Rural development has become the key to promoting new urbanization and urban and rural integration, and improving rural human settlements is an important foundation for rural development. The environmental quality of rural human settlements in 6 municipal districts and 30 counties (county-level cities) in Jianghuai Region of Anhui Province was taken as the research object, a complete set of rural settlement construction evaluation index system has been set up, which consists of five subsystems, such as living conditions, economic development, infrastructure, public service and eco-environment, Using the Fully Arrayed Polygon Aggregate Index Method and Spatial Analysis Method to evaluate the quality of rural human settlements in counties of Jianghuai Region of Anhui Province, and to explore its spatial differentiation characteristics and its influencing factors. The results show that the spatial differences of rural human settlements' environmental quality in the Jianghuai Region of Anhui Province are significant, and the rural human settlements' environmental quality in the eastern region is higher than that in the western region. Meanwhile, The spatial aggregating feature are obvious. The quality of rural human settlements shows the high value agglomeration in the southeast region (Chaohu) and the low value agglomeration in the northwest region (Huainan and Lu'an). The quality of rural human settlements is affected by various factors such as natural environment, socio-economic development, regional culture and so on. Regional culture plays a relatively stable role in the quality of rural human settlements, while water resources, the population attractiveness and infrastructure have a significant impact on the quality of rural human settlements. Through the comprehensive quality analysis, the classification guidance of rural human settlements construction was proposed, which provided the basis for improving the quality of rural human settlements in Jianghuai Region of Anhui Province.

Soil erosion is recognized as one of the most serious ecological and environmental issues today. A rainfall-runoff erosivity factor, together with the effects of duration, magnitude and intensity of rainfall event, can be used to evaluate a rainfall event's potential ability to cause erosion. It is important to study the temporal and spatial distribution characteristics of rainfall erosivity in Ganyu District of Lianyungang, which is of great significance to the evaluation of soil loss, risk assessment and management in the northern rocky mountain area. Taking the Ganyu District as the study case, the daily rainfall data of 12 precipitation stations in Ganyu District during 1954-2014 in a rainfall erosivity model proposed by the Chinese scholar Zhang Wenbo were applied. The Inverse distance weighted space interpolation method, Mann-Kendall non-parametric test variation coefficient and rescaled range analysis were applied to analyze the temporal and spatial variation characteristics of rainfall erosivity. The results show that the range of annual rainfall erosivity in Ganyu District was 2 048.3-12 369.2 MJ·mm·hm^-2·h^-1·a^-1 with an average value of 6 154.9 MJ·mm·hm^-2·h^-1·a^-1, which is consistent with the temporal variation of annual rainfall and erosive rainfall. The distribution curve of rainfall erosivity has a single peak. The rainfall erosivity from April to September is 89% of the whole year. The duration of flood season in Jiangsu Province is same as that in Ganyu District. The rainfall erosivity in a year was divided into four periods, including high-value period, mid-value period, low value period and non-erosive period. The rainfall erosivity from July to August accounted for 61.5%, so the risk of soil erosion in this period is high. In the spatial distribution of the Ganyu District, the rainfall erosivity decreased and the contours gradually concentrated from southeast to northwest as a whole. The interannual variation of the R value in coastal area is larger than that in inland area, and the trend of change is obvious in different regions. The whole area of Ganyu area showed a low degree of variation without a significant upward trend. The analysis showes that the rainfall erosivity will continue to increase after 2014 and soil erosion will be further aggravated.

