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A sludge-based adsorbent (SBA-Air) was prepared using rapid pyrolysis under an air atmosphere to adsorb Pb2+ from aqueous solutions. The maximum Pb2+adsorption capacity of SBA-Air was 117.96 ± 1.22 mg/g, which was only slightly lower than that of SBA-N2 (SBR prepared under an N2 atmosphere) with 0.99% of reduction rates. The Pb2+ adsorption capacity of SBA-Air was affected by initial solution pH, adsorbent dosage, and adsorption time. The Pb2+ adsorption onto SBA-Air could be best fitted by pseudo-second-order kinetics model and Langmuir isotherm model, which was similar to that onto SBA-N2. Thermodynamic analysis suggested that the Pb2+ adsorption onto SBA-Air was spontaneous and endothermic. Chemical adsorption (live functional group complexation, π- π adsorption, and ion exchange) was the main adsorption mechanism for Pb2+ onto SBA-Air. The experimental results suggested that sewage sludge can also be prepared into an effective, reusable, and environment-friendly SBA for Pb2+ adsorption under a simple and low-cost air preparation atmosphere.

The frequency of urban storms has increased, influenced by the climate changing and urbanization, and the process of urban rainfall runoff has also changed, leading to severe urban waterlogging problems. Against this background, the risk of urban waterlogging was analyzed and assessed accurately, using an urban stormwater model as necessary. Most studies have used urban hydrological models to assess flood risk; however, due to limited flow pipeline data, the calibration and the validation of the models are difficult. This study applied the MIKE URBAN model to build a drainage system model in the Beijing Future Science City of China, where the discharge of pipelines was absent. Three methods, of empirical calibration, formula validation, and validation based on field investigation, were used to calibrate and validate the parameters of the model. After the empirical calibration, the relative error range between the simulated value and the measured value was verified by the formula as within 25%. The simulated runoff depth was consistent with a field survey verified by the method of validation based on field investigation, showing the model has good applicability in the study area. Then, the rainfall scenarios of different return periods were designed and simulated. Simulation results showed that, for the 10-year return period, there are overflow pipe sections in northern and southern regions, and the number of overflow pipe sections in the northern region is more than that in the southern region. For the 20-year return period and 50-year return period, the number of overflow pipe sections and nodes in the northern region increased, while for the 100-year return period, the number of overflow nodes both increased. With the increase in the rainfall return period, the pipe network load increased, the points and sections prone to accumulation and waterlogging increased, and the regional waterlogging risk increased. The southern region is prone to waterlogging because the pipeline network density is higher than that in the northern region and the terrain is low-lying. This study provides a reference for the establishment of rainwater drainage models in regions with similar database limitations and provides a technical reference for the calibration and validation of stormwater models that lack rainfall runoff data.

To assess the urban waterlogging mitigation effectiveness on low impact development (LID) in semi-mountainous regions, the Storm Water Management Model (SWMM) of a semi-mountainous region combined with GIS was generalized. The SWMM was calibrated and validated through maximum seeper depth of the checkpoints, and various LID scenarios have been designed according to local conditions. The discharge processes of outlets, surface runoff, peak flow and peak time were analyzed in different scenarios. The results show that: all the flow processes of outlets in the LID scenario are gentler than that in the status quo scenario, and the effectiveness of LIDs in semi-mountainous regions are different from that in plain regions because of the slope influence; in semi-mountainous regions, the LID effectiveness on surface runoff reduction decreases with the increase in rainfall return period or the extension of rainfall duration, but remains almost unchanged with the increase in rainfall peak coefficient; the LID effectiveness on control peak flow reduction is not remarkable with the change in rainfall characteristics, and the LID effectiveness on peak time delay is poor. This research can provide decision support for regional small-scale measures of urban waterlogging mitigation and reduction in semi-mountainous regions. HIGHLIGHTS The SWMM of a typical semi-mountainous region was established utilizing ArcGIS and the surveyed maximum seeper depth.; The numbers, properties, and locations of LIDs were designed based on the local characteristics.; The results indicated that LIDs effectiveness is related to slope in the study area.; This research can provide technique support to resilient cities design in semi-mountainous regions.

