Monitoring and Ecological Risks of Heavy Metals of Urban Soils in Different Functional Areas Based on Plasma Technology

Heavy metal pollution in soil has become a global environmental problem in recent years. This study assessed heavy metals' pollution distribution, level and ecological risk in soils from different functional areas in Shihezi City, China. Heavy metals (Cr, Cu, Pb, Zn, Ni, and Cd) were measured using atmospheric pressure discharge plasma and inductively coupled plasma mass spectrometer. The mean concentration of all heavy metals in soil was higher than heavy metals' background values. The spatial distribution of Cr is the most different, and the distribution of Cu and Zn are similar in other functional regions. The single pollution index indicated that the heavy metals in industrial, traffic, and residential areas were enriched, and the pollution of Cd was more severe than others. The Nemerow pollution index showed that the near Manas River basin coast is alert (still clean), the industrial area is moderately polluted, and all other functional areas are lightly polluted. The potential ecological risk index demonstrated that only the nearshore Manas River Basin is at a mild ecological risk level, while all other functional areas are at a moderate ecological risk level. The determinate power of DEM, temperature, and precipitation were all over 65%, which meant that the topographic and climatic factors were the main factors affecting the change of heavy metal content. Secondly, socio-economic factors are important factors to promote the change of heavy metal content in soil.

Assessment of Value Changes and Spatial Differences in Land Use Based on an Empirical Survey in the Manas River Basin

Land integration is an important means of increasing the multifunctional value of arable land. The scientific measurement of the integrative value of arable land before and after land consolidation can improve farmers’ overall understanding of the value of arable land, increase their awareness of arable land protection, and encourage them to implement arable land protection policies. Additionally, it can provide a theoretical basis for the formulation of reasonable compensation standards for arable land in various areas of the Manas River Basin and effectively promote the use of the “Shawan model”. In this paper, the sample used for the survey was made up of 380 farmers from 10 villages in three different regions of Shawan City (county-level city). The participatory farmer assessment (PRA) method was used to conduct a detailed investigation of the integration of farmers’ cultivated land, while the landscape pattern index method was used to analyze the intensity of the cultivated land integration pattern. By constructing a measurement system for the integrative value of cultivated land and adding up the economic, pro-ecological, and social values before and after the integration of the cultivated land, estimated using the income reduction method, the equivalent factor method, and the shadow engineering method, we found that the cultivated land in each region of Shawan City (county-level city) was more effectively integrated, the scale of the field expanded, the shape of the patches tended to be more regular, and the field surface more flat. However, the degree of integration varied from region to region, with the degree of integration from the largest to the smallest as follows: oasis agricultural zone > oasis/desert ecological zone > hilly zone. We found that the integration of cultivated land has a significant effect on the integrated value of cultivated land, and the value of cultivated land in different regions showed different degrees of improvement after integration. The cultivated land of villages located in the oasis/desert ecotone showed a significant overall improvement after integration, followed by cultivated land in the oasis agricultural area. The value of cultivated land increased significantly, while the value of cultivated land in the hilly area showed less improvement after integration. The value of cultivated land integration in different regions is related to the intensity of the cultivated land integration, the per capita cultivated land area, the ecosystem biomass, and the crop planting area. The purpose of this paper is to effectively diagnose and promote the “Shawan Model” (land integration), formulate reasonable compensation standards for cultivated land in different regions of the Manas River Basin, and implement cultivated land protection policies.

Spatiotemporal variation in groundwater level within the Manas River Basin, Northwest China: Relative impacts of natural and human factors

The Manas River Basin (MRB), Northwest China, is an arid basin dependent on irrigation for agriculture, and human activities are believed to be the primary factor affecting the groundwater level fluctuations in this basin. Such fluctuations can have a significant adverse impact on the social economy, agricultural development, and natural environment of that region. This raises concerns regarding the sustainability of groundwater use. In this study, we used ArcGIS spatial interpolation and contrast coefficient variance analysis to analyse groundwater level, land-use change, and water resource consumption patterns from 2012 to 2019 in the plains of the MRB. The aim was to determine the main factors influencing the groundwater level and to provide a scientific basis for the rational development, utilisation, and management of water resources in this area. During the study period, the groundwater level decreased, increased, and then fluctuated with a gradually slowing downward trend; the decline ranged from −17.82 to −11.67 m during 2012–2019. Within a given year, groundwater levels declined from March/April to August/September, then rose from August/September to March/April, within a range of 0.29–19.05 m. Primary factors influencing the groundwater level included human activities (e.g., changes in land use, river regulation, irrigation, and groundwater exploitation) and natural causes (e.g., climate and weather anomalies). Human activities were the primary factors affecting groundwater level, especially land-use change and water resource consumption. These results provide a theoretical basis for the rational exploitation of groundwater and the optimisation of water resource management in this region.

Hydrological process simulation in Manas River Basin using CMADS

The inability to conduct hydrological simulations in areas that lack historical meteorological data is an important factor limiting the development of watershed models, understanding of watershed water resources, and ultimate development of effective sustainability policies. This study focuses on the Manas River Basin (MRB), which is a high-altitude area with no meteorological stations and is located on the northern slope of the Tianshan Mountains, northern China. The hydrological processes were simulated using the China Meteorological Assimilation Driving Datasets for the SWAT model (CMADS) using the Soil and Water Assessment Tool (SWAT) model. Simulated runoff was corrected using calibration/uncertainty and sensitivity program for the SWAT. Through parameter sensitivity analysis, parameter calibration, and verification, the Nash–Sutcliffe efficiency (NSE), adjusted R-square ({R}_{\text{adj}}^{2}), and percentage bias (\text{PBIAS}) were selected for evaluation. The results were compared with statistics obtained from Kenswat Hydrological Station, where the monthly runoff simulation efficiency was \text{NSE}\hspace{.25em}=0.64, {R}_{\text{adj}}^{2}\hspace{.25em}=0.69, and \text{PBIAS}\hspace{.25em}=\mbox{--}0.9, and the daily runoff simulation efficiency was \text{NSE}\hspace{.25em}=0.75, {R}_{\text{adj}}^{2} = 0.75, \text{PBIAS} = −1.5. These results indicate that by employing CMADS data, hydrological processes within the MRB can be adequately simulated. This finding is significant, as CMADS provide continuous temporal, detailed, and high-spatial-resolution meteorological data that can be used to build a hydrological model with adequate accuracy in areas that lack historical meteorological data.

Analyzing Macro-Level Ecological Change and Micro-Level Farmer Behavior in Manas River Basin, China

Environmental degradation is closely related to unreasonable land use behaviors by farmers. In this study, participatory rural assessment (PRA) is used to conduct a detailed survey of farmers and plots and to collect relevant natural and social statistics. The accuracy of remote sensing data is verified by comparative analysis, and the change in status of various land use types in each research period is reflected by the change in the dynamic degree and change in range. We examine how farmers’ attitudes and behaviors affect environmental degradation, using a sample of 403 farmers in China’s Manas River Basin. Due to age, education, income and other differences, farmers’ land use behaviors, as well as their attitude toward and feelings about environmental degradation, vary greatly. We found that most farmers considered the environment to be very important to their lives and crop production, but nearly 21% did not know the causes of environmental degradation and nearly 8% did not consider the environmental impacts of their crop production activities. A new model for oasis expansion—land integration—is presented here. This model can increase the area of cultivated land, reduce cultivated land fragmentation, save irrigation water, improve the field microclimate and form a good ecological cycle. Through land transfer, ecological compensation and ecological protection incentives, the government should guide farmers’ land use behaviors toward cooperation with the river basin’s ecological protection and land use planning.