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Table of Content

    28 April 2016, Volume 31 Issue 4 Previous Issue    Next Issue
    Resource Ecology
    The Temporal and Spatial Variations of Ecological Services in the Tibet Plateau
    HUANG Lin, CAO Wei, WU Dan, GONG Guo-li
    2016, 31 (4):  543-555.  doi: 10.11849/zrzyxb.20150296
    Abstract ( )   HTML ( )   PDF (12787KB) ( )   Save
    The Tibet Plateau is one of the vital zones to the national ecological security pattern, and the maintenance and enhancement of its ecological barrier function is the core objective of ecological protection in this area. This paper analyzed the variations of macrostructure and services of ecosystems in Tibet Plateau from 1990 to 2010, and integratedly assessed its ecological barrier function. The results showed that: 1) In recent 20 years, the ecosystem pattern in Tibet Plateau is stable, and the change of ecosystems is relatively slow. The grassland area increased in the northern and western Tibet Plateau, glaciers and permanent snow covered area retreated, and lake and swamp wetland area expanded. 2) The average annual water conservation quantity of forest, grassland and wetland ecosystems in Tibet Plateau was 89.52 billion m3, water conservation amount per unit area being 744.48 m3/hm2. The carbon sequestration capacity of forest, grassland and wetland ecosystem reached 1.95 Pg C, presenting the pattern of gradually decreasing from southeast to northwest. 3) The annual average soil water erosion modulus is 3 876 t/km2, and annual soil erosion quantity is 1.02 billion tons in the Tibet Plateau. The retention rate of ecological soil conservation service was 66%. The annual average soil wind erosion modulus is 1 581.2 t/km2 and soil wind erosion quantity was 1.899 billion tons in the Tibet Plateau. The average sand fixation service quantity was 2.83 billion tons, and the retention rate of the average annual wind prevention and sand fixation service was 66.5%. 4) The water conservation capacity has improved in the past 20 years. The carbon sequestration amount reduced by 0.87% in the former 10 years and increased by 3.71% in the latter 10 years. In water erosion zones of the Tibet Plateau, the soil erosion amount and the soil conservation amount decreased, while the retention of soil conservation services continued to rise. The overall trends of wind erosion amount, ecosystem wind prevention and sand fixation service went downward due to weakened wind strength and increased vegetation coverage, while the retention rate of ecosystem wind prevention and sand fixation service continued to increase.
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    Study on the Change and Optimization of Landscape Pattern in the Basin of Northwest Hebei Mountains—A Case Study of Huailai County, Hebei Province
    CHEN Ying, HA Kai, HE Wen-long, WANG Zhi-tao, FENG Fei, MEN Ming-xin, DING Qing-long
    2016, 31 (4):  556-569.  doi: 10.11849/zrzyxb.20150361
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    Optimal allocation of land resources is an effective way of sustainable utilization of land resources. The study has paid more attention to the problem of the land quantity structure which often took maximum economic benefit as the goal while ignored the influence of spatial pattern on ecological processes, so the eco-environment problems were becoming more and more serious. The landscape pattern was closely related to ecological processes. The change of landscape patterns would influence the ecosystem functions. Therefore, optimized regulation of landscape patterns is of great importance for maintaining the stability of ecosystem functions. The basin of Northwest Hebei mountains is in the upper zone of Beijing. The changes of landscape pattern have important influence on the eco-environment of Beijing and even the whole region. Huailai County in this region is close to Beijing. Under the background of coordinated development of Beijing, Tianjin and Hebei, Huailai County plays an important ecological role in the ecological protection of Beijing and Tianjin. This study takes Huailai County as an example to analyze the characteristics of landscape patterns with three remote sensing datasets in 1993, 2003 and 2013. Results indicate an increasing landscape fragmentation in this area. From 1993 to 2013, the number of landscape patches in the study area increased by 1 664, the degree of fragmentation index increasing from 5.44 to 6.38, landscape shape index increasing from 44.46 to 47.38. Meanwhile, the connectivity presents a downward trend. Generally, the stability of landscape pattern was decreasing. In combination with the distribution of different landscape types patterns on the terrain niche and the functions of ecosystem services, minimum cumulative resistance model was used to construct the landscape components of ecological source, ecological corridors and ecological nodes. The ecological corridors all distribute round the towns and Guanting Reservoir, and along major rivers and roads as well. Ecological nodes concentrate at the river confluences north and south to the Guanting Reservoir, valley mouth, river flat, and reservoirs and wetlands around the town and woodland. The obtained dIIC and dPC show that river confluences and the surrounding area of the reservoirs are the most important to landscape connectivity. Based on the above research, maintain areas, restoration areas, enhancement areas and protection areas of landscape are divided which will be useful for the optimization of ecological landscape. According to the characteristics of differentiation, the corresponding measures of optimized allocation of landscape in each kind of region are discussed.
