In order to timely monitor the ecological environment changes during the development of water energy and coordinate the relationship between hydropower development and ecological environmental protection, Landsat TM/OLI images in 1987, 2004 and 2015 were selected according to the timeline of Qingjiang hydropower cascade development. Four evaluation indexes, namely, modified adjusted soil vegetation index (MASVI), wet index (WET), land surface temperature (LST) and normalized difference soil index (NDSI), were extracted to represent the four aspects of greenness, humidity, heat and dryness. A new remote sensing ecological index (RSEI) was generated using principal component analysis to evaluate the ecological environment of Qingjiang hydropower development zone. Results show that:(1) The RSEI of the middle and lower reaches of the Qingjiang River in 1987, 2004 and 2015 were 0.443, 0.664, and 0.515, showing a trend of first rising and then declining. (2) The ecological environment improvement areas are mainly distributed in the low hilly areas and flat plain areas, while the ecological environment degraded areas are mainly distributed in the water conservancy hubs and their affiliated reservoir areas, the Karst mountains along the coast, and the hilly areas where the Qingjiang River afflux into the Yangtze River. (3) The ecological environment of Qingjiang hydropower development area is most closely related to the MASVI and the NDSI. The average correlation of the 3 years between ecological environment and these two indexes is 0.879 and -0.916, respectively. Improving vegetation coverage and controlling bare and dry surface are the keys to the environmental restoration of hydropower construction areas.

GIS technology, field investigations, and statistical methods were used to analyze the spatial characteristics of the rural settlement patterns in Bole County and an ecological security protection pattern was built for the optimization of rural settlement. The results show that:(1) the spatial distribution, size and shape of rural settlements in Bole are sparse in the north and south, dense in central regions, larger in the east, and smaller in the west, with characteristics of "overall in rule" and "local with complexity"; (2) the rural settlements are divided into four shape-discrete distribution combinations:large scale-complex-centered, medium scale-complex-centered, medium scale-regular-sparse, and small scale-regular-sparse; (3) a pattern to protect the ecological security of woodlands and water areas as source areas would require rural settlements to be established based on a division into four optimization areas as for key remediation, restricted expansion, moderate construction, and concentrated development. These results could provide a scientific basis for planning and developing rural settlement oases and protecting fragile ecological environments based on strategic plans for ecological civilization construction and rural revitalization.

Urban-rural ecotone is a transitional zone between urban and rural areas with frequent changes in land types and the prominent contradiction between human and land. Taking the urban-rural ecotone of Beijing as the research object, we developed a new index of tree canopy and analyzed the changes of tree canopy in rural residential areas in 2002 and 2013 based on the true color aerial photographs of August-September 2002 and WordView-2 satellite images of August-September 2013 with the resolution of 0.5 m in order to provide some useful theoretical and practical guidances for the ecological environment construction of rural residential areas under the background of the current rural revitalization. The results show that the overall tree canopy in the urban-rural ecotone increased from 19.54% to 22.15% from 2002 to 2013, the number of rural residential areas decreased by 428, and the average tree canopy in residential areas increased from 17.78% to 25.01%. From the tree canopy level, the proportion of rural residential areas with high coverage and very high coverage in 2013 increased by 14.27 percentage points and 6.45 percentage points respectively compared with that of 2002. The proportion of rural residential areas with very low coverage decreased by 0.13 percentage points during this period. In terms of spatial distribution, for both 2002 and 2013, the tree canopy in rural residential areas showed an increasing trend with the increase of ring roads. Over the 11 years, the tree canopy in old residential areas reduced from 19.03% to 16.39%. The probability matrix analysis of land transfer showes that the construction land is the most stable and the probability of keeping itself unchanged is 84.50%. The tree canopy in the newly emerging rural residential areas (25.70%) is significantly higher than that in the disappeared rural residential areas (15.54%). Statistical analysis on the changes of rural residential areas in different change modes show that the tree canopy rates of the expanded, newly increased and marginally increased rural residential areas were 25.05%, 25.70% and 27.71%, respectively.

