Land resources science is a new discipline taking land resources as an integrated research object. Marked progress made in comprehensive research covers the following aspects: investigation and exploitation of land resources;evaluation of land resources types and characteristics,quantity and quality;land resources consolidation and transformation;sustainable land resources use and management;land use general planning and land resources strategy;optimal land use allocation and its intensive use; and land resources security and ecological friendly land use model.Based on the analysis of the research progress in land resources sciences and reviewing the main achievements of Chinese land resources discipline in recent years, this paper discusses deeply on the tasks and prospects of land resources discipline development along with the rapid national economic and social development,predicts the developmental trend of land resources science on the basis of analyzing the developmental goal and prospect of land resources discipline.Furthermore, it puts forward that there are eight key development fields and main research directions of land resources science in China.The key research fields and directions of land resources science in the future are as follows:(1)To enhance the theoretic study of land resources discipline,especially land resource classification,driving forces and impacts of LUCC,innovation of land resources discipline system;(2)to attach importance to macro strategic study of land resource,especially the optimal strategy of land resource and sustainable use models under the guidance of sciences developmental views;(3)to promote the research and application of the new ideas,new principle,new technology and new methods of general land use planning in order to serve well for the regional decision-making of socio-economic harmonious development;(4)to study deeply the evaluation index system,technical methods of intensive land use,probe into the criterion of optimal land use and standard of regional and industrial land use;(5)to strengthen research of the principle,model and demonstration of land resource safe and ecological friendly land use in order to put forward the sciences guidance for realizing sustainable land use;(6)to study theory,method and ensuring system of the modern landscape land consolidation,and the mechanism and models to upgrade intergraded productivity of land resources;(7)to probe into the management model and policy of rural land resources,especially study the science ways for land-lost farmer employment,and food security and arable land protection based on the analysis of new condition and new question of regional development; and (8)to study and develop the land resource information system,and make the most of"3S"technology,model method and expert decision-making system to realize the informationization and systematization in the process of land resource research and management.

The types and metal concentrations of the plant communities in Jinchang’s Ni /Cu mining areas in desert of Northwestern China were investigated.The number of plant species in different zone is in the order:strip mine ( 20 species) >around new tailing pond zone ( 13 species) >around strip mine zone ( 8 species) >around old tailing pond zone ( 6 species) >old tailing pond ( 5 species) .Thirty-two species belonging to 30 genera and 14 families were found growing on the spoil heap, including 9 dominant species:Echinops gmelini Turcz, Asterothamnus centraliasiaticus Novopokr, Crepis flexuosa ( Ledeb.) Clarke, Mulgedium tataricum ( L.) DC., Phragmites communis Trin., Stipa sp., Peganum harmala L., Nitraria sphaerocarpa Maxim., and Ceratocarpus arenarius L.The investigation showed that E. gmelini, C. flexuosa, M. tataricum, P. communis and C. densa were adaptive pioneer species, and planting Stipa sp. and C. arenarius could be used to remediate contaminated lands.The average Cu concentration in the aboveground plants was 52.9mg/kg, which was higher than the average concentrations of other metals.Ni concentrations in the aboveground plants were 5.1 ～155.6mg/kg, and the average value was 39.1mg/kg.Ni and Cu concentrations in the aboveground of C. arenarius were the highest, 155.6 and 239.0 mg/kg, respectively.The result of regressive analysis indicated that uptake and enrichment of Ni by the plants was closely associated with Cu, and Ni concentrations in the plants were enhanced with the increased Cu concentration.

Under the background of global environmental change, the shortage of water resource has already become a problem of resource and environment which has been paid much attention in the world. Since China is a country with water resource shortage, it is significant to study the change of urban water consumption. There are many factors that influence water consumption and among them climate is very important. In this paper, the climate water consumption is separated from the total water consumption by polynomial model and the method of statistical analysis is used to explore the relationship between the climate water consumption and the climatic factors and its changes in 241 Chinese cities .The conclusions are as follows:Temperature, precipitation and humidity are the main factors that affect the climate water consumption. In winter, the regional disparities between the South and the North are significant. In spring, the regional disparities between the East and the West are significant. In most cities of China there exists a positive correlation between climate water consumption and the temperature in summer and autumn. In many cities there exists a positive correlation between climate water consumption and the winter/spring temperature.In recent years, the global temperature has increased apparently, which results in extreme weather and extreme climate environment and it is also an important factor that results in the increase of urban climate water consumption. As the urbanization of Chinese cities accelerate, the contradiction between the supply and demand of urban water is also emerging out more frequently. Since the trend of subalpine timberline becomes more obvious with the increase of latitude, the contradiction between the supply and demand of urban water in the northern Chinese cities is much outstanding. In the seasons and areas where eco-environmental water requirement is the chief one, there exists a significant negative relation between climate water consumption and precipitation. When precipitation influences climate water consumption through influencing human body, there exists a significant positive relation between climate water consumption and precipitation. Effect of humidity on urban water consumption results from the interaction of humidity and high temperature, and only in the seasons and areas where it is too dry or too wet can it work.

