According to geological sediment, paleontological evidence, historical and locol records preserved from ancient times, recent meteorological observations and vegetation survey materials, the author studied the evolution and distribution characteristics of the climate and vegetation types in the loess plateau, Gansu Province. The results show that during the Quaternary Ice Age, the sandy loess zone in the Gansu Loess Plateau was arid desert and semi-desert, and the typical loess zone was arid steppe. During imerglacial period the former changed into subarid steppe and the latter into humid forest and subhumid forest steppe. Before hundreds of years, the vegetation in the Gansu Loess Plateau was much better then that at present. Forest could be seen in the southeastern part and higher rocky mountains of this area. Afterwards, because of unreasonable economical activities of mankind it leaded to deterioration in ecological environment and desertification in climate. Nowadays the northern and central parts of the sandy loess zone and the typical loess zone have already been arid and subarid desert, subdesert and steppe. Only in the southern and southeastern parts of the typical loess zone, the subhumid forest and steppe and humid forest still continue to exist.

By use of seven operationally monospecific sera of chicken (see Annual Report of the Institute of Genetics, Academia Sinica, 1981", p. 34-35), analyses of constitutions of flocks and genetic relationship were studied among some breeds of "White Plumage Ukokkei" (Chinese native chicken breeds). Comparative studies on "Peking Yukei" (Chinese native chicken breed) and White Leghorn Beijing Line 1 were also carried out. The experiment results denoted as follows:First, 7 blood-group factors in the same breed of domestic fowl inter different genie factors or in the same genie factor of the different breeds were measured. The significant differences were found among distribution frequencies of the blood-group factors (P<0.01). Second, the highest and lowest distribution frequency of blood-group factors are specific in each breed. Third, the amount of constitutive type of blood-group factors and their frequencies varied with flocks. It means that genetic constitutions of different flocks are different.The coefficients of homozygosity of blood-group gene in these flocks are lower (0.1519-0.1768).The genetic distances (calculated by the distribution frequency of the blood-group factors) of some "White Plumage Ukokkei" are smaller, but their genetic similarities are larger. On the contrary, the genetic distances between some "White Plumage Ukokkei" and White Leghorn Beijing Line I are larger, but their genetic similarities are small, whereas the genetic distances, between all the breeds described above and "Peking-Yukei" are of intermediate type.

Studing natural grasslands of 84 counties in Guizhou Province and analysing 1331 quadrate samples, this paper explains that they are the grasslands with secondary characteristics, most of them are unstable, situated in the succession from grasses to bush to forest, besides, there are also relatively stable alpine meadows and bush-grasslands with plagioclimax.The grasslands in Guizhou Province are mainly scattered patchily among the woodlands and agricultural fields. Large area of these grasslands are located on the middle-mountain areas and plateaus with the elevation above 1000 m, these places are characterized with small population, long distance from settlements and difficulty of accessibility. The grasslands often stretch contineously as a belt on the ridges and tops of the middle-mountains.The total coverage of the grasslands in Guizhou, is about 80-85%. The thickness of the grass layer is about 60-70 cm, and the yeild of the fresh grasses is about 6,000-9,000 kg/ha. The growing times of green grass is about 240-300 daysannually. There are 96% of grasslands can be used for cutting for making hays. The grasslands in Guizhou abound with variant plants, mainly winter-green or evergreen grasses. The alpine meadows have relatively high value for animal husbandary. Most of them are suitable to exploitation with advantage ous. condition.The quality of the grasslands in Guizhou is poor, 76.5% of them are deficient in legumes, which occupy only 0.96% of the total grasses by weight, they are the grasses with low content of protien. There are about 40% of these grasslands with thin soils depth less than 30 cm, and there are about 50% of the grasslands with slopes more than 25%, about 74.8% with bare rocks or stones and 25% are suffered from soil erosion. The durability for grazing is poor. All of these, to some extent, are the limitation of their exploitation.

