Research on Ecological Water Cycle and Purification in Rural Landscape——Take Zhangjia Village Ecological Wastewater Treatment Project in Henan Province as an Example

Rural landscape is not only a natural landscape,but also a cultural landscape.The improvement of rural environment in Lushi County is carried out under the background of“Building Beautiful Villages”.Through the plan of environmental improvement,the appearance of villages in rural areas will be significantly improved,and the gap between urban and rural areas will be shortened.This research addresses the problems of scarce water resources,imperfect rainwater collection facilities,and increased environmental pollution in rural areas,and explores a flexible,effective,and integrated landscape ecological water treatment system that integrates with natural ecosystems.The practice has shown that the flexible combination of different technical measures according to local conditions and the construction of ecological water self-circulation and self-purification systems can reduce maintenance costs and achieve sustainable landscape.The virtuous cycle of the revetment’s micro-ecology greatly improves the environmental carrying capacity of the landscape.Reasonable water management system is more flexible in dealing with unexpected problems.The thesis proposes landscape design strategies for water circulation and water purification in rural areas,and applies them to actual design cases.It attempts to introduce a combined treatment system to achieve a more diverse landscape concept and further explore the healthy and sustainable development of rural water environment.

Ecological water demand of natural vegetation in the lower Tarim River

We have appraised the relationships between soil moisture, groundwater depth, and plant species diversity in the lower reaches of the Tarim River in western China, by analyzing field data from 25 monitoring wells across eight study sites and 25 permanent vegetation survey plots. It is noted that groundwater depth, soil moisture and plant species diversity are closely related. It has been proven that the critical phreatic water depth is five meters in the lower reaches of the Tarim River. We acquired the mean phreatic evaporation of different groundwater levels every month by averaging the two results of phreatic evaporation using the Qunk and Averyanov formulas. Based on different vegetation types and acreage with different groundwater depth, the total ecological water demand （EWD） of natural vegetation in 2005 was 2.4×10^8 m^3 in the lower reaches of the Tarim River. Analyzing the monthly EWD, we found that the EWD in the growth season （from April to September） is 81% of the year＇s total EWD. The EWD in May, June and July was 47% of the year＇s total EWD, which indicates the best time for dispensing artificial water. This research aims at realizing the sustainable development of water resources and provides a scientific basis for water resource management and sound collocation of the Tarim River Basin.

Environmental and ecological water requirement of river system: a case study of Haihe-Luanhe river system

In order to reduce the environmental and ecological problems induced by water resources development and utilization, this paper proposes a concept of environmental and ecological water requirement. It is defined as the minimum water amount to be consumed by the natural water bodies to conserve its environmental and ecological functions. Based on the definition, the methods on calculating the amount of environmental and ecological water requirement are determined. In the case study on Haihe-Luanhe river system, the water requirement is divided into three parts, i.e., the basic in-stream flow, water requirement for sediment transfer and water consumption by evaporation of the lakes or everglades. The results of the calculation show that the environmental and ecological water requirement in the river system is about 124×108 m3, including 57×108 m3 for basic in-stream flow, 63×108 m3 for sediment transfer and 4×108 m3 for net evaporation loss of lakes. The total amount of environmental and ecological water requirement accounts for 54% of the amount of runoff (228×108 m3). However, it should be realized that the amount of environmental and ecological water requirement must be more than that we have calculated. According to this result, we consider that the rational utilization rate of the runoff in the river systems must not be more than 40%. Since the current utilization rate of the river system, which is over 80%, has been far beyond the limitation, the problems of environment and ecology are quite serious. It is imperative to control and adjust water development and utilization to eliminate the existing problems and to avoid the potential ecological or environmental crisis.