Taking the region around Hangzhou Bay as a study area, the urban land information was extracted from TM images of 2003 and 2006 through the decision tree method together with the shape index. And the characteristics of urban expansion in cities of Hangzhou, Shaoxing and Ningbo were further discussed. The overall Kappa coefficients of urban land were all above 0.87 through precision test and proved that: it was feasible to extract the information of the urban land. The area of urban land in 2003 and 2006 was 914.04 km² and 1286.1 km² respectively. A net increase of the urban land in the study area within four years was 372.06km², and the number was 192.6km² in the major cities; the increase of urban area in Hangzhou, Shaoxing and Ningbo was 43.7 km²; and that of the others was 145.6 km².It revealed that the small cities played a dominant role in the process of urbanization, but the bigger cities’ were relative weak. The urban land in Hangzhou and Shaoxing expanded obviously, and especially the expansion of Xiasha district in Hangzhou and Paojiang industrial park in Shaoxing were more remarkable. However, the smallest expansion occurred in Ningbo, especially in Yuyao urban district. In expansion direction, Hangzhou urban districts mainly developed toward northwest and north; while Ningbo urban district spread in all directions evenly.

In the 21st century, global urbanization has become an inevitable trend of the development of human society, urban expansion would unavoidably transform ecological land-use such as forest, farmland, grassland, swamps and water area, which have important ecological service functions, into land used for urban construction purpose. Consequently, this will exert great impact on ecosystem in the urban, the regional and even global scopes. In the future rapid urbanization process, it is very important to protect necessary ecological land-use for sustaining well-being of urban ecosystem itself, improving living standards of urban citizens and realizing urban sustainable development. With a case study of Shenzhen, a special economic zone of China, this paper combined ecological conceptual model of landscape with assessment methods for valuation of ecosystem service function, and with the support of GIS technique, established a spatial analysis model for urban minimum ecological land-use. Meanwhile, according to four scenes which reserved ecological land-use respectively by 30%, 40%, 50% and 60%, it analyzed the reasonable spatial distribution of minimum ecological land-use. The outcome demonstrated that the minimum ecological land-use model can extract the type of lands which have important urban ecological service functions.

On the basis of analysis of MODIS data reflected spectrum characteristics on ocean, the remote sensing parameters of suspended sediments have been marked by selecting MODIS available channels in this paper,and the relevant inversion model of quantitative remote sensing data monitoring for suspended sediments has been established with ocean color data measured from nine stations on Fujian coastal waters in 2003-2004.The suspended sediment concentration on the coastal waters of Fujian in 2001-2005 has been calculated by using the quantitative remote sensing inversion model which has been established,and according to calculation results the characteristics of the spatial distribution and variation of suspended sediments concentration have been analyzed in the same region,specially,the movement characteristics of suspended sediments in Minjiang River estuary have been analyzed. The results indicate that the relationship between the suspended sediment concentration in the coastal waters of Fujian and the remote sensing parameters of suspended sediments based on MODIS blue(0.438-0.448μm) and green(0.545-0.565μm) channel data show exponential function,and the remote sensing quantitative model has gained a good effect and high accuracy,and can fulfill the quantitative survey of the distribution and variation of suspended sediments in the coastal waters of Fujian. Finally,the results will be considered as a basis for further research in this region.

Based on RS and GIS technology, the paper studied the spatial characteristics of marsh change in Heilongjiang Province and analyzed the influence of human activities on marsh. What’s more, we knew of the spatial characteristics of marsh in the field of administration planning. The authors reconstructed spatial data of wetlands from 1954 to 2000 by integrating topographic map in 1954 and TM image in 2000 in Heilongjiang Province. Furthermore, combining patch centroid change model, landscape parameters and Euclid shortest-path function, we analyzed marsh shrinking characteristics and regularity of regional differentiation, and further discussed the cause of marsh shrinking in the perspective of the impact of human activities on marsh shrinking. The results showed that: area of wetlands had dramatically decreased from 7.914 million ha to 3.035 million ha in Heilongjiang Province for the last 50 years; in general, the centroid of marsh moved to the northwest of Heilongjiang Province, which showed that marsh shrinking maily occurred in the northeast; marsh landscape went to fragmentation; the shrinking areas were mainly concentrated in the Sanjiang Plain, Songnen Plain, Da Xing’an Mountains and Xiao Xing’an Mountains. There are three major humanity reasons which led to marsh shrinking: population growth and constant land reclamation; farm development policy of building state farm; and the spatial relationship between wetland shrinking and major highways.