Based on the 1951-1980 climatic data of about 500 stations and a wealth of the agro-climatic information, a summary of the agroclimatic regionalization of China is given in this paper. This regionalization is made up of three levels.The first level, there are three main agroclimatic areas. The east monsoon main area, humid and subhumid, with tolerable and plentyiful rainfall in the warm period, has good climatic productive potentiality. In the northwest main area, water deficit greatly himders the function of light and heat factors. Its southern boundary is set by the 50% frequency line of the annual precipitation ≥ 400mm, with number of days of gale wind as a subsidiary index. In the Qinghai-Xizang Plateau main area, the heat insufficiency hampers the full utilization of the light-water resources. The accumulated temperature (above 0℃) of 3000℃ and the warmest monthly mean temperature of 18℃ are taken together as the boundary of this area.The second level: Fifteen agroclimatic zones are delineated based on the heat demand of the cropping systems and main crops. The east monsoon main area, is divided into ten agroclimatic zones using mean annual lowest temperature and the accumulated temperature above 0℃ as the criterions. In the northwest main area, the accumuluted temperature above 0℃ is used as index. There are two zones, i. e. the arid middle temperate zone and the arid south temperate zone. In the Qinghai-Xizang Plateau main area, ∑t( ≥ 0℃) and the temperature of the warmest month are taken as criterions for delineation. On this basis, Qinghai-Xizang Plateau is divided into three agroclimatic zones, i. e. plateau temperate zone, plateau subfrigid zone and plateau frigid zone.The third level reflects agroclimatic types. Based on regional agroclimatic features, with emphasis on moisture condition and agroclimatic calamity, fifty-five agroclimatic regions arc delineated (see Fig. and Tab.).

The Ruoergai Plateau is the largest distribution area of peatland in China, various natural features, such as, relatively depressed lands during the Quaternary, Geomorphic features of wide Valley and mild hilly land as well as cool and humis climate. Provided a good condition for development of mires and peat accumulation, and therefore a particular ecological environment of upland mires was formed. The main type of mires is the waterlogged peat land on the wide valley with rare species of helophytes and many birds and few beasts, hence it formed a specific landscape. The grassland of mires in the region is a good grazing land and peat is an impro-tant resource. Both area of distribution is about the same over 4600 km²; and storage capacity of peat which is the first place in China is reached to 76 × 10⁸m³ and has an improtant value for exploitation. The exploitation of mires and peat resource must follow the principle of pursuing ecological and economic benefits.At present, there is an indication that the Ecological environment trends to be worse, for example, the environment is in danger of being desert, and therefore attention is must paid to-that.The large scale drainage of in ire is not suitable in this region and the extablishment of ecological mire conservancy area is urgemly needed. The Potential of peat exploitation which is of importance in local economy is vary great and the principle of comprehensive exploitation and utilization of the resource combined with conservation is must followed.

Hunan Province is in the middle part of the subtropical zone in China and in the transition region of the eastern and western parts of the mid-subtropics. The natural environment and re- sources are imbued with a distinct transition characteristic. Within the Hunan Province the natural condition is advantageous, the structure of natural resources of agriculture is fine, as well as the utilization ratio of land and energy of sunlight is high. But the resources are affected by regional distinctions of the natural and social economy, and present a distinct regional transition. This paper makes a primary investigation mainly on the reginal distinctions, the present condition of exploitation and utilization, and the orientation of rational exploitation anduilization of resources.The forests, the cultivated land and grassland resources are the three major sectors of agricultural natural resources. Hunan is one of the important forestry regions on the south of Changjiang River. Its amount of forest reserves occupies the fourteen position in China. But it is still not reasonably utilized at present and has the tendency to come down. We should strengthen the forestry construction of mountain areas and build Hunan into a large-scale base of timber forests and economic forest in the region on the south of Changjiang River. Hunan is one of the provinces with more people and less cultivated land in China. Although the total output of grain occupies the fourth position in the country, but the exploitation of resources does not balance. It has not yet fully to bring out the productive potentiality of resources. Only in the Basin of Lake Dongting it is possible to be built into one of the largest bases of commodity grain. The fragment, pieces and intersecting distribution of plough and forest are the distinctions of grassland resources of Hunan, which is classified as two types: (1) fragmentary grassland of the low-mountain and hill, (2) the continous grassland of the middle-mountain. In the light of its distinct of the suitability, We should adopt a thousand and one families or the main orientation of utilization of resources. The middle-mountain grassland is the outcome of the unstable stage of abverse succession in ecosyston of evergreen broad-leaf forests. If it is to be used as great grazing land, a prudent altitude should be adopted.