Assessment of impact of water diversion projects on ecological water uses in arid region

In arid regions, large-scale water diversion from rivers leads to significant changes in river flow regimes, which may have large impacts on ecological water uses of river-dependent ecosystems, such as river, lake, wetland, and riparian ecosystems. To assess the integrated impact of water diversion on ecological water uses, we proposed a hierarchy evaluation model composed of four layers representing the evaluation goal, sub-areas of the influenced region, evaluation criteria, and water diversion schemes, respectively. The evaluation criteria for different types of ecological water uses were proposed, and the analytical hierarchy process was used for the integrated assessment. For a river ecosystem, the percentage of mean annual flow was used to define the grade of environmental flow. For a lake ecosystem, water recharge to the lake to compensate the lake water losses was used to assess the ecological water use of a lake. The flooding level of the wetland and the groundwater level in the riparian plain were used to assess the wetland and riparian ecological water uses, respectively. The proposed model was applied to a basin in northern Xinjiang in northwest China, where both water diversion and inter-basin water transfer projects were planned to be carried out. Based on assessment results for the whole study area and two sub-areas, an appropriate scheme was recommended from four planning schemes. With the recommended scheme, ecological water uses of the influenced ecosystems can be maintained at an acceptable level. Meanwhile, economical water requirements can be met to a great extent.

A preliminary study on ecological waterdemand estimation in the arid region─A case in the Qaidam Basin

The paper emphasized the relationship between environment and water taking ecological demand water (EWD) in the Qaidam Basin─an inner basin in northwestern China, as a key issue to discuss based on landscape umpping. First of all. the spatial heterogeneity of ecosystem can be reflected well by landscape pattern; secondly, landscape patterns adjust closely with environmental changes; finally, water condition is the key ecological factor for landscape pattern in the arid region.The landsat TM image of 1:100,000 on September 22, 1996 were calibrated with topographical map of the same scale, and then landscape patterns were interpreted and mapped. As a result the Qaidam Basin could be divided into 14 main types, including 67 subtypes. Concerning the characteristics of the EWD of each sub-type, the EWD in the whole basin could be estimated according to the following formula:V= (E - P ) * S = r (KEo - P ) * S Where, V is the ecological demand for Water (m3), E is the evaporation potential on terrestrial surface (m). P is the precipitation in landscape unit (m), S is the area of landscape unit (m2), Eo is the evaporation potential on water surface (m), K is the evaporation coefficient, and r is the coverage.According to the results, the ecological demand for water of desert vegetation is about 9,65×108m3, while it is about 24.48×108m3 for the lake in the inner basin. Therefore, the total EWD occupies approximately 65.7％ of the total water resources in the basin. In conclusion, the quantitative method based on landscape ecological mapping is feasible, which attentively transfers the 'point'information to the 'area'. However, the preliminary results are expccted to improve by further field delta.

Environmental Water Price Based on Water Environment Capacity and Ecological Water Consumption: A Case Study of Hefei

With the development and reform of water price policy, the most common view is that the total cost of water price can reflect the tradable traits of water resources, which can enhance the water use efficiency and achieve water resources sustainable utilization. Besides in actual pricing operation, from the angle of protection cost, water price characterizes the cost of controlling pollution and protecting water environment. Based on the two factors of water environment capacity and ecological water consumption embodied by the environment water price, this paper puts forward an effective environmental water price calculation model based on three elements of sewage treatment fee, ecological water price and water quality maintenance fee. And this paper takes the data of Hefei as an example, calculates reasonable environmental price, comparing which with the existing price, and finds the main existing problem which needs to be solved urgently in management.

Land use/land cover change responses to ecological water conveyance in the lower reaches of Tarim River,China

The Tarim River is the longest inland river in China and is considered as an important river to protect the oasis economy and environment of the Tarim Basin.However,excessive exploitation and over-utilization of natural resources,particularly water resources,have triggered a series of ecological and environmental problems,such as the reduction in the volume of water in the main river,deterioration of water quality,drying up of downstream rivers,degradation of vegetation,and land desertification.In this study,the land use/land cover change(LUCC)responses to ecological water conveyance in the lower reaches of the Tarim River were investigated using ENVI(Environment for Visualizing Images)and GIS(Geographic Information System)data analysis software for the period of 1990-2018.Multi-temporal remote sensing images and ecological water conveyance data from 1990 to 2018 were used.The results indicate that LUCC covered an area of 2644.34 km^(2) during this period,accounting for 15.79%of the total study area.From 1990 to 2018,wetland,farmland,forestland,and artificial surfaces increased by 533.42 km^(2)(216.77%),446.68 km^(2)(123.66%),284.55 km^(2)(5.67%),and 57.51 km^(2)(217.96%),respectively,whereas areas covered by grassland and other land use/land cover types,such as Gobi,bare soil,and deserts,decreased by 103.34 km2(14.31%)and 1218.83 km2(11.75%),respectively.Vegetation area decreased first and then increased,with the order of 2010<2000<1990<2018.LUCC in the overflow and stagnant areas in the lower reaches of the Tarim River was mainly characterized by fragmentation,irregularity,and complexity.By analyzing the LUCC responses to 19 rounds of ecological water conveyance in the lower reaches of the Tarim River from 2000 to the end of 2018,we proposed guidelines for the rational development and utilization of water and soil resources and formulation of strategies for the sustainable development of the lower reaches of the Tarim River.This study provides scientific guidance for optimal scheduling of water resources in the region.