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    Resource Evaluation
    Effect of Progress in Artificial Irrigation and Drainage Technology on the Change of Cultivated Land Pattern in the Past 50 Years in Manasi River Watershed
    LI Jian-jun, LUO Ge-ping, DING Jian-li, XU Wen-qiang, ZHENG Shuan-li
    2016, 31 (4):  570-582.  doi: 10.11849/zrzyxb.20150370
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    The analysis of relationship between artificial irrigation and drainage technology development and cultivated land change pattern has vital significance in the research of irrigation agriculture development in arid areas. Manasi River Watershed was taken as the study area. The topographical map of Manas River Watershed in 1960, remote sensing images taken in 1976, 1989, 1997, 2006 and 2013, historical maps of water conservancy, and other original data were processed by remote sensing image possessing and spatial analysis in geographic information system, and the artificial irrigation and drainage canal system at five stages and land use classification in six periods were obstained. Then the length index of artificial irrigation canal system and the indices describing cultivated land pattern, i.e. oasis reclamation rate, net cultivated land coefficient, perimeter-area rate, were calculated. Finally, stepwise regression method was used to explore the effects of artificial irrigation and drainage technology on the change of cultivated land pattern. The results showed that: before the application of drip irrigation, the distribution pattern of cultivated lands in Manasi River Watershed was determined by the spatial distribution of irrigation and drainage canal system, especially the distribution pattern and the length of sublateral canals, the regression equation being y=0.43x+7.38 (R2=0.90, n=33, P=0). After the application of drip irrigation, the change pattern of cultivated lands was determined by the distribution of pipe networks of drip irrigation, especially the distribution pattern and length of main pipe and branch pipes, resulting in the increase of water use efficiency from 0.38 (1960s) growth to 0.65 (2010) in the watershed.
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    Evaluation on Soil Erosion Effects Driven by Land Use Changes over Danjiang River Basin of Qinling Mountain
    LI Ting, LIU Kang, MA Li-yang, BAO Yu-bin, WU Lei
    2016, 31 (4):  583-595.  doi: 10.11849/zrzyxb.20131354
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    Using ArcGIS 10.0 and InVEST Sediment Retention Model, we analyzed the temporal and spatial characteristics of land use change from 2000 to 2010 in Danjiang River Basin, and simulated the change rules of soil erosion and soil conservation under different land use patterns in different periods in order to explore the effect of land use and land cover change on soil erosion and soil conservation. The result indicates: Bare land reduced a large percentage of 90.18 (831.06 hm2) and mainly transferred to water body. Farmland reduced a large area of 5 197.24 hm2 (4.11%) mainly converted to shrubs and towns. The action of grain for green project has begun to show its effects. The reservation and recovery of wetland was particularly effective. During the last ten years, the tendency of soil erosion in this basin was slowing down, but the situation is still serious that most areas are in intensity degree or middle degree of erosion. Taking the feature of land transfer during the study period into consideration, the transition of plough to shrubs was the primary cause of alleviating soil erosion. On the contrary, the inversed transition of forest land, shrubs or grassland to plough was the mainly cause of intensification of soil erosion. The total actual soil conservation in the year of 2000 and 2010 was 5.35×108 and 5.47×108 t, respectively. The soil conservation of ecosystem had an improvement in the whole region because the woodland, which covered more than half of the study area, had stable quantity of soil conservation per unit area. The soil conservation function of ecosystem is a result of all factors. Ensuring a certain area of forest land, and arranging reasonable spatial distribution of grain for green project under artificial intervention are the prerequisites of preventing deterioration of large area soil erosion in Danjiang River Basin of Qinling Mountain. Meanwhile, attention should also be paid to the preservation of arable land.