Given a changing environment, estimating a flood magnitude corresponding to a desired return period considering nonstationarity is crucial for hydrological engineering designs. Four nonstationary design methods, namely expected waiting time (EWT), expected number of exceedances (ENE), equivalent reliability (ER), and average design life level (ADLL) have already been proposed in recent years. Among them, the EWT method needs to estimate design flood magnitudes by solving numerically. In addition, EWT requires estimating design quantiles for infinite lifespan, or extrapolation time (textra), to guarantee the convergence of the EWT solution under certain conditions. However, few studies have systematically evaluated pros and cons of the EWT method as to how to determine the textra and what kinds of misunderstandings on the applicability of the EWT method exist. In this study, we aim to provide the first investigation of various factors that influence the value of textra in the EWT method, and provide comprehensive comparison of the four methods from the perspectives of textra, design values and associated uncertainties. The annual maximum flood series (AMFS) of 25 hydrological stations, with increasing and decreasing trends, in Pearl River and Weihe River were chosen for illustrations. The results indicate that: (1) the textra of EWT is considerably affected by the trend of AMFS and the choice of extreme distributions. In other words, the textra of stations with increasing trends was significantly smaller than that of stations with decreasing trends, and the textra was also larger for distributions with heavier tail; (2) EWT produced larger design values than ENE for increasing trends, and both EWT and ENE yielded larger design values than ER and ADLL for higher return periods, while complete opposite results were obtained for decreasing trends.

In this study, we presented welding process between Rogers laminates and aluminum substrate with SAC305 alloy. The samples were characterized in terms of temperature cycling test, mechanical shock test and constant acceleration test. The characterizations were performed by using field emission scanning electron microscope, and the compositions were identified by energy dispersive spectroscopy. The results showed that some interesting changes of the solder layer took place after the test. Before the test, the thickness of solder was uniform and about 40 µm; the IMC layer was not obvious; there were voids in the solder itself and solders joints, but no cracks were found. After the test, the thickness of solder changed slightly; the IMC layer was obvious and the thickness was about 6 µm; the voids in the solder grew bigger, but there were no cracks yet. The intermetallic compounds of tree-like morphology run through the solders and the main composition was Au-Sn-Ni alloy. In the test each layer diffused to solder at different levels, but the degree of Au, Ni and Ag diffusion was the most prominent.

Urban water supply systems consist of water intaking, water delivery, water purification, water distribution, and other processes that require energy. As urban population increases, water resources must be drained from a larger watershed and delivered through longer pipelines. Additionally, the requirements of water purification techniques are being raised, and higher building height poses challenges to water distribution. All these factors have caused evident changes in the energy use in the water supply system. Estimation of the energy used in the water supply system is one of the bases for low-carbon city construction and assessments. This paper provides a method for assessing the energy use by a water system in an urban area and performs a case study for Beijing, China. This study investigated the urban water supply system of Beijing from 1979 to 2017 by collecting data of water sources, water treatment techniques, delivery pipelines, water pressure, and seepage rates. It estimated the energy use per cubic unit of water in the water supply system and plotted the trend through time. The results showed that the energy use per cubic unit of water supply in Beijing increased from 0.30 KWh to 0.65 KWh from 1979 to 2014. After the commissioning of the South-to-North Water Diversion Project in 2014, the energy use per cubic unit water was altered structurally and remained steady, because the water transported by the project replaced groundwater and reduced the electricity requirement for pumping. The results demonstrate that the South-to-North Water Diversion Project significantly helps Beijing reduce carbon emissions.

Since 1999, the surface vegetation coverage in the Yanhe River Basin has undergone constant change. The ecological environment in the basin has improved partially; however, water scarcity remains a critical issue for the Loess Plateau. The current quantitative analysis of runoff evolution affected by climatic and anthropogenic elements in the study area is insufficient. To evaluate the influence of anthropogenic elements and climatic variation on runoff evolution, we used the SWAT hydrological model to study key hydrological processes under different simulation scenarios along the river basin in this study. Overall, the runoff volume of the Yanhe River Basin showed a significant downward trend, although different trends were observed over different periods. Runoff declined from 1981 to 1998 and increased after 1998. A comparative analysis of three different scenarios shows that climate change contributes approximately twice as much to runoff evolution as land use changes. Climate change causes runoff to decrease by 65.64%, whereas land use change causes runoff to increase by 34.36%. The decrease in runoff in small watersheds is primarily due to climatic factors, whereas vegetation restoration is beneficial to the increase in runoff in small watersheds. The research results will be valuable in comprehending the quantitative influence of climatic and anthropogenic factors on the hydrological evolution of the Yellow River Valley.

