Groundwater assessment of Halabja Saidsadiq Basin, Kurdistan region, NE of Iraq using vulnerability mapping

Abstract

Halabja Saidsadiq Basin is located in the northeastern part of Iraq covering an area of about 1278 km 2 with a population of about 190,727. Groundwater is the principal source of water in this area. Agricultural practices within the basin are widespread and located close to groundwater wells. This poses imminent threat to these resources. DRASTIC model integrated with GIS tool has been used to evaluate the groundwater vulnerability of this area. In addition, the DRASTIC model was modified using nitrate concentrations and sensitivity analysis to modify the recommended weighting value to get accurate results. The modified rates were calculated using the relations between each parameter and the nitrate concentration in the groundwater based on the Wilcoxon rank-sum non-parametric statistical test. While, to calibrate all types of modifications, the Pearson's correlation coefficient was applied. The standard vulnerability map of the studied basin classified the basin into four zones of vulnerability index including very low (34 %), low(13 %), moderate (48 %), and high (5 %) vulnerability index, while the combined modification classified the area into five classes: very low (7 %), low (35 %), moderate (19 %), high (35 %), and very high (4 %). The results demonstrate that both modified DRASTIC rate and weight were dramatically superior to the standard model; therefore, the most appropriate method to apply is the combination of modified rate-weight.

Possibility of Groundwater Pollution in Halabja Saidsadiq Hydrogeological Basin, Iraq Using Modified DRASTIC Model Based on AHP and Tritium Isotopes

“…In addition, movement towards groundwater starts from the high elevation area in the north, upper east, south, and southeastern part towards the southwestern part, which is closed to the Derbandikhan Dam ( Figure 3). Furthermore, several streams exist on the studied basin, including Sirwan, Zalm, Chaqan, Biara, Reshen, and Zmkan [2]. Also, many springs located inside of the studied basin ( Figure 4).…”

“…The first spring group that it is discharging under 10 L/S, (for example, Anab, Basak, Bawakochak, and other 30 different springs). The second group having discharges ranged between 10 to100 L/S, (for example, Sheramar, Qwmash, Khwrmal, and Kani Saraw), The final group was those that have water discharge of more than 100 L/S (for example, Garaw, Ganjan, Reshen, Sarawy Swbhan, and Agha) [2][3][4][5][6][7][8][9][10][11][12]. Furthermore, several streams exist on the studied basin, including Sirwan, Zalm, Chaqan, Biara, Reshen, and Zmkan [2].…”

“…Vulnerability assessment has been performed as a crucial part of protection policy on land uses planning and groundwater protection zoning [1]. Various methods have been recommended for mapping groundwater vulnerability, namely; DRASTIC, COP, VLDA, GOD, AVI, and SINTACS [2]. These models have been recommended for different groundwater aquifers assessment, including inter-granular, leaky, and fissure aquifers, while, the EPIK [3,4] and PI models [5], which were typically recommended for the assessment of vulnerability in karstic aquifers.…”

Magnitude and Direction of Groundwater Seepage Velocity in Different Soil and Rock Materials

“…The studied area divided into two sub-basins based on surface water flow contributes in the catchment, including Halabja-Khurmal and Said Sadiq sub-basins [5]. The area is covered around 128,000 square hectometer, with a population of over 200,000 in 2015 [6]. The studied area is characterized by a distinct continental interior climate, nearly 45˚C -50˚C in the summer and about 0˚C -10˚C in the winter, and it has a Mediterranean weather type, with total annual precipitation ranging between 500 and 700 mm.…”

Assessing the Vulnerability of Groundwater to Pollution Using DRASTIC and VLDA Modelsin Halabja Saidsadiq Basin, NE, Iraq

“…As a result, on the basis of the arithmetic averages from previously applied normalized weights, the weight value for VLDA proposed to be is 0.286, 0.251, 0.191 and 0.271, respectively [12,23]. While for this study, the new corresponding weights of DRASTIC model in HSB were proposed using sensitivity analysis method.…”