In this paper, the exploitation, utilization and enhancement of marine living resources in the world, especially in the China have been described and discussed. The main contents of present paper are summarized as follows:1. The term "marine living resources" is here employed in a broad sense and includes the all living body (microbes, algae, seagrass, mangrove and animals) in the marine environment(including esturies). We should be discussion it from the point of view of ecosystems.2. China is a country rich in marine living resources. Nearly ten thousand species of marine organisms were found from the coastal zone and the shallow water of the continental self of China.3. The amount of photosynthetic production in water of Pohai Sea( Yellow Sea, East China Sea and South China Sea is about 3.5 × 10⁸ tons of carbon/year. According to the theoretical estimates from data on primary production the total year production of fish biomass is about 16 million tons.4. Marine living resources is exploited and utilized as foods, raw materials for industries, feed, fertilizer, new energy resources and ornament. Marine pharmacan which play an rapor-tant role in Chinese traditional medicine has attracted the attention of public in China and other countries.5. Though there was overfish in some areas in the ocean, the future of .vorld production of marine fisheries will be bright.6. Mariculture is greatly developed in China. At the present time, over 40 species of marine algae and animals are cultivated, the annual yield have increased to more than 50×10⁴. tons.7. Protective management is very important in maintaining the high aboundance biomass of marine living resources.

The basic task of the agricultural production is to transform into commodity and economy. .The direction of the agricultural development and the aim of the information System for agricultural resources are to promote the agricultural commercialization, specialization and regionalization.This system is divided into four levels-national, provincial, prefectural and district. The information centre is composed or three softwares: the data bank, the model base, and the dialogue sub-system. The national information centre includes the date bank, the model base, the image base, the simulation base, the documentation base and the bialogue generation and management sub-system.The internal source data base stores the specific data obtained from the survey of agricultural resources. The image base stores the remote sensing images and digital geographic maps. The model base deals with decision making.

This thesis approach to the methodology of series study for the land resources, including classification, evaluation, optimization model and carrying capacity of land resources, taking the oasis of the Hutubi County, Xinjiang Uygur Autonomous Region as an example.First, the type of land resources was divided and the system of classification was established. Then, the elementary types of land resources were used as a land mapping unit to evluate the land quality and its suitability. Based on these results and the main natural, ecologic, social and economic conditions affecting land use, the optimization scheme for the utilization of land resources was selected by linear programming through IBM-PC computer. At last, based on the yield levels of the first-class land resources, the population supporting capacity of land was calculated to meet the productive conditions which the optimization scheme should require. That is to calculate how many people could support by one mu or one ha arable land based on the calculation of mean intakes of calorie and protein every member in our country. The calculations, compared with year 1984, demonstrated that population supporting capacity under the optimization scheme of land use will enhance evidently.

During 1963-1972, a large-scale "International Biology Plan" was led and organized by UNESCO. Quite a few countries and a great number of scientists took part in the plan. The plan accumulated many data about primary biological production in the different regions of the world. But it also costs a great deal of time and money. Therefore, several scientists started to set up various models to calculate the biological productivity and to draw up biological productivity maps. The Miami Model is one of them.The Miami Model consists of two formulas that described a large number of mutual relationships between the real survey value of biological productivity and the local average temperature and average rainfall of different zones on the earth. The two formulas are:where: y1 = Primary biological productivity according to temperature (g/m2/year); y2 = Primary biological productivity according to rainfall (g/m2/year); t = Local annual average temperature (°G); p = Local annual average rainfall (mm); and e = The base of natural logarithm.Finally, according to Liebig's restrictive factor law, the local productivity is either y1 or y2 whichever is smaller. We collected some 600 meteorological data, and culcalated them using Miami Model, and then, drew up" Miami Model Productivity Map (Isogram) in China".Due to the map, the total primary biological productivity in China is 8.27×109t per year. It is 6.64% of the total world's primary productivity (124.5 X 10't per year). China's per km2 productivity is 861.45t per year which is equal to the world's level. China's per capita productivity is 8.14t per year which is only one-third of world's average (28.55 t per year).

本世纪六十年代以后,美国联邦政府、州和地方政府对土地资源和水资源逐步实行了立法,设立了相应的管理机构,并随着陆地卫星影像和电子计算机在资源调查与评价中的广泛应用,土地适宜性评价的方法向着合理化和精确化的方向发展,不断改进和完善。 美国较为系统的土地评价方法是农业部土壤保持局的“土地潜力分级”系统,该系统主要从土壤的特征出发来进行土地潜力分级,分为潜力级、潜力亚级和潜力单位三个等

In this paper the methods of estimation of plant density by the distance sampling, the parametric and .nonparametric estimation were discussed. Using a practical example, the theoretical formulas were examined. It was found that the nonparametric estimation based on ordered statistic is more available and useful for survey and investigation of forest resources.

