California Simulation of Evapotranspiration of Applied Water and Agricultural Energy Use in California

The California Simulation of Evapotranspiration of Applied Water (Cal-SIMETAW) model is a new tool developed by the California Department of Water Resources and the University of California, Davis to perform daily soil water balance and determine crop evapotranspiration (ET c ), evapotranspiration of applied water (ET aw ), and applied water (AW) for use in California water resources planning. ET aw is a seasonal estimate of the water needed to irrigate a crop assuming 100% irrigation efficiency. The model accounts for soils, crop coefficients, rooting depths, seepage, etc. that influence crop water balance. It provides spatial soil and climate information and it uses historical crop and land-use category information to provide seasonal water balance estimates by combinations of detailed analysis unit and county (DAU/County) over California. The result is a large data base of ET c and ET aw that will be used to update information in the new California Water Plan (CWP). The application uses the daily climate data, i.e., maximum (T x ) and minimum (T n ) temperature and precipitation (P cp ), which were derived from monthly USDA-NRCS PRISM data (PRISM Group 2011) and daily US National Climate Data Center (NCDC) climate station data to cover California on a 4 km×4 km change grid spacing. The application uses daily weather data to determine reference evapotranspiration (ET o ), using the Hargreaves-Samani (HS) equation (Hargreaves and Samani 1982, 1985). Because the HS equation is based on temperature only, ET o from the HS equation were compared with CIMIS ET o at the same locations using available CIMIS data to determine correction factors to estimate CIMIS ET o from the HS ET o to account for spatial climate differences. Cal-SIMETAW also employs near real-time reference evapotranspiration (ET o ) information from Spatial CIMIS, which is a model that combines weather station data and remote sensing to provide a grid of ET o information. A second database containing the available soil water holding capacity and soil depth information for all of California was also developed from the USDA-NRCS SSURGO database. The Cal-SIMETAW program also has the ability to generate daily weather data from monthly mean values for use in studying climate change scenarios and their possible impacts on water demand in the state. The key objective of this project is to improve the accuracy of water use estimates for the California Water Plan (CWP), which provides a comprehensive report on water supply, demand, and management in California. In this paper, we will discuss the model and how it determines ET aw for use in water resources planning.     

A Case Study on Environmental Evaluation and Planning for Range and Forest Management by Means of Geographic Information System （GIS）

The aim of this research is to identify the most suitable land for forestry, afforestation and rangeland management in Hamadan province. This research has been accomplished using Makhdoum＇s model. In this research 30 digital data layers are used. The Geographic Information System （GIS） has been used as main tool and overlay method has been used to implement the mentioned model. The results of this research revealed that the extent of favorite areas for fifth grade forestry, favorite areas for fourth grade afforestation, and favorite areas for third grade and fourth grade range management in the studied area. Based on the results of this research, the studied area has limited potentials for forestry and afforestation activities. The obtained results of evaluation also showed that the rangelands of Hamadan province are extremely poor. Since the rangelands have a substantial role in preservation of soil and water, therefore it is necessary to take appropriate measures for better exploitation of rangelands.     

Study on Entropy Weight Coefficient Method and Application for Water Quality Evaluation

In order to evaluate the quality of water environment, the conception of entropy is applied in information science, and the entropy weight model is built to evaluate comprehensively water quality. The indexes weights of water quality are determined by value of entropy. This kind of method is applied on evaluating water quality in the new water to be built. The result shows that the water quality in it which supply water is between grade Ⅲ and Ⅳ, and the result is similar to that of gray related method.     

Assessment of Soil Water Content and Remote Sensing Techniques--Case Study of Kiwi Orchard （Portugal）

Soil water management plays an important role in the response of kiwi plants （Actinidia deliciosa A. Chev.）. In GuimarSes district soil moisture content is monitored in kiwifi＇uit orchard as a routine parameter. Drip irrigation system is the method used. This crop tends to have high water requirements and extends over a wide area in Portugal, requiring innovative solutions to achieve better benefits. A method that correlates soil and crop conditions with the parameters of remote sensing was established in this study. To assess the level of accuracy of soil moisture measurements from satellites, it is important to compare satellite image with ground real data （namely the frequency domain reflectometry （FDR）, Diviner 2000）. The combination of multispectral satellite images produces an image representative of vegetation vigour, density and health. In this study, Landsat satellite images （2011 and 2013） are used and vegetation indexes are calculated for different periods of time, using the software Idrisi Taiga. The information of vegetation indexes is crossed with data of soil moisture, in situ, to establish a correlation between both of them. Thus, it allows to improve the soil water content monitoring, in particular for the soil water balance optimization and its effect on kiwi biornass production.     