According to attributes of ecological water requirements, evaluation methods of river ecological flow was proposed in terms of water quantity and water quality. The water quantity evaluation methods included water resources utilization ratio method, measured runoff method, consumption coefficient method; and the water quality evaluation method was established based on wastewater-runoff ratio factors. The standards for water quantity and water quality evaluation were also proposed. Seven major basins of China, including the Songhuajiang River, the Liaohe River, the Haihe River, the Yellow River, the Huaihe River, the Yangtze River, and the Zhujiang River, were studied as examples by using the above methods. The results indicated that if these rivers were evaluated merely from water quantity, the ecological flow is lower than the water requirements standards in the Haihe River and the Yellow River; however, if these basins were evaluated at the same time of water quantity and water quality, the ecological flow is higher than the water requirement standards only in the Songhuajiang River, the Yangtze River and the Zhujiang River. These showed that actual ecological water shortage could be revealed only by evaluation methods on the basis of "water quantity" and "water quality" in China.

Using the data of monthly 20cm pan evaporation and its impact climatic factors(for instance, sunshine duration, wind speed, relative humidity, precipitation and daily temperature, et al.)at 14 meteorological stations in middle reaches of the Yarlung Zangbu River over Tibet from 1981 to 2005,the variations of annual and seasonal pan evaporation and the trend were analyzed by using the method of linear trend analysis. Main results were as follows:(1)Significant negative trend of annual pan evaporation were detected at the most stations, and the mean rate of decrease was 109.92 mm /10a (99% confidence level),especially in summer (-51.79 mm /10a, 99% confidence level). In terms of spatial distribution, the trend of annual pan evaporation increased in Milin county where the rate of increase was 41.22 mm /10a (95% confidence level),but the decreasing trends were found at the other stations,the rate of decrease was (1.23~348.68) mm/10a, which is obvious in Gongga county. (2)Significant negative trends of annual sunshine duration and wind speed were found in middle reaches of the Yarlung Zangbu River over Tibet. Significant positive trends of annual mean relative humidity and precipitation were detected. Significant increasing trend of annual mean temperature was detected, an increase of 0.33℃/10a. While the increasing trend of annual mean minimum temperature(0.52℃/10a)was higher than that of annual mean maximum temperature(0.27℃/10a), and the decreasing trend of daily temperature was significant(-0.29℃/10a).(3)It is thus obvious that the decrease of annual pan evaporation was mainly caused by the significant decrease of the annual sunshine duration and wind speed as well as obvious increase of annual mean relative humidity, the daily temperature and precipitation may also play an important role in an unknown mechanism.

Ecological footprints model is a method of measuring the sustainable development. In recent years, ecological footprints model has been a widely accepted tool to quantify the sustainable development level in many fields. However, ecological footprints model neglected the sustainability of economy and science technology. In order to improve the veracity of the model we join the economic factors, and they would provide suggestions for the sustainable development of mining cities in central Liaoning. We calculated ecological footprints(EF),ecological carrying capacity(EC) and budget of mining cities in central Liaoning between 1985 to 2005 by ecological footprints model; after coupling ecological footprint, ecological carrying capacity and economic factors by P-S-R model, we got synthetic ecological carrying capacity index and estimated synthe-tic ecological carrying capacity level of mining cities in central Liaoning between 1985 to 2005. Results showed that: in mining cities in central Liaoning between 1985 to 2005, the EF increased from 1.79 ha to 3.53 ha, the increasing rate was 97.43%; the EC increased from 0.78 hm² to 0.81 ha; the budget increased from -1.01 ha to -2.73 ha, the increasing rate was 190.17%; the synthetic ecological carrying capacity index reduced first, then increased from 2000; the synthetic ecological carrying capacity level was very high in 1985, lower in 1990, common in 1995 and 2000, and high in 2003 and 2005. The changing trend between ecological carrying capacity and synthetic ecological carrying capacity index was alike. The test result indicated that synthetic ecological carrying capacity index was developed from ecological carrying capacity, the relativity between them was high; and the synthetic ecological carrying capacity index was coupled by ecological carrying capacity, ecological footprints and economic factors, the richness of indicators could also improve the veracity of the estimated results. So the explorative research of ecological footprints model and economic factors was carried out which could give some use for reference of the other research about ecological footprints model.

Based on the analsis of the hydrogeological conditions of the survey region, the groundwater recharge and discharge quantity is calculated with water balance method. The result of calculation is negative balance. After groundwater mining, the water source being mainly from the increased recharge of the Yellow River. The pumping test and the numerical simulation show that the increased recharge of the Yellow River is 3.45×10⁴m³/d. According to water level forecast, after the water source being developed for 20 years or for 2 years running under adverse hydrological and meteorological conditions, the lowering of both water level is less than one-tenth of the aquifer thickness. This indicates that a mining rate of 3×10⁴m³/d is assured which can satisfy the water supply demand of the thermoelectric plant.

