IWRA Proceedings

AbstractSURFACE WATER MANAGEMENT FROM BÂRLAD WATERSHED Authors: Gheorghe Purnavel Soil Erosion Control Research and Development Centre Perieni, E-mail perieni@spectral.ro, Fax. 0235412837 “Craving for water” of the humanity or perspective of “water crises” is term, which appear more frequently in prognosis studies of different international and national organisms. In our country areas, which are in difficulty with surface and underground water sources, by the INMH study, are located in central part of Dobrogea and Moldavian Tableland and us a result these resources must be careful utilised and protected quantitative and qualitative. Hydrographical network of Barlad River with 2,565 km length and 7,220 km2 drain the Central Moldavia Tableland and Tutova Hill’s area through Barlad River and their most important affluent The Central Moldavia Tableland and Tutova Hills, like subdivision of Moldavian Tableland, drained by Barlad River are strongly affected by erosion processes that have a great impact under the quantitative and qualitative surface water from this area. The management of surface water from Barlad watershed are assured by Vaslui Water Management System, like a subdivision of Water Direction Prut from Romanian Environment Minister. Soil Erosion Control Research and Development Centre Perieni are involved in surface water management from Barlad watershed through a study concerning hill lake sedimentation’s and water quality of them under impact of soil erosion processes. In the studied reservoirs, sedimentation processes are due to the deposit of sediments from the main water supply of the reservoir and of those that are due from erosion from hill slopes and watersheds located nearby of the reservoir. Degradation of water quality is mainly due to decreasing of water depth and natural adding of fertilises elements. Regarding sedimentation of Cuibul Vulturilor reservoir it comes out that: Rate of sedimentation reservoir was of 32.63 % with 2.33% average ratio by year: Sedimentation ratio by year is of 221,430-cm. in comparison with 10,000 cm. who was anticipated in 1977; The bigger sediment effluence provide from the little watersheds who are directly coming into the reservoir (7.93–9.87 to/hectares from the direct slopes and 1.8–30.5 to/ha from these kind of little watersheds. Regarding water quality degradation of Cuibul Vulturilor reservoir it comes out that: In June, when the level of precipitation is higher, the value of nitrogen, phosphorus and potassium concentration is also higher; The higher concentration value of studied elements are recorded on the laterally inputs; The comparative analyze of tow situation watershed with erosion control works and same watershed without erosion control works, set of some conclusions: The erosion are reduced under acceptable limits (17.2 m3/ha without erosion control works relative to 3.9 m3/ha with erosion control works); A proper cultivation structure mixed with erosion crop system reduced erosion and sediment effluence with 20%; A good erosion control works capitalized efficiently rainfall, surface runoff are reduced with 11-30%; An adequate reclamation of outlet network reduces gully erosion with 60%; Ensemble of land reclamation (cultivation structure, erosion crop system, erosion control works on outlet network) reduces erosion and sediment effluence with 23%