Urgent challenges to water resources management for the next decade and beyond include Water Governance, Water & Food, Water & Nature, Water & Energy, and Water & Health including Sanitation, Water & Transboundary Cooperation and Climate Change & Adaptation, all of which are related to water security in regional & global scales. To respond to these challenges, water management strategies in both China and World need to address the two pillars of water demand management (WDM) and water supply management (WSM), broadly conceived, and the appropriate mix of WDM and WSM. This paper will address this urgent issue in global vision. By analysis, it was recommended as follows: at local level to carry out knowledge-transfer and exchange of the experiences and best practices about WSM; at country level to develop Guidelines for improving a joint WSM and WDM (eventually to be developed at river basin/district level). Since situations in each continent or sub—continent are very different, it is necessary to address specific Regional Guidance Reports including: a first Part, devoted to the assessment of available water resources and demands by using hydrological methods for estimating resources, and demand survey and predictions; a second Part on the organizations, institutions, tariffs and training and educational dimension of a joint WSM and WDM, at international level to develop a draft of an U.N. Convention oriented to foster a joint WSM and WDM for trans—boundary basins and/or under conditions of competitive uses and/or water scarcity. With reference to the above cited aims, the objectives could be limited on four aspects: WSM at local and country level (and short term); WDM at local and country level (and short term); Joint WSM and WDM at national level for medium and long term; Joint WSM and WDM at international/regional level for medium and long term.

Forest area in Liupan Mountains is important water conservation area of Loess Plateau. This area experienced large-scale afforestation during the past 3 decades, and the landscape patterns has been changed greatly. These changes have result in consequently changes of characteristics of main hydroecological progress and ecological function. Based on analysis of the dynamic and components characteristics of hydrological process, this paper discussed possible changes of landscape caused by afforestation and their hydroecological impact based on simulation results made by a distributed hydrological model TOPOG, in order to offer a hydroecological view for the undertaking afforestation activity in Liupan Mountains and Loess Plateau. The preliminary scenario simulation and analysis imply that total runoff at catchment outlet will decrease total runoff of catchment if increasing area of Larix principris-upprechtii woodland through cutting natural broadleaf woodland or reclamation of shrub patches. The decrease of total runoff can reach 28% when the area ratio of Larix principris-upprechtii patches enlarges from 11.5% to 58%. While reclamation of shrub patches also might reduce availability of water resources because runoff undulating will enlarge.

Yongding River, as the mother river of Beijing city, has been dried up from Sanjia Dian since 1980s. The naked riverbed and the desertification of its both sides play a main role of sandy weather in spring of Beijing. The Quaternary period underground water of the west Beijing has been drained off, because of the overload of the underground water plus with no supply pouring into. The ecological system of Yongding River has severely been devastated. If we want Yongding River to be recovered, we should clarify the quantity of the most active and the most important water. This paper calculated the instream ecological flow in three monitored sections of Yongding River Guanting Reservoir with wetted perimeter method. The three sections are Guanting Reservoir (under dam), Yanchi and Lugou Bridge. Respectively, the flows in the instream of each section are 3.7 m³ s^-1 (the normal flow year, P=50%, 1978) accounting for 20.7% of the average annual flow, 4.1 m³ s^-1(the normal flow year, P=50%, 1981) accounting for 20.1% of the average annual flow and 1.3 m³ s^-1 (the normal flow year, P=50% ,1978) accounting for 22.1% of the average annual flow. If the supplies are according to the calculated flows, Yongding River will return back from it. Still according to the Tennant method, the Yongding River will maintain a health situation.

By analyzing basic characteristics of mountainous river systems, this paper established an index system of mountainous river health assessment from both an ecological service perspective and the perspective of meeting human needs, and has built a mountainous river health evaluation model based on Projection Pursuit theory. Taking a typical mountainous river in southwestern China as an example, this paper investigated its health status prior to and after hydropower development. The result showed that the comprehensive health situation after hydropower development is significantly better than that in the current situation. In addition, this paper proposed countermeasures for river health maintenance based on an analysis of structural features of the evaluation result.

