Vízügyi Közlemények, 2004 (86. évfolyam)

1-2. füzet - Orlóci István: A közösségi vízgazdálkodás felé

A közösségi vízgazdálkodás felé 65 Hungary (Figures 11 and 12). The changing area of the forests is a deterministic element of the landscape development of the Hungarian lowlands (Figure 15). Combining the demand for "more forest" with the "give space to excess water, turn it to wetland" concept one could achieve an up-to-date landscape development and give a chance to economic growth as well. Our river valleys have outstanding natural and ecological values even at allEuropean scale, disregarding the fact that all rivers have been regulated long ago or nowadays and some 70 km river length is impounded. The canalisation of the rivers Tisza and Körös-system was justified primarily by the provision of irrigation water to the agriculture, to crop production, which is fighting drought in a continuous basis. Figure 13 shows the variation of water shortage of meadows and grasslands within the growing season, which can also be considered valid to the natural vegetation. In the more peaceful countries of Europe river regulation has started in the 16th and 17th centuries. In the Danube Basin one had to create in the deteriorated marshland-type region of the size of a country a new social-habitat, in the 18-19th centuries. The strong will to remain alive was the main force in controlling floods and formed the basis of the growth of the population (Figures 1 and 14). Thus the main activity was the fighting of floods, while the utilisation of rivers started a bit later. In the past one and half centuries river training works made for controlling floods and ice-conveyance and for enhancing navigation (Table VII.) had cut the length of our rivers by one-third and the rivers started their new life in artificial excavated channels at many reaches. These man-made channels are, sometimes considered today as the natural state. The total length of more than 4000 km of the new system of levees, built along with the river training works, created a new flood channel that involved also the former flood-plains. River regulation and the agricultural activities made on the flood-plains have changed the natural conditions and created new social and life conditions as well. Flood levees have sot to say separated the population from the rivers and the successful fighting of floods had created a false feeling of security. These notional factors still have their effects today in dealing with the economic development of flood prone areas. Earlier rivers were considered as natural (and energy) resources the usefulness of whose was determined by the frequency and magnitude of flooding. As contrasted to this the rivers became the source of danger, the causes of life-risks, when their flood-plains were built-in and used for agricultural production. The primary task of integrated river basin management is establish the mutually beneficial inter-relations of the people, the river, and the landscape with the use of a proper information and management system (of monitoring, planning, dissemination, public-hearing, etc.) and maintain the operation of the whole system. The tasks of managing our rivers are set by restrictive constrains and options of useful features. Namely, one should apply new methods for sustaining the protection ability of the flood control system; for the meeting of water demands, for securing the structures and functions of the ecosystem; for securing communal water supply