In the process of rapid urbanization, the construction land in China has expanded rapidly. It is essential to analyze the characteristics and causes of the changes in construction land in time and space, which would promote the sustainable use of land resources in China. Based on the MODIS Land Cover Type product (MCD12Q1) in the years 2001, 2006, 2011 and 2017, the characteristics of temporal and spatial changes in construction land in different economic regions and geomorphological areas were analyzed with the help of economic and geomorphological data. It was found that: (1) The expansion intensity of construction land (EI) gradually weakened in China in the three periods from 2001 to 2006, 2006 to 2011, and 2011 to 2017, and the expansion speed (ES) gradually slowed down. (2) The expansion of construction land in 2001~2017 mainly occurred in the eastern region, which had the strongest EI and the fastest ES. In the three periods, the EI in the eastern region gradually weakened, and the ES gradually slowed down; the EI in the central region gradually became stronger, and the ES gradually became faster; the EI in the western region became weaker first and then stabilized, and the ES gradually slowed down; the EI in the northeast region weakened first and then stabilized, and the ES became faster first and then slowed down. (3) The expansion of construction land in 2001~2017 mainly occurred on the plains, with the strongest expansion intensity while the fastest expansion speed in the hilly areas; the EI on the plains gradually weakened during the three periods, and the ES gradually slowed down; the EI in the hilly areas became weaker first and then became stronger, and the ES slowed down first and then became faster; the EI on the mountainous areas gradually became stronger, and the ES became faster first and then became slower; the EI on the plateaus gradually became stronger, and the ES gradually became faster. It can be seen from the results that the intensity and speed of construction land expansion in different economic zones were different, which was mainly affected by the corresponding regional policies of the nation in different periods; different geomorphological types also affected the spatial and temporal characteristics of construction land expansion.

The purpose of this study is to analysis the spatial-temporal pattern evolution and intensive use changes of rural residential land in Jiangsu province from 1987 to 2015.The research methods included land-use dynamic index, kernel density estimation, landscape pattern index and Intensity measurement index system. The results show that: 1) The rural residential land in Jiangsu province from 1987 to 2015 was in a continued expansion, and appears a tendency of increased with fluctuation, the data shows that the fastest speed of scale change in rural residential land happened in south Jiangsu and central Jiangsu. 2) From the situation of transfer-in and transfer-out in rural residential land, on one hand, Jiangsu province has a total of 5.863×105hm2of transfer-in rural residential land from 1987 to 2015, and 84.79% was came from arable land occupation. The ratio of rural residential land transfer from arable land ranks as: northern Jiangsu >southern Jiangsu> central Jiangsu. On the other hand, the rural residential land was decreased by 2.836×105 hm ², and 54.26% transformed to urban land, and 40.88%reclaimed to cropland. It was mainly reclaimed to cropland in northern Jiangsu and mainly transformed to urban land in south Jiangsu and central Jiangsu.3) From the perspective of the spatial distribution of rural residential land, the spatial differentiation of rural residential density is obvious, showing a multi-core clustering distribution, and the overall spatial pattern characteristics of west close to east sparse is presented. The average area of rural residential land patches in Jiangsu province from last 30 years, and the shape of patches tends to be regular, residential aggregation index also clustered. 4) From the results of intensive utilization evaluation, the intensity of rural settlements follows as: northern Jiangsu >central Jiangsu >southern Jiangsu, which is characterized by a gradient from high to low. In summary, the spatial pattern of rural residential land in Jiangsu Province tended to be regular and clustered, and the regional intensive utilization degree difference was obvious.We should promote land use system reform, optimize the allocation of resource space, and promote the integration of urban and rural development and rural revitalization according to regional differences.