Ecological water demand:the case of the slope systems in the East Liaohe River Basin

The ecological water demand (EWD) is the least water amount required to maintain the structure and the function of the special eco-system and the temporal scale of a study on the EWD must be a season's time. Based on GIS and RS with the source information of hydrological data of 46 hydrological gauges covering 52 years and the digital images of Landsat TM in 1986, 1996 and 2000, the landscape patterns, precipitation and runoff in the East Liaohe River Basin were analyzed. With the result of the above analysis, the spatial and temporal changes of the ecological water demand in the slope systems (EWDSS) of the East Liaohe River Basin (ELRB) were derived. Landscapes in the ELRB are dispersed and strongly disturbed by human actions. The hydrological regime in ELRB has distinct spatial variations. The average annual EWDSS in the ELRB is 504.72 mm (324.08-618.89 mm), and the average EWDSS in the growth season (from May to September) is 88.29% of the year's total EWDSS .The ultimate guaranteeing ratio of the EWDSS in ELRB is 90%. The scarce EWDSS area in the whole year and in the growth season are 60.47% and 74.01% of the entire basin respectively. The trend of scarce EWDSS area is most serious according to the quantity and area of scarce EWDSS regions.

Contribution of national bioassessment approaches for assessing ecological water security： an AUSRIVAS case study

River managers in Australia are managing in the face of extremes to provide security of water supply for people, production and the environment. Balancing the water requirements of people, environments and econo- mies requires that water security is viewed holistically, not just in terms of the water available for human consump- tion. Common definitions of water security focus on the needs of both humans and ecosystems for purposes such as drinking, agriculture and industrial use, and to maintain ecological values. Information about achieving water security for the environment or ecological purposes can be a challenge to interpret because the watering require- ments of key ecological processes or assets are not well understood, and the links between ecological and human values are often not obvious to water users. Yet the concepts surrounding river health are inherently linked to holistic concepts of water security. The measurement of aquatic biota provides a valuable tool for managers to understand progress toward achieving ecological water security objectives. This paper provides a comprehensive review of the reference condition approach to river health assessment, using the development of the Australian River Assessment System （AUSRIVAS） as a case study. We make the link between the biological assessment of river health and assessment of ecological water security, and suggest that such an approach provides a way of reporting that is relevant to the contribution made by ecosystems to water security. The reference condition approach, which is the condition representative of minimally disturbed sites organized by selected physical, chemical, and biological characteristics, is most important for assessing ecological water security objectives.

Ecological Water Requirement Estimates for Typical Areas in the Huaihe Basin

Aquatic ecosystems require ecological water allocation to prevent from being damaged by natural disasters and undue exploitation. This paper discusses and estimates the ecological water requirements （EWRs） of typical areas in the Huaihe Basin to determine rational allocations of water resources and pro- mote regional improvements of the ecological environment. The main river course, including Hongze Lake and Nansi Lake, was selected as the study subject. Calculational methods for the river and lake EWRs were based on the reasonableness of the results and data availability. The monthly guarantee rate method was used to calculate monthly, flood period, non-flood period, and annual EWRs for the main river course and the main tributaries at two different guarantee rates. The minimum water level method was used to calculate annual EWRs for Hongze Lake and the upper and lower Nansi Lake of 1.521×10^9 m^3, 0.637×10^9 m^3, and 0.306×10^9 m^3. The results were used to evaluate the rationality of the quantity of water resources allocated to ecological uses in the Huaihe Basin during 1998-2003. The result shows that the present water resource allocations in the Huaihe Basin cannot satisfy the basic ecological requirements for some years, especially years with less precipitation.