Applying of pesticides can help to save labor costs, inhibit crop pests and diseases and increase the economic benefits in agricultural production. However, excessive application of pesticides not only damages users' health, but also endangers food safety and pollutes the environment. From the perspective of maximizing social benefits and private benefits, the external costs of pesticide over-utilization in rice production was calculated, which includes the loss of pesticide users, consumers of agricultural products and non-target organisms in the environment, by application of the pesticide environment accounting tools (PEA), environmental impact quotient (EIQ) and damage control models. Based on the results, it was estimated for the optimum cost of pesticide application and the cost of over-application. The results show that:(1) Now, it is quite serious for the excessive pesticide application in rice production in China. In 2016, the cost of pesticide application was 225.3 yuan·hm^-2 (at constant 1990 prices), which was respectively 1.45 times and 1.22 times of the optimum society and private pesticide application cost. (2) Since 1990, it was gradually increased and shown an upward trend for the external cost of pesticide application in rice production. From 1990 to 2016, it was increased from 11.2 to 76.7 yuan·hm^-2 for the external cost of pesticide application in rice production, which was increased 5.8 times with 7.3% rate of growth per year. (3) It is inconsistent in quantity and rate of growth for the optimal application of pesticide per hectare under the social and private interests. It was 155.5 and 184.0 yuan·hm^-2, respectively for the optimum application cost of social and private pesticides in 2016, the latter was 18.3% higher than the former. From 1990 to 2016, the gap was increased from 11.0 to 28.5 yuan·hm^-2 between the pesticide best society application costs and the best private application costs. The growth rate of the optimum dosage for private farmer was faster than for the society. Therefore, the public sector should reasonably regulate the production of highly toxic pesticides, develop low-toxic pesticides and biological pesticides, strengthen the training of pesticide application technologies, promote the socialized prevention and control of crop pests and diseases, strengthen the integrative pest management approach, and vigorously promote the harmful biological comprehensive prevention or physical control measures, so as to solve the problem of excessive pesticide application and reconcile inconsistencies in pesticide application cost.

Intercropping in non-irrigated apple orchards, especially before prominent fruit production, is an agroforestry style fairly prevailing in tableland areas of the Loess Plateau owing to the large-scale expansion of apple cultivation. In order to emphatically take apple trees as principal components in orchard management and set up favorable intercropping system, the overall investigation of intercropping types was carried out in the typical tableland areas in the boundary of Shaanxi Province and Gansu Province, and in some representatively selected orchards, the height, basal diameter, branching activity of apple trees and the soil moisture of 3-meter-deep profiles under the growth influence of the intercrops were comparatively determined with control as well. Through those the intercropping principles and the suitability of related intercropping practices were analyzed. Meanwhile the intercropping normalization operation was dealt with out of both the actual situation and the growth process of apple trees. The results indicated that based on the growth change of fruit trees, 3 different intercropping periods were discriminated as follows:early young stage, late young stage, and adult stage. From the beginning of the late young stage on, it became strict to select intercrops, which were strikingly required to possess the characteristic of shade tolerance. Dwarf crops with shallow roots were obviously superior in time and space. The growth of fruit trees under watermelon or sweet potato intercropping was better than under wheat or maize intercropping. Among the high-stalk crops with deep roots (wheat, maize, rape, and millet), the inhibition effect of maize on the growth of fruit trees was lower. Wheat intercropping in just keeping empty the ground patch around each fruit tree resulted in the no-branching proportion of about 65%. There were the differences of water consumptivity between different intercrops, of which the water consumption depth of wheat was down to 3 m, maize 1 m, soybean 0.4 m, and white clover 1.6 m. Soil water consumption within the year didn't obtain rehabilitative offset in wheat or white clover growing for 5-9 years old. The competitive relationships of intercrops with fruit trees can be shown according to the growth of fruit trees and the soil moisture consumption by intercrops. The underground competition of dwarf crops with shallow roots is relatively weak, but white clover is an exception in particular, its competition shouldn't be ignored. Ecological niche separation is the key to intercropping, especially for high-stalk crops with deep roots and shallow-root crops which will have some inevitable root overlap to fruit trees. It is inadvisable to implement double cropping or continuous cropping after wheat harvest. It is necessary to plough as soon as early for white clover in decline. Intercropping proceeding would need to pay attention to soil fertility maintaining crops, and to comprehensively take account of such aspects as ecological niche separation, rotation cropping, proper crop yield, fruit tree decline, etc.