This research examines the poor villages released in the Thirteen-Five Planning of Hubei, Hunan and Jiangxi provinces in the middle reaches of the Yangtze River. The Specific Methods of Nuclear Density Analysis (SMDNA), Nearest Neighbor Index (SNI), Kernel Density (KD), Moran Index (MI) and Overlay Analysis (OA) and other spatial analysis methods were selected to analyze the quantity, spatial distribution density and pattern, and vertical differentiation of the poor villages. The results show that: (1) the inter-provincial distribution of poor villages is different in the middle reaches of the Yangtze River. Hunan having the largest number, followed by Hubei and Jiangxi province, and there are typical “plain” poor villages and “mountainous” poor villages, and the quantitative characteristics are different at multi-level scales such as provincial, national poor counties, provincial poor counties, non-poor counties and urban circles; (2) the distribution of poor villages is low-value clustered in urban groups or urban circles, high-value clustered in mountainous area at the provincial borders; even in the contiguous poor areas of Wushan, Wulingshan and Xuefengshan; and significantly clustered in Jianghan Plain; (3) the vertical space differentiation of poor villages is significant too. The poor villages are mainly distributed in plain area with altitude below 200m, and with the increase of altitude, the number of poor villages is decreasing. The research helps to better understand the spatial pattern of poor villages in the middle reaches of the Yangtze River and implement a more scientific ‘targeted poverty alleviation’ strategy.

Quality of urbanization development, to a certain extent, reflects the development level of a national and regional population, land, society and economy. From the five aspects of population, land, society, economy and urban-rural coordinated development, we constructed a set of urbanization development quality evaluation index system and used the entropy method and spatial correlation analysis method analyzed the urbanization development quality of counties in Hubei Province in 2009 and 2017. The results show that: (1) the quality of urbanization development  is on the rise as a whole with a high improvement speed; (2) the quality of urbanization development in space presents a significant spatial positive correlation, and the concentration of the lower-quality county is higher than that of the higher area; (3) the low-quality county is mainly located in the western region and the concentration in the central region like Yichang area is gradually increasing, the high-quality county is mainly concentrated in the Wuhan area. Through this research, Some countermeasures and suggestions were put forward for promoting the development of high-quality urbanization in Hubei Province.

The regional integration is a key content of the development of urban agglomerations. While the transport network is one of most important driving forces for the integrated development of urban agglomerations. Located at the intersection of “the Belt and Road” and “the Yangtze River Economic Zone”, the Chengdu-Chongqing Urban Agglomeration plays an important role in promoting the economic growth of western China. Based on complex network analysis method, this paper investigates the integrated development process and pattern of Chengdu-Chongqing Urban Agglomeration from perspective of transport supply network and transport demand network, which is represented by passenger flow. Besides, the impacts of transport network construction on the integrated development of urban agglomeration also is discussed. The result shows: (1) Construction of transport infrastructure expands the connect channels between cities significantly, which contribute to formation of a polycentric and equalized structure of transport network. These new transport infrastructure shapes the rudiment of urban corridors and clusters. (2) The transportation demand network measured by passenger flow still presents a dual-cores structure centered on Chengdu and Chongqing, and the polycentric structure in Chengdu-Chongqing Urban Agglomeration has not been formed. The operation of HSR lines have greatly strengthened the passenger flow between cities along the HSR. (3) The improvement of transport infrastructure network has promoted the connections of cities in Chengdu-Chongqing Urban Agglomerations. However, the level of functional integration demonstrated by intercity population mobility and industrial cooperation is still low, which restricts the process of transportation integration in return. In general, it is necessary to explore paths to integrate the transportation system with local social-economic development for Chengdu-Chongqing Urban Agglomeration, such as intercity population mobility, industrial cooperation as well as urban-rural integration between cities in these area. Meanwhile, construction transport infrastructure is an efficient way for optimizing the spatial structure of Chengdu-Chongqing Urban Agglomeration at this stage, for achieving the deep and comprehensive integration of region. Besides, the governments of the main cities should strengthen dialogue and cooperation to avoid unbridled competition between cities in infrastructure construction and industrial development.