A Distributed Time—Variant Gain Hydrological Model (DTVGM) based on remote sensing (RS) is proposed. The model contains several sub—models, such as snowmelt model, runoff model. It produces outputs including snow cover, evaporation, runoff, etc. All inputs for the model are derived from remote sensing data. Data from the Lhasa River basin is used in this study, including USGS—SRTM DEM, TRMM precipitation and Modis—LST. More than eight years (2001–2008) of daily hydrological data set was selected to calibrate the model. Based on the comparison of the observed and estimated runoff, the model's averaged efficiency of daily runoff simulation is over 0.6. The error of water balance was less than 5%. Distributed modeling results are quite satisfactory. This study provided a promising approach to resolve hydrology and water resources problems in ungauged or sparsely gauged basins.

Soil erosion was very serious in the Guishui area of Guanting reservoir. In order to control the non-point source (NPS) pollution of soil loss there, a distributed soil erosion and sediment transport sub-model with less parameters and more convenient application was built in this paper, which was composed of the USLE model and the sediment transport model. Firstly, USLE was used to calculate soil erosion after suitable calculation formulae of its factors were selected. And then the watershed was generalized into river network, we applied the relation between S-curve and pollutant-collecting area coefficient we had established into the solution of one-dimensional water quality transportation equation gained from Laplace transform and inverse Laplace transform, and derived the distributed sediment transport model. Finally, relied on DEM, this paper made research on the model application in Guishui watershed by picking up geographical information from the soil map and land-use map of Guishui watershed. Application results indicated that this model can not only be used to make research on the sediment pollution resulting from NPS pollution, but also on the spatial distribution of soil erosion, offering scientific foundation for realizing best agricultural management in this watershed. The soil loss in Guishui watershed mainly comes from the mountain and hill with large slope and low vegetation coverage, therefore, the key for controlling the soil loss shall be taken on the mountain and hill in this watershed.

Due to water shortages, many districts and cities have started reusing wastewater as an inexpensive supplemental source of water. This study was conducted to evaluate the suitability of various sites for construction of decentralized wastewater reclamation facilities, to identify suitable conditions for reclaimed water reuse in various industries, and to provide helpful information for the formulation or revision of urban wastewater reclamation policies. To accomplish this, the factors influencing the construction of wastewater reclamation facilities were analyzed taking Beijing as an example. In addition, the suitability of wastewater reclamation by water consumers from government institutes, colleges and hotels in Beijing was evaluated after consideration of the water consumption of several consumers in each of these industries. The results indicate that most government institutes and one- and two—star hotels are not suitable, while most hotels of three—star or higher level and most colleges are suitable, for the construction of wastewater reclamation facilities.

Water quality evaluation is important because it could provide guidance when determining water utility. But many interacting impact factors are involved in water quality evaluation systems, making water quality evaluation difficult. Principal component analysis (PCA) is widely used in water quality evaluation because it can eliminate the correlation among factors. However, PCA ignores the degree of data dispersion, which is considered by information entropy (IE). To solve this problem, a model combined PCA and IE methods to obtain the weights of indicators is proposed in this paper, and the proposed model was applied to assess the reused water quality of Jinshui River in Zhengzhou City in 2009. The evaluation results were compared with those using PCA and IE methods for the same data. The results proved that the method is feasible and practical, and it can provide a theoretical basis and decision reference for the utility of unconventional water.

Tongzhou District has been put forward as the new developing centre of Beijing City. But the serious water deficiency and pollution restricted the local sustainable development. In this paper, an integrated water resource carrying capacity (IWRCC) model was developed under the sustainable development principle and the “natural—social” water cycle to quantify IWRCC of Tongzhou District. Three scenarios were designed to increase IWRCC and results showed that there was a great gap between IWRCC and the development plan in Tongzhou District. Water shortage restricted urbanization and sustainability seriously and transferring water from other regions besides promoting water saving and controlling pollution in the region would be the most feasible solution for Tongzhou District to mitigate the water shortage stress.