A general multi-objective programming model for minimum ecological flow or water level of inland water bodies

Assessment of ecological flow or water level for water bodies is important for the protection of de- graded or degrading ecosystems caused by water shortage in arid regions, and it has become a key issue in water resources planning. In the past several decades, many methods have been proposed to assess ecological flow for rivers and ecological water level for lakes or wetlands. To balance water uses by human and ecosystems, we proposed a general multi-objective programming model to determine minimum ecological flow or water level for inland water bodies, where two objectives are water index for human and habitat index for ecosystems, respectively Using the weighted sum method for multi-objective optimization, minimum ecological flow or water level can be determined from the breakpoint in the water index-habitat index curve, which is similar to the slope method to de- termine minimum ecological flow from wetted perimeter-discharge curve. However, the general multi-objective programming model is superior to the slope method in its physical meaning and calculation method. This model provides a general analysis method for ecological water uses of different inland water bodies, and can be used to define minimum ecological flow or water level by choosing appropriate water and habitat indices. Several com- monly used flow or water level assessment methods were found to be special cases of the general model, including the wetted perimeter method and the multi-objective physical habitat simulation method for ecological river flow, the inundated forest width method for regeneration flow of floodplain forest and the lake surface area method for eco- logical lake level. These methods were applied to determine minimum ecological flow or water level for two repre- sentative rivers and a lake in northern Xinjiang of China, including minimum ecological flow for the Ertix River, minimum regeneration flow for floodplain forest along the midstream of Kaxgar River, and minimum ecological lake level for the Ebinur Lake. The results illustrated the versatility of the general model, and can provide references for water resources planning and ecosystem protection for these rivers and lake.

Carry forw ard Soil and Water Ecological Culture and Build Rich and Beautiful Home

The most directly expressions of the relationships between human and nature lie in the relationships between human and water,human and soil（ stone）,human and vegetation（ plant）. Water,soil and vegetation are interdependent,restricted coexisted and developed from one another,which are integrated and correlated. The history of human＇s survival and development on the earth is one related continuously with water,soil（ stone）,vegetation（ plant）,which involves with the protection and reasonable utilization of water,soil and vegetation resources（ also known as soil and water ecological resources）,and it has summarized and accumulated abundant culture concerned with the harmonious coexistence of human with water,soil and vegetation,which is the soil and water ecological culture. All peoples of China have accumulated rich soil and water ecological culture in the long term,such as integrated view of nature,nature admiring,nature praising,nature protection and reasonable utilization of nature. It is especially important and urgent in the current times to carry forward soil and water ecological culture.

Climate Change from the Perspective of Soil and Water Ecological Theory

The earth s ecological environment is declining at an unprecedented rate,and human survival is facing great risks.Among the global changes,the most serious ones are climate change and global warming.Analyzed from the theory of soil and water ecology,the root cause of this problem lies in the disordered and uncontrolled human activities,which only pay attention to the interests of development and ignore the purpose of development.From the source,it is the consequence of human excessive interference and damage to the earth s water and soil ecology.It is urgent to protect and repair the earth s water and soil ecology,realize carbon neutralization as soon as possible,and prevent the irreversible disaster caused by global warming from the source.

Safety Evaluation of Water Environment Carrying Capacity of Five Cities in Ningxia Based on Ecological Footprint of Water Resources

[Objectives]To make safety evaluation of water environment carrying capacity of five cities in Ningxia based on ecological footprint of water resources.[Methods]With the help of the grey relational model,15 indicators were selected from the natural,economic,and social aspects,and the most influential factors in the three fields were selected.Based on the concept of ecological priority,the water resources carrying capacity of the five cities in Ningxia from 2010 to 2019 was calculated with the help of the water resources ecological footprint model.Then,the indicators of the water resources ecological footprint model were coupled with the existing indicators to establish a comprehensive evaluation indicator system.Finally,the changes of the water environment carrying capacity of the five cities in Ningxia were analyzed with the help of the principal component analysis(PCA).[Results]The ecological pressure of water resources and the ecological deficit of water resources in the five cities were relatively large.Specifically,Yinchuan City had the most obvious deficit of water resources but good carrying capacity;Zhongwei City had a large ecological deficit of water resources,poor carrying capacity,and the largest ecological pressure index of water resources;Guyuan City had low water resources ecological deficit,water resources ecological carrying capacity and water resources ecological pressure index.[Conclusions]Through the analysis of the coupling indicator system,it can be seen that the water environment carrying capacity of the five cities is in an upward trend,indicating that the water environment in each region tends to become better.

