2023-10-24

Examinations and tests were conducted for the current study to evaluate the environmental reality of the Duhok Valley and the role of some plants growing on its side in treating pollutants, which transport the water of Duhok Dam and the various wastewater of the city to flow into the Mosul Dam Lake, transporting pollutants to it. As the water is used during its course to irrigate the crops scattered on both sides of the valley and to water the livestock and poultry sometimes. Six sites were identified for collecting water samples, starting from February 2021 until January 2022, using clean Poly ethylene terephthalate bottles that were washed with sample water several times before filling them. Samples for dissolved oxygen and biochemical oxygen demand were also collected in special bottles of 100 ml with a tight stopper. With the least possible aeration according to the internationally approved methods, water samples, soil, benthic sediments, and plants were collected seasonally to determine heavy metals from three sites (N1, N3, N6). Physical and chemical tests were conducted to estimate the temperature, electrical conductivity, pH, total hardness, alkalinity, negative and positive ions, and some heavy elements (Pb+2, Cu+2, Co+2, Ni+2), in addition to estimating parameters for irrigation such as sodium adsorption ratio (SAR), residual sodium carbonate (RSC), percentage of sodium (% Na), permeability index (PI), Kelly ratio (K.R), and latent salinity (PS).

2007-07-10

The study was conducted, on Pinus brutia Ten natural forest in Zawita Region which is located 16 Kilometers to the North of Dohuk city in Iraq, covering an area of 5781 Hectare The study depended on investigating the possibilities of planning and testing forest road networks by applying, five densities different for forest road, viz: 10,15,20,25 and 3.0 km/sq.km, two main road alignments i.e. contour road alignments and valley road alignments in addition to three extraction systems to extract the tree logs along the extraction distances according to time schedules prepared to construct the road networks gradually during the period of time between the years 2007-2066 which is the needed period of time to convert the forest of Zaweta pine from non-regular forest in to regular forest. The three proposed extraction systems were the Agricultural Tractor Massey Ferguson MF 185 S.A4-248, the skyline Koller K300 and combination between the Agriculture Tractor and the skyline. The results revealed that the average extraction distances and their costs decrease unequally as the road density increases and these averages were less in value in the case of valley roads than the averages in the case of contour roads. The forest land area form and gradient is effectiveness in extraction distance averages. For difference is the yield distribution or forest land & found areas free from trees is role in findings these the study For double extraction is large effectiveness in extraction costs. Results als showed Skyline in regions which no reaching it the road is method effective when linking using it with forest road. That the total costs of roads and extraction become very near to each other around the limits of the optimum road density. Further more the results showed that the best recommended forest road densities, calculated upon the total cost of roads and extraction system, were 1 km/sq.km by using the agricultural tractor and valley roads, 1.5 km/sq.km by using the skyline and valley roads and 1km/sq.km of contour roads by the combined use of tractor and skyline finally, the tractor performance was the best among the three extraction systems.