Bao Anming

Simulation analysis on the regulation of overflow ecological water consumption in arid areas - A case study in the Canmrik ecological area of the mainstream zone of the Tarim River

After analyzing the regulation of overflow ecological water consumption in the Canmrik ecological area of mainstream zone of the Tarim River, in this paper a model of ecological bifurcation is developed, the dynamic overflow process of ecological bifurcation is simulated, and the quantitative relationships between the volume of ecological water consumption and the ecological conservation extent and overflow time are analyzed using GIS, advance of freshet and RS means. The results reveal that the effects of discharge and time of ecological bifurcation on the efficiency of ecological water consumption are significant, there is a geometrical exponential relationship between the efficiency of ecological bifurcation and the water supply with different discharges and different times under the same ecological water consumption, hypsography plays an important role in ecological water consumption, the regulation of ecological water consumption cannot be equated with the ordinary farming irrigation system, a serious water waste will result and the prospective ecological benefits will not be able to be achieved if an ordinary ecological bifurcation is implemented. The efficiency of ecological water consumption can be increased by 30% by selecting the bifurcation schemes in an optimized way, which is of the utmost importance for arid areas with shortage of water resources.

Study on snowmelt runoff simulation in the Kaidu River basin

Alpine snowmelt is an important generation mode for runoff in the source region of the Tarim River basin, which covers four subbasins characterized by large area, sparse gauge stations, mixed runoff supplied by snowmelt and rainfall, and remarkably spatially heterogeneous precipitation. Taking the Kaidu River basin as a research area, this study analyzes the influence of these characteristics on the variables and parameters of the Snow Runoff Model and discusses the corresponding determination strategy to improve the accuracy of snowmelt simulation and forecast. The results show that: (i) The temperature controls the overall tendency of simulated runoff and is dominant to simulation accuracy, as the measured daily mean temperature cannot represent the average level of the same elevation in the basin and that directly inputting it to model leads to inaccurate simulations. Based on the analysis of remote sensing snow maps and simulation results, it is reasonable to approximate the mean temperature with 0.5 time daily maximum temperature. (ii) For the conflict between the limited gauge station and remarkably spatial heterogeneity of rainfall, it is not realistic to compute rainfall for each elevation zone. After the measured rainfall is multiplied by a proper coefficient and adjusted with runoff coefficient for rainfall, the measured rainfall data can satisfy the model demands. (iii) Adjusting time lag according to the variation of snowmelt and rainfall position can improve the simulation precision of the flood peak process. (iv) Along with temperature, the rainfall increases but cannot be completely monitored by limited gauge stations, which results in precision deterioration.

Using Limited Observations to Inverse Dynamically Groundwater Spatial Distribution: A Case Study from the Lower Reaches of Tarim River, China

Tarim River is a typical inland river.Riverbank plant communities mainly depend on the flood and groundwater to maintain their growth. The groundwater table depth, one of eco-environment factors, determines constitution, distribution and growth of natural plant. Since 2000,continuously monitoring of groundwater has been carried by Tarim River Management Bureau and Xinjiang Institute of Ecology and Geography, Chinese Academy of Science, with setting cross section and observation wells, and some pertinent researches and analyses have been done (Chen et al., 2003, Deng, 2005). Using limiting observation data to inverse groundwater spatial distribution will play a more dominant role in rational evaluation and scientific ecosystem management in the lower reaches of Tarim River. In this paper, the groundwater flowing processes and the water-table fluctuating processes during the past 3 years were simulated to obtain the spatial and temporal distribution of groundwater table by means of the GIS-assisted FEFLOW modeling based on the Digital Elevation Model data (DEM) and hydrogeologic data obtained in the Alagan section, one representative section of 12 groundwater monitoring sections, in the lower reaches of Tarim River. The model can be applied with relatively limited data to reappear the dynamic change of groundwater. Then groundwater table and calculated groundwater table depth can be used to analyze the relationship between groundwater and eco-environment. The results of model showed that groundwater was affected by river leakage, the main effective transverse region was 1.0 km from the river and within this effective region the groundwater depth was below 9 m.