The newly added quota of construction land is very vital to the regional economic development.With the rapid growth of economy,the contradiction between construction land supply and demands has become further sharpened due to the scarcity of land resources. Therefore rational allocation of construction land is becoming more and more urgent. In order to allocate the newly added regional construction land rationally and scientifically, taking Jiangsu as an example,this paper first selects 13 factors as original indexes.Then principal components analysis method is applied to integrate these factors into three indexes,which are population resource, economic society,and urban development. Based on these indexes, the study applies AHP-GEM model to allocate the newly increased quota of construction land in Jiangsu Province.Result shows that the proportions of the allocation could be divided into four levels.In all of the three first level cities,Suzhou has the maximum allocated proportion (18.80%), followed by Wuxi and Nanjing with the percentages of 16.78 and 11.20 respectively.The second level consists of Nantong (7.93%) and Changzhou (7.81%).At the third level,Yangzhou, Zhenjiang, Yancheng,Taizhou and Xuzhou are allocated 6.03%,5.91%,5.51%,5.33%,and 5.00% respectively. Finally,Huaian,Lianyungang and Suqian belong to the forth level with the percentages of 3.65, 3.03 and 3.01 respectively. At the end of this paper,conclusions and suggestions for the newly added construction land allocation are presented.(1) The result basically reflects the increased construction land demand in a region.(2)AHP-GEMmodel combines the advantages of both AHP method and GEM method. Hence,it is more objective to allocate the newly added construction land quota using AHP-GEM model.(3)Choosing an appropriate index is important to apply this model.This index should better be a forecast value.(4)With minor modifications, this model can be adopted to allocate the newly added construction land at all levels, such as state, provincial,and county levels etc.

青藏高原草地植被和牲畜是影响该地区生态环境的主要影响因素, 因此, 研究此两项因素及 其之间的关系, 对于保护青藏高原生态环境、促进经济发展具有重要的意义。为此, 论文利用 2003—2004 年青藏高原天然草地产草量观测资料, 经过GPS 定位, 与NOAA/AVHRR 植被指数建 立了天然草地产草量反演模型及不同区域尺度天然草地年最大产草量、载畜量估算模型; 同时, 利 用粮食、油菜、青饲料等农业产量和林地面积等资料, 估算了青藏高原精、粗饲料的载畜能力, 分别 建立了天然草地以及考虑补饲后的草畜平衡监测模型, 分析了青藏高原及其县、地、省等不同区域 天然草地以及区域总体牲畜承载能力和草畜平衡状况。结果表明: 青海和西藏在天然草地和农业等 其它补饲共同承载下, 2003—2004 年年平均最大载畜能力分别为3 140×104、2 865×104 只标准羊单 位, 超载率分别为16%、78%, 两省平均超载率为45%。分地州来看, 两省除青海的果洛州和玉树州 实际牲畜数量没有超过当地的最大承载能力、青海海西州和西藏林芝地区草畜基本平衡以外, 其余 地州均有不同程度的超载, 其中果洛州和玉树州天然草地牲畜超载率分别为- 11%、- 26%, 利于“三 江源”地区天然草地植被的恢复和生态环境的改善; 青海黄南州、海北州、海南州、西宁市、海东地区 和西藏昌都、那曲、阿里地区牲畜超载率为45%～97%, 西藏拉萨市、日喀则、山南地区达115%～ 153%, 这些地区应适当降低牲畜数量或加大补饲力度, 以减轻对当地生态承载的压力。青海牲畜超 载的县主要位于东部, 西藏超载的县主要位于西部和南部大部地区。

The water surplus and deficiency (WSD) was calculated with precipitation and reference crop evapotranspiration which were calculated with Penman-Monteith method recommended by FAO in 1990,based on climatic data of 93 meteorological stations in the Yellow River Basin(YRB) authorized by the National Climatic Bureau from 1957 to 2001. Meanwhile, the WSD distribution map of the YRB was also generated through the Kriging method. The result shows the spatial distribution of WSD is strongly affected by climatic and geographical factors,and WSD decreases from north to south in the YRB,and from northwest to southeast in the northern part of the YRB. From 1957 to the end of the 1990s,the WSD presented an increasing trend. At the same time,the seasonal variation of WSD was obvious,being more obvious in spring and summer but less in winter and autumn, and with distinct regional variation.

以受人类活动强烈干扰的黄土高原典型丘陵沟壑区安塞县纸坊沟为例，以该区土壤侵蚀最严重的1958年为参照年，主要运用替代工程法、影子价格法和机会成本法等方法，分析了1938~2000年该流域土壤保持服务功能价值的动态变化过程，并通过对流域综合治理与退耕还林草投入成本价值的对比核算，初步评价了流域水土保持治理的效益。研究表明，从1938~1978年，由于人类不合理的活动使大面积植被遭受破坏，导致流域土壤保持功能显著降低，年土壤保持价值减少了1.01×108元。随小流域综合治理和退耕还林(草)政策的实施，土壤保持功能及其价值逐年增加，1978~2000年土壤保持价值增加了0.77×108元。除去流域治理和退耕还林草投入总成本1.56×106元，1975~2000年年均净获土壤保持价值量6 414.4×104元,表明流域综合治理是卓有成效的。但与植被破坏前的1938年相比，2000年的土壤保持服务价值与之仍有一定差距，土壤保持服务价值为1938年的78.5%，因此，流域综合治理仍然是任重而道远。图1表3参24

