基于卫星遥感和气象监测的大渡河源水源涵养红线区生态环境与功能评价

为了解大渡河源水源涵养红线区生态环境与水源涵养功能状况,利用多源遥感数据,采用主成分分析法构建指标体系,对其2000~2019年的生态环境状况以及水源涵养功能进行评价,结果显示:(1)研究区生态环境状况有所改善,增长速率为0.06/10a,北部生态环境状况优于南部。生态环境状况分级结果:优占5.88%、良占52.62%、一般占27.81%、较差占2.16%、差占0.27%,主要为良和一般。阿坝县生态环境状况最佳,生态环境改善速率最快的是红原县。(2)研究区水源涵养生态功能保持良好,水源涵养功能等级为优占1.18%、良占20.09%、一般占49.77%、较差占27.37%、差占1.58%,主要为一般和较差。研究区水源涵养生态功能保持良好,北部优于南部,增长速率为0.20/10a。阿坝县水源涵养功能最强,壤塘县水源涵养功能改善速度最快。(3)生态环境状况和水源涵养功能较好的地区集中在阿坝县中北部、壤塘县东北部、金川县东南部、红原县西部以及马尔康县中部、北部地区。(4)研究区1990~2019年显著增暖,降水显著增多,蒸发量减少。暖湿气候条件利于研究区生态的恢复,蒸发量的减少有益于研究区的水分保持,使生态环境状况和生态功能趋于好转。总体来讲,研究区生态环境与功能整体良好,北部优于南部,对研究区南部进行生态保护的任务较为紧迫。

四姑娘山国家级自然保护区四川红杉枯落物及土壤的水源涵养功能研究

通过对四姑娘山国家级自然保护区四川红杉林地表土壤和林下枯落物的实验分析，得出四姑娘山自然保护区四川红杉林0～40cm深度的土壤层最大贮水量为1841．5t／hm2，林下枯落物最大持水量为105．4t／hm2，四姑娘山自然保护区四川红杉林水源涵养最大值为1944．7t／hm2。

山东省地下水资源状况分析——地下水水源地涵养补源措施与保护对策

山东省属于我国北方严重缺水的省份之一，地表水资源较为贫乏，绝大多数工业企业及县级以上城市均依靠地下水作为主要供水水源，长期以来，由于缺乏对水源地的涵养与保护，并且开采量逐年递增，导致其生态环境逐步退化，一系列环境地质问题接连发生，供水安全隐患不断增大。本文根据山东省环境条件、地下水形成与转化特征，结合以往部分试验研究资料，提出了保障地下水水源地持续开发利用的措施与对策。

Research on Water Conservation Function of Typical Forests in Jinyun Mountain

[Objective] This study aimed to explore the relationship between different forest types and water conservation function. [Method] Based on field survey and experimental analysis, water conservation function of four typical forest stands in Jinyun Mountain of Chongqing was explored, including conifer-broadleaved mixed for- est, evergreen broad-leaved forest, bamboo forest and shrub forest. [Result] The re- sults showed that the order of saturated water storage capacity of soil in four forest stands was shrub forest （266.48 mm） 〉 conifer-broadleaved mixed forest （190.40 mm） 〉 evergreen broad-leaved forest （186.80 mm） 〉 bamboo forest （174.80 mm）; the order of maximum water-holding capacity of litter was shrub forest （8.06 mm） 〉 conifer-broadleaved mixed forest （4.71 mm） 〉 evergreen broad-leaved forest （4.32 mm） 〉 bamboo forest （3.34 mm）; the order of canopy interception in various forest stands was conifer-broadleaved mixed forest （16.15%） 〉 evergreen broad-leaved for- est （14.70%） 〉 bamboo forest （12.64%）. [Conclusion] The study had great signifi- cance to rational manage forest resources, improve water environment and realize scientific management and use of water resources.