Study on the biomass change derived from the hyperspectral data of cotton leaves in canopy under moisture stress

In this study, an ASD spectrometer made in USA is used to derive the hyperspectral data of cotton leaves in canopy in north Xinjiang. The integral area variables of red edge are used to estimate the total nitrogen (TN) content in cotton leaves in canopy. The first order differential of reflective spectra is carried out. The analysis methods based on the spectral position variables are derived from the first order differential spectral data. The analysis on the correlation between the integral area of red edge (SDr, regarded as the independent variable) and the TN content (regarded as the function) is carried out, and the correlation mathematical model between the integral area of red edge and the TN content in canopy leaves of cotton varieties named as Xinluzao No.6 is developed. The analysis on the correlation between the chlorophyll content and the TN content in single cotton leaves in canopy growing under the irrigation with different water volumes is carried out. The results show that there is a significant positive correlation between the chlorophyll content and the TN content (R = 0.8723, n = 39), and the data of chlorophyll content can be used to estimate the TN content in single cotton leaves; the correlation between the integral area variable of red edge and the TN content in cotton leaves in canopy is significant, their correlation coefficient is 0.7394 (n = 40), the TN contents in canopy leaves of cotton varieties named as Xinluzao No. 6 and No. 8 can be accurately estimated by using the developed model, and their RMSE values are 0.3859 and 0.4272 respectively. After researching, it is considered that there is an applying potential to use the integral area variables of red edge for estimating the TN content in cotton leaves in canopy, and the mathematical model developed with the third-side area variables has a high applying value in deriving the TN content in crop canopy. It is also considered that it is feasible to recognize the moisture stress suffered by cotton plants by researching the shift and change extent of red edge, and the key is to develop the corresponding rational recognition index system.

Evaluation of Wind Erosion in Xinjiang Based on Grid Method

Abstract Soil wind erosion is the driving force for land degradation, regional environment deterioration, and sandstorms in arid and semiarid regions. To evaluate the degree of wind erosion, a radial primary function network model was developed to carry out the network emulation analysis in Xinjiang, China, in which the grids of 1,000 × 1,000 m has been delimited as the basic research units. The related factors affecting wind erosion were extracted by geographic information system technology. Moreover, its calibration samples were selected from the typical distribution areas of different wind erosion to determine the model parameters. The results show that wind erosion disaster is extremely serious over 50% of the land in Xinjiang, with more than one fourth of the total suffering from more serious wind erosion. The regions with extremely serious wind erosion are distributed throughout east Xinjiang and in south and north Xinjiang. Spatially, wind erosion is roughly high in the southeast but low in the northwest and high in the basins but low in the alpine regions. After comparison and validation with the previously published research results and long-term observations, it is concluded that the research achievements in this study are in accord with the overall distribution pattern of wind erosion in Xinjiang. This method has potential for spatial assessment of wind erosion hazards.

Study of impacts of floods on the water quality in an arid zone: the case of the Tarim River in Northwest China

This paper presents the results of the study undertaken at the Tarim River Basin in Northwest China to analyze impacts of flooding on water quality. It was shown that irregular rainfall was the cause of flash floods that affected many ecosystems and eroded soils. Simulation results and the existence of relationships between flood volume and flood peak allowed potential model application that included flood peak estimation. The analysis of water pollution through sample sediment was helped by spectroscopy techniques and it was found that the flood was the main cause of many chemical elements in water. The floods affected the quality of water in the Tarim River where it was slightly basic with pH = 8.1 before flooding and acidic with pH = 6.9 after flooding.