Due to the urban rainstorm waterlogging problem which has frequently occurred in recent years, this paper establishes a rainwater pipe network system model for the newly built future science park area in Beijing based on the MIKE Urban model under the support of fundamental data in aspects of catch basin, storm sewer, land utilization, etc. Because of the lack of measured runoff data, this paper uses the runoff coefficient as the check objective to implement the experience calibration of the model parameters, verifies the model through the “6.23” storm runoff process in Beijing and establishes the regional model. On this basis, this paper simulates three designed rainfall runoff processes under different recurrence periods and obtains the simulation result of cumulated water quantity, pipe load, etc. in the corresponding catchment area of the research area. This paper concludes through analysis that the easy flooding and waterlogging points under different simulation scenarios in the research area provide the decision basis for the storm waterlogging risk management and rainfall resource utilization in this area.

Aiming at more frequent urban waterlogging problems in China, a system of rainwater drainage pipe network by SWMM (Storm Water Management Model) was constructed, using Beijing Future Science Park as the study area. The empirical runoff coefficient method is used for model parameter calibration and validation of “6.23” and “7.21” rainfall runoff processes to build the regional SWMM model and simulate regional rainfall runoff processes in different return periods. Comprehensive runoff coefficient and flood peak flow are used as indicators to analyze the above simulation results. In terms of the whole area, both elements increase with longer design return period, the same as regional flood risk. In terms of the local area, comprehensive runoff coefficient of sub-catchment area increases with a longer design return period, but different with various underlying surface conditions. Among them, the comprehensive runoff coefficient of green land with better permeability is only 0, while the corresponding value of road area with permeability of 90% is 0.89, to indicate the differences in spatial distribution of regional flood risk along with the underlying surface conditions. The above research results provide the technical support for the construction of regional low impact development measures (Low Impact Development, LID) and urban flood warning.

Extreme climate conditions, such as typhoon rainfall events, are common throughout coastal watersheds. However, despite the increasing interest in the impacts of rainstorm patterns on runoff pollution, research in this area is still inadequate. Therefore, an urban water quantity/quality model was constructed to evaluate the distribution characteristics of non-point source (NPS) pollution based on 12 typhoon rainstorm events that occurred within the 2008–2019 period. The rainstorm events were categorized as either an early pattern (EP), middle pattern (MP), or late pattern (LP), and the effects of these patterns on the NPS pollution of urban receiving water in Southeast China were investigated. For the 12 typhoon rainstorms under investigation, the results showed that 97.2% of the peak concentration time (PCT) of pollution indices occurred after the peak rainfall time (PRT), indicating a lag effect of the PCT, compared to the PRT. Additionally, it was observed that the EP rainstorm events are more likely to cause severe NPS pollution owing to their association with the longest lag time (135–180 min) and the earliest deterioration time (280–303 min). Moreover, the pollution load intensity (PLI) showed a strong response to urbanized land-use. In particular, the average PLI of the midstream watershed was found to be higher than that of other watersheds. These results provide useful information for the design of effective strategies for rainfall-runoff pollution mitigation in coastal urban watersheds in China.

It is reasonable to simulate the hydrologic cycle in regions with drastic land use change using a distributed hydrologic model in the dynamic land use mode (dynamic mode). A new dynamic mode is introduced into an object-oriented modularized model for basin-scale water cycle simulation (MODCYCLE), a distributed hydrologic model based on sub-watersheds, and the hydrological response unit (HRU). The new mode can linearly interpolate data for the years without land use data and consistently transfer HRU water storage between two adjacent years after a land use data update. The hydrologic cycle simulation of the Sanjiang Plain in China was carried out from 2000 to 2014 in the dynamic mode using land use maps of 2000, 2005, 2010, and 2014. Through calibration and validation, the performance of the model reached a satisfactory level. Replacing the land use data of the calibrated model using that of the year 2000, a comparison model in the static land use mode (static mode) was built (i.e., land use unchanged since 2000). The hydrologic effects of land use change were analyzed using the two models. If the land use pattern remained unchanged from 2000, despite the average annual runoff increasing by 4% and the average annual evapotranspiration decreasing by 4% in this region only, the groundwater storage of the plain areas in 2014 would increase by 4.6 bil. m3 compared to that in 2000, rather than the actual decrease of 4.7 bil. m3. The results show that the fluxes associated with groundwater are obviously more disturbed by land use change in the Sanjiang Plain. This study suggests that the dynamic mode should be used to simulate the hydrologic cycle in regions with drastic land use change, and the consistent transfer of HRU water storage may be considered in the dynamic mode.