Calibration and validation of SiBcrop Model for simulating LAI and surface heat fluxes of winter wheat in the North China Plain

The accurate representation of surface characteristic is an important process to simulate surface energy and water flux in land-atmosphere boundary layer. Coupling crop growth model in land surface model is an important method to accurately express the surface characteristics and biophysical processes in farmland. However, the previous work mainly focused on crops in single cropping system, less work was done in multiple cropping systems. This article described how to modify the sub-model in the SiBcrop to realize the accuracy simulation of leaf area index(LAI), latent heat flux(LHF) and sensible heat flux(SHF) of winter wheat growing in double cropping system in the North China Plain(NCP). The seeding date of winter wheat was firstly reset according to the actual growing environment in the NCP. The phenophases, LAI and heat fluxes in 2004–2006 at Yucheng Station, Shandong Province, China were used to calibrate the model. The validations of LHF and SHF were based on the measurements at Yucheng Station in 2007–2010 and at Guantao Station, Hebei Province, China in 2009–2010. The results showed the significant accuracy of the calibrated model in simulating these variables, with which the R~2, root mean square error(RMSE) and index of agreement(IOA) between simulated and observed variables were obviously improved than the original code. The sensitivities of the above variables to seeding date were also displayed to further explain the simulation error of the SiBcrop Model. Overall, the research results indicated the modified SiBcrop Model can be applied to simulate the growth and flux process of winter wheat growing in double cropping system in the NCP.     

Spatio-temporal changes in rice area at the northern limits of the rice cropping system in China from 1984 to 2013

Rice area has been expanding rapidly during the past 30 years under the influence of global change in northeastern China,which is the northernmost region of rice cultivation in China. However,the spatio-temporal dynamic changes in rice area are still unclear,although they may have important policy implications for environmental protection and adaptation to climate change. In this study,we aimed to identify the dynamic changes of the rice area in Heilongjiang Province of northeastern China by extracting data from multiple Landsat images. The study used ground quadrats selected from Google Earth and the extraction of a confusion matrix to verify the accuracy of extraction. The overall accuracy of the extracted rice area was higher than 95% as a result of using the artificial neural network(ANN) classification method. The results showed that the rice area increased by approximately 2.4×106 ha during the past 30 years at an annual rate of 8.0×104 ha,and most of the increase occurred after 2000. The central latitude of the rice area shifted northwards from 46 to 47°N during the study period,and moved eastwards from 130 to 133°E. The rice expansion area accounted for 98% of the total change in rice area,and rice loss was notably rare. The rice expansion was primarily from dryland. In addition,rice cultivation in marshland and grassland played a minor role in the rice expansion in this region.     

Design and Implementation of Agricultural Information Data-Delivery System Based on Web

Data-delivery of agricultural information is a very tedious work, traditional data-delivery patterns and methods can not meet the requirements of the practical work. This paper provided the design idea and implement method for data-delivery system of agricultural information based on Web. Report and data will be separated in this system, and the person can change template and data at any time on demand. The problem that report template and data fixed together would be solved. The agricultural information resources sharing would be also implemented.     

Linking a farmer crop selection model(FCS) with an agronomic model(EPIC) to simulate cropping pattern in Northeast China

In this paper, authors established a farmer crop selection model(FCS) for the three provinces of Liaoning, Jilin and Heilongjiang of the Northeast China. With linking to the environmental policy integrated climate model(EPIC), the simulated results of FCS model for maize, rice and soybean were spatialized with 1 km×1 km grids to obtain cropping pattern. The reference map of spatial distribution for the three staple crops acquired by remote sensing imageries was applied to validate the simulated cropping pattern. The results showed that(1) the total simulation accuracy for the study area was 78.62%, which proved simulation method was applicable and feasible;(2) simulation accuracy for Jilin Province was the highest among the three provinces with a rate of 82.45% since its simple cropping system and not complex topography;(3) simulation accuracy for maize was the best among the three staple crops with a ratio of 81.14% because the study area is very suitable for maize growth. We hope this study could provide the reference for cropping pattern forecasting and decision-making.     