The research methods of the optimization of the layout of the rural residential points in the area of the disaster-prone area of the geological disaster were discussed, and the comments for the scientific planning of the layout of the rural residential land under the threat of the geological disaster were provided. Taking Dongtou County of Zhejiang Province as an example, eight factors i. e. forest coverage rate, geological rock group, elevation, slope, rainfall, density of geological disaster points, population density and highway density were selected as evaluation indicators, the gray correlation analysis model and ArcGIS spatial analysis method were applied to classify the geological disaster susceptibility grade, so as to obtain the distribution of administrative villages and settlements in different geological disaster-prone areas. The results show that the proportion of the moderately geological disaster-prone area and the highly geological disaster-prone area in the studied area of Dongtou County reached to 42.46%, which includes 91.36% of historical geological disaster points in Dongtou County. 45 administrative villages and residential areas such as Douyan Village, Xilang Village and Tantou Village are located in the moderately geological disaster-prone area, accounting for more than 50% of the total area of each village or residential area, 27 administrative villages and residential areas such as Tantou Village, Tong'ao Village and Zheng'ao Village whose coverage are more than 70% of the total area of each village or residential area. The corresponding optimization direction is proposed to provide scientific basis for the planning of disaster prevention and mitigation based on the geological disaster susceptibility situation of each administrative village and the current distribution of residential space.

For assessing the impacts of different water conditions on maize yield and environmental emissions of maize production, and for identifying the corresponding improvement measures, the meteorological data, and the data of fertilization, irrigation, soil properties as well as the development of maize growth were all collected in Taigu County, Shanxi Province from 2002 to 2016. The emissions of CO₂, NH₃, N₂O and nitrate leaching during the period of maize growing season with changing amounts of rainfall and fertilization were simulated by using the DNDC model. The life cycle assessment approach was applied to quantitatively evaluate the impact of maize growth on the resource use and environmental emissions; Then the relationships between rainfall and the resource consumption and emission were analyzed, and the reasonable amounts of fertilization and irrigation under different rainfall patterns were recommended. (1) When the rainfall ranged from 300 mm to 600 mm, the rainfall was positively correlated with the emissions of CO₂, nitrate leaching and NH₃ volatilization (P<0.05), while it was negatively correlated with N₂O emission. (2) When the rainfall was above 560 mm, namely abundant rainfall year, the comprehensive impact factor in the whole process of maize production ranged from 0.19 to 0.20, it was in the range of 0.17-0.27 in normal year with the rainfall from 380 to 560 mm, while it was 0.3 in dry year with the rainfall below 380 mm, respectively. The whole process of maize production had much high impacts on the environment in the dry year, followed by the normal year and abundant rainfall year. (3) The results of numerical simulation indicate that when the rainfall was below 380 mm and fertilization rate was fixed, with the increasing of the irrigation amounts, the yield was increased and the environmental emission was reduced, and the comprehensive impact factor declined to less than 0.2. Under rainfed conditions, the comprehensive impact factor will fall to 0.2-0.3 and the yield was only decreased by 3.15% when the fertilization rate was reduced to 210-315 kg·hm^-2; In the normal year, if the fertilization rate was decreased by 15% to 20%, the yield did not drop remarkably, but the impact on the environment was reduced obviously. Global warming potential, eutrophication potential, energy consumption and land use were correlated with the annual rainfall patterns. Irrigation has a great influence on the environment in the whole process of maize production. The sufficient irrigation led to high yield and less environmental impact, while the shortage of water resulted in low yield and much more environmental impact. Therefore, it is suggested to increase the amount of irrigation in dry years, and to decrease fertilization rate to reduce the environmental impact of maize production in rainfed areas.

The climate change has significant effects on the potential distribution of Martes zibellina in Daxing'anling region. Eight key environmental factors, including four climate variables (Bio1, Bio2, Bio5, Bio6), three topographic variables (slope, aspect, elevation) and vegetation type, were selected to simulate the potential distribution of Martes zibellina in Daxing'anling by using MaxEnt model with the current and the future climate change scenarios (RCP 4.5, 8.5). The Priority Protection Areas (PPAs) and the target PPAs were identified by Zonation and ArcGIS. The results show that:(1) The suitable habitats of Martes zibellina are mainly distributed in the central and the northwestern parts of Daxing'anling with the current climate scenario, which is 13.74% of the total area of Daxing'anling region; (2) With the future climate change scenarios, the suitable habitats of Martes zibellina would be decreased by 7.21-13.72 percent compared to the current area; (3) Under current climate condition, the PPAs of Martes zibellina are mainly distributed in the northeast of Ergun City, the southwest of Mohe County, the west of Huma County and the east of Genhe City, and 46.19% of the target PPAs have been conserved by protected areas (PAs). The protection gaps were mainly distributed in the central and the east of Genhe City, and the juncture of Ergun City and Mohe County. It is recommended to set ecological corridors and more PAs to provide strong guarantee for the effective protection of Martes zibellina.