Due to the joint impact of climate change and human activities, vegetation cover area in Loess Plateau has been tremendously improved. However, vegetation restoration will lead to high water use, which might pose a great threat to the water sustainability of regional ecosystems. In order to analyze the spatiotemporal characteristics of water consumption, this study estimated the actual evapotranspiration (AET) based on the SEBAL model. The study found that precipitation and AET increased significantly (5% confidence level) with the rising of vegetation coverage in the period of 1990–2015. The increase rate of precipitation was 1.91 mm/a, higher than that of AET (1.68 mm/a). From a spatial perspective, the AET of Loess Plateau is increasing from northwest to southeast. The high-AET area (AET > 400 mm) was also extremely enlarged from 39% (1990) to 73% (2015) with the vegetation recovery. In terms of the intra-annual variability, the AET from March to April is usually much higher than the precipitation in different hydrological years, which suggests that the spring drought is a potential threat for vegetation growth in Loess Plateau. At last, this study introduced an index of rainwater utilization potential indicator (IRUP) to analyze the water supply and demand in Loess Plateau. It found that IRUP values are positively correlated with NDVI (Normalized Difference Vegetation Index), indicating that the available water for vegetation growth is seemingly increasing with the vegetation cover area enlarged in the whole region.

The melting properties and the heat capacity of the solid state and the melt state 4’-bromomethyl-2-cyanobiphenyl (OTBNBr) were determined. The enthalpy, entropy and Gibbs free energy of fusion were also calculated. The solubility of OTBNBr in eight organic solvents was experimentally measured at temperatures from (283.15 to 323.15) K by using a static method. The reasons for the differences of the solubility of OTBNBr in various solvents are discussed by using the intermolecular interaction. Furthermore, the experimental solubility values were well correlated by the modified Apelblat equation, the λh equation, the Wilson model and the van’t Hoff equation. Finally, the temperature dependence of the activity coefficient and the van’t Hoff enthalpy in the tested solutions was investigated and is discussed.

The solubility data of spironolactone form II in six pure solvents and binary solvent mixtures of ethyl acetate and methanol were measured over the temperature range from (278.85 to 317.75) K by using a dynamic method under atmospheric pressure. The results show that the solubility of spironolactone form II in pure solvents increases with increasing temperature while the solubility in binary solvent mixtures increases with the increasing of the fraction of ethyl acetate. This phenomenon is well explained by using relative dielectric constants of the solvents. The solubility data of spironolactone form II in pure solvents were well correlated by the modified Apelblat equation, the Wilson model and the NRTL model while the solubility of spironolactone form II in binary solvent mixtures were correlated by the modified Apelblat equation and the CNIBS/R-K model. Furthermore, the thermodynamic properties of the dissolution process of spironolactone form II were also determined by using the van’t Hoff equation.

The solubility of cefuroxime acid in (acetonitrile + water) mixtures was experimentally determined at temperatures from (278.15 to 313.15) K by using a dynamic method at atmospheric pressure. The solubility increased with the increasing of temperature, and it reached the maximum at acetonitrile molar fraction of 0.713 at constant temperature. The experimental solubility data were correlated well by using the modified Apelblat equation, the λ h equation and the van’t Hoff equation, respectively. The Akaike’s Information Criterion (AIC) was used to select the best model for correlating the solubility of cefuroxime acid. Furthermore, the dissolution enthalpy, entropy and Gibbs free energy change of cefuroxime acid were also calculated by using the van’t Hoff equation.

The solubility of calcium-l-lactate pentahydrate (CLLP) in binary ethanol + water and acetone + water solvent mixtures was measured in the temperature range of 278.15 K to 313.15 K by using a synthetic method. The solubility of CLLP increases with increasing temperature, whereas it decreases with the increase of the initial mole fraction of ethanol or acetone. The solubility data were correlated by using the modified Apelblat equation, the CNIBS/R-K equation, and the hybrid model, respectively. It was found that the modified Apelblat equation could give better correlation results both in ethanol aqueous solutions and in acetone aqueous solutions. The dissolution enthalpy, entropy, and Gibbs energy change of dissolution of CLLP in these solvent mixtures were obtained by using the modified van’t Hoff equation.