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    Spatial-temporal Characteristics of China’s Agricultural Net Carbon Sink
    CHEN Luo-ye, XUE Ling, XUE Yan
    2016, 31 (4):  596-607.  doi: 10.11849/zrzyxb.20150430
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    This article uses the county-level dataset to analyze the spatial-temporal characters of agricultural net carbon sink from 1991 to 2011 in China. Research shows that: 1) Overall, the agricultural net carbon sink is positive and increasing, with a net increase of 93.7% during this period. 2) The structure of agricultural carbon sink is relatively stable with rice, wheat and maize accounting for about 80% all together, while the structure of carbon source in the same period changed greatly that the main contributing factor of the carbon source changed from pesticide to agricultural fertilizer. 3) The spatial distribution shows the gap of agricultural net carbon sink among regions is narrowing, and there exists three kinds of agricultural carbon ecological zones. 4) During the period of 1991-2011, counties with negative net carbon sink increased in amount and mainly located in the Southwest China and Inner Mongolia. The decreasing agricultural activities, low absorption of carbon during the growth of agricultural grains, more agricultural input factors, and livestock-leading agricultural activities in these regions may be the main reason.
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    Change of Soil Organic Carbon with Different Years of Spartina alterniflora Invasion in Wetlands of Minjiang River Estuary
    JIN Bao-shi, GAO Deng-zhou, YANG Ping, WANG Wei-qi, ZENG Cong-sheng
    2016, 31 (4):  608-619.  doi: 10.11849/zrzyxb.20150425
    Abstract ( )   HTML ( )   PDF (4338KB) ( )   Save
    The Minjiang River estuarine wetlands is an important tidal wetland ecosystem in Southeast China, as it locates at the boundary between mid and southern subtropical climate zones. The exotic C4 grass Spartina alterniflora was found in Minjiang River estuary in 2002, and since then it had rapidly replaced native plants and become one of the dominant vegetation types in the Shanyutan wetland. Plant invasions could change the quantity and quality of the soil organic carbon (SOC) pool, and thus have potential impacts on ecosystem function and global carbon cycling. In order to understand the carbon sequestration potential of Spartina alterniflora, we investigated SOC, soil organic carbon density (SOCD), soil organic carbon stock (SOCS) and soil physico-chemical properties at 0-60 cm depth of Spartina alterniflora wetlands with Y4 (﹤4 a), Y8 (4-8 a) and Y12 (8-12 a) chronosequence using space instead of time method. SOC of Y4, Y8 and Y12 in the Spartina alterniflora wetlands in the Shanyutan ranged between 14.34-16.95, 16.92-20.18 and 17.34-23.5 g·kg-1, respectively with mean values of 15.5, 17.77 and 19.71 g·kg-1. SOCD of Y4, Y8 and Y12 of ranged between 9.59-12.08, 11.31-13.11 and 13.94-16.08 kg·m-3, respectively with mean values of 10.68, 12.29 and 15.01 kg·m-3. The SOCS in 0-60 cm were 65.24, 73.99 and 90.30 t·hm-2, respectively. What’s more, the SOC in the surface soil of 0-20 cm increased significantly as invasion years extended. Soil C/N, clay and silt composition all increased with invasion years, while soil bulk density and sand composition decreased. SOC was influenced by many factors. The high positive correlation between SOC and C/N suggests that they mainly derive from terrigenous organic matters. Furthermore, SOC and soil moisture, salinity, pH, mean grain size, clay fraction were significantly positively correlated, while negatively correlated with bulk density and sand fraction. They played an important role in determining SOC through affecting microbial activity. Our results suggested that the increase of SOC in the Spartina alterniflorawetland in the short-term possibly due to the large amount of input litter biomass and lower decompo-sition. Spartina alterniflora has strong ability of accumulating organic carbon and effectively enhanced the carbon storage in the estuary wetland.
