Local PM10 and PM2.5 emission inventories from agricultural tillage and harvest in northeastern China

Mineral particles or particulate matters(PMs) emitted during agricultural activities are major recurring sources of atmospheric aerosol loading.However,precise PM inventory from agricultural tillage and harvest in agricultural regions is challenged by infrequent local emission factor(EF) measurements.To understand PM emissions from these practices in northeastern China,we measured EFs of PM_(10) and PM_(2.5) from three field operations(i.e.,tilling,planting and harvesting) in major crop production(i.e.,corn and soybean),using portable real-time PM analyzers and weather station data.County-level PM_(10) and PM_(2.5) emissions from agricultural tillage and harvest were estimated,based on local EFs,crop areas and crop calendars.The EFs averaged(107 ± 27),(17 ± 5) and 26 mg/m~2 for field tilling,planting and harvesting under relatively dry conditions(i.e.,soil moisture 15%),respectively.The EFs of PM from field tillage and planting operations were negatively affected by topsoil moisture.The magnitude of PM_(10) and PM_(2.5) emissions from these three activities were estimated to be 35.1 and 9.8 kilotons/yr in northeastern China,respectively,of which Heilongjiang Province accounted for approximately45%.Spatiotemporal distribution showed that most PM_(10) emission occurred in April,May and October and were concentrated in the central regions of the northeastern plain,which is dominated by dryland crops.Further work is needed to estimate the contribution of agricultural dust emissions to regional air quality in northeastern China.     

上海市青浦区农业非点源污染的流域分配研究

根据遥感技术得到的土地利用类型、河网、道路、圩区等信息,结合地理信息系统(GIS)的空间分析功能,建立了在多种空间因素影响下确定农业非点源污染负荷的流域分配方法。在此基础上,以上海市青浦区为例,得到了该区各河段中的污染负荷量．从而为寻求流域内合理的土地利用模式和农业非点源污染排放总量的控制方法提供决策依据。     

调整农村能源结构是改善西部农业生态环境的核心问题之一

农村能源建设是农业生态系统的中心枢纽之一，通过小型高效沼气池发酵，一方面，改善了我国绝大部分地区农户用能结构及居住环境条件，促使农民的传统生活习惯向现代文明转变，提高农民的生活质量。另一方面，可减少薪柴的樵采，保护植树造林成果，提高森林覆盖率，治理水土流失，实现农作物秸杆的合理利用，增加土壤有机质，改善农业生态环境，促进农业可持续发展。     

干旱定义及其指标评述

本文对气象、水文、农业、经济四种干旱类型的概念进行了论述，并对这四种干旱类型之间的并、交和包含关系及其指标进行了探讨。     

A dual-interval fixed-mix stochastic programming method for water resources management under uncertainty

In this study, a dual-interval fixed-mix stochastic programming (DFSP) method is developed for planning water resources management systems under uncertainty. DFSP incorporates interval-parameter programming (IPP) and fuzzy vertex analysis (FVA) within a fixed-mix stochastic programming (FSP) framework to address uncertain parameters described as probability distributions and dual intervals. It can also be used for analyzing various policy scenarios that are associated with different levels of economic consequences since penalties are exercised with recourse actions against any infeasibility. A real case for water resources management planning of Zhangweinan River Basin in China is then conducted for demonstrating the applicability of the developed DFSP method. Solutions in association with α-cut levels are generated by solving a set of deterministic submodels, which are useful for generating a range of decision alternatives under compound uncertainties. The results can help to identify desired water