目前水温预报的降水资料严重不足，特别是无资料地区将很大可能利用卫星遥感反演获取降水信息，丹遥感资料提供的降水时间尺度往往较长，难以满足水文预报需求。论文提出了一种基于统计，针对独立降水事件，将长时段降水聚解为短时间尺度降水的方法。研究将此方法应用于史灌河七邻雨量站，分别聚解了七邻6h、3h、2h、1h降水为10min降水。研究表明，该方法计算简单，能保证模拟的总量同实际的完全一致，雨强同实际的基本一致，具有较好的区域适应性。图6表6参8

From the angles of the response of ecosystem and tourist perceptions,the response of Liupan mountain ecological tourism attraction trails to human being tourism trampling disturbance was studied.This study was conducted to investigate the patterns and extent of trampling impacts along the main tourism trails.In addition to vegetation change represented by cover reduction (CR) and floristic dissimilarity (FD),leftover reduction(LD),increase of soil hardness (SHI) and Index of Land Cover Impact (ILCI),the Limits of Acceptable Change(LAC) was also added as indicator for tourist impact.The results show that trampling disturbance mainly were limited in 1 to 3 miles along the trail;the composite ecosystem in Xiao Nanchuan with arbor,bosk and grass got most serious disturbance.Using ILCI and LAC Index the responses of the three typical ecosystems were assessed.The ILCI values of the investigating sections along the 1-meter trail impact is seriousy disturbed,then 2-3 meters, and beyond 3 meters,it is seldomly disturbed.Based on Limits of Acceptable Change (LAC) questionnaires filled out by visitors,the standard of acceptable change in ground coverage was found to be 55.7 % of the coverage reduction from the trail.from this standard,the investigating areas along the 1-meter trail far exceed the LAC.The impac variables are correlated to the gradient,border area gradient and width of the trail.The Index of Land Cover Impact (ILCI) could be an useful index to evaluate the tourism disturbance.The results also indicate that the current tourism disturbance has had some negative effect on the tourist experience and ecosystem.Some suggestions for management were offered to minimize the trampling impacts of this trail.Improving the development environment,strengthening the planning of tourism attraction,and establishing the forest system and tourism information system would offer important guidance to the promotion of sustainable development of Liupan Mountain.

In the recent years, Qinghai Lake has experienced severe declines in water level and its watershed is in an advanced state of ecological degradation, which resulted from both natural (climatic) and anthropogenic factors. However, information concerning human activities (e.g., land use/cover change) is scarce, therefore, it is necessary to know land use change and its effects on ecological degradation in the lake watershed. This would help us to have a better understanding of the effect of human activity on the processes of land degradation in the past and may enable the improvement of future planning strategies.Based on the multi-temporal remotely sensed data in 1977,1987,2000 and 2004, this study analyzed the land use change characteristics in the Qinghai Lake watershed from 1977 to 2004 and investigated the spatial difference of land use structures between different counties, by the using of transition matrix of land use types and land use dynamic degree. Then land use intensity in the Qinghai Lake watershed was calculated and compared with other typical regions in China. The conclusions of the study can be drawn as follows: (1) Land use change was characterized by constant land decrease for ecological function and land increase for production as well as degraded land from 1977 to 2004, for instance, the water body area decreased 292.70 km² in the last 30 years. (2) The increase of farmland and sand derived respectively from occupying the grassland and transferring from the lake sand due to the decline of water level in the Qinghai Lake, the sand area increased 103.22km²because of the decline of water level from 1977 to 2004. (3) The changing rate of farmland area,residential area,sand area and forest area has been slowed down since 1977 while the water area decreased obviously from 2000 to 2004 (0.71%)and the grassland area changed slowly all the year round. On the whole watershed, the changing rate of all the land use types had the characteristics of interannual variation. (4) The differences of land use structures between four counties were obvious with most of the sand distributed in Haiyan (more than 70%),at the same time, Gangcha and Gonghe had 90% of forest and more than 95% of farmland of the whole watershed, moreover, changes of land use structures were various between these four counties. (5)The variation of land use intensity in the Qinghai Lake watershed was insignificant from 1977 to 2004 while the average value of integrated index is 186.47. The comparison of land use intensity between the Qinghai Lake watershed and other typical regions showed that human activity had little effect on the land use/cover change in this study region, so the related researches on regional environmental and ecological problems should pay more attention to the driving process of natural factors.