It is of great significance to scientifically identify the spatiotemporal evolution and the driving factors for the spatial optimization of rural settlements, intensive utilization of rural land and planning formulation of village-level land use. This paper takes the Dujiangyan City as the study area, using grid analysis and geographic detector to quantitatively analyze the spatiotemporal evolution characteristics and driving factors of rural settlements in the past ten years. The results show that: (1) The spatial distribution of rural settlements in Dujiangyan City is significantly different. The density and aggregation of rural settlements in the east and southeast is relatively high; rural settlements are distributed along the valley in the hills and mountains of the north and northwest. (2) During 2005-2015, the dynamic changes of rural residential quantities and areas varied within different time periods, and the quantities and areas show increase firstly and then decline. The number of rural settlements increased from 16 543 to 26 018 after declining to 25 890, and the rural residential area increased from 6 161.43 to 7 265.43 hm ² after declining to 7 043.01 hm ². (3) The dynamic change of residential land is mainly affected by topographic conditions, cultivated land area and distance from the road, and the spatial distribution of rural settlements shows a certain cultivated land and road directivity. (4) Influence P value calculation results are affected by the type of division, but have little effect on the ordering of results.

Based on the spatial distribution and spatial interaction of tourism industry economic activities, the basic development elements of tourism industry are regulated, and then the optimal industrial element allocation plan is found to release the potential of regional tourism economic development. According to central place theory, Gunn’s theory of tourist destination zone and the theory of tourism industry elements spatial interaction, collect data related to tourism industry development in Dalian, and extract tourism nodes and tourism channels based on the transportation network data set by using GIS network analysis method, construct tourist areas at all levels and optimize the spatial organization of the tourism industry. The results show that:5 first-level tourism nodes, 12 second-level tourism nodes, 10 first-level tourism channels and 12 second-level tourism channels are optimized, on this basis, 5 first-level tourism areas,17 second-level tourism areas and a total of 22 domains are built, the organic combination of tourism nodes, tourism channels and tourism areas forms the spatial organization network of Dalian's tourism industry, recasting Dalian's tourism development axis, expanding the space for tourism development, optimizing tourism industry spatial pattern, and realizing efficient use of industrial elements in warm and cold tourism activities zone. Expand rural tourism development space and promote the transformation, upgrading and high-quality development of rural tourism.

The logistics industry of China has undergone a rapid development since the Reform and Opening up. A-level logistics companies are leading companies in the logistics industry. The quantity and the quality of A-level logistics companies in a region is a significant factor that impacts investor’s incentives to invest and run businesses there, so local governments usually support and supervise the development of A-level logistics companies. Based on the A-level logistics company data of China from 2007 to 2017, this paper analyzes the spatial distribution and heterogeneity of A-grade logistics companies by employing the standard deviation ellipse analysis, the kernel density estimation, and global and local autocorrelation analysis. Also, the geodetector model was used to analyze the influencing factors of the spatial distribution of A-grade logistics companies and the interactions between different factors. The main results are as follows: (1) The development of A-grade logistics companies could be divided into three stages: 2005-2007 (the starting stage with slow growth), 2008-2012 (the rapid growth stage), and 2013-2017 (the mature stage with slow growth). The structure of the A-grade logistics companies showed a trend of “middle heavy, two light”, i.e., the percentage of 3A and 4A companies increased while the percentage of 1A and 5A companies decreased. (2) The spatial distribution of A-grade logistics companies shows the pattern of “South (slightly westward)-North (slightly eastward)”, spreading from the eastern coast to the inland areas. The spatial heterogeneity patterns evolved from “two-core, multi-center” to “three-core, multi-center”, and to “three-core, contiguous-development”. (3) The spatial distribution of A-grade logistics companies shows the agglomeration characteristic at the provincial-level, and the degree of agglomeration increased first and then decreased. The distribution of hot and cold spots of logistics companies did not change much during the 10 years, and the gradient characteristic of hot and cold spots was obvious and gradually enhanced. (4) The significant factors that affect the spatial distribution of A-grade logistics companies are market scale, population density, urbanization level, degree of opening up, and regional economic strength; the influence of the interactions between two factors appeared to be stronger than that of a single factor.