Lashihai, a RAMSAR wetland, is a famous plateau lake and wintering place for migratory birds in the northwest of Yunnan Province. In order to understand the changes of waterfowl and their habitat in Lashihai wetland, the line-transect survey had been conducted during the winter season (November to March) of 2013, 2014 and 2016. The results show that a total of 45 species of waterfowl, belonging to 15 families 11 orders, were recorded in winter, in which 9 species were resident and 36 were migratory birds. The population of Rallidae in Gruiformes is the largest, accounted for 90.08% of all. The maximum population of waterfowl recorded on a single-day was over 130 000. Among them, one species was the national first-grade protected bird and four species were the national second-grade protected bird. The Fulica atra was dominant species, and Gallinula chloropus, Anser anser and Anas strepera were common species. Both the annual average population and species number of waterfowl in Lashihai wetland were increased over years, and the variance-analysis show that the change of species number among years was significant (P<0.001). The population and species number of waterfowl both reached the peak in February; the monthly mean diversity index H was increasing month by month. The factors potentially influencing waterfowl of Lashihai include the decrease of feeding sites and the increase of tourism activities. Up to now, the tourism projects and routes have not directly threatened the waterfowl. In conclusion, the quality of waterfowl's habitats in Lashihai has been maintained, but the conservation of major protected species needs more attention and research. Suggestions for waterfowl monitoring and habitats protection in Lashihai have been put forward, which would also provide reference for waterfowl conservation in other areas.

Winter cover crops were proved to be useful to improve soil fertility and the ecological environment and the study of the effects of winter cover crops on soil physical and chemical properties and microbiological properties could provide data support for the promotion of winter cover crops in North China Plain. Taking winter fallow as control (CK), a pot experiment with three cover crops, Vicia villosa (Vr), Orychophragmus violaceus (Ov) and Brassica campestris (Bc), planting in cinnamon soil was conducted to study the effects of winter cover crops on soil physical and chemical properties, microbial biomass and enzyme activity. The results show that the biomass of winter cover crops followed the order of Vr>Bc>Ov. Compared with CK, winter cover crops increased soil moisture, available phosphorus, soil microbial biomass carbon, nitrogen and phosphorus content significantly (P<0.05). Additionally, soil alkaline phosphatase, invertase and urease activities were also increased. The content of available phosphorus under Ov were highly promoted by 33.3% (P<0.05). Soil moisture in Bc was significantly increased by 16.7%, while soil bulk density was reduced significantly by 16.8% (P<0.05). In addition, microbial biomass carbon, microbial biomass nitrogen, microbial biomass phosphorus, soil alkaline phosphatase, invertase and urease activities were increased by 30.5%, 32.3%, 85.4%, 11.4%, 17.7% and 21.7%, respectively. Considering winter cover crop biomass and its influence on soil physical and chemical properties, soil microbial biomass and enzyme activity comprehensively, Brassica campestris is the best winter cover crop followed by Orychophragmus violaceus and Vicia villosa in the North China Plain.

A field experiment in the "winter green manure-double cropping rice" and the "winter planting and breeding-double cropping rice" was conducted to measure the CH₄ and CO₂ emissions under different planting and breeding systems. The gas emissions were measured using the static chamber plus a greenhouse gas analyzer. The correlation between CH₄ and CO₂ emissions and main environmental factors and plant factors was also analyzed. The winter plants include ryegrass (Lolium perenne) and milk vetch (Astragalus sinicus). The goal of this rotation system is to return green manure and chicken manure to soils and reduce the application amount of fertilizers during the rice growing period. The results shows that compared with the winter fallow-double cropping rice, winter planting green manure or planting and breeding had no obvious effect on the seasonal variation of CH₄ and CO₂ emission in the paddy field, but affected the magnitude of the fluxes. The CO₂ cumulative emissions of the "milk vetch and grazing chickens treatment" were higher than the "winter fallow treatment", the "ryegrass treatment", the "milk vetch", and the "ryegrass and chicken treatment" by 150.23%, 2 034.43%, 102.08% and 98.68%, respectively (P<0.05). Compared with the winter fallow-double cropping rice, the milk vetch and chicken treatment significantly reduced the cumulative emissions of CH₄ by 42.67% (P<0.05), and "ryegrass and chicken treatment" and "milk vetch treatment" increased by 21.40% and 48.55%, respectively (P<0.05). CH₄ flux was positively correlated with air temperature, and negatively correlated with dry weight and aboveground volume. There was a significant positive correlation between CO₂ flux, dry weight and aboveground plant volume. The CO₂ flux was negatively correlated with soil temperature and PAR.