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    Policies and Optimal Amount of Rural-Urban Land Conversion: From the Perspective of Externalities Internalization
    CHEN Zhu, ZHANG An-lu, HUANG Ling-xiang
    2016, 31 (4):  620-628.  doi: 10.11849/zrzyxb.20150320
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    This paper attempts to empirically analyze the effects of current policies on the optimization process of rural-urban land conversion. Firstly, a decision model of rural-urban land conversion was constructed on the assumption that local governments are decision makers. The model illustrates that land regulation and land conversion taxation both restrain land conversion, but they have different impact on land conversion. Secondly, the decision function of local government in land conversion was simulated and the influence of policies on land conversion was estimated with the reference to the externalities amount in Hubei Province. In the empirical process, the study generalizes and integrates land regulation and taxation policies, including annual land use plan, fees for new construction land, fees for new cultivated land development and fees for occupying cultivated land. Then the decision-making of local government in rural-urban land conversion under land regulation and/or taxation policies were compared. The result shows that both land regulation and taxation decrease rural-urban land conversion significantly. Specifically, the amount standard of taxation is accordance with externalities, but land regulation excessively restrains land conversion. The results also present that the targets of above policies are different from the perspective of externalities internalization. At last, suggestions are provided on the basis of results.
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    Analysis on the Differences and Influential Factors of Cultivated Land Quality Gradation at Different Scales
    LIU Lu, ZHOU Sheng-lu, TIAN Xing, WANG Xiao-rui, SU Quan-long, ZHU Yan, WANG Jun-xiao
    2016, 31 (4):  629-638.  doi: 10.11849/zrzyxb.20150412
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    With the rapid development of economy and the progress of the society, land resource management has been transformed from quantity management to quantity-quality ma-nagement, in which the accuracy of the cultivated land quality grade plays a vital role. Currently, due to the various needs of management such as meticulous management and macro-control, cultivated land quality grading at different scales are needed. However, the results of cultivated land quantity grade differ greatly in accuracy, quantity and spatial distribution because of the effect caused by different scales. Thus, analyzing the scale difference towards cultivated land quantity grade, exploring influencing factors and realizing data integration between different scales on this basis has significant implications to improve the management of land resource quality. This paper conducted a case study of the Donghai County in Jiangsu Province. Firstly, the scale effect on regional cultivated land quality gradation at three different scales (1∶5 000, large scale; 1∶100 000, medium scale; 1∶500 000, small scale) were investigated. The studied scale effect included the differences in terms of the landscape characteristic, grades structure and spatial distribution. Various methods including spatial autocorrelation model, gradient analysis and the Binary Logistic Model were adopted. Then, the natural and socio-economic factors of these scale effects were studied by employing the Binary Logistic Model. The main results were as follows: 1) For the studied three different scales, the corresponding grading results, though in line with each other in general, differed in the spatial distribution of each quality grade. In terms of spatial distribution characteristics such as spatial clustering and variation, the spatial autocorrelation and gradient analysis showed that the consistency between medium scale and large scale was relatively better than that between small scale and large scale. Compared with the cultivated land grading in large scale, the precision of the cultivated land grading in small scale was better than that in medium scale. 2) The influencing factors of cultivated land grading varied from scale to scale. The Binary Logistic Model analysis implied that the grading differentiation between large scale and medium scale was mainly affected by elevation, vegetation cover, patch cohesion, the proportion of cultivated land area, and the ratio of the cultivated land units between two scales. For the cultivated land grading differentiation between large scale and small scale, it was mainly influenced by slope, road density and patch aggregation. 3) The differences of cultivated land quality gradation among different scales are obvious, and it was subject to a number of objective factors, so exploring the conversion and organization of cultivated land grading at different scales was particularly necessary.