The South—to—North Water Transfer (SNWT) Project is one of the four largest trans—boundary projects in China. With the construction and operation of the project, increased attention has been paid to the risk factors which are induced by the uncertainties. The analysis and management of integrated risk are also put before the project managers. It is extremely important to reduce and control the integrated risks involved in the operation of the project. In this study, Baoying Station on the eastern route of the SNWT Project was chosen as the study area, and Bayesian Network (BN) theory is used to evaluate the probability of the integrated risks. Based on the reasoning of BN, the final integrated risk probability of Baoying Station is estimated to be 0.025% and the risk level is “lower level”. Analysis of the scenario shows that the probability of integrated risk is most severe when management and maintenance conditions of the pump in use deteriorates. More attention should be paid to this important risk factor during the operation of the project.

Growing interests in simulating changes in hydrological processes on global and regional scales have been raised by more frequent strong floods and droughts on the global scale induced by climate change, which would have significant impacts on social and economic systems, food security and the survival and development of humans. General circulation models (GCMs) perform reasonably well in simulating current climate in terms of annual or seasonal averages on large spatial scales, thereby showing the capability to provide inputs for studies associated with hydrological responses to climate change on continental or global scale. However, the models perform poorly on small spatial and time scales relevant to regional impact analysis. The Statistical Downscaling Model (SDSM) is considered a very useful tool to address spatial-matching problems. It enables the study of climate change response to be carried out on local scales. In this paper, the applicability of SDSM in the Bosten Lake Basin was evaluated and the model was used to analyze the trends in future maximum and minimum temperature in this watershed. First, maximum temperature and minimum temperature were selected as the predictands. Appropriate meso-scale atmospheric variables were selected as downscaling predictors. Then, a statistical transfer function between them was constructed by the United States National Centers for Environmental Prediction (NCEP) re-analysis data set and observations at four stations. The first 30 years (1961–1990) of the obtained data series (1961–2001) was used to calibrate the model, while the remaining ten years (1991–2001) of data series was used to validate the model. The results show good agreement between the observations and the outputs from the model. On the basis of this, with the outputs of Hadley Centre Coupled Model, version 3 (HadCM3) under A2 and B2 scenarios respectively, the calibrated SDSM model generated future daily temperature series, which were subsequently used to analyze the temporal trends. The results show that there is an obvious increasing trend for the future maximum temperature and minimum temperature in the Bosten Lake Basin on daily, monthly, seasonal and yearly scales, respectively. The increase in the A2 scenario is larger than in the B2 scenario. The largest increase was found in summer while the smallest was in winter. This study would provide a scientific basis for further study of climate change over the Bosten Lake Basin.

As the country's political, economic and cultural center, with the advantage of strong capacity on integrated innovation, Beijing should set an example on achieving economic efficiency and ecological stability. Under this background, building the Capital Eco-economic Zones (CEEZ) in Beijing mountainous areas is the inevitable trend of scientific development. The geographical scope of CEEZ includes 7 mountainous districts, and the spatial structure is “two mountains, five rivers, seven organizing groups” based on the framework target of “one region, three bases, and one platform”. The formation of CEEZ has profound implications, especially for the optimization of capital mountain eco-environment construction during the transitional period from extensive development mode at the expense of resources to intensive and sustainable development mode based on ecosystem protection. In order to develop CEEZ, principles such as breaking the restriction of administrative boundaries and giving priorities to the development of ecological construction should be followed. The final goal in the next 10–15 years is to build the capital eco-industrial economic corridor, to expand its geographic scope, and to develop the eco-economic growth pole in northern China.