In order to assess the immobilization efficiency of heavy metals before and after leaching with acid rain, changes of soil pH, availability of Cu, Cd, Pb and P and their chemical fractions under simulated acid rain (SAR) with pH of 3.5, 4.5 and 5.6 were investigated through a leaching experiment for phosphorus-based materials amended soil. Results show that applications of potassium dihydrogen phosphate (PDP) and hydroxyapatite (HAP) significantly increased soil pH and available P, and decreased available Cu, Cd, and Pb by the transformation of them from the active fractions to the inactive ones. Soil pH values in PDP-3.5 and HAP-3.5 treated soils were decreased by 0.45 and 0.47 unit than PDP and HAP soils, respectively. Available P was decreased and available of Cu and Cd were increased in PDP treated columns with leaching of SAR(P<0.05). Soil total Cu in HAP treated columns and total Cd in control columns were decreased by 14.5%-15.9% and 20.4%-26.5%, respectively, and exchangeable fraction of Cu and Pb in HAP and PDP treated columns were increased with leaching of SAR. Soil total P, resin-P, HCl-P, and residual-P were increased with the application of HAP and PDP. Soil resin-P and total P, however, were decreased in PDP treated columns, and stable P was increased significantly in HAP and PDP treated columns after leaching with SAR(P<0.05). The findings of the study indicated higher immobilization efficiency of Cu, Cd, and Pb and lower release risk of P was found in HAP than PDP under leaching of SAR.

Four dominant plant species and their rhizosphere soil samples were collected from the nonferrous metal mine of Baoshan, Hunan Province. The plant species were identified as Dianthus superbus, Caryopteris incana var. incana, Dendranthema indicum and Patrinia villosa. Concentrations of Cd in the plants and soil were determined, and it was found that Dendranthema indicum and Dianthus superbus had the stronger ability to absorb Cd from soil than Caryopteris incana var. incana and Patrinia villosa. Due to its high-metal accumulation capacity, Dendranthema indicum and Dianthus superbus showed a potential ability to apply in artificial ecological restoration system. Based on morphology, RDP-Ⅱ identification system and 16S rDNA gene sequence analysis, three Cd-resistant strains of bacteria (BS1, BS2, BS3) isolated from the rhizospheric soil were finally confirmed as Sphingomonas echinoides, Massilia flava and Bacillus aryabhattai. Their minimal inhibitory concentration levels against cadmium were up to 300, 100, 80 mg·L^-1, respectively. Three factors, including temperature, adsorption time and pH may influence their Cd²⁺ absorption ability. The results show that, under the condition of initial concentration of 50 mg·L^-1 Cd exposure, the optimal growth temperature of three bacterial strains was 30℃, and their biosorption amounts of Cd²⁺ increased slowly with time going on. The adsorption reached saturation when the strains were cultured for 30 to 36 h. Strain BS2 exhibited higher Cd adsorption rates of 57.32% and 54.15% under the condition of pH 5.5 and 6.5 than others. The Cd²⁺ adsorption rate of strain BS1 reached 18.83% to 29.14%, under three pH conditions. Strain BS3 showed the maximum adsorption rate of 40.66% only at pH 6.5.