Simulation Modeling in Plant Breeding： Principles and Applications

Conventional plant breeding largely depends on phenotypic selection and breeder＇s experience, therefore the breeding efficiency is low and the predictions are inaccurate. Along with the fast development in molecular biology and biotechnology, a large amount of biological data is available for genetic studies of important breeding traits in plants, which in turn allows the conduction of genotypic selection in the breeding process. However, gene information has not been effectively used in crop improvement because of the lack of appropriate tools. The simulation approach can utilize the vast and diverse genetic information, predict the cross performance, and compare different selection methods. Thus, the best performing crosses and effective breeding strategies can be identified. QuLine is a computer tool capable of defining a range, from simple to complex genetic models, and simulating breeding processes for developing final advanced lines. On the basis of the results from simulation experiments, breeders can optimize their breeding methodology and greatly improve the breeding efficiency. In this article, the underlying principles of simulation modeling in crop enhancement is initially introduced, following which several applications of QuLine are summarized, by comparing the different selection strategies, the precision parental selection, using known gene information, and the design approach in breeding. Breeding simulation allows the definition of complicated genetic models consisting of multiple alleles, pleiotropy, epistasis, and genes, by environment interaction, and provides a useful tool for breeders, to efficiently use the wide spectrum of genetic data and information available.     

SPEIPM-based research on drought impact on maize yield in North China Plain

The calculation method of potential evapotranspiration(PET) was improved by adopting a more reliable PET estimate based on the Penman-Monteith equation into the standardized precipitation evapotranspiration index(SPEI) in this study(SPEI PM). This improvement increased the applicability of SPEI in North China Plain(NCP). The historic meteorological data during 1962–2011 were used to calculate SPEI PM. The detrended yields of maize from Hebei, Henan, Shandong, Beijing, and Tianjin provinces/cities of NCP were obtained by linear sliding average method. Then regression analysis was made to study the relationships between detrended yields and SPEI values. Different time scales were applied, and thus SPEI PM was mentioned as SPEI PMk-j(k=time scale, 1, 2, 3, 4,…, 24 mon; j=month, 1, 2, 3,..., 12), among which SPEI PM3-8 reflected the water condition from June to August, a period of heavy precipitation and vigorous growth of maize in NCP. SPEI PM3-8 was highly correlated with detrended yield in this region, which can effectively evaluate the effect of drought on maize yield. Additionally, this relationship becomes more significant in recent 20 yr. The regression model based on the SPEI series explained 64.8% of the variability of the annual detrended yield in Beijing, 45.2% in Henan, 58.6% in Shandong, and 54.6% in Hebei. Moreover, when SPEI PM3-8 is in the range of –0.6 to 1.1, –0.9 to 0.8 and –0.8 to 2.3, the detrended yield increases in Shandong, Henan and Beijing. The yield increasing range was during normal water condition in Shandong and Henan, where precipitation was abundant. It indicated that the field management matched well with local water condition and thus allowed stable and high yield. Maize yield increase in these two provinces in the future can be realized by further improving water use efficiency and enhancing the stress resistance as well as yield stability. In Hebei and Beijing, the precipitation is less and thus the normal water condition cannot meet the high yield target. Increasing of water input and improving water use efficiency are both strategies for future yield increase. As global climate change became stronger and yield demands increased, the relationship between drought and maize yield became much closer in NCP too. The research of drought monitoring method and strategies for yield increase should be enhanced in the future, so as to provide strong supports for food security and agricultural sustainable development in China.     

洱海流域不透水面遥感信息提取技术研究(英文)

[目的]研究洱海流域不透水面遥感信息提取技术,以期开发水污染形成时空过程动态模拟平台。[方法]采用线性光谱分离技术,实现V-I-S模型求解,从2009年Landsat5的TM数据中对洱海流域进行不透水面遥感信息提取,利用植被、高反照度、低反照度和裸土4种最终光谱端元的线性组合,模拟TM波谱特征,并对其分布范围、空间特征等进行了分析。[结果]中等分辨率影像适合于流域尺度的不透水面提取,其结果可靠、精度较好。[结论]该研究结果为选择洱海非点源污染的调控策略、协调经济发展与环境保护的关系提供了决策依据。     

洱海流域不透水面遥感信息提取技术研究

[目的]研究洱海流域不透水面遥感信息提取技术,以期开发水污染形成时空过程动态模拟平台。[方法]采用线性光谱分离技术,实现V-I-S模型求解,从2009年Landsat5的TM数据中对洱海流域进行不透水面遥感信息提取,利用植被、高反照度、低反照度和裸土4种最终光谱端元的线性组合,模拟TM波谱特征,并对其分布范围、空间特征等进行了分析。[结果]中等分辨率影像适合于流域尺度的不透水面提取,其结果可靠、精度较好。[结论]该研究结果为选择洱海非点源污染的调控策略、协调经济发展与环境保护的关系提供了决策依据。     