Four problems are discussed in this paper.(1) The area of the Loess Plateau is 39.1×10⁴ km² instead of 56×10⁴km² or 43×106 km², in which the area of the loess plateau in the middle reaches of the Huanghe River is 31.9×10⁴ km².(2) The control and exploitation of the Loess Plateau should be combined closely together. The exploitation should be carried out in the course of the control, and the former pormotes the latter. It is incorrect to put undue emphasis on one of them.(3) In the first place, water loss should be avoided, so as to reduce the soil loss. The measure for water conservation is to ameliorate the soil in order to enhance the ability of water storage of soil.(4) Since 1971 the sediment load of the Huanghe River has reduced 36% in which the sedement yield reduction by water-soil conservation occupies 48%. It is thus proved that the idea of the "water-soli conservation is the basis of harnessing the Huanghe River" is correct.

In this paper, the methods calculating the spatial distribution of agroclimatic resources (temperature, humidity, precipitation, wind speed, etc.) in mountainous areas are presented. For suiting to the application of computer in the research of mountain climate, the calculating models are represented by functional relations and the spatial distribution maps of agro-climatic resources on fine mesh are drawed up by computer. The climatic effects of topography obtained from the application of these methods in the Shaxi River basin, in the midwest of Fujian Province, are also introduced. The effects of microtopography on thermal resources can be divided into four types: the temperature-increasing, -decreasing, -variable and -invariable, in which the greatest increasing and decreasing effects correspond to the effects of decrease and increase by 100-250 m in elevation respectively. The effect of meso- and microtopography on precipitation is affected by the topography and the prevailing wind direction with precipitation. And the effect of microtopography on wind speed is related to the topography and the angle between the wind direction and the topography. The spatial distribution maps of accumulated temperature above 10℃ (∑t10) and annual precipitation (P) in the Shaxi River basin show that the methods of calculation proposed in this paper may effectively disclose the macro and micro variations of spatial distribution of agroclimatic resources in mountainous areas, and their effects are very satisfactory.

China is a country which is deficient in forests. China just had some partially data about it's forest resources until the 'Four-Five' Survey, a thorough investigation made on forests in the midseventies. It was the first time for China through the 'Four-Five' Survey to find out the forest resources of the whole country, including the gross area of forests, the area and growing stock of woodland and sparse woods land, and the area of shrubbey. Meanwhile, the geographic distribution of the forests, the structure of dominant species and the age composition were also found out exclusively. Most provinces, autonomous regions and municipalities made the surveys by means of the small-group investigation, surveying all woodlands one by one. Afterwards, every province made macrosampling survey of it's forest resources, named as 'Five-Five' Survey from 1978 to 1981. The results of those two surveiys are almost identical and show clearly that China's forests are so little that it's forest cover rate is far lower than the average level of the world and that of the typical countries in the world.The area of China's forest regions in the early period of history was about several times larger than that of today. The present situation of woods and lumber deficiency was caused by forest fire, destructive lumbering, and especially the overreclaiming and overgrazing over the past thousand years in China's agricultural society. This damaging process has been still continuing.China's natural conditions and the situation of the land are suitable for forestry. China can expand the area of forests by a big margin and rise the growing stock. It is possible for China to expand it's forests to 252 million ha. and rise the growing stock more than 21000 m3, both are more than two times that of the present. Even though, China's forest resources will not meet all the needs of ecological environment protection and the demands of economic growth.

The Loess Plateau is a unique physico-geographic unit in China. There are some divergence of concept about it's boundary. This paper points out, that such divergence is due to different understanding of natural characteristics of the regions which are the transition from the Loess Plateau to surrounding natural regions.In the paper, several different concepts are reviewed, such as the Loess, the distributional region of the Loess, the Loess Plateau and the neighbouring distributional region of the Loess, the Loess Plateau, and the typical loess geomorphological region; all these concepts should not be confused. Finally, criteria and index for dividing the boundary of the Loess Plateau are discussed. Based on field investigation and landsat image interpretation, the boundary of the Loess Plateau is delimited.

