ایجاد یک سیستم ترکیبی مدیریت منابع آبی در حوزه‌های آبریز جنوب آفریقا

Water resources management is a contentious challenge in Southern Africa. Scarce resources, often poor quality, unfavourable temporal and spatial distribution and competing stakeholders characterise the water resources in this region. The following general objectives and techniques are investigated: (a) Development of dynamic water balance and erosion models for three study catchments using remotely sensed and other data, (b) assessment of water demand and usage of the different user sectors and stakeholders, (c) design and simulation of “What if?” scenarios to investigate trends and interactions of the complex water resources planning process, and (d) development and implementation of strategies to solve water allocation conflicts. The product of the project, the prototype IWRMS, is an innovative computer based toolset designed as an assembly of tested, validated and well documented procedures comprising techniques of database management, remote sensing, GIS, process modelling, decision support and implementation strategies. The modelling results and first prototype installations in Southern Africa show the applicability of this system.

Water resources management in Southern Africa is a complex challenge which requires an appropriate integrated approach if strategic and prognostic planning should be based on sound scientific findings in order to optimise and conserve the precious land and water resources. Sustainable water resources management is of paramount economic and political importance for semi-arid Southern African countries. The climate in this region is characterised by precipitation patterns unfavourably distributed in space and time (Fig. I ) and high evapotranspiration rates reaching up to 90% of the incoming annual precipitation. As a result, water resources management is forced to balance the water supply between areas and times of water deficiency and those having a manageable water surplus. The proposed Integrated Water Resources Management System (IWRMS) will be a toolset of validated computer based procedures, integrated into a database-centred, spatial decision support system. Its concepts and components are shown in Fig. 2. 1.1 Study areas Three test catchments, reflecting typical water resources conflicts and being under enormous pressure for an improved management strategy, were selected and comprise the Mkomazi River in Kwazulu-Natal (A = 4400 km2) in South Africa, the Mbuluzi River (A = 3000 kn?) in Swaziland and the Mupfure (A = 12000 km*) in Zimbabwe (Fig. 1). A still strong diversity between communal (tribal, small scale farming, poor) and commercial (plantations, large scale farming and foresting, prosperous) land is significant for test areas like it is for most of the whole subcontinent. All three countries involved face the challenge of implementing a new water law, which is characterised by emphasising principles of Integrated Water Resources Management, mainly to improve equity in access to water resources for all people, and to strengthen the environmental demands.

A sophisticated Integrated Water Resource Management System for semi-arid catchments in Southern Africa has been outline. This system comprise (a) validated standard and new methods procedures to acquire information , (b) tools to analyse this information and simulate planning scenarios, (c) components to manage and present the information, (d) the information itself and (e) a comprehensive and open framework structure to integrate the components. Future activities will concentrate on the successful implementation of this assembly in the user community of the target region whereby one key feature is to structure the project’s results into a multilevel decision support according to the end-users’ requirement and prerequisites.