The solubility of l-alanyl-l-glutamine (Ala-Gln) in pure water and ethanol–water mixed solvents was measured using a synthetic method from 283.15 to 313.15 K. Molecular dynamics simulation was carried out to explain the effect of ethanol content on the solubility of Ala-Gln. The radial distribution function was used to evaluate the interactions between solute molecules and solvent molecules. The solubility data was correlated by four thermodynamic models, including the hybrid model, Wilson model, NRTL model, and UNIQUAC model. It was found that the NRTL model could give better correlation results than the other models. The dissolution properties of Ala-Gln solutions, including the free Gibbs energy, the dissolution enthalpy, and the dissolution entropy, were calculated by using the modified van’t Hoff equation.

LIDs are frequently utilized measures in urban waterlogging management in the world and the evaluation of their effectiveness through model gets a lot of attention in urban hydrological research. In this study, a typical urban unit of Handan, China was selected, and regional SWMM model was calibrated and validated through measured maximum waterlogging depths (MWD) of typical positions; the LIDs effectiveness on runoff process in different return period events were evaluated through the SWMM. The results show that LIDs have an effect on decreasing total runoff quantity and peak discharge and the effectiveness is more significant when the return period is small. The research provides a technical support to the scientific management of local flood and waterlogging and supplies a reference to local Sponge City planning.

The transformation process of soil water plays an important role in the hydrological cycle, and is a link to other water processes. Study on the regularity of soil water transformation under agricultural plantation is favorable to understanding the influence of human activities on soil water conversion. Typical crop was selected in Beijing-Tianjin-Hebei(BTH) region and the study on regularity of field-scale soil water transformation was carried out by means of crop-soil water field experimental observation combined with model simulation. In the field experiment, testing and observation of irrigated and rainfed maize were simultaneously carried out in the adjacent fields respectively to form a comparative experimental study. The experimental observation data were used to establish the soil water model, which is calibrated in many aspects, such as field water content change during the maize growth period, the soil profile water content distribution at different moments, maize leaf area index and plant height. The results show that this model has an efficient simulation effect. Quantitative study on field evapotranspiration regularity, field soil water flux under irrigated and rainfed modes, impact mechanism of soil water deep seepage during maize growth period was achieved through the simulation of soil water process, and related reference conclusions were also proposed for water resources management and conservation in BTH.

Beijing is located on the North China Plain with five rivers, which belong to the Hai River Basin. Its continental monsoon climate with uneven precipitation distribution is extreme likely lead to serious urban flood disasters. According to the disaster results, urban storm flood in Beijing can be classified into four types. Here typical extreme storm flood events and their characteristics in Beijing were analyzed in detail. It showed that storm flood events in recently decades had a trend, which centered in a relatively small area with high intensity and short duration. The main reasons of urban storm flood disaster were urbanization and basic facilities with low flood and drainage standard. Urbanization means land utilization significantly altering hydraulic processes, and extreme storm can easily exceed those facilities capacity. In order to deal with urban storm flood, Beijing government have taken four measurements, which were upgrading and reconstruction of rainwater pumping stations, improving projects of small and medium rivers, building sponge city, and implementing the West Suburb Storm-water Regulation Project. In addition, the flood warning and emergency management system has been established. Furthermore, some measurements were pointed to be done in the future, including improvement of the flood control management system, improvement of flood control plans, strengthening flood warning system, and strengthening social management and public awareness of flood prevention. With these improvements of management and engineering measurements, it can be more secure under intensive storms in Beijing. These experiences of flood control in Beijing can provide references for other cities.

Urban flooding occurs frequently in many regions of China. To reduce the losses caused by urban flooding, sponge city (SPC) and low-impact development (LID) have been carried out in many Chinese cities. However, urban flooding is influenced by various factors, such as climate, land cover characteristics and nearby river networks, so it is necessary to evaluate the effectiveness of LID measures. In this study, the Storm Water Management Model (SWMM) was adopted to simulate historical urban storm processes in the mountainous Fragrance Hills region of Beijing, China. Subsequently, numerical simulations were performed to evaluate how various LID measures (concave greenbelt, permeable pavement, bio-retention, vegetative swales, and comprehensive measures) influenced urban runoff reduction. The results showed that the LID measures are effective in controlling the surface runoff of the storm events with return periods shorter than five years, in particular, for one-year events. Furthermore, the effectiveness on traffic congestion mitigation of several LID measures (concave greenbelt, vegetative swales, and comprehensive measures) was evaluated. However, the effective return periods of storm events are shorter than two years if the effectiveness on traffic congestion relief is considered. In all evaluated aspects, comprehensive measures and concave greenbelts are the most effective, and vegetative swale is the least effective. This indicated that LID measures are less effective for removing ponding from most storm events in a mountainous, low-lying and backward pipeline infrastructure region with pressures from interval flooding and urban waterlogging. The engineering measures including water conservancy projects and pipeline infrastructure construction combined with the non-engineering measures were suggested to effectively control severe urban storms.