This paper deals with the new tendency about the land and biological resources of seaco-at zone and their exploitation and utilization of China, which discusses about the soils and land resources, biological resources, which including living organisms fragmites, shelter belt trees, mangloves, and Spartine anagleca, of seashore zone and their exploitation and utilization.After the exploitation and utilization of the resources of the seacoast zone, it should be greatly hasten the economic, social and ecological benefits of China.

In this paper, there is an overall evaluation about territorial resources in Poyang Lake district and the strategy of exploitation and renovation is proposed. Poyang Lake district is rich in natural resources and has enormous exploitable potentialities. But the economic development in Poyang Lake district has been influenced by frequently happened natural calamities (such as flood, drought et al.), unreasonable economic structures, under developed commodity production, higher increasing human population as well as science, technology and culture behind and worsening environment. In order to exploit and renovate Poyang Lake district, there is a series of strategic suggestions, such as (1) prevent flood and drought, (2) bring the water of the lake into full play, (3) optimize economic and industrial structure, (4) utilize the territory resources reasonably, (5) bring the agricultural superiority of the district into full play, (6) control population growth strictly, (7) increase intelligen-tial investment, (8) raise population quality and (9) promote the progress of science and technology.

Dabieshan mountain area in west Anhui lies to the transition zone of subtropical moist and semi-moist monsoon climate. It is rich in species of biotic resources. But forestry, the main resource there, has been atrophied seriously. Now the local people are looking for extension arid substitution for resource conversion in their living and producing. The basic model of resource conversion is: resource-product-commodity-money-resource. During the earlier stage of the model, the emphasis should be laid on development and utilization, and the later should be laid on protection and extension. Each link of this model has a certain substitute in different time and space. So the efficient measures should be adopted to compose a proper model in order to ensure the peasants in this mountain area to go out of their poor life and become wealthy quickly.

Li and Rb values in 131 soil samples collected from 1982 to 1983 within an area of 60 km² in the known hydrothermal active areas and their vicinity in Tengchong, Yunnan Province have been determined. The Li and Rb anomali es delineate two known hydrothermal active areas, rather consistent with the anomalies of the known geochemical indicator elements, including Hg As Sb Bi and B, and further confirm their prospects. At the same time Na and K values in hot waters of this field have also been determined and interpreted.Correlation analyses of Li, Rb and the known geochemical indicators are made. There exists a certain linkage between fossil geothermal systems and salt lakes. It is concluded that the presence of Li and Rb in soil could well be used to delineate geothermal fields, and geothermal systems could be exploited not only as energy resources, but also as mineral resources.

It's the core of regional economic development in choosing industrial development model on the basis of the systematic charasteristic of Ganjiang Valley. The main points of industrial development model of Ganjiang Valley are as follows: (1) promote the utilization of resources effectively. (2) produce superior and replaced products. (3) realize the transform of industrial structure of resources producing-processing-technology applying gradully tend to from lower reaches to upper. (4) promote ecology-economy good circle so that resource exploit and territory administer tend to upper reaches to lower.

Hainan Island is the largest island of tropical zone in our country. It has plenty of natural resources, good geographic position and great potentialities of economic development. It has also a special strategic significence in the developing of national construction.Because Hainan Lsland is situated in the open front line of China and the world economic centre is now transfering to Asia-Pacific area, we ought to fully utilize these favourable conditions and develop economic relations with countries of the world and further expand the backing role of the mainland.The strategic aims of economic development in Hainan Island are as follows; 1. to make Hainan Island into a synthetic open area, in which trade, industry agriculture are integrated and banking, toursim, service etc are managed simultaneously. 2. a new island with reasonal-ble industrial structure, advanced science and technology, well-off life and high level of material civilization and mental civilization. 3, to work out plans such as strengthening macrocosm research, controling population, developing industry and agriculture, selecting talent people and setting up provincial level administrative body. 4. to take measures to make adjustment promote open and development, regulate industrial structure, introduce foreign capital and ally with mainland positive factors, strengthen capital construction and pay more attention to intelligence invest and scientific research. 5. to abopt more favourable policies in order to encourage the investors of mainland and foreign countries to set ap factories on Haitian Island. 6. to develop tropical crops, tropical forestry, cultivating, tropical product processing, tourism, energy resources and mineral resources. 7. to improve transport and communication conditions and set up different types of factories.There is a vast prospect of economic development on Hainan Island. As long as we insist on long-term open policy, well absorb the strong points of mainland and abroad to make Hainan Island become one of the important bases to realize the vigorous economic development of our country in the end of the century and a pioneer to make our country go into the advanced ranks of the world in the next century.