In order to estimate the resources status before the storage of Baihetan and Wudongde hydropower project, surveys of Ichthyoplankton resources were carried out in Jiaopingdu section of the lower Jinsha River from 2016 to 2018. The results showed that there were 7 fish species with drifting eggs, five of which were endemic to the upper Yangtze River, including Jinshaia sinensis, Leptobotia elongate, Coreius guichenoti, Rhinogobio ventralis and Leptobotia rubrilabris. In 2016, 2017 and 2018, the total eggs quantity of fish with drifting eggs were 0.21×108 ind, 0.22×108 ind and 0.25×108 ind, respectively, and spawning grounds were located in Yuanmou, Yongren, Pingdi, Jinjiang and Geliping sections. Sections above the Jiaopingdu were large in scale of fish with drifting eggs, which will be inundated after the storage of Jinsha River second stage project, and then the propagation of fish maybe affected. It is suggested that the spawning habitat should been protected and restored in flowing sections of mainstream and tributary above the end of Wudongde reservoir based on the results of the research.

In this paper, Based on the measured data of summer mean flow from 1957 to 2016 at Zhimenda Hydrological Station in the source area of the Yangtze River, Plateau summer monsoon(PSM)and South Asian summer monsoon(SASM) during 1957-2016. The means of morlet wavelet method,catastrophe test and sliding correlation coefficient was adopted to analyze the variation characteristics of summer mean flow in the source region of the Yangtze River and its relationship with the PSM and the SASM. The results showed that in the past 60 years, the summer mean flow in the source area of the Yangtze River had shown an increasing trend. In 1957-1997, the summer mean flow was relatively less, and in 1998-2016, the summer mean flow began to increase. The summer mean flow in the source area of the Yangtze River had undergone a significant change from decreasing trend to increasing trend around 1995. There were significant positive and negative correlations between summer mean flow and PSM and SASM in the source area of the Yangtze River, and significant negative correlations between PSM and SASM. PSM and SASM influenced summer precipitation and runoff in source area through atmospheric circulation changes. Understanding of the relationships between PSM and SASM has important implications for the water resources management in the source regions of the Yangtze River.

River habitat is an important component of river ecosystems which play an important role in maintaining river health. River habitats assessment can provide an important basis for the protection and restoration of degraded river ecosystems. We established an evaluation system which is specific to the characteristics of the mainstream in the Yangtze River, with ten indexes from three aspects of the river physical morphology, riparian zone habitat and water environmental characteristics. Based on the evaluation system, comprehensive assessment of river habitats was carried out from August to September 2017 in 127 survey sections of three regions, which are the lower reaches of the Jinsha river, the Three Gorges Reservoir, and the middle and the lower reaches of the Yangtze river. The evaluation results show that the river habitat comprehensive index (RHI) of the three regions are 133.9, 124.6 and 130.8, respectively, which were all at the “good” level. The river hydrology and disturbance by human activities are the main driving factors affecting the habitat quality of the lower reaches of the Jinsha River. The river canalization and hardening degree, riparian vegetation cover and riparian vegetation bandwidth are the main driving factors affecting the habitat quality of the Three Gorges Reservoir and the middle and lower reaches of the Yangtze River. In the next step, we should continue to protect the integrity of aquatic habitats in the upper reaches, to carry out restoration of the riparian, the bottomland and the connectivity of rivers and lakes in the middle and lower reaches, as to build an ecological corridor and biodiversity conservation network of the Yangtze River.

With the rapid socio-economic development in the plain river network area, river networks are strongly influenced by human activities, which degrades the physical habitat evidently. The Taihu Basin was taking as a case study. Six physical habitat indicators were selected to establish the evaluation system, including the weighted curvature, box dimension, actual integration of river network, regional river slope, river network density and river network complexity. Moreover, the Improved Entropy Weight and Matter Element Model was adopted to quantify the physical habitat of different catchments. The results show that: The quality levels of physical habitat vary mostly between “relatively good” to “bad”. The ranking order of habitat factors is: Box dimension>River network complexity>Regional river network weighted curvature > Actual integration of river network=River network density>Regional river network slope. The spatial variation of physical habitat in the Taihu Basin is obvious, while the quality of physical habitat of the western hilly area is better than that of the highly urbanized eastern plain area. Physical habitat evaluation on the river network scale is capable of representing the status quo of the basin directly, and effectively improves the performance of plain river network evaluation.