This study produced a drought map for the Fenhe River basin covering the period from 150 BC to 2012 using regional historical drought records. Based on meteorological and hydrological features, the characteristics and causes of water scarcity in the Fenhe River basin were examined, along with their impact on the national economy and ecological environment. The effects of water scarcity in the basin on the national economy were determined from agricultural, industrial, and domestic perspectives. The impact on aquatic ecosystems was ascertained through an evolution trend analysis of surface water systems, including rivers, wetlands, and slope ecosystems, and subterranean water systems, including groundwater and karst springs. As a result of these analyses, strategies are presented for coping with water scarcity in this basin, including engineering countermeasures, such as the construction of a water network in Shanxi, and the non-engineering approach of groundwater resource preservation. These comprehensive coping strategies are proposed with the aim of assisting the prevention and control of water scarcity in the arid and semi-arid areas of China.

It is very important to evaluate water quality in environment protection. Water environment is a complicated system, traditional methods can not meet the demands of water environment protection. In view of the deficiency of the traditional methods, a BP neural network model and a RBF neural network model are proposed to evaluate water quality. The proposed model was applied to evaluate the water quality of 10 sections in Suzhou river. The evaluation result was compared with that of the RBF neural network method and the reported results in Suzhou river. It indicated that the performance of proposed neural network model is practically feasible in tha application of water quality assessment and its operation is simple.

Because of Boundary types and geologic conditions, which possess random and obscure characteristics, groundwater heads vary with the conditions. The prediction of groundwater level is one of the main work of hydraulic government, which is predicted based on the history data and the relative influence factors. Therefore, prediction precision depends on the accuracy of history data. Data mining has provided a new method for analyzing massive, complex and noisy data. According to the complexity and ambiguity of groundwater system, a new integration of grey with neural network model is built to forecast groundwater heads, which were used to judge whether future groundwater heads were extraordinarily over the history range or not. This method overcomes the disadvantages which the grey method only predict the linear trend. The methods were used to analyze the random characteristics of groundwater heads in anyang city . The results indicate that the method is reliable, and reasonable

The environment have varied sharply since 1980s in China owing to the influence of climate change and human activities, which makes precipitation process become more and more nonlinear and dynamic and hard to be described. The fractal dimension is a fit index to describe the complexity of the hydrologic series quantitatively and Wavelet Transform is a feasible method for the study of the nonlinear and dynamic process. Using the fractal dimension based on Continuous Wavelet Transform (CWT), the complexity distributions of different precipitation process of which is from 1980 to 2000 in Hand an and the other is from 1980 to 2009 in Qilijie basin, are illuminated respectively in this study. The result indicates that the precipitation process since 1980s in Qilijie basin is more complex than that in Hand an and the fractal dimension of the precipitation in urban area is lager than that in other areas both in two typical regions. This study can provide technical guidance for the research of hydrologic system and reference for water management in the local region.

The hydrologic system is dynamic and nonlinear because of the influence of climate change, vegetation, topography and human activities, which makes the system variable, complex and hard to be described and characterized. Wavelet Analysis which has Multi-resolution Analysis function can mine more detail information in multiscale and adapt to the dynamic and nonlinear system. The periodicity and the trend of different hydrologic series in Liu-Kuang zone of Handan are illuminated with Morlet Wavelet Transform in Multi-time scales in this study. It is illustrated that the same periods (6years and 9years) exist in different hydrologic series in Liu-Kuang zone; the similar variety and the similar trend also exist in different hydrologic series whether in the 6 years scale or in the 9 years scale. This study would provide technical assistance for the integrated management and utilization of water resources of the local watershed.

The periodicity and the trend which are nonlinear and dynamic are the crucial characteristics of hydrologic elements. The nonlinearity and dynamicity of these properties become more and more remarkable because the influence of geography, vegetation and the human activities. Wavelet Transform is the feasible method for the study of the nonlinear and dynamic system. The periodicity and the trend of precipitation in different mountain regions of Handan are illuminated with Morlet Wavelet Transform in Multi-time scales in this study. It is illustrated that the same periods (5years and 9years) exist in the precipitation in different mountain regions of Handan and there are the similar varieties and the similar trend in the same scale in different regions. This study would provide technical resorts and experiences for the research of water cycle and water resources management in the local basin.