In the early 1970's guided by the policy of "Grain must be taken as the key link in agriculture", people in Hubei and some other provinces in China started a "land reclaimed from lake" upsurge, which however incurred some knotty problems in the reclaimed areas. Ecological and economic cost-benefit analyses are made in this paper based on the data obtained from the reclaimed lake regions. It is concluded that land-reclamation should be regarded as a kind of disadvantageous action because of its adverse impacts on agricultural ecology, fishery, navigation and the climate in the reclaimed areas, which has been shown in recent years despite its limited benefits in grain production and in the elimination of oncomelania, the host of blood fluke.This paper points out that only by exploiting and utilizing lake resources properly can lakes be well manayed and protected, and can those renewable and valuable resources be constantly available for human beings.

The Southern part of Fujian Province, situated in the south sub-tropical zone of China with rich and varied natural resources, is a valuable-land in Fujian. It has an important strategic position facing to Taiwan province, and near to Hongkong and Macao. In the golden triangular area of South Fujian, there are three cities and 19 counties, which cover an area of 25,000 Sq. Km, with a population of over ten millions. The physical environment is-quite varied and human activities add to the complexity in delta. This region is known popularly as an overseas Chinese native land and treasured place for industrial and agricultural production in addition to the fine climate conditions and the rich natural resources.Exploit natural resources and cultivated lang have a long history. Nevertheless, due to the unreasonable expolitation in the past, there exist the soil erosion, soil and water loss, environmental degradation and damage of landscape. This paper is trying to define a way of development in the South Fujian from four aspect:1. Adjusting agricultural structure and rationally using physical resources are an important way to increase land productivity.2. It is an important subject to control the soil and water loss, appositely to exploit natural resources, and protect environment in South Fujian.3. Rationally using the shoal and point bar, develop fishery and protect aquatic resources.4. According to local conditions, emphasis should be laid on the combination of land utilization and conservation, the preservation of land productivity to make the ecological environment better, and take care of land function, land productivity and land suitability.

The Gudong Oil Field, with an area of 68 km², is located to the north of the mouth of the Huanghe River. Considered from the viewpoint of geomorphology, it is in a land-sea transitional zone.This land was formed during the past decade by the shifting of the tail channel of the Huanghe River and the deposition of the sediment carried by the river. Since 1976, the Huanghe River has changed its tail channel from the Diaokou Tiver to the Qingshuigully, through which it now empties into the Laizhou Bay.The natural environment of this region is very complicated and there exist a lot of potential disasters in the oil field and the surrounding area, such as stormy tides, the flooding of the Huanghe River, the erosive retreating of the coastline, etc. All these could threaten the security of the oil field. If some of these potential disasters happened simultaneously, it would be extremely dangerous to the oil field.For the safety of the Gudong Oil Field, the author puts forward the following suggestions:1.Reinforcing the dykes by broadening their widths and meanwhile increasing their heights to 6.0 m above sea level in order to protect the oil field from demages caused by exceptional stormy tides and the flooding of the Huanghe River.2.Planting Spartina townsendii (Rice Grass) on the beaches as vastly as possible to reduce wave action, slow down the current speed, and protect the beaches; building a breakwater of 5.5 m high along the high-tide line to protect the coast from erosion.

The Lingding Bay, 2110km² in erea, is situated in the northestern part of the zhujiang River mouth in Guangdong Province. The area abounds in resources of tidal flat soils. Through centuries the inhabitants of the area have built dikes around it and brought it under cultivation. The main crops are rice and sugar cane.The present paper discusses the physico-chemical properties of the soils. Its texture is medium clay. The salt and organic matter contents are generally 0.2-1.5% and 1.5-2.2%, respectively. They are mostly neutral-alkaline in reaction with pH value (between, 6.5-8.0). The natural fertility of the soils is high. The soil data are very useful for the area development, especially for the rational production system of agriculture and fishery. The development prospect of this area is very promising.