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    The Impact of Uncertainty in Satellite Remote Sensing Retrieval of Water Vapor Column on Simulation of Global Solar Radiation
    RAO Jun-feng, ZHANG Xian-feng, LIAN Jing-fang
    2016, 31 (4):  639-648.  doi: 10.11849/zrzyxb.20150431
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    The radiative transfer equation simulation method is an accurate and effective way to obtain global solar radiation indirectly. However, the accuracy of this method is affected by the atmospheric parameters input into the equation. The satellite remote sensing retrieval of water vapor column is analyzed to be at 68.3% confidence level based on comparing the satellite remote sensing products with ground measured data in the period of 2005-2013 in Hong Kong. After collecting other related atmospheric parameters between 2005 and 2013, such as aerosol optical depth, aerosol single scattering albedo, and Total Column Ozone, which affect the transmission of solar radiation, the basic atmospheric environment is simulated. The relative error of global solar radiation simulation (250-2 800 nm) is obtained by running the radiative transfer calculation library in the basic atmospheric environment. The conclusion shows that the relative error of global solar radiation simulation is 1%-3%. The relative error is higher in winter than in summer. The primary factor that decides the relative error is wavelength. The relative error is bigger at the wavelength that has a strong absorption of water vapor. The secondary factor is solar zenith angle. The relative error is bigger to estimate global solar radiation with the radiative transfer simulation method when the solar zenith angle is bigger. The conclusion offers an important reference to the error control when using the radiative transfer equation simulation method to get the global solar radiation.
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    Research of the Mean Annual Water Balance during 1980-2013 in Chaobai River Basin
    ZHOU Xiao-zhen, PAN Xing-yao, ZHU Yong-hua, HU Ya-zi
    2016, 31 (4):  649-657.  doi: 10.11849/zrzyxb.20150346
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    In order to study the responses of water balance components to different land cover characteristics in long-term average scale in Chaobai River Basin, the data of precipitation, streamflow and evaportranspiration from 1980 to 2013 were adopted to calibrate a coupled water and heat balance model. Moreover, the change of the streamflow was predicated based on the reasonable forecasting of the underlying surface in the next ten years. The results showed that the model was applicative very well in Chaohe and Baihe river basins. On the basis of the existing underlying surface information, 11 situations of the change of the underlying in the future is predicted respectively by use of both data of the forest land area and the underlying surface parameters of grass watershed. The stremflow in the future was predicated based on the 11 situations respectively. The results showed that the streamflow ranges from 26.47 mm to 53.55 mm in Chaohe River Basin and the streamflow ranges from 17.57 mm to 41.53 mm in Baihe River Basin. The innovation of this work is predicting the streamflow based on the predicting of underlying surface in the future. It is of great significance for the study of water resources and formulating the water managements.

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    Study on Temporal and Spatial Variation of the Dry-wet and Its Influence Factors in Xinjiang Based on Aridity Index
    ZHANG Yan-long, LIU Pu-xing
    2016, 31 (4):  658-671.  doi: 10.11849/zrzyxb.20150345
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    Based on the collected climate data regarding daily temperature, precipitation, wind speed, sunshine hour as well as related humidity from 53 meteorological stations, and atmospheric circulation index and sunspot in the study region during 1961-2013, evapotrans-piration (ET0) was estimated by applying Penman-Monteith model. Additionally, Inverse Dis-tance Weighted was applied to comprehensively investigate the temporal-spatial variations of ET0, precipitation and aridity index (AI). The abrupt change and period of ET0, precipitation and AI were characterized using comprehensive time series analysis conducted with moving M-K test and Morlet wavelet. Principal component analysis was employed to analyze the factors that influenced the AI. The results showed that: In recent 53 years, precipitation displayed an increasing trend (8.81 mm/10 a), ET0 and AI presented decreasing trend on the whole at the rates of -28.73 mm/10 a and -0.05/10 a, suggesting that the regional climate trended to be wetter in Xinjiang. As for annual distribution, ET0 and precipitation both exhibited unimodal distributions with peaks appeared in August (137.12 mm) and July (24.58 mm), the maximum in September (0.9), and the minimum in January (0.46). Spatially, the ET0 in southern Xinjiang was greater than that in northern Xinjiang, and that of east was greater than that of west; the precipitation in northern was greater than that in southern. The spatial patterns of AI and precipitation were opposite. Overall, the AI in south was greater than that in north, and that in basin was greater than that in the mountains. The M-K trend of AI was between 0 - -0.02/a, and the decreasing trend of AI in north was more extraordinary than that in south, consistent with the facts that the north of Xinjiang was wetter than the south. The abrupt changes for ET0 and precipitation occurred in 1987 and 1981, respectively. There were two distinct point mutations of AI in 1981 and 1984. Morlet wavelet and its power spectrum analysis showed: Precipitation exhibited periods of 6.49 a, 5.71 a and 4.35 a (p≤0.05), ET0 showed the period of 21.37 a (p≤0.2), and AI had periods of 6.62 a and 3.45 a (p≤0.1), indicating that it was related to atmospheric circumfluence and El Niño events to some extent. Principal component analysis demonstrated: AI was positively correlated with temperature and negatively correlated with precipitation, and the southern part of Xinjiang was more sensitive to precipitation than the northern part. Correlation coefficient between AI and WYMI, and ENSO were 0.46 (p≤0.05) and -0.34 (p≤0.05), respectively.