基于HEC-HMS模型的八一水库流域洪水重现期研究

不透水率是不透水层面积与总用地面积的比值,它是研究城市水文的一个重要指标.以福州市晋安区八一水库流域为例,应用WMS 7.1软件构建流域结构,将流域分为A,B两个子流域,基于相关数据建立HEC-HMS水文模型对降雨-径流进行模拟,从而构建起不透水率与洪水重现期的关系.结果表明:(1)随着城市化的进程,19a间全流域不透水率持续增长,变化区间在5％-10％之内;(2)子流域A重现期为100、50、25年一遇的洪水随着不透水率的增长,分别提前了20、8、3a;(3)子流域B的重现期为100、50、25年一遇的洪水随着不透水率的增长,分别提前了25、10、4a.     

下垫面覆盖类型变化对城市热岛的影响

目的快速发展的城市化进程改变了下垫面的性质和结构，从而影响了城市的热量平衡，导致城市热岛效应蔓延。研究城市下垫面变化及其对城市热岛的影响，对缓解城市热环境、减少社会经济损失有重要意义。方法本文利用2002—2017年北京市朝阳区Landsat系列遥感影像计算研究区域归一化植被指数（NDVI）变化，并基于大气校正法利用Landsat热红外波段进行地表温度（LST）反演，进一步对所获地表温度进行归一化处理；同时利用2002—2017年北京市朝阳区谷歌全色卫星影像，基于DeepLabv3 + 网络利用深度学习对朝阳区下垫面分类并分析其动态变化。结果（1）朝阳区15年间平均地表温度呈上升趋势，城市热岛逐年加剧；至2017年，区内不再存在单一热岛中心，而转为复杂的镶嵌式结构、多中心分布。（2）15年间不透水面面积共减少71.02 km2，降幅20.98%；水域面积共减少2.53 km2，降幅24.12%；植被面积共增加73.54 km2，增幅56.57%。（3）对地表温度与下垫面类型动态变化相关性进行分析表明，地表温度与不透水面面积呈正相关，与植被面积呈负相关关系。（4）从总量来看，2012—2017年朝阳区与城市热岛效应成负相关关系的植被与水域面积总量增加明显，但城市热岛效应不降反增。结论植被和水域对城市热岛效应的缓解作用在用地强度、建筑密度和人类活动不断增长的前提下逐渐变得有限。在现有城市发展模式下，朝阳区地表温度将继续上升，城市热岛进一步加剧。      

通辽地区重点研究时段地下水资源模拟评价与分析

本文在综合叙述通辽地区水资源动态模拟评价基本原则与水资源系统水量转化关系的基础上，应用均衡模拟法和有限单元模拟法对通辽地区重点研究时段地下水资源进行了系统评价，评价了降雨入渗量，潜水蒸发量，水库渗漏量，河渠渗漏量，侧向净补给量随降雨量，水面蒸发强度，水库蓄水量，水位，河渠流量与地下水埋深的动态变化机理及其已开发地下水资源量。     

Sentinel-1A数据在高原山区短期土地利用监测中的应用——以贵州省安顺市为例

为推动雷达数据在高原山区的应用,以贵州省安顺市为例,利用SAR数据并辅助TM影像、DEM等数据,以灰度图像差值法、混淆矩阵法等为基础,对星载Sentinel-1A雷达数据进行短期土地利用监测的可行性做初步探究.结果表明:(1)差值获取的土地利用变化信息简单直观,有部分伪变化;(2)土地利用变化阈值范围是-0.4~3.6.城市建设用地及植被变化差异有统计学意义,水体变化差异无统计学意义;(3)变化信息监测总准确率均达到80%,Kappa系数均在0.7以上,基本达到数据统计分析的一般准确率要求.因此,Sentinel-1A数据监测高原山区土地利用变化可达到实际应用标准,并结合DEM可有效降低高原山区气候和地形等因素的影响.     