Exploring the evolution situation of river-lake connected channel is an important link for assessing the impact of major human activities on the river-lake relationship. This paper takes the Songzikou outlet, a river-lake connected channel of Dongting Lake as the research object. The long-term water level-discharge relationship curves of Songzikou outlet were established to analyze the change characteristics of channel erosion and deposition. The reliability of the results is verified by the measured cross-section data. At the same time, the driving factors of channel erosion and deposition changes in Songzikou outlet were analyzed. The results show that the water level-discharge curve method is consistent with the measured cross-sectional topographic data. The decrease of water level under the same discharge corresponds to the channel erosion in this period, and the rise of the water level under the same discharge corresponds to the channel deposition in songzikou outlet. The main driving factors of channel erosion and deposition are different in different periods at Songzikou outlet. From 1968 to 1981, the main factor was the channel planform change caused by the river bend cutoffs of the lower Jingjiang River. From 1981 to 2003, the channel deposition was mainly caused by the channel erosion at the upper Jingjiang River due to the operation of Gezhouba Dam. During the period of 2003-2018, the channel erosion was mainly caused by the sharp change in the proportion of water and sediment due to the operation of the Three Gorges Dam.

The palaeoflood event is the response of the surface hydrological system to extreme climatic change. The study results of the palaeoflood hydrology research in the upper reaches of the Hanjiang River are integrated in this paper, and many loess-paleosol profiles recorded palaeoflood events at the frontier of the T1 terrace land in the upper reaches of the Hanjiang River are summarized. Ten episodes of palaeoflood events have occurred in the upper reaches of the Hanjiang River since the lateglacial, which were estimated to 12 600-12 400 a BP, 11 500-11 400 a BP, 9 000-8 500 a BP, 8 500-8 400 a BP, 7 500-7 000 a BP, 5 500-5 000 a BP, 200-4 000 a BP, 3 200-2 800 a BP, 1 900-1 700 a BP and 1 000-900 a BP respectively. Combined the ages of the palaeoflood events with the results of different proxies of climatic change research at domestic and abroad, it is indicated that the ten episodes of palaeoflood events in the upper reaches of the Hanjiang River were coincided with the period of global climatic instabilities or transitions since the lastglacial, these illustrate that the palaeoflood events are responses to climatic change in the upper reaches of the Hanjiang River. The upper reaches of the Hanjiang River is located in the southern part of China's north-south transition zone and its ecological environment is fragile. The river basin environment is very sensitive to climatic change. The Hanjiang River has undergone any major changes in the frequency and scale of river floods caused by climatic change, which will have an impact on the agriculture and economic prosperity of the Hanjiang River. The study results provide scientific basis and are of great significance in understanding the interaction between river hydrological system and climatic change in the upper reaches of the Hanjiang River and semi-humid area of China.

Soil moisture is a key factor affecting the growth and development of vegetation on the surface, which also an essential part of the hydrological cycle of lithosphere-hydrosphere-biosphere-atmosphere. Its dynamic change can reflect the comprehensive information of surface hydrologic process. Based on the collected data from real-time monitoring systems of rainfall and soil moisture of upper, middle and lower slope positions in a typical basin of the Three Gorges Mountain area from May 2018 to May 2019 monitored by high-resolution TDR water probes and a small meteorological station, the variation of soil moisture and its response to precipitation were analyzed in different temporal scales. The results showed that: (1)In the monthly scale, the soil moisture content had a great seasonal difference. From May to July, it was the saving period (the average soil moisture content of 0~80 cm is 38.40%), and from August to October was the consumption period (the average soil moisture content is only 35.04%). (2) In the daily and hourly scales, different depths to precipitation were distinct significantly. The response of shallow layer (0~40 cm) to precipitation was faster (lag time <0.5 hours), and the trend of soil moisture change was similar to the process of rainfall; the response of 40~80 cm depth soil to rainfall had obvious hysteresis (lag time >0.5 hours), and in descending order of soil depths, the response luffing showed a decreasing trend and the retardation time was gradually increased. (3) Under different precipitation conditions, the soil moisture content showed markedly different variation. With different levels of rainfall changing from moderate rain to heavy downpour, the higher the rain intensity, the faster the growth rate of soil moisture, and the response time of soil water content increased synchronously. (4)The effect was different of soil moisture at different sites. The response curve of the upper slope site to precipitation was stable, but the middle and lower sites fluctuated greatly. It can be seen that different microtopography of different sites can change the response of soil moisture to precipitation.