There are a large number of rural settlements in nature reserves in China, such as villages, hamlets, farms, small industrial enterprises and other constructed facilities. The distribution of rural settlements in nature reserves is the result of multiple factors such as the local natural environment and social economy. Carrying out the suitability analysis of the settled land in nature reserve can guide the sustainable rural development of the nature reserve in the future and provide reference for decision-making in coordinating nature protection and economic development. The Chinese government has formulated an ecological protection plan to implement immigration of residents from the core and buffer areas in nature reserves. Taking the Yaoluoping Nature Reserve in Anhui Province as an example, based on GIS technology, 10 indicators were selected from three aspects including natural conditions, ecological constraints and social economy to construct an evaluation index system to find suitable land for settlement in this Nature Reserve. The results show that the construction suitable area of the Yaoluoping Nature Reserve accounts for 21.80% of the total area, concentrated in lower mountainous valleys of the northern part of the nature reserve. The construction restricted area accounts for 19.03% and the construction prohibited area accounts for 59.17%. In the existing settlements, 75.10% are distributed in the construction suitable area, 8.44% in the construction restricted area, and 16.46% in the construction prohibited area. According to the evaluation results, three layout optimizations for development, restriction and relocation are proposed for the existing settlements. This regulation strategy protects the biodiversity of core areas with rare and endangered species while establishes the development space for habitation in the protected area in line with the actual situation.

To explore the diversity and characteristics of traditional rural weed communities in response to heterogeneous habitats, the ruderal species composition of Canhuashan Village were investigated. The village is located in northeastern Sichuan Province and retains various types of traditional rural habitats such as farmland, ponds, cemeteries and forests. The investigation were conducted in October 2016, and January, May and August 2017, and TWINSPAN classification and canonical correspondence analysis (CCA) were employed to analyze the ruderal communities. A total of 238 weed species belonging to 181 genera and 61 families of recorded in the area, with dominant families of Compositae and Gramineae. Six ruderal community types were identified by using the TWINSPAN. Illumination intensity and soil moisture were the main environmental factors affecting the distribution of ruderal communities as result of CCA analysis, indicating that weed species, habitat types and community types showed similar distribution patterns, which was consistent with the results by using TWINSPAN. This research highlighted that traditional villages were characterized by diversified habitat types affected by the process of traditional production and living of rural aborigines, and this would be the important maintenance mechanisms of rural biodiversity.

In order to investigate the characteristics of nitrogen and phosphorus pollution in the west bank of the Wangyu River and its impact on the water quality of the Taihu Lake, the concentrations of nitrogen and phosphorus in various forms were measured at four representative tributaries in the west bank of the Wangyu River in November of 2017, and March and June of 2018. The form composition, seasonal and spatial distribution of nitrogen and phosphorus and their influence on the quality of water diversion were studied. The results are as follows:(1)The average concentrations of TN in Bodugang, Xutangqiaohe, Gushiqiaohe and Zhangtanghe were 4.93, 5.20, 2.27, 3.78 mg·L^-1, respectively, and the average TP concentrations were 0.18, 0.23, 0.16, 0.15 mg·L^-1, respectively; NO₃^--N and PO₄^3--P were the main forms of nitrogen and phosphorus, respectively. (2)The average concentration of TN in Bodugang, Xutangqiaohe and Gushiqiaohe in summer were the highest, which were as 1.24, 1.44 and 2.01 times as that of the lowest season, respectively; Along the inflow direction to Wangyu River, the concentration of nitrogen and phosphorus in the four tributaries had a downward trend. However, the water quality of the river entry section of the tributaries does not meet the water quality target (Class Ⅲ) of the regional water function zoning. (3)91.3% of the water sections in the study area were at the moderate eutrophication level and 56.5% of the water sections were in phosphorus-limited state. (4)EC, COD_Mn and Chl-a were the main factors affecting the distribution of nitrogen and phosphorus forms. The influx of nutrients in the study area has a great impact on the water quality of the Wangyu River, especially phosphorus pollution. It is necessary to strengthen the reduction of dissolved phosphorus concentration in water bodies. Nitrogen pollution is the most serious in summer which is the diversion period of the Wangyu River. It is necessary to strengthen the pollution control of the tributaries entering the river to ensure the water quality during water diversion.