By using environmental isotopes and hydrochemical components as tracers in surveying water circulation, this paper revealed the groundwater circulation characteristics in the Yongding River Basin.By field surveying and groundwater sampling in the shallow and deep aquifers, the hydrochemistry and hydrogen and oxygen isotope components were measured.Then the spatial distribution rule and evolvement tendency of δD and δ18O and hydrochemical components of the groundwater in the deep and low aquifers were analyzed for revealing the groundwater cycle characteristics in the Yongding River Basin.The results indicated that the main recharge source of the groundwater in the piedmont region is precipitation, and evaporation process of different degrees has undergone after groundwater recharge from rainfall in the basin. Feeble evaporation process has occurred in the mountain region and intene evaporation process in the plain region, especially intense evaporation-concentration process for the groundwater in the shallow aquifer in the plain region.The hydrochemical characteristics of the groundwater manifested that the mineralization degree of the groundwater ascends gradually from the mountain region and the piedmont plain to the seashore plain, and from the shallow aquifer to the deep aquifer.Evident inter-aquifer recharge phenomena exist between the shallow groundwater and the deep aquifer under the plain.While the phenomenon of seawater encroaching to the aquifer does not exist.

The effects of Bahia grass (Paspalum notatum) and its litter on dynamics of soil moisture and water balance were studied by using Lysimeter in the slopeland of red soil.The results indicated that surface runoff coefficient of Bahia grass’ coverage (A), Bahia grass’ mulching (B) and CK (C) was 1.35%, 2.78% and 32.74% respectively.Surface runoff of C was 24.25 times of A and 11.78 times of B.Changing laws of monthly mean soil moisture of A, B and C showed that the effects of ground cover on soil moisture were different because of seasons and that different ground cover could increase or decrease soil moisture.Their annual mean soil moisture was B (27.09%)>A(26.46%)>C(26.27%).There were obvious differences between every gradient of water balance.On condition that precipitation was 1 808.5mm in 2002, the total runoff depth of A, B and C was 1 245.24mm, 1 453.81mm and 1 383.23mm respectively; their evapotranspiration was 562.74mm, 347.91mm and 413.82mm respectively; their annual soil moisture variation was 0.52 mm, 6.78mm and 11.45mm respectively.

Land use efficiency and benefit are the most important indexes measuring rationality of land resources utilization.It is of great significance to the study on the impact of land policy change on land use efficiency and benefit for land policy assessment and revision.In this paper, the authors try to reveal the impacts of urban land policy reform on land use efficiency and economic benefit using quantitative approach,taking Shenzhen Special Economic Zone (SEZ),the pioneer of urban land policy reform in China as a case. First of all,land policy reform is reviewed from two aspects,which are changes in land property rights and changes in the system of land rent and land price.On one hand,the impacts of policy changes on land transaction were decomposedinto four implement variables,including prescription of land property rights,transferability of land property rights,ways of transaction in primary land market,and ways of transaction in secondary and tertiary land markets based on reviewing land policy reform.A multiplicative model is employed here to integrate their changes and calculate the value of implement variable of land policy.On the other hand,land use efficiency and economic benefit are calculated.The result indicates that their changes are approximately synchronous with the changes in land policy.Land policy,land use efficiency and economic benefit finally show significant correlations with coefficients of 0.743 and 0.879, respectively.This result also proves that land policy reform in China did bring significantly positive effects in socioeconomic development.

Agriculture ecological security is the foundation of regional ecological security, and is the basis of sustainable development.Based on the existing study on the ecological security in and out of China, the evaluation indexes of ecological security of agriculture sustainable development in Fujian province was carried out.According to the evaluation indexes, Fujian province was taken as a case study and its ecological security situation of agriculture sustainable development from 1981 to 2004 was assessed quantitatively.The result shows: the security index of agriculture production environment decreased from 0.573 in 1981 to 0.424 in 1996, a decreased of 26% and an annual average decrease ratio of 1.63%; then it increased from 0.424 in 1996 to 0.476 in 2004.The security index of agricultural resources decreased unsteadily from 0.623 in 1981 to 0.350 in 2004, a decrease of 43.82% and an annual average decrease ratio of 1.83%; but during the period of 1998 to 2004, it decreased sharply from 0.517 to 0.350, an annual average decrease ratio of 4.76% which was 2.6 times of the average decrease ratio of the 24 years.While to variation of rural development index, it can be divided into two stages:the first stage was from 1981 to 1998, during this period the index increased from 0.285 to 0.629, an increase of 120.7% and an annual average increase ratio of 6.71%; and the second stage was from 1998 to 2004, and the index was in a steady situation.The variation of the ecological security index of regional agriculture sustainable development (CESIRASD) can be divided into three stages:the first stage was from 1981 to 1986, during this period the index decreased from 0.482 to 0.446; the second stage was from 1986 to 1998, the index increased from 0.446 to 0.529; and the third stage was from 1998 to 2004, and the index decreased from 0.529 to 0.472.Taking 2003 as an example, the main obstacles of ecological security of regional agriculture sustainable development was diagnosed.The result shows that the main threats came from the two aspects:the agricultural resources security and agriculture production environment security.The limiting contributions of agriculture resource security, agriculture producing environment security and rural social development were 45.32%, 33.92% and 20.76% respectively.Finally, in order to improve the ecological security level of agriculture sustainable development in Fujian province, some advices were put forward, such as intensifying protection of the cultivated land, improving the multiplecropping index and the production of the grain, reducting resources input per unit area, developing advanced agricultural production technology and construction of eco-agriculture, etc.

