O Estado atual dos conhecimentos sobre os recursos de água do Nordeste

Resumo

            The work is divided up into 5 parts. The first, by way of introduction deals with appeciations of a general nature on water resources and their utilization, without attempting to situate the descriptions geographically.

            The second part refers to the important question of the availability and adequacy of basic factual information relating to the occurrence, characteristics, use and control of water resources; schedules, tables, graphs and maps are given to show what actually exists, what has already been done, and what is being done at present to acquire a systematic knowledge of the water resources in the nine states from Maranhão to Bahia inclusively by means of collecting data on rainfall, climate, underground water, fluvial regimen, evaporation, transpiration, quality of the water, meteorology, sediment transportation, etc. Discussions are presented on the need for the data and the adequacy of Áhat is available, and for each case specific suggestions and recommendations for improvement are put forward.

            In the third part another aspect of the present State of knowledge is discussed: the hydrological analysis and interpretation of basic data. The most widely used method for hydrologically scaling the dans and reservoirs built in the region is briefly described and criticized in this part.

            The tendency for losses by evaporation to increase with increasing control of the surface water and the interrelationship between the damming projects in a basin are discussed in the penultimate part of the report.

            Finally a concise scheme is set forth for pursuing the activities necessary to a general improvement of knowledge and to make good use of the water in the Northeast.

            The main generic conclusions to be drawn from the studies made are as follows:

1. Present knowledge of the surface and subterranean water resources of the Great Northeastern Region is very poor.
2. This deficiency is due to three direct causes: the first and main cause is the severe lack of basic hydrological data; the second, which depends partly on the first, is the absence of adequate studies and interpretative analysis of the information that is available; while the third is the lack of skilled technicians engaged in the study of the countless aspects of regional hydrology. ·
3. Though there are exceptions, the greater part of the information now available is based on work done 15 years ago or more. It the last decade, very little has been done in the way of systematically studying, or broadening the knowledge of water in the Northeast.
4. By statutory impositions and others, and also probably through ignorance of any other way of meeting certain demands for water, there is a tendency towards indiscriminate control of the river basins by daws; if this tendency grows, there may arise (and perhaps already have arisen in certain areas) serious problems, amongst others, a loss in availability of the water resources.
5. The methods (mentioned in this work) generally used for hydrologically scaling the daws in the Drought Polygon are inadequate and should be abandoned.
6. The underground stage of the hydrological cycle is extremely important for the Northeast; it is, however, little understood and neglected in the solution of many problems of water supply.

            The basic causes of the deficiencies observed in the present state of knowledge and utilization of water are varied, complex and interdependent; to discuss them all, in their various aspects, would need a whole chapter for this purpose only. One fundamental cause, however, stands out from the others, and that is the lack of formal recognition - on the part of the public administration, the technicians themselves and even the national, state and regional research and planning bodies - of the importance of the basic data and the necessity of systematically obtaining them.

            To bring about a change in this situation, it will be necessary:

1. To realize that in order to have water and use it well, the characteristics of its availability must be known; and knowledge demands observation, analysis and interpretation.
2. To have a technical staff, fully qualified and interested in tackling the manifold problems involved in the various stages of investigation and planning of use of water resources.
3. To have a bureau specifically interested in the water problems of the region and extraneous to any executive activity as regards the actual construction work, so as to reduce to a minimum any possibility of partiality, fluctuation in budget assignments and deflection of efforts towards such work at the expense of the collection and analysis of data.

            To this end, it is recommended:

1. a) That the training of technicians and auxiliary personnel should be promoted, and encouragement be given to undertaking of technical and scientific work in connection with water resources.
2. b) That a start be made as soon as possible on the planning and putting into practice of a system of collection of basic data covering every stage of the hydrological cycle, with especial emphasis, in the initial stage, on work on fluviometry, underground water, evaporation and pluviometry.
3. c) That there be organized, as part of the activities of the future Superintendency for Development of the North-East (SUDENE). a service or sector devoted to water research, mainly to be engaged in:

            1) Promoting, co-ordinating and pursuing activities related to the systematic knowledge and to the rational utilization and control of surface and underground water in the Great Northeastern Region; and

            2) Checking and diagnosing all isolated undertakings related to water resources that that have been programmed so as to situate them in global plans for the development of river basins and ground water reservoirs.

            To prepare this report various kinds, of information ware obtained including the compilation of data, reconnaissance trips, interviews and inquiries with public organization, etc. The authors gratefully recognize the unfailing goodwill displayed by technicians, administrators and civil servants belonging to such agencies as: the National Department of Anti-Drought Works; the Water Division, Meteorology Service and National Department of Vegetable Production, of the Ministry of Agriculture; the São Francisco Valley Commission; of the National Department of Reclamation Works; the Special Health Service; The Bank of the Northeast; the Petroleum and Energy Council (C.P.E.) of the state of Bahia; the Pernambuco Development Council (CODEPE), etc.

            Special recognition is due to the enthusiastic and efficient assistance received from Major Paulo Teixeira Costa of the Engineers, assigned by the Directorate of Ways of Transport of the War Ministry to collaborate with the Council on Development of the Northeast (CODENO) in this work.