The evolution of urban landscape pattern and spatial form is a response to rapid urbanization, and the special geographical environment of  the areas surrounding lake in western plateau makes the spatial and temporal evolution of urban settlements different from plains, mountains and other regions. Landsat TM/ETM+/OLI remote sensing imageries were used to interpret urban patches in Dianchi region from 1990 to 2018, and landscape indices were calculated and then used to deeply analyze the evolution characteristics and morphological regularities of sixteen towns. The results show that from 1990 to 2018, urban settlements in the areas experienced the undulated evolution which displays a “low-speed growth-high-speed growth-rational growth” pattern. From 2000 to 2010, urban settlements expanded fastest and the expansion rate had reached 54.2%. The patterns of evolution in different periods and different directions were significantly different. The spatial characteristics and development direction of town patches are obviously non-independent and compact. Using K-means clustering to divid urban patches into four types of agglomeration, the result showed that the large patch dominant type accounted for 6.7%, high-density cluster type accounted for 35.8%, medium-density cluster type and low-density scattering point type accounted for 48.6% and 8.9%, respectively. In term of the spatial pattern, urban expansion of these areas appeared as a “central-peripheral” expansion characteristic: Qianwei, Yiliu, and other peripheral neighborhoods expanded rapidly, while Biji, Haikou, and other central neighborhoods grew slowly. In Wuhua and Guandu regions, the numbers, degrees of aggregation and cohesion of urban patches showed an increasing trend, and both the connectivity and aggregation between towns were increasing with the increase of patch numbers, though these two indices had little impacts on fragmentation of patches. The town patches were mainly distributed in areas with an altitude of 1 900-2 100 m and a slope of less than 9°. They had strong correlation with population and GDP, and showed strong transportation and river directionality.

In order to reveal the present situation and change rule of major meteorological disasters in Anhui Province and guarantee the stable and high yield of grain crops, disaster affected rate and damaged rate data of four major disasters (drought; flood; wind and hail disaster; low-temperature freezing and snow disaster) in 78 cities/counties in Anhui Province from 1986 to 2017 were collected and analyzed. By using the methods of climate trend rate, grey correlation and R/S analysis, the spatial and temporal variations and future development trend of four major meteorological disasters in Anhui Province and their correlations with total grain yield were analyzed. The results showed that: (1) Disaster affected rate and damaged rate of the four major disasters all showed declining trends and were obviously lower in recent ten years. The high value areas of disaster affected rate and damaged rate mostly existed in Huaibei Area, Southern Anhui Mountain Area and Dabie Mountain Area, while the low value areas mostly existed in areas along Huaihe River, between Yangtze River and Huaihe River and along Yangtze River. (2) It was predicted that in the future, disaster affected rate and damaged rate of drought would decline continuously，and the flood would decline unnoticeably, while the wind and hail, low-temperature freezing and snow disasters would change from a downward trend to a steady or slightly upward trend. (3) Grey correlations between disaster affected /damaged rate of major disasters and total grain yield from high to low were as follows: flood, low-temperature freezing and snow disaster, drought, wind and hail. This indicates that flood is the main meteorological disaster affecting the grain yield in Anhui Province.