In order to evaluate the pollution level and ecological risk of antibiotics in the typical Eriocheir sinensis aquaculture environments of Jiangsu Province, the residues of five classes of antibiotics (macrolides, tetracyclines, beta-lactams, quinolones, sulfonamides) in surface water and sediments of four ponds in Gaochun and Jintan were analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The results show that there was a certain degree of antibiotic contamination in water of both Gaochun and Jintan Eriocheir sinensis ponds. The main antibiotics in Gaochun water were quinolones, tetracyclines and macrolides, while the five classes of antibiotics were evenly distributed in Jintan water. Among them, residual of antibiotics was the highest in GC2 water, including chlortetracycline hydrochloride (241.99 ng·L^-1), spiramycin (198.53 ng·L^-1), ciprofloxacin (168.81 ng·L^-1), sarafloxacin (165.40 ng·L^-1), norfloxacin (126.17 ng·L^-1), enrofloxacin (117.42 ng·L^-1) and enoxacin (103.08 ng·L^-1). The concentration of antibiotics in sediments was relatively low. Correlation analysis between antibiotic residues and corresponding water pollution indicators show that the residual concentrations of clindamycin, doxycycline, and penicillin G sodium salt were significantly correlated with COD_Mn. The risk quotients (RQ) indicate that there was a certain extent of ecological risk of antibiotics in the Eriocheir sinensis aquaculture environments of Gaochun and Jintan, especially the macrolide and quinolone antibiotics in GC2, which directly affected the growth of phytoplankton such as algae. The use of antibiotics should be controlled in the breeding process to reduce the ecological risk.

In order to obtain the pollution status of heavy metals in suburban farmland soils of Tianjin City, five heavy metal elements including As, Pb, Cd, Cr and Ni in 327 farmland soil samples from four suburban areas of Dongli, Xiqing, Jinnan and Beichen Districts were collected and analyzed. Results show that the average concentrations of As, Pb, Cd, Cr and Ni in soils were 10.01, 33.71, 0.32, 56.95 and 33.50 mg·kg^-1, respectively, which were higher than their soil environmental background values of Tianjin except for Cr. Among the five heavy metals, Pb, Cd and As exceeded the "Soil Environmental Quality Risk Control Standard for Soil Contamination of Agricultural Land (GB 15618-2018)" with the exceeding rates of 3.06%, 14.07% and 0.31%, respectively. It suggested that contamination by Cd occurred in some of the farmland soils in Tianjin suburbs, and a small amount of farmland soils were contaminated by Pb and As, while the risk of soil contamination by other heavy metals was low. Evaluation of pollution degree of heavy metals in farmland soils by both single factor pollution index method and Nemerow comprehensive pollution index method show that the contamination of Cd in Tianjin suburban soils was at the alerting level. High Cd concentrations were mainly distributed in Dongli District, and in orchard soils. Other heavy metals were at safe levels. Overall, except for Cd, the risk of heavy metals pollution in surburban farmland soils of Tianjin City was low.

The concentrations of 8 metals (Hg, As, Pb, Cd, Cu, Cr, Zn and Ni) were measured in the surface soil (0-20 cm) from 89 farmlands in Xuzhou, China. Sources and spatial distributions of the heavy metals were analyzed using multivariate approaches and the ordinary Kriging method. Major conclusions are as follows. The mean concentrations of all 8 heavy metals in the soil were below the critical limits of the national safety standards, therefore meeting the farming requirement. The mean concentrations of Hg, Pb, Cu and Cr were higher than the background values of Xuzhou and Jiangsu, which suggested a potential metal contamination. In terms of the soil type, Cd, As, Cr, Zn and Ni in paddy soil were relatively enriched among different soil plantations. The concentrations of Hg in dark brown soil was relatively low and Pb in yellow soil was high among 4 types of soil. Principal component analysis and correlation analysis indicate that the sources of Cd, As, Cu, Zn and Ni were mainly parent materials, whereas Pb and Hg have anthropogenic sources. High concentrations of As, Zn, Cr and Ni were noted in the north of Tongshan District and Peixian County and in the west of Jiawang District. The concentrations of Pb, Cd and Cu peak was in Pizhou, while the highest concentration of Hg was likely related to human activities in urban areas.

Effects of 4 amendments[biochar, phosphate rock, calcium carbonate (CaCO₃), and attapulgite] combined with compost on copper (Cu) and cadmium (Cd) concentrations in romaine and available Cu and Cd in a Cu-Cd contaminated soil were investigated in a pot experiment. The results show that although amendments could decrease the available Cu and Cd concentrations in soil, while because of the activation by compost, amendments combined with compost still increased available Cu and Cd concentrations in soil compared with the control, but they decreased Cu and Cd concentrations in romaine by 4%-28% and 2%-35% respectively, and the remediation efficiency of CaCO₃ combined with compost was better than other treatments. Relativity analysis show that compost alone and amendments combined with compost could inhibit the uptake and transport of Cu and Cd by romaine, thus reduced their accumulation in romaine.

