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This study utilizes the freefall as a simple and useful tool for measuring end depth discharge EDD in triangular channels having stone beds. For this task, forty-five triangular channel models are constructed and examined all having 360 cm length and end drop fall of 20 cm. In these channel models, three channel side slopes z = 0.7, 1.0 and 1.3, five bed slopes St = 0.00, 0.0033, 0.005, 0.010 and 0.020 and three bed stone diameters ds = 5 mm, 10 mm and 15 mm are tested. The laboratory results demonstrated straight line relationships for the variation of end depth ye with critical depth yc and the variation of end depth with uniform normal depth yn for different values of z, St and ds tested in this study, while, the relation between ye/yc and bed slope St showed a quadratic expression. Moreover, the relationship for the dimensionless discharge with both channel bed slope St and the ratio of end water depth ye to bed stone diameter ds (ye/ds) has been presented by a simple empirical power equation with high determination coefficient which can be applied for subcritical and supercritical states of flow for the range of upstream Froude number Frn between 0.14 and 1.27.

The present study deals with the hydraulic behavior of smooth triangular channels with free overfall in order to obtain useful relationships for the estimation of end depth discharge (EDD) in terms of brink depth (yb), channel side slopes (m) and channel bed slope (So). For this purpose, twelve triangular channel models have been built and tested having 3.6 m length and 19 cm drop at brink with different values of side slopes (m = 0.75, 1.0 and 1.25) and different channel bed slopes (So = 0.0, 0.0033, 0.0067 and 0.02). Experimental results of all models showed straight line relationships for the end depth ratio (EDR) for different values of (So) and (m) with high determination coefficients and low values of root mean square error. A quadratic equation is obtained for the variation of EDR with (So). An empirical expression is obtained for a dimensionless discharge in terms of (So) for all channel models tested for both subcritical and supercritical flow conditions with the range of Froude number in the approach channel between 0.64 and 4.15. Two methods (direct and indirect) are proposed for the estimation of EDD in which the outcome results compared quite well with the available data of previous studies.

In the present investigation, the stability of rockfill weirs protected by gabions and subjected to overtopping flow rates under the effect of high flow rates have been studied experimentally. Five weir models with different downstream slopes [1V:2.5H,1V:3H,1V:4H,1V:5H,1V:7.5H]were constructed and tested. Fifty eight experiments were conducted for five cases of stepped gabions laying on the downstream slope[ laying gabions with one layer and no connections (M-1),laying gabions with lateral connections (M-H),laying gabions with longitudinal connections (M-V), laying gabions with two layers(M-2),and laying gabions with three layers(M-3)] using three gravel diameters (11.11,15.9 and 22.25)mm.From the data analysis, a set of equations were obtained for the estimation of failure unit discharge in terms of equivalent gravel diameter, relative submerged intensity of gabions, gabions layer solidity, and tangent of internal friction angle of gabions, for each case of gabions laying. A simple method was presented for the design of rockfill weirs protected by stepped gabions in terms of maximum failure discharge with the help of design charts obtained from the present study. A mathematical model depending on the characteristics of the physical model was derived for each slope giving failure unit discharge values that agree quite well with the experimental values. Comparing results of the present study with those of other investigations shows that rockfill weirs protected by gabions stand much higher failure unit discharge than earth weirs protected by gabions.

The main objective of the study is to assess the training needs of the forest and rangeland staff in the Iraqi Kurdistan Region (IKR). The procedure is to identify the training needs in all forestry aspects: (forest development, forest protection, forest range management, agro-forestry, environment, tourism and recreation and forestry extension), determining the relationship between the respondents training needs and some of their personal and occupational features, explore the problems and obstacles in the protection and development of forests in IKR; consider the respondents' suggestions for developing and improving Iraqi Kurdistan Region forests. The research samples included 132 employees representing about 77.19% of the research population. The data was collected through questionnaires and personal interviews. The following are the main findings of the study: The results show that 49% of the respondents need extensive training in all the studied forestry disciplines and that there is a significant correlation between the need for training and each of the independent variables (age, career service and origin). Besides, the three stated variables altogether explain about 33.7 % of the variance in the IKR forest and rangeland staff's' need for training. In light of the study findings, the recommendations was developing training plans and programs for the Iraqi Kurdistan region forest and rangeland staff in the prioritized topics the respondents desire to be trained in. [ABSTRACT FROM AUTHOR]