Jinlong Zhou

VLDA model and its application in assessing phreatic groundwater vulnerability: a case study of phreatic groundwater in the plain area of Yanji County, Xinjiang, China

Based on the GOD method and DRASTIC model for groundwater vulnerability assessment, in this paper, VLDA model for assessing phreatic groundwater vulnerability is proposed, where V is lithology of vadose zone, L is the pattern of land use, D is groundwater depth, and A is the aquifer characteristics. As a case study, the paper assesses the vulnerability of phreatic groundwater in Yanji County of Xinjiang by using the VLDA model as the tool and GIS as the platform, and matches the vulnerability with nitrate content of the phreatic groundwater in September 2009. The results indicate that areas with highly vulnerable pore phreatic groundwater account for 40.83% of the total inland area of Yanji County, including most of the northwestern area (such as the groundwater wellfield in Korla City) and Yanji Town. It is also discovered that areas with phreatic groundwater of higher vulnerability essentially coincide with areas with higher nitrate content, indicating the feasibility of using VLDA model to assess groundwater vulnerability.

Impact of mineral concentration on capillary water rise in sandy soil

This article summarizes results of the experiment on capillary water rise in sandy soil with different combinations of grain sizes and mineral concentrations (1g.L^-1, 30 g.L^-1, 100 g.L^-1 and 250 g.L^-1). Tests show that: in coarse sandy soil, capillary water height has positive correlation with mineral concentration and the capillary water height from solution of mineral concentration of 250 g.L^-1 is evidently lower than those of other three solutions with mineral concentrations of 1 g.L^-1, 30 g.L^-1 and 100 g.L^-1 in the same time period; in fine sandy soil, capillary water height at the late stage of observation presents a descending sequence of 1 g.L^-1, 250 g.L^-1, 100 g.L^-1 and 30 g.L^-1 for the solution groups; in silty soil, capillary water height of the solution with mineral concentration of 30 g.L^-1 is obviously higher than those of the other three solution groups. It is also found that: with higher mineral concentrations, density of the solutions impacts on gravity potential of capillary water and evaporative crystallization in the capillary tubes impacts on the matrix potential of capillary water, and the process of capillary water rise is impacted by these two factors in combination.

Salinization of deep groundwater in plain areas of Xinjiang: causes and countermeasures

AbstractThe salinization of deep groundwater is one of the serious geographical environmental hazards. The present study collected groundwater samples from 60 wells with depth over 100 m in the plain areas of Xinjiang from October to November of 2011. The comparison of hydrochemical data obtained in 2011 and 2003 in the same wells indicated that salinization occurred in a spot-like pattern in Xinjiang. Among the 60 groundwater samples, 20 samples were seriously salinized, which made up to 33.3% of the total wells. Through the analysis of the characteristics of salinization of deep groundwater in this region, four causes of salinization and four countermeasures to prevent salinization were put forward.

Calculation of groundwater use by natural vegetation in the non-irrigated plain areas in Xinjiang

This paper takes the non-irrigated plain areas in Xinjiang as the study area, where the natural vegetation draws water mainly from the shallow groundwater to satisfy its demands. Through interpretation of TM satellite images and hydro-geological investigations, understanding of the unsaturated strata, shallow water depth, distribution and coverage of natural vegetation was obtained. Based on calculation units divided by using GIS techniques and data of shallow water evapo-transpiration from the typical area groundwater balancing experimental stations, parameters of phreatic water evaporation and vegetation conversion parameters were decided and thus the total groundwater use by the natural vegetation in the study area is calculated as 63.7762×108m3/a under current conditions.

Preliminary analysis of the effectiveness of desalting leaching using spring irrigation for use of brackish water for under-film drip irrigation of cotton

In the plain irrigation districts in the Tarim Basin, Xinjiang where water resources are scarce, irrigation using brackish water is of great significance. The biggest problem with brackish water irrigation is salt accumulation in soil. The focus of concern of people is that, after 1-year application of brackish water irrigation, whether it is necessary to leach salt using winter irrigation or spring irrigation before sowing of the next year. This paper comprised data of easily dissolvable salt of 0∼60cm in soil which monitored from monitoring area S1 before and after spring irrigation in 2010 in Tarim Township of Yuli County, Xinjiang and salt tolerance indexes during germination, seedling and budding, flowering and boll generating, and boll opening periods of cotton (which are 7.1 g/kg,6.9g/kg,8.2g/kg and 9.2g/kg). The result shows that: in monitoring area S1, we can desalt leaching using spring irrigation once every other year to maintain the germination and growth requirements. The soil desalting ratio of monitoring area S1 before and after spring irrigation is 11.9%∼84.2%. Then we can conclude that the effectiveness of desalting leaching using spring irrigation in monitoring areas S1 were significant.

Current situation and discussion on ground water quality of major cities in Xinjiang of China

Groundwater quality in the 7 key cities is classified by utilizing analytical method of grey correlation degree in the light of 42 monitoring results of groundwater samples from April -June 2003 in Xinjiang Uygur Autonomous Region, China, setting each city as evaluating unit, Groundwater Environmental Quality Standards (GB/T 14848-93) as evaluation criterion, and choosing the 7 pollutants (total hardness, mineralization, ammonia nitrogen, volatile phenol, permanganate index, sulfate and chloride) as evaluating factors. Appraisal result shows: mineralization and total hardness are larger, the total water quality is better. It is pointed out that groundwater protection and quality control over groundwater resources should be strengthened to realize its sustainable utilization. Several suggestions are raised on groundwater pollution prevention.