Water is the foundation of all ecosystems, whether terrestrial or aquatic. In terrestrial ecosystems freshwater not only provides critical water supply for transpiration during plant photosynthesis and drinking water for animals, but also transports, redistributes and stores energy, nutrients and contaminants. In aquatic and snow ecosystems, water is the medium in which the ecosystem functions and so its state mediates all transactions in these systems. Ecosystems are not passive responders to water but through their structure and function can manage water and associated microclimate – forests, grasslands, organic terrain wetlands, and beaver ponds being just a few examples.
This chapter will examine the surface water budget in terms of the water continuity equation as a manifestation of the hydrological cycle. To solve the continuity equation for water, the chapter will review hydrological processes and how they interact with vegetation, animals, soils, geomorphology and climate in the context of the catchment. The coupling of the mass and energy continuity equations in controlling hydrological processes will be discussed. How hydrological processes and their ecosystem interactions are managed by humans will be introduced. Then the chapter will review calculation schemes for the surface water budget via one-dimensional land surface schemes and catchment-based hydrological models, noting the data requirements, uncertainty and limitations of these models and the balance required between model complexity and physical representation of hydrology. This will give the conceptual ideas and basic mathematics of conservation laws and transport processes that form the basis of many models in the forthcoming chapters.
Hydrological Processes as a Fundamental Component of Aquatic and Terrestrial Ecosystems
The hydrological cycle is the flow and storage of water, as liquid, solid or vapor, on and near the Earth's surface. This cycling is a fundamental function of the Earth system and, through its associated latent energy transformations and other influences on land surface characteristics, ensures the habitability of the planet. A representation of the global hydrological cycle is found in Figure 4.1 where it can be seen that there are substantial flows between ocean and land – evaporation and river discharge from land transfer water directly to the oceans or through precipitation and ocean water is evaporated and then forms precipitation over land.
The Association of Southeast Asian Nations (ASEAN) is committed to deepening and broadening its internal economic integration and linkages, with the participation of the private sector, to realise an ASEAN Economic Community by 2010, ASEAN's endgoal. The fishery sector is one of the 11 priority sectors identified by ASEAN Leaders. Roadmaps have been developed to ensure that the various measures are effectively and aptly implemented to create an integrated market and production base for each of these sectors. The implementing guidelines fall under two categories: (1) common measures, which cut across all the 11 priority sectors; and (2) specific measures, which have direct relevance to a specific sector. This paper discusses the Roadmap for Integration of the Fisheries Sector, including the results of the key informant interviews conducted by the WorldFish Center's research team in 7 out of the 10 ASEAN countries visited. The paper also includes insights on the existing common and specific measures contained in the roadmap, as well as recommendations on some additional strategies that can help hasten the implementation of the roadmap agreement in member countries.
In December 1997, ASEAN Heads of State and Government unveiled the ASEAN Vision 2020. This document, among other things, envisioned a more economically integrated ASEAN. In particular, the ASEAN Vision 2020 foresees a stable, prosperous, and highly competitive regional economic area where there is free movement of goods, services, investments, and capital. Hence, the concept of an ASEAN Economic Community (AEC) would seem to be consistent with the economic aspect of this Vision.
Under this initiative, the AEC will see the ASEAN becoming a single market and production base. The diversity that characterises the region will be turned into opportunities and business complementation to make ASEAN a more dynamic and stronger segment of the global supply chain and world economy. It attempts to combine the economic strengths of member states for regional cohesiveness and enhanced global competitiveness by accelerating the integration of the various economic sectors in the member countries.
Email your librarian or administrator to recommend adding this to your organisation's collection.