An Evaluation Study on Water Ecological Civilization Construction in Coal Mining Subsidence Area

By combining expert consultation and field investigation,an evaluation system,consisting of 29 indices in 5 aspects of water safety,water ecology,water management,water landscape and water culture,was established for water ecological civilization construction in coal mining subsidence areas.The weight of the indices was determined using improved group-decision fuzzy analytic hierarchy process and fuzzy mathematical method,and their score was determined according to their value before the pilot and the value at the end of the pilot.Combined with the weight,the actual score of the indices was obtained.Finally,a comprehensive index of water ecological civilization in coal mining subsidence areas was obtained.Through the weight and score of the indices,the construction status,existing problems and future tasks of coal mining subsidence areas were analyzed,in order to provide a reference for the region to further clarify the direction and key tasks of water ecological civilization construction.

The Theory of Soil and Water Ecology is the Common Theoretical Basis in the Field of Ecological Environment

From the perspective of system concept and practical needs,the field of ecological environment needs new theories that can grasp the whole and command the overall situation.Soil and water ecology is the holistic view of nature of seeing both macrocosm and microcosm,is the largest common divisor of various types of ecosystems on the earth and will effectively integrate all ecological processes related to human beings,animals and plants.Starting from the principle of soil and water ecology,the paper resolved that:①the essence of landscape,forest,field,lake,grass,sand and ice is soil and water ecology and;②the fundamental reason of the ecological and environmental crises of climate change,global warming and loss of biodiversity lies in the change and destruction of the earth’s soil and water ecology.The theory of soil and water ecology is a major scientific issue related to the fundamental and overall situation of the ecological environment,is the golden key to understand and solve contemporary ecological and environmental issues and is the common theoretical basis in the field of ecological environment.

Conservation Grading of Water Ecological Spaces in the Muling River Basin

Along with the urban construction and industrial development, the original continuous riverway of the Muling River has been dammed into river sections of different lengths, which has seriously destroyed ecological environment of the basin. In view of this, it is urgent to protect water ecological environment of the basin. This paper took the national ecological environment conservation instructions as the guidance, combined with the administrative division, planning and actual conditions of the basin, proposed principles and schemes for the grading of water spaces in the basin, as well as the hierarchic control requirements, to provide instructions for the conservation of the river basin.

Thoughts on the Construction of Urban Water Ecological Civilization in Northeast China

Based on the ongoing construction of water ecological civilization in China,the connotation and specific requirements of ecological civilization and ecological civilized city are analyzed in detail. Combining with present situation and characteristics of water resources,water environment and water culture in Northeast China,the main contents to be considered in the construction of water ecological civilization in Northeast China are discussed,which could provide the reference for construction of water ecological civilization city.

Ecological characteristics of planktonic ostracoda in the western waters of Taiwan Straits

In the sea area west of the middle line of Taiwan Straits, 116°40′～120°30′E, 22°22.9′～25°43′N, four cruises of comprehensive survey were conducted by the Third Institute of Oceanography, State Oceanic Administration, from May, 1984 to February, 1985. The data concerned were taken from the quantitative samples obtained by using large-sized standard zooplankton nets, while the values adopted such as hydrological and chemical data of the various stations were from the average values of the field data of each one-meter layer.

Protection and Restoration of Soil and Water Ecology to Achieve Harmonious Coexistence between Human and Nature

At present,the ecological environment crisis of global concern,such as climate warming and biodiversity loss,the fundamental reason is the change and destruction of the earth's soil and water ecology.Therefore,protecting and restoring the authenticity,diversity,cleanliness and integrity of soil and water ecology,we should coordinate and deal with the relationship between human beings and soil and water ecology,and realize the harmonious coexistence between human beings and nature from the three aspects of protecting natural soil and water ecology,protecting and restoring natural soil and water ecology,building and regenerating artificial soil and water ecology.