Seasonal variation of arsenic concentrations is critical for arsenic exposure assessment and related health risks assessment. An endemic arsenism area in Inner Mongolia caused by exposure to arsenic in drinking water was selected as the study area. The arsenic concentrations in drinking water for different seasons were determined. The exposure doses of arsenic through direct ingestion, indirect ingestion and dermal contact were estimated. Moreover, the carcinogenic health risk was assessed. The results show that the average intake of arsenic for male and female in the study area were 1.80 and 1.89 μg·kg^-1·d^-1, while the corresponding values in control area were both 0.08 μg·kg^-1·d^-1. The intake of arsenic from dermal contact for male and female in the study area were 8.89×10^-4 and 1.10×10^-3 μg·kg^-1·d^-1, while the values were 4.18×10^-5 and 4.93×10^-5 μg·kg^-1·d^-1 in control area. More than 99.93% of the total intake of arsenic were from ingestion pathway. Moreover, the total arsenic exposure dose from summer and winter accounts for more than 89.04% of the whole year. Carcinogenic health risks of males and females in the endemic area were 3.75×10^-5 and 3.67×10^-5 a^-1, respectively. It can be concluded that the intake of arsenic through ingestion pathway was the dominate exposure pathway of arsenic in drinking water. In addition, the arsenic exposure dose was the highest in summer. Carcinogenic risk of arsenic exposure through ingestion and dermal contact exceeded the acceptable risk.

A kind of psychrophile strain named pseudomonas flava WD-3 was isolated from the sediments of Nansihu Lake in winter, and it was used as the microbial carrier. The carbonized rice straw was prepared to be biocarbon as adsorbent, and the biochar-fixed Pseudomonas flava WD-3 bacteria was added into the vertical flow constructed wetland sewage treatment system to discuss the removal efficiency of nitrogen in wastewater of low temperature and to simulate the kinetics of degradation of pollutants in constructed wetland by a simplified Monod Model. The results demonstrate that the removal efficiency of nitrogen in waste water in constructed wetland was increased significantly, when hydraulic retention time was 5 d. The degradation kinetics of TN, NH₄⁺-N, NO₂^--N, NO₃^--N were accorded with the Monod Model by biochar-fixed Pseudomonas flava WD-3.

The effects of simultaneous pretreatment with ultrasonic and thermo-chemical on high solid sludge disintegration for improved energy efficiency were investigated. The sludge was pretreated at specific energy of 9551 kJ·kg^-1 total solids (TS), temperature of 73℃, and alkaline dosage of 0.085 g·g^-1, which were optimal conditions obtaining maximum sludge disintegration in previous study. Experimental results show that the mean particle diameters (dp) of pretreated sludge with solid contents of 3%, 5%, 10%, and 15% were decreased by 40.14%, 58.01%, 93.63%, and 17.46%. Besides, the dp10, dp50, and dp90 of pretreated sludge with solid content of 10% decreased by 88.38%, 93.85%, and 96.74% after pretreatment. In terms of sludge disintegration, the increased soluble chemical oxygen demand (SCOD) concentration of pretreated sludge had a positive correlation with solid content of sludge, while the disintegration degree (DD) showed a reverse trend. The maximum DD of 50.3% was obtained in sludge with solid content of 3%. The organic matter composition of pretreated sludge was also examined. It indicated that soluble protein and carbohydrates concentrations of sludge with 10% solid content were much higher than those of sludge with 3%, 5%, and 15% solid content. Moreover, the biodegradability of pretreated sludge with 10% solid content was as high as 88.94%. Therefore, the simultaneous pretreatment with ultrasonic and thermo-chemical has a good application prospects in high solid sludge disintegration.

Following the rapid socioeconomic development and advancement of new socialist countryside construction in recent years, rural river regulation has become an increasingly crucial part of water conservancy work. Evaluating the ecological benefits of rural river regulation and identifying problems arising during regulation and after implementation have great significance for future guidance on the comprehensive, centralized regulation of rural rivers. A Status-Response-Benefit (SRB) system is established in accordance with the functions and features of rural rivers based on the project objectives and regulation measures in Pilot Planning for Comprehensive Regulation and Interconnection of Medium and Small-sized Rivers in Key Counties of China. 18 evaluation indicators have been selected for six features, including river connectivity, water quality, riparian zone condition, hydrobiology, river landscape, and management, building a multi-dimensional, multi-level ecological benefit evaluation model, setting evaluation standards, indicator weights and evaluation grades. This system can provide an important reference for the further development of methods to evaluate ecological benefits in comprehensively regulated rural rivers, as well as the practical application of these methods.