1. Utilisation of en international watercouroe [system) in an equitable and reasonable manner within the meaning of article 6 requires taking into account all relevant factors and circumstances, includingt (a) geographic, hydrographic, hydrological, climatic and other factors of a natural character; (b) the social and economic needs of the watercourse States concernedt (c) the effects of t.he use or urms OF a11 internetional watercourse [eyatem] in one watercourse Stata on other watercourse States; (d) existing and potential uses of. the international watercourse [system] t - 139 -(0) aoneervetion, protection, development and economy of use of the water resouroes of the international wateraourse [system] and the aoets of measure8 taken to that ef feat a (f) the availability of alterna*ivea, of corresponding value, to a partkular planfled or existing u&e, 2. In the application of arl.icle 6 or paragraph 1 of the preeent article, watercourse States concerned shall, when the need arises, enter into consultetions in 8 spirit of co-operation. Weteraourse States shall utilise an intrrnational wateraourse [system] in such a way 88 not to cause appreciable harm to other watercouree States. voblicratioa.. co-aa9rate Watercourse States ehall co-operate on the baais of sovereign equality, territorial integrity and mutual benefit in order to attain optimum utili0ation and adequate protection of an international watercouree [system 1. 1. Pursuant to article 9, watercourse States shall on a regular basis exahange reasonably available data and information on the condition of the watercourse [system], in particular that of a hydrological, meteorological, hydrogeological and ecological neture, a8 well a8 releted forecasts. Jl.291 This article is based on article 9 a6 proposed by the previous Special Rapporteur in 1984. lw This article is based on article 10 as proposed by the previous Special Rapporteur in 1987. lil/ Thin article is based on article 15 [16] as proposed by the Special Repporteur in l.PflB.