Water holding effect of subalpine dark coniferous forest soil in Gongga Mountain, China

Because of the distinction of soil property and humus content, soil water content is not ideal to indicate whether it is suitable to the growth of plant. Mainly based on the PF-a numerical value denoting the water regime of soil and connected with the growth of plant, the study combined the moisture percentage of soil with PF to research in quantity the interrelation between the moisture percentage and PF in different succession phases of subalpine dark coniferous forest in Gongga Mountain. The results showed that: (1) In the same PF value, the moisture percentage in humus horizon increased gradually with the devel-opment of the succession of the dark coniferous forest; The moisture percentage of over-mature forest was the highest and>mature forest>half-mature forest>young growth forest; (2) With the increase of soil depth, the soil bulk density increased and the moisture percentage decreased, but the difference in the percentage of moisture was not notable in different succession phases. (3) In different succession series, the vegetation affected the soil water characteristics by increasing the soil organic matter, improving the soil construction, receding the soil bulk density and enhancing the soil porosity; (4) The humus horizon of the dark coniferous forest soil has the highest water holding capability in this region.

Evaluation of water resources conserved by forests in the Hani rice terraces system of Honghe County,Yunnan,China：an application of the fuzzy comprehensive evaluation model

The Hani Rice Terraces System, based on gravity-flow irrigation, is one of the Globally Important Agricultural Heritage Systems(GIAHS) pilot sites selected by FAO in 2010. The water resource plays an important role in the sustainable development of this system. The value of water conserved by the forest is influenced by natural, economic and social factors. In this paper, the water quality, per capita water resources, per capita GDP and population density are chosen as indices to construct an index system for a comprehensive evaluation of water resources value. The weights of these indices are 0.443, 0.31, 0.141 and 0.106 respectively, which are determined by the analytic hierarchy process(AHP) method. The water resources value has been assessed by the fuzzy comprehensive evaluation model. The results show that the water resources value in the Hani Rice Terraces System is 4.25 RMB/m^3. Evaluating the value of water resources in the Hani Rice Terraces System can provide a reference for ecological compensation, for raising public awareness of the importance of protecting the system, and ultimately achieving its sustainable development.

Study of soil and water conservation Function on Slope with Different Planting Patterns for a Typical Small Watershed in Karst Region of Guizhou Province

Ten runoff plots with different planting patterns were established for experimental observation in Yangjichong small watershed of Longli County in Karst region of Guizhou Province. Results show that under the same rainfall condition, shrub land, natural grassland and abandoned land presented the best function of soil and water conservation. The function of soil and water conservation was poor for arbor planting pattern, because the shrub layer, herb layer and forest floor were not formed. Because of no-tillage, surface crust and other effects, the function of soil and water conservation in slope farmland was better than that in runoffplots with arbor planting pattern.

Modelling Ecosystem Water Supply Services across the Lancang River Basin

Ecosystem services related to water supply are now a hot topic in ecology and hydrology. Here, water supply service in the Lancang River basin was evaluated using the newly developed model InVEST. We found the mean annual water supply in Lancang River basin is approximately 7.24E＋10 m3 y-1 with 23.87% from main stream and 76.13% from the tributaries. There is an increasing trend downstream. Grasslands and forests contribute 71.66% of the total water. A comparison of water supply capacity per unit area for ecosystems of different composition indicates that there is a decreasing trend from broad- leafed forest, mixed coniferous and broad-leafed forest, bamboo forest, coniferous forest, shrub forest and grassland. Two-thirds of the total water is provided by an area covering 40% of the total basin area. This study provides guidelines for the efficient management of water resources in the Lancang River basin.

Areas Benefiting from Water Conservation in Key Ecological Function Areas in China

Ecosystem services are transferred from the service-providing area to the service-benefiting area to satisfy human needs through some substance, energy or information. Most studies focus on the provision of ecosystem services and few focus on the demands on ecosystem services and their spatial distribution. Here, on the basis of the flow of water conservation services from the providing area to the benefiting area, the benefits produced by water conservation service are investigated and the benefiting areas are identified. The results indicate that in 2010 the water conservation service of key ecological function areas provided irrigation water for 1.67×105 km2 of paddy fields and 1.01×105 km2 irrigated fields, domestic water to urban residents and industrial water to factories, mines and enterprises of 2.64×104 km2 urban construction land and domestic water to rural residents across 3.73×104 km2 of rural settlements and formed 6.64×104 km2 of inland water which can be used for freshwater aquaculture, downstream regions comprise 1.31×104 km of navigable river, which can be used for inland shipping. The benefit areas of the key function areas located in the upper and middle reaches of the Yangtze River are greater and more influential benefit areas. To protect these key function areas, more attention should be paid to the maintenance and improvement of water conservation. Some benefit areas have access to the benefits produced by water conservation of nine key ecological function areas and cover 17% of the overall benefit area and the length of their channels benefited accounts for 7%. Multiple key ecological function areas should be taken into account equally in the formulation of ecological compensation policies. These research findings can serve as a scientific basis for the compensated use of and ecological compensation for ecosystem services provided by key ecological function areas.