This paper makes use of the monthly natural runoff data from1956 to 2000, the monthly air temperature data and precipitation data from 1956 to 2004 to analyze the evolution characteristics of the runoff in the Yarlung Zangbo River basin in the later half of the 20th century and the relation between runoff evolution and climatic change.The results show that the interannual evolution of the runoff in the Yarlung Zangbo River basin is stable, but the intraannual distribution of the runoff is extremely uneven, the maximum monthly runoff accounts for 30.1%, while the minimum runoff only accounts for 2.1%, and indication of the great difference in the runoff between low water season and flood water season.The climate in the Yarlung Zangbo River basin is calefactive, and the increasing trend of the precipitation is obvious, having the same evolution periods with runoff.After elementary analysis of the decadal runoff in the Yarlung Zangbo River basin, we found that the increase of the water supply is mainly controlled by climate change, but is also affected by the changes of the earth surface conditions in the basin and maybe a representation of the long period of variation of high and low stream flow. Relevant data are required to validate and analyze this kind of periodic variations.

The method that linked material flow with nutrient flow was adopted in this article in order to study nitrogen and phosphorus nutrient flows in the whole process from the fertilizer input to the consumption of corn.Nutrient flow model was firstly established in corn productionconsumption system.Taking the year 2004 for example, in which the characteristics of nitrogen and phosphorus in maize ( including straw) and the efficiency of resources utilization were estimated.In 2004, 5.496×106 tons of nitrogen (N) and 2.112×106 tons of phosphorus ( P2O5) were applied into corn field in the form of chemical fertilizers; and 3.429×106 tons of nitrogen (N) and 1.394×106 tons of phosphorus ( P2O5) were harvested, in which 75%(N) and 68%( P2O5) were consumed.Corn was used for making staple feed.The total amount of N and P2O5 that came into the families, including directly by plant products and industrial products, and indirectly by animal products, occupying 22.8% and 13.6%, respectively.The ratio of returning straw to the field was quite low—phosphorus was about 80%, higher than that of nitrogen, which was 47%.So the returning straw to the field was regarded as an effective measure for phosphorus utilization. Nutrient flow began with the input of resource in the corn production-consumption system, but the utilization efficiency of resources was very low.Lots of resources were consumed by corn production, while 1 ton of nutrients in corn was produced, nitrogen and phosphorus which were consumed in the form of fertilizer were equal to 5.2 tons of coal and 12.1 tons of phosphorite, respectively.Therefore, optimizing nutrient flow in the entire corn production-consumption system was vital to the improvement of efficiency of nutrient resources and minimization environmental pollution.

Based on Principal Component Analysis (PCA) for remote sensing image, a new method was applied into identifying the spatio-temporal distribution of sea reclamation quickly and exactly. Taking Xiamen City as an example, the combinations of Remote Sensing Images, 1993 and 1996, 1996 and 1998, 1998 and 2001, 2001 and 2003, and 2003 and 2006, were identified by PCA approach for the distribution of sea reclamation in the above five periods. In order to study the driving factors of sea reclamation at different development stages of Xiamen City, several indicators such as population, throughput of sea ports, gross industrial output value, etc. were chosen into the regress equation of the driving forces. As a result, the policy of city development, rapid industrialization and rapid increase of population are the main driving factors of sea reclamation in Xiamen City. Consequently, Strategy Environmental Impact Assessment of urban policy, Sea Area Utilization Demonstration and Payment were advised for the government to governing the sea reclamation activities.

To research the changing patterns of current regional cultivated land and explore its impact on grain productivity is of great significance.Taking Northeast China as a study area,this paper analyzed the impact of the cultivated land change on grain sown area,per unit grain yield and total grain yield,and also the impact of the change of main crop planting structure on grain yield.The result shows: ⑴The cultivated land increased 188.8×10⁴ha with a general trend of increase in the northern part and decrease in the southern part in view of the spatial distribution.⑵The grain sown area has increased 162.67×10⁴ha.Per unit grain yield in most high-yield cultivated land presented an increase trend;per unit grain yield in mid-yield cultivated land presented a steady-going trend and furthermore with little increase in a few places;the changing trend of per unit grain yield in most low-yield cultivated land presented an increase trend.⑶The area of high-yield cultivated land,mid-yield cultivated land and low-yield cultivated land increased by 34.44×10⁴ha,12.57×10⁴ha and 141.83×10⁴ha respectively,but their increase amount of grain yield was 305.04×10⁴t,14.25×10⁴t and 122.88×10⁴t respectively.This shows the increase of both per unit grain yield in high-yield cultivated land and area of low-yield cultivated land promoted the increase of total grain yield in Northeast China.⑷The grain yield of four major crops in Northeast China presented different changing trends: the corn presented an "increase-decrease-increase" trend,the rice and wheat presented an "increase-decrease" trend and the bean yield increased continuously.The grain sown area of the four major crops presented a fluctuated changing trend: the corn presented an "increase-decrease-increase" trend,the bean sown area increased continuously,the rice sown area presented little increase and wheat presented an "increase-decrease" trend.In view of the regional difference,the corn production in Northeast China was further concentrated in Jilin province while that of bean,rice and wheat production further concentrated in Heilongjiang province.In a word,the grain production in Northeast China presented an obvious specialization and regionalization trend.