Timely and accurately obtaining the planting area of winter wheat and its spatio-temporal change is very important for improving the accuracy of crop yield estimation and food security ensurance. The phenological period of winter wheat is greatly affected by the geographical conditions and human factors, and the extraction accuracy of planting area in a large area by remote sensing is easily affected by the phenological differences. Using MODIS EVI and Landsat as data sources, the winter wheat planting area was extracted by comparing the reference time series with the time series which were to be classified after zoning the study area with winter wheat EVI similarity and elevation information, and the spatial-temporal change process of winter wheat planting area in Hubei Province from 2009 to 2017 was analyzed. The results show that: (1)The average extraction accuracy of winter wheat area was 95.3% with city-level R ² greater than 0.90, which was better than the extraction accuracy that of  no-zoning; (2) Winter wheat was widely distributed in the middle and northern part of the study area, especially in Xiangyang County and Zaoyang City; (3) There was an obvious spatial-temporal pattern of expansion to the Northwest and Southeast for the spatial distribution of winter wheat; (4)The planting area of winter wheat showed an overall upward trend with an increase of 4% in 2017 compared with 2009, which increased first and then decreased from 2009 to 2017. The method of crop area extraction based on EVI similarity can improve the accuracy of planting area and provide an effective method for remote sensing monitoring of the spatial-temporal change of winter wheat area in a large area.

The transfer of farmers to off-farm employment is considered to be the main driving force of farmland transfer. However, the farmland transfer rate still remains stagnant in the case of non-agricultural employment is very common. The development of agricultural production service outsourcing affects the driving effect of non-agricultural employment on farmland transfer by changing the opportunity cost of farmers engaged in agriculture. Based on the micro-survey data of farmers' households of Hubei province in 2018, we empirically tested the influence of off-farm employment on farmland circulation and the intermediary role of outsourcing services in agricultural production by using the binary discrete model and the intermediary effect model. The results showed that: (1) Non-agricultural employment is conducive to increasing the outsourcing of agricultural production services, thus promoting the farmers to rented out their agricultural lands and inhibiting the transfer of agricultural lands. (2) The outsourcing of agricultural production services inhibits the transfer of agricultural land and promotes the rented of agricultural land. (3) If the influence of agricultural production service outsourcing is ignored, it will be overestimated for both the positive effect and the negative effect of off-farm employment on farmland transfer market supply and demand. These can provide an important explanation for the contradiction between the high degree of off-farm employment of farmers and the low rate of farmland transfer in reality. Agricultural production service outsourcing not only can optimize the allocation of rural labor resources, but also reshape the supply and demand structure of the farmland transfer market in China.

Nonpoint source pollution control of cultivated land is not only an important measure to build a beautiful China and a beautiful countryside in the new era, but also a necessary link to improve the quality of cultivated land, ensure the sustainable development of regional agricultural production and achieve ecological health. Firstly, this study theoretically analyzed the willingness and behavior mechanism of farmers to participate in the control of nonpoint source pollution of cultivated land based on theory of planned behavior and then used the binary logistic model and principal component analysis to conduct an empirical test on the household survey data of Xiangyin County that is a main grain producing county on the south bank of Dongting Lake.The results indicated that, only 61.29% of the surveyed farmers were willing to participate in the control of nonpoint source pollution of cultivated land in investigation region; degree of increase in economic benefits from participation in nonpoint source pollution control, improve the surrounding environment from participation in nonpoint source pollution control, influences of agricultural technicians, energy and ability to participate in nonpoint source pollution control, once or now a village cadre all had a significant positive impact on farmers' willingness to participate in nonpoint source pollution control of cultivated land; however, farmer's age had a significant negative impact on farmers' willingness to participate in nonpoint source pollution control of cultivated land. In view of the above, in the process of nonpoint source pollution control of cultivated land, the local government should strengthen the policy propaganda and agricultural technicians' technical guidance of nonpoint source pollution control of cultivated land, give full play to the exemplary role of village cadres, strengthen the awareness of farmers as the main body in the control of nonpoint source pollution of cultivated land, promote farmers' self-efficiency and social responsibility, effectively safeguard the interests of farmers, guide farmers to actively participate in nonpoint source pollution control of cultivated land and build beautiful-ecological Dongting Lake.