digital land suitability maps of the entire Fitzroy catchment, showing areas that are more and less suitable under different combinations of land use and irrigation systems, and aquaculture. The activity will employ statistically based digital soil mapping methods to rapidly and objectively generate 30 m × 30 m grids of a wide range of soil attributes (e.g. depth of soil, texture, pH). The digital soil mapping will be informed by a soil sampling campaign. The existing set of rules for different combinations of land use and irrigation systems, and aquaculture will be refined. The rules will be applied to the digital soil mapping grids and climate grids to generate land suitability maps of the catchment.Availability of waterThe availability of surface water across the Fitzroy catchment will primarily be assessed using three types of hydrological models: (i) landscape model (AWRA-L), (ii) river system model, and (iii) hydrodynamic model (MikeFlood) (see surface water hydrology activity, Chapter 5). The landscape model will be used to quantify water fluxes across the Fitzroy catchment. These fluxes will be used as input to the river system and hydrodynamic models. River system models are well suited to modelling regulated...