Based on the concept of “flood resource utilization”and influencing factors of adjusting the limited level of reservoirs during the flood season, an indices-evaluating system and estimating method about risk and performance related to the adjustment of limited level was set up, and the risk management countermeasure of the water level adjustment was discussed.Taking Wuqiangxi reservoir as an example, this study comprehensively evaluated the risk and performance brought by adjusting the limited level and the application the fuzzy-optimum-seeking method to adjust the limited level.According to the comprehensive analysis, it is feasible to raise the current limited level of 98.00m to 100.00m in the flood season.Under the condition of the low flood control risk,some 1.85 ×108m3 of flood probably excreted can be utilized efficiently, but this project must be carried out only at strengthening the risk management of real-time dispatching. Obviously, it is important to heighten the limited level and reserve more flood to realize the flood resource utilization.

This paper gives a comprehensive description of the researches of land use change at farm household level from the four aspects of investigation respect,research content,study method and data collecting means, and summarizes the features of the researches on land use change at farm household level.The main features are: ( 1)Most of the researches give notices on the land use change of hot regions, particularly on the tropical-forest area. ( 2) Lots of the researches attribute the land use changes on the pressure of subsistence to the population growth and the agriculture expansion which is also related with the population growth. ( 3) The attention of researches is being converted from land use type change to both land use conversion and land use intensity change. ( 4)More and more methods are applied by the researches of land use change at farm household level and integrated methods are appreciated by more and more studies. ( 5) The impacts of the decision-making behaviors of land users or managers on land use change are emphasized by most researches. ( 6) The social survey using questionnaires becomes a main toolof data collecting,but more and more investigations combine the social survey using questionnaires and the techniques of “3S” to get the data on land use change and its driving forces at farm household level, and devote to connecting the social survey data and the remote sensing data. Although much progress has been made in theory and practice of land use change research at farm household level, and some important results have been obtained, there still have certain problems in previous researches.These problems go as follows:the results of land use change study at farm household level can not be easily applied to other microeconomic agents, the results in one region should be much carefully applied to any other regions, the relation and interaction between different hierarchical data have been neglected, the acquiring cost of data which contains economic data and its corresponding space information is still an obstacle for the land use change research at agricultural household level, and the relation between spacial characteristics of farm household’s behaviors and the land use change’s spatial distribution has not been adequately emphasized.Furthermore, some suggestions of further studies on land use change at agricultural household level are put forward in this paper.These suggestions include applying multiple-level research angle, using game theory to analyze the land use change determined by the interaction of different agents, applying multilevel analysis in empirical study, emphasizing the impact of spacial characteristics of farm household’s behaviors on land use change and its spatial distribution, improving data acquisition means, building continuous survey system comp-rising of given farm households and so on.

Researches on water cycle in Taihang Mt. is vital not only to mountainous areas but also to groundwater recharge in adjacent piedmont.As one of the essential recharge sources for North China Plain (NCP) , a few results on status of water cycle and groundwater recharge into NCP have been reported, and the associated mechanisms have not been revealed clearly.Here, the mechanism and recharge processes of water in Taihang Mt. to NCP, with a case study in Niujiazhuang Catchment and the nested Shimen Catchment within it which is located at the middle of Taihang Mt., were presented.The results, from April to November 2004 for example, indicate the amount of lateral recharge from mountainous area to the adjacent piedmont was 1.53×106m3 with recharge ratio ( calculated by total recharge /total precipitation) of 0.242 in the order of upper reaches

According to meteorological datasets from 1961 to 2005,we selected drought days,relative wetness index,standard precipitation index, temperature anomaly and percentage of sunlight anomaly as evaluation indices of drought.Based on the method of information diffusion,level standards of agricultural drought that correspond to different evaluation indices were established.Then we assessed drought in Sichuan Basin during 1961-2006 with the fuzzy comprehensive evaluation method,and gave the drought occurrences frequency of each city.The results showed that severe spring drought,severe summer drought and extremely severe late-summer drought occurred in Sichuan Basin in 2006.Late-summer drought occurred in all the 17 cities,of which 13 cities witnessed extremely severe late-summer drought in the Basin.On average,the sparse precipitation weather occurred about once every 30 years in late summer.High-temperature occurred once every 60 years.About 29%of stations encountered the shortage of precipitation,and 90% of stations encountered high temperature,which occurred once over 50 years.Spring drought and summer drought mostly occurred in northwest and south of Sichuan Basin,about once per 2.5 years,late-summer drought mostly occurred in east of Sichuan Basin,about once per 2 years.