The livelihoods of poor people living in rural areas of Indus Basin Irrigation System (IBIS) of Pakistan depend largely on irrigated agriculture. Water duties in IBIS are mainly calculated based on crop-specific evapotranspiration. Recent studies show that ignoring the spatial variability of factors affecting the crop water requirements can affect the crop production. The objective of the current study is thus to identify the factors which can affect the water duties in IBIS, map these factors by GIS, and then develop the irrigation response units (IRUs), an area representing the unique combinations of factors affecting the gross irrigation requirements (GIR). The Lower Chenab Canal (LCC) irrigation scheme, the largest irrigation scheme of the IBIS, is selected as a case. Groundwater quality, groundwater levels, soil salinity, soil texture, and crop types are identified as the main factors for IRUs. GIS along with gamma design software GS + was used to delineate the IRUs in the large irrigation scheme. This resulted in a total of 84 IRUs in the large irrigation scheme based on similar biophysical factors. This study provided the empathy of suitable tactics to increase water management and productivity in LCC. It will be conceivable to investigate a whole irrigation canal command in parts (considering the field-level variations) and to give definite tactics for management.

The paper summarizes the results on the quality of surface water of the Gornji Banat region (Serbia, Yugoslavia). Based on different classifications, statistic data processing was made and the conclusions on the usability of the water for irrigation are given. According to the results obtained there is an urgent need for efficient measures to improve the quality of canal water and the control the polluters.

5 water samples were taken from the irrigation channel nearby Kamendin, Sirig, Becej, Backo Gradiste, Backi Petrovac which is part of DTD (Danube-Tisza-Danube) system (Serbia, Yugoslavia). Content of Cd (cadmium), Pb (lead), Hg (mercury), As (arsenic), Cr (chromium), Ni (nickel), F (fluorine), Cu (copper), B (boron) in water samples was analyzed. The origin of these elements in the waters and the effect of potentional pollutant was analyzed. Also, deviation of content of these elements from permissible amounts which were announced in the Book of Regulation was commented.

Quality, high and stable yield in plant production often depends on irrigation. This paper deals with analysis of water usability for irrigation on some irrigation systems in Vojvodina (Serbia, Yugoslavia) during 1997. Included irrigation systems are characteristic taking into consideration soil type, way of irrigation, cropped area and production level (intensity), in fact - water requirements. This irrigations, which are organized for three years period, will provide the base for recommendation of chemical and biological dimension, water and soil sampling points and frequency. The main reason for mentioned investigation is poor legislation in this field in the Republic of Serbia and FR Yugoslavia.

Nowadays, different profile of experts are present opinion that surface water quality are exchanged. Type and degree of mineralization content exchange are shown by argumentation. The work have carried out taking into consideration suitability of Danube water for irrigation. The results of chemical investigation from three sample locations (Bezdan, Novi Sad and Banatska Palanka), Serbia (Yugoslavia) during the period 1981-1995, were analyzed. The main statistical parameters and tests of homogeneity are used during the work. Results have pointed put more or less concentration decreasing of analyzed parameters. From statistical point of view, exchange of electrical conductivity and potassium are prominent on all three localities.

From two locations in the Vizelj channel (Serbia, Yugoslavia) in the early spring and before irrigation water samples were systematically taken in order to examination the content of harmful and dangerous matter. Content of Cd, Pb, Hg, As, Cr, Ni, F, Cu, B in water samples was analyzed. The origin of these elements in the water and the effect of potentinal pollutants were analyzed. Also, deviation of content of these elements from permissible amounts which were announced in the Book of Regulation was commented.

Upon the construction and introduction of overflow lagoons for gravitational precipitation, starch production plant wastewater drained into the river (channel) Nadel, satisfy quality conditions established for irrigation of crops which bare waters with high salinity.

Excessive enrichment of fluoride threatens ecological stability and human health. The high-fluoride groundwater in the Chagan Lake area has existed for a long time. With the land consolidation and irrigation area construction, the distribution and migration process of fluoride have changed. It is urgent to explore the evolution of fluoride under the dual effects of nature and human. Based on 107 groundwater samples collected in different land use periods, hydrogeochemistry and isotope methods were combined to explore the evolution characteristics and hydrogeochemical processes of fluoride in typical high-fluoride background area and elucidate the impact of anthropogenic activities on fluoride migration. The results indicate that large areas of paddy fields are developed from saline-alkali land, and its area has increased by nearly 30%. The proportion of high-fluoride groundwater (>2 mg/L) has increased by nearly 10%, mainly distributed in the new irrigation area. Hydrogeochemical processes such as dissolution of fluorine-containing minerals, precipitation of carbonate minerals and exchange of Na⁺, Ca²⁺ on the water-soil interface control the enrichment of fluoride. The groundwater d-excess has no obvious change with the increase of TDS, and human activities are one of the reasons for the increase of fluoride. The concentration of fluoride is diluted due to years of diversion irrigation in old irrigation area, whereas the enrichment of δ²H, δ¹⁸O and Cl⁻ in new irrigation area indicates that the vertical infiltration of washing alkali and irrigation water brought fluoride and other salts to groundwater. Fertilizer and wastewater discharges also contribute to the accumulation of fluoride, manifesting as co-increasing nitrate and chloride salts. The results of this study provide a new insight into fluoride migration under anthropogenic disturbance in high-fluoride background areas.