Ecosystem Service Value Assessment for National Key Eco-function Zones for Water and Soil Conservation

National key eco-function zones for water and soil conservation are exceptionally fragile areas in terms of their eco-environments and are also severely affected by water and soil loss. They have been a focus of attention from all sectors of society. This research assesses important ecosystem service functions and their values using such indexes as NPP, soil conservation quantity and water conservation quantity. The result indicates that the ecosystem services of China＇s eco-function zones for water and soil conservation are worth 3268.90×10^8 CNY in total, of which organic matter production accounts for 530.96×10^8 CNY, nutrient substance circulation and storage 301.91×10^8 CNY, carbon fixation and oxygen release 1616.16×10^8 CNY, soil conservation 442.70×10^8 CNY and water source conservation 816.20×10^8 CNY. Of the four functional zones, the Guangxi-Guizhou-Yunnan Area registers the highest value of 1551.30×10^8 CNY, and the Three Gorges Reservoir Area the lowest value of 448.15×10^8CNY. In terms of ecosystem service value per unit of area, the Guangxi-Guizhou-Yunnan Area takes the first place, followed by Three Gorges Reservoir Area and the Dabie Mountain Area, which are roughly equivalent, and finally the Loess Plateau Area is at the bottom.

Analysis on the Spatio-temporal Patterns of Water Conservation Services in Beijing

The shortage of water resources is a key factor limiting the sustainable development of the economy and society in Beijing. This study analysed the spatiotemporal patterns of Beijing’s water conservation services(WCS) based on the water balance equation at multiple scales, including city, main functional areas and key districts and counties, determined the differences in the water conservation amount among different land cover types and investigated the reasons for the spatiotemporal differences in the water conservation amount. The results indicated that:(1) compared to 2005, water conservation amount increased substantially in 2010. However, the overall water conservation capacity was low.(2) Among the various land cover types in Beijing, the average water conservation capacity decreased in the following order: wetland, forest, grassland, cropland, bare land and artificial surface.(3) The average water conservation amount in the main functional areas of Beijing varied substantially and was positive only in the ecological conservation area(ECA).(4) The water conservation capacity of each district and county varied substantially within ECA, among which the contribution of the forest in Miyun District, Huairou District and Pinggu District was the highest. The changes in the spatiotemporal patterns of Beijing’s WCS were the synthetic effects of changes in the land covers and meteorological conditions. This study is helpful in achieving the sustainable utilization of water resources in Beijing.

Pedotransfer Functions for Estimating Soil Bulk Density:A Case Study in the Three-River Headwater Region of Qinghai Province,China

Bulk density(BD) is an important soil physical property and has significant effect on soil water conservation function. Indirect methods, which are called pedotransfer functions(PTFs), have replaced direct measurement and can acquire the missing data of BD during routine soil surveys. In this study, multiple linear regression(MLR) and artificial neuron network(ANN) methods were used to develop PTFs for predicting BD from soil organic carbon(OC), texture and depth in the Three-River Headwater region of Qinghai Province, China. The performances of the developed PTFs were compared with 14 published PTFs using four indexes, the mean error(ME), standard deviation error(SDE), root mean squared error(RMSE) and coefficient of determination(R^2). Results showed that the performances of published PTFs developed using exponential regression were better than those developed using linear regression from OC. Alexander(1980)-B, Alexander(1980)-A and Manrique and Jones(1991)-B PTFs, which had good predictions, could be applied for the soils in the study area. The PTFs developed using MLR(MLR-PTFs) and ANN(ANN-PTFs) had better soil BD predictions than most of published PTFs. The ANN-PTFs had better performances than the MLR-PTFs and their performances could be improved when soil texture and depth were added as predictor variables. The idea of developing PTFs for predicting soil BD in the study area could provide reference for other areas and the results could lay foundation for the estimation of soil water retention and carbon pool.