The accumulation and chemical forms of vanadium (V) in the seedlings of two sweet maize (Zea mays) cultivars under V stress were investigated by pot experiment. The results show that the distribution of V content in two sweet maize cultivars was much higher in roots than in shoots, more V enriched by the roots of maize seedlings. The V content of the roots of Meitiannuo No.8 accounted for 83.91%-89.09% of the total, and Yitian 608 was for 84.59%-92.33%. Among the stems and leaves of different maize varieties, the chemical form of V is mainly ethanol extracted (F_E), but V speciation were mainly in the chemical forms of HCl extractable (F_HCl) and residue state (F_R) in roots, respectively. It indicates that V in the roots of Meitiannuo 8 maize was mostly less active organic acid salt, pectin acid salt and protein binding state, while V in Yitian 608 maize was deposited at the root with heavy metal phosphate or oxalate, which is hardly soluble in water, avoiding the ability of excessive V to transfer from the roots to the shoots, reducing the toxicity of V to maize seedlings. Yitian 608 is more resistant to V. The results provide a theoretical basis for exploring the absorption and tolerance mechanism of sweet maize seedlings to V.

Cadmium contamination of rice grains has become an important factor affecting the quality and safety of rice in China. To explore relationships between Cd contamination in rice and various environmental factors, spatial mapping was carried out. Eleven environmental factors were selected for study. Using a decision tree model and a reasoning mapping method, the main factors controlling Cd contamination in rice were identified in a case study area, and a spatial prediction technology for identifying rice with Cd levels in excess of the Chinese standard was established. The results show that transportation distance, soil organic matter content and amorphous iron content were the main factors correlated with Cd contamination in rice. Rice having Cd contents exceeding the standard in the study area were extracted and classified into five grades according to their associated risk degree. The empirical accuracy of this classification method was 85.71%. In addition, a subordinate degree spatial analysis method was used to make spatial predictions of rice areas having Cd levels exceeding the standard threshold, based on information from limited sampling points. The classification accuracy using this method reached to 91.67%, representing a marked improvement, compared with the simple decision tree and traditional interpolation mapping results. However, the decision tree model developed in this study predicts the spatial distribution of Cd contamination risk in rice, making it of practical significance to mitigating Cd contamination risks in rice.

In order to understand the crop responses to climate changes in Tibetan during 1980 to 2015, the crop yield, the temperature and precipitation were analyzed with empirical orthogonal function (EOF). Results show that crop yields along Yarlung Zangbo river and in Nyingchi region were sensitive to precipitation and temperature. The most sensitive area of highland barley and spring wheat was in the middle and lower reaches of Yarlung Zangbo river. Meanwhile, the most sensitive area of legume crops was found to be in Lhasa and the south-east Tibet. The most sensitive area of rapeseed crop was in Lhasa. Before 1984, the highland barley output was in a relatively low-yield stage. It was in a period of volatility between 1994 and 1999, and turned into a high-yield stage after 2000. The change of highland barley output in this region was in good agreement with the time coefficient corresponding to the first mode of temperature and precipitation EOF, which indicate that the highland barley output had obvious response to climate change, and its sensitivity to temperature was better than that to precipitation.

This study aimed to evaluate the potential hazard of haloacetic acid in drinking water of Shihezi City to human health. From July 2017 to June 2018, the raw water, finish water, and pipe network water of a water plant in Shihezi City were sampled. GC-μECD detection and analysis were used to measure the concentration of haloacetic acid. Changes in the concentration of haloacetic acid in different processes and season effluents were analyzed. The health risks of drinking water exposure were also evaluated. Results show that the average concentrations of monochloroacetic acid, dichloroacetic acid, monobromoacetic acid, dibromoacetic acid, tribromoacetic acid, bromodichloroacetic acid, chlorodibromochloroacetic acid, and bromochloroacetic acid in the finish water of a water plant in Shihezi City were ND, 0.21, 0.45, 5.90, 2.00, 1.10, 4.50, and 1.50 μg·L^-1, respectively. The concentrations of DCAA did not exceed the requirement of GB 5749-2006. HAAs were relatively high in summer, temperature was positively correlated with HAAs, and pH was negatively correlated with HAA concentration. The concentration of HAAs in drinking water in Shihezi does not cause potential harm to human health.