Satellite sensor data analysis of urban surface temperatures and land use / land cover

With the rapid population growth, urbanization has become a common trend all over the world since the 20th Century. Meanwhile, urban air temperature is rising gradually in all the cities. In this paper, we took an oasis city—Urumqi as an example, investigated application of integration of remote sensing and geographic information systems (GIS) to detect the land use/cover change and urban growth, besides assessed their impacts on land surface temperature in this region. The results indicated as fellows: 1) during the last 20 years from 1990 to 2009, land use of Urumqi appeared a dramatic variation; 2) The mean annul temperatures of the land surface in Urumqi were 21.63°C and 25.39°C in 1990 and 2009, respectively. 3) According to the characteristics of the standard classification maps of land surface temperature and they revealed that the urban development had raised the land surface temperature of the urban. 4) Integration of remote sensing and GIS was an effective way to monitor and analyze urban growth pattern, and evaluate the urbanization impact on land surface temperature.

Net Primary Productivity (NPP) of Oasis Changes in Trends in Xinjiang and Responses to Climate Change Analysis in 1981-2000

Using the Xinjiang NPP data simulated by GLOPEM from 1981 to 2000, combining with the corresponding meteorological data, vegetation data and LUCC, the spatio-temporal changes of NPP and climate factors in 1981-2000 were analyzed. The correlation between climate factors and NPP was also analyzed. Finally, the responses of the NPP changes to climate changes were studied. The results showed that, (1) during 1981 and 2000, the annual NPP increased remarkably, the temperature and the precipitation also increased. NPP increased in spring, summer and autumn, but there was spatio-temporal variance between inter-annual changes of NPP and the changes of meteorological variations. (2) the inter-annual changes of NPP and meteorological variations were positively correlated, the growth of NPP was less than that of temperature and precipitation. The year that NPP peaked was not correspondent with the year that the temperature and precipitation peaked, yet the growth rate of NPP lag behind of that of temperature and precipitation slightly. (3) in 1990s, the correlation coefficients between NPP and meteorological variations increased more or less than 1980s. Moreover, the coefficients of the higher vegetation cover types were generally greater than that of the lower vegetation cover types.

Development of environmental information system for the Tarim River Basin.

The environmental information system is a thematic analysis subsystem in the water redistribution management system for the Tarim River Basin.This paper studies mainly the general design,structure and functions of the thematic analysis subsystem and the integration with other subsystems.Firstly,the ecological quality indices(EQI),such as the biological abundance index,vegetation coverage index,hydrographic net density index,land degradation index and pollution load index,are used to investigate the environmental quality in the Tarim River Basin.Secondly,a quota method is put forward for calculating the ecological water demand of natural vegetation.Thirdly,some indexes including the ecological degeneration index,risk degree index and regeneration degree index are calculated based on the concept of ecological risk assessment and the method of landscape ecology,and the corresponding ecological risk is analyzed and assessed.The results show that it is of the obvious practicality and maneuverability to take the means of ArcGIS+Oracle9i+ArcSDE to develop the environmental information system.The study results can be used to carry out the thematic assessment and analysis of ecological environment in arid areas,and can also be referred in developing other systems concerned.

The impacts of urban landscape pattern on urban land surface temperature: —Taking Urumqi as an Example

Urbanization has become an important contributor for global warming and urban air temperature is rising gradually in all the cities. It means that urban land use and land cover (LULC) changed became critical in determining the urban environment quality. This paper presents an integrated study to investigate and identify landscape pattern which have the influence to increase of land surface temperature, using Geographical Information Systems (GIS) and remote sensing. In this paper, an oasis city-Urumqi as an example, which explores the temporal and spatial characteristics of land use and land cover change from 1990 to 2004, and the land surface temperature variation from 1990 to 2004. Results shows that land use of Urumqi appeared a dramatic variation during the last 15 years. The mean annul temperatures of the land surface in Urumqi were 21.41 °C in 1990 and 31.12 °C in 2004, respectively. In particular, the land surface temperature and landscape pattern index had shown the close relationship. To sum up, integration of remote sensing and GIS was an effective way to monitor and analyze urban LULC, and evaluate the landscape pattern impact on land surface temperature.