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    The Spatial Distribution and Monthly Variation of Soil Moisture of Sub-alpine Shrubs in Qilian Mountains
    ZHAO Yong-hong, LIU Xian-de, ZHANG Xue-long, NIU Yun, ZHAO Wei-jun, LIU Bing-fang
    2016, 31 (4):  672-681.  doi: 10.11849/zrzyxb.20150280
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    In order to explore the spatial distribution and monthly variation of soil moisture of the main shrub types in the Qilian Mountains, permanent sample plots were set up for five shrub types in the small watershed of Pailugou of Qilian Mountains, including Caragana jubata, Salix gilashanica, Dasiphora fruticosa, Berberis diaphana and Caragana tangutica. The soil moisture at the depth layer of 0-10, 10-20, 20-30, 30-40, 40-60 cm was measured in a growing season. The results showed that: 1) Among the five shrub plots, the soil moisture differed obviously, according to the following decreasing order: Caragana jubata, Salix gilashanica, Potentilla fruticosa, Berberis diaphana and Caragana tangutica. 2) At the spatial scale of the studied small watershed of Pailugou, the soil moisture was jointly influenced by several factors, such as the elevation (precipitation), slope aspect, vegetation, and soil. This leads to the increase of soil moisture with increasing elevation (higher soil moisture at higher plot) and terrain shading effect (higher soil moisture on shaded slops than on sunny slope). 3) The degree of variation of soil moisture in the growing season can be basically classified into the low or middle intensity for all the five shrub types. The variation coefficients of soil moisture in the same soil layer basically following the decreasing order of Berberis diaphana > Caragana jubata > Salix gilashanica > Potentilla fruticosa > Caragana tangutica.