基于耕地图斑数据的土壤有机质估测方法研究——以大兴区南部耕地为例

基于测土配方采样点调查数据和土地利用现状数据,构建常规耕地质量评价中的土壤有机质含量的面状数据;基于此,采用面克里格法和序贯高斯条件模拟法估测北京大兴区南部耕地土壤有机质含量,并采用验证图斑的点数据和面数据形式进行精度评价,进而探寻基于面数据的土壤有机质含量最优估测方法。结果表明,面克里格法和序贯高斯条件模拟法对研究区耕地土壤有机质空间分布的估测效果具有一致性,但序贯高斯条件模拟法的平滑作用较弱,且单次随机模拟的局部特征变化更突出;点验证和面验证的相关系数与一致性系数表明,面克里格法和序贯高斯条件模拟法可以用来估测耕地土壤有机质含量;在多次随机模拟和变异函数拟合准确性的综合作用下,序贯高斯条件模拟估测精度更高。     

城市景观组分影响水质退化的阈值研究

运用景观格局与水质监测方法评价城市景观变化对河流水质的影响,是当前景观格局-效应研究的热点问题.为实现城市发展目标与水环境保护目标的统一,需要科学判断城市景观变化对水质的影响程度与范围,特别是以城市不透水表面为代表的景观组分变化,是目前水质退化研究中的核心对象,而对水质退化的景观阈值研究目前尚存争论.基于截面数据进行统计分析,构建阈值判定方法,选择深圳市为案例研究区,研究快速城市化地区的河流水质退化的景观阈值水平.结果表明,在深圳市,河流缓冲区宽度为100-200 m时,景观变化对水质显著性影响最高(P＜0.001).缓冲区内,景观变化与耗氧、营养盐等类指标呈指数关系,具有显著性,是这类指标变化的最主要影响因素;同时,景观变化与有毒物质及重金属等类指标呈指数关系,具有显著性,但并非这类指标变化的最主要因素.影响水质退化的不透水表面比例阈值水平介于38.2％-50％之间,最小阈值水平为38.2％,即当流域缓冲区内不透水表面百分比超过38.2％时,河流水质显著退化.     

武汉市2015年不透水面的提取及其空间自相关分析

利用分类回归树(CART)从高分一号遥感影像提取武汉市2015年不透水面,总体精度为94.17%,Kappa系数为0.8986,满足精度要求.然后通过Moran指数I和Moran散点图对武汉市13个城区的不透水面盖度进行了空间自相关分析.结果表明,Moran指数为0.2412,高度显著,说明武汉市13个城区的不透水面盖度存在较强的正向空间自相关.同时,位于武汉市中部的武昌区、青山区、江岸区、江汉区、汉阳区和硚口区都位于Moran散点图的第一象限,说明武汉市不透水面在中部地区高度集聚;其他7个城区位于第二象限,说明这7个城区的不透水面盖度较低且呈离散分布.总体而言,武汉市2015年13个城区不透水面盖度存在较强的空间自相关,且中部高,四周低,与实际情况基本一致.     

An integrated model for simulation of border-check irrigated dairy pasture production systems

Border-check irrigation is the predominant method of applying water to dairy pastures in Australia. Dairy pastures consume 40% of total irrigation water in Australia and, with irrigation water security in Australia under threat from climate variability/change and rising demands from other users, socio-economic pressure for water savings in the dairying sector are increasing. Currently, there are no simulation tools that successfully link factors controlling irrigation efficiency at the within-bay scale to management factors that drive economic water productivity (principally pasture growth, pasture consumption and animal production).A simulation framework was developed to connect a biophysical research model of weather-soil-plant animal interaction in dairy systems (‘DairyMod’) to a surface irrigation hydraulic model, SRFR (Simulation of basin, border and furrow irrigations). The connection enabled simulation of the effects of border-check irrigation scheduling and event management on irrigated pasture production systems. Modifications were made to DairyMod, in which the paddock surface was represented as a point, so that it could accommodate infiltration data in a one-dimensional form, from the surface irrigation model SRFR. Multiple simulations of DairyMod were run each representing different discrete spatial zones within an irrigation bay, and the SRFR routines connect each discrete spatial zone with information on the advance front water depth.Model integration and the workings of the integrated model are described, and the process used to verify the integrity of the data transferred between the two models is presented. Comparisons of data input and output parameters from the stand-alone models and the integrated model confirmed that the data transfer between the models within the integrated framework did not introduce new sources of errors.Preliminary output for a scenario involving three irrigation durations is also presented. The scenario represented a perennial ryegrass based pasture on a texture contrast clay loam soil over a period of 10 years using measured climate data. Model predictions agreed well with data reported in the literature for annual irrigation amounts and pasture growth. It was demonstrated that the integrated model could be used effectively to determine how pasture production varied with changes in irrigation management such as irrigation duration. A limitation of the integrated model was its dependence on two sets of infiltration models that were difficult to relate to each other.