The present paper discusses agricultural water supply in the plain downstream of the Ha-ihe Basin, where water is unsatisfied with water demand. On the basis of water saving policy concerned with water development and management, the concept of an analytical model for decision making is suggested in this paper. The model can be used for either large area or small area. In this paper a large plain area of the Haihe Basin is taken as a case study.The mathematical model is obtained as follows: Where: Z = total profit (value of the objective function);B=benefits of water use;C = costs of water supply; = management level at e;I = water duty; A = irrigation acreage to be developed by using different flooding technigues, subscript of i;n = farming structure (cropping system);m = source of water (water supply combination);P = reliability of water supply. In this study, n and m are constants.There are many constraints involved in the model such as water amount, irrigation acreage, irrigation technique etc.The results show that water saving would be of the most important alternative to solve the problem of water shortage in the Haihe Plain. The net benefit of water supply through water saving techniques can be positive in a dry year. Enhancing the irrigation management should be emphasized on water saving. On the basis of water saving agricultural water resources can be supplemented through water diversion from the Changjiang (Yangtze River) to the Haihe Plain with a reasonable scale. Before the implementation of the water diversion a countermeasure of adjusting the cropping system of the Haihe Plain to mitigate water shortage is likely to be advisable.

Tarim River is the longest inland river in China.It is located at the north of the Tarim Basin.However,the river flow in the 357-km-long section of the lower reaches had been cut off since 1972.The groundwater level had declined from 2.9～7.0m to 8.1～12.9m.In order to protect the eco-environment and save the existing vegetation in the lower Tarim River,a total volume of 13.8×10⁸m3 of water was delivered to the lower reaches from May 2000 to July 2003, in five times.Based on groundwater monitoring data before and after the fifth water transfer,this paper analyses the features of responses of groundwater table pre- and post-delivery of water to the lower reaches of the Tarim River.Before water transfer,the groundwater table was generally a horizontal line but after that,it presented a binary polynomial curve. The relationgship of ground-water table and distance from the river was thus expressed binary polynomial.Furthermore,the calculative formula of groundwater recharge volume was established by means of groundwater balance.The results of calculation showed that the average depth of groundwater has come back respectively from 9.0m to 3.0m and from 9.0m to 7.4m at Yingsu section and Yiganbujima section in the vicinities of the river(0～1000m).The total volume of groundwater recharged was 8.01×10⁸m3 after the fifth water transpfer.All these can provide referenced index for the evaluation of benefits from water transfer.

Based on the cumulate soil water replenishment model,soil erosion mode l,and multiple objective nonlinear optimum models,an allocation model for spatia l optimization of land resource was established.The method includes four steps.T he first step,with the objective of making spatial distribution of water resourc e suitable for crop growth in the study area,is to establish the water distribut ion models based on grid data model,SCS discharge model and the principle of wat er content equilibrium.The second step is to establish a soil water prediction model to analyze watershed soil and water loss situation.In this step,Digital El evation Model(DEM),land use map,soil type distribution map,climate,meteorologica l and hydraulic data are required.The third step is to integrate the water conte nt distribution model,soil and water loss model,and a multiple objective model f or land use optimization in order to get the quantitive structure of land use.Th e last step is to allocate the optimized land use structure spatially based upon the current land use patterns and the principles of ecology.To test the model,a typical watershed,Xingzihe watershed,on the Loess Plateau in northern Shaanxi p rovince was selected as the study area.As a result,land resources at the watersh ed were allocated based on the local integrated regulation programming.The ecolo gical and economic benefits of the optimum land use structures were discussed.It is indicated that the eco,environment of the study area would be apparently imp roved after watershed regulation.Moreover,the local farmers' income would be gre atly increased,and the major source of agricultural income would be shifted to w oods and fruits.At the same time,the case study also revealed that both of the e conomic benefit and the ecological benefit will increase until the management de gree reaches 30%.When the degree exceeds 30%, the economic benefit will continue to increase but the ecological benefit will remain almost unchanged.The propose d method can produce better result for local land use structural regulation.

The paper applies the dualistic distributed hydrological model (WEP-L model) to stu-dy the evolutionary laws of the Yellow River Basin's water resources under the impact of human activities.The water resources assessment results under present underlying surfaces are compared with those under historical underlying surfaces,and the water resources assessment results under no water use condition are compared with those under water use condition as well. By contrast,it is shown that the quantity and compositions of water resources changed distinctly under the impact of intensive human activities.The two main variations are as follow:(1)the surface water resources reduced but the ground water resources which is unrepeatable with the surface water resources increased;(2)the special water resources reduced but the general water resources increased accompanied with increase of the effective evaporation,namely,effective utilization of precipitation.The research achievement can be referenced for comprehensive management and the water safety strategic planning of the Yellow River Basin.