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    Research on Wild Plant Flora and Cultivated Plant Construction in Huaibei National Urban Wetland Park
    WANG Li-long, ZHANG Zhe, JIN Xiu-long, LU Lin
    2016, 31 (4):  682-692.  doi: 10.11849/zrzyxb.20150494
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    Wetland park is an ideal way of wetland protective utilization. As far as January 2016, China has 706 national wetland parks and 46 national urban wetland parks. Till now, most wetland parks have no specification of construction design. In recent years, the number of wetland park rose quickly in China, but the guidance for wetland park construction is few, and thus it led to the fact that influential wetland park is few. As it is a new thing, there is no much construct theory for it. A lot of wetland parks lack of full consideration of regional nature and society, and can’t deal with the relationship between wetland protection and recreation entertainment, so the wetland ecosystem was often destroyed by human activities. In this work, a survey on wild plant flora was conducted in the national urban wetland park at coal mine subsidence of Huaibei City. The construction of cultivated plants was evaluated. The results showed that: 1) There are 115 species of wild plants belonging to 42 families and 95 genera, including 6 families of monocotyledon plants belonging to 27 species, 35 families of dicotyledon plants belong to 87 species, and 1 family of pteridophytes plant belonging to 1 specie. Gramineae, Compositae and Leguminosae are dominant families. The composition of genera is relatively dispersed, all being single species or few species genera. The wetland plant species take obvious advantage, which are mainly farmland weeds. 2) The wetland vegetation can be divided into 2 vegetation type groups, 5 vegetation types and 18 formations. Phragmites australis, Typha orientalis, Paspalum paspaloides, Imperata cylindrical, Chenopodium album and Cynodon dactylon are the dominant species in the wetland park and format a large area of dominant communities. 3) There are 34 species of cultivated plants which belong to 19 families and 31 genera, and mainly are Populus × canadensis ‘I-214’, Salix babylonica, Euonymus japonica and Zoysia tenuifolia. 4) There are 10 exotic plants, in which Gaura parviflora is recorded for the first time in Anhui Province. We put forward some protection and restoration strategies towards the main problems about the protection of wild plants and the construction of cultivated plants in the park. Park management department should not only clarify the core and buffer areas of the wetland park, but also need to carry out different measures for the core and its surrounding area, and protect the wild flora and its environment. The selection of cultivated plants should give priority to native plants, and use external plants as less as possible. Invasive plants have had great influence on the landscape of the park and other plants, so manual removal and other measures should be taken to stop their expansion. The main plants in the wetland park should be notated with names. The popularization and education on wetland plants and ecology would reduce the public damages to the plants in the park.
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    Resource Research Method
    Remote Sensing Inversion of ET0 in Eastern Agricultural Area of Qinghai Province Based on Ridge Estimation
    GAO Si-yuan, CUI Chen-feng, FAN Yu-ping
    2016, 31 (4):  693-702.  doi: 10.11849/zrzyxb.20150432
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    In this study, ET0 values were calculated by using the Penman-Monteith equation and the meteorological data of the 12 weather stations in the eastern agricultural area of Qinghai Province from 2003-2005. Remote sensing data was assimilated with the digital elevation models (DEM), land surface temperature (LST), and normalized difference vegetation index (NDVI) to acquire the data set with time resolution of ten days and the spatial resolution of 1 km. Then a multivariate retrieval model between ET0 and these variables was established. Since there is a strong correlation among these independent variables, for example the correlation index R2 of LST and NDVI is about 0.7 on average, a partial least-squares regression cannot be directly established. This study established a model with the ridge estimation method which can reduce the model error and improve the retrieval accuracy. The minimum retrieved accuracy reached 76.19% and 83.54% in 2013. Compared with traditional methods, the checkpoint variance was significantly reduced and the retrieval accuracy was improved. The model met the requirements of practical application.
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    Comprehensive Discussion
    Progress in Remote Sensing Recognition and Spatio-temporal Changes Study of Urban and Rural Land Use
    LI Guang-dong, FANG Chuang-lin, WANG Shao-jian, ZHANG Qiang
    2016, 31 (4):  703-718.  doi: 10.11849/zrzyxb.20150324
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    Land use and cover changes play an important role in the study of global environmental change and sustainable development. This paper summarizes the related research progresses in two fields, land use and cover information recognition based on remote sensing images and their spatial and temporal changes. The study found that land use and cover studies have already formed a particular research paradigm under the support of RS and GIS technique. There is an important research trend of combination of multi analysis methods, multi data sources and multiple periods. Current studies have made significant progress in the recognition of ecological-production-living space. However, much attention has been paid on the studies in cities especially big cities, while the studies in small and medium-sized cities and towns do not obtain enough attention. The studies in spatiotemporal changes of land use and cover focus on urban and rural units. The causes, consequences, characteristics, processes, patterns and measuring methods of urban expansion and urban sprawl are the main aspects of urban land use and cover studies. Cultivated land protection and rural residential land changes are the focuses of rural land use and cover studies. There is an undesirable tendency that urban land use and cover received more attentions than rural ones. Future studies should pay more attention to improving problem-orientated research and application of research findings, so as to build an innovative research framework suitable for China. Integrated studies of multidisciplinary and multi-field should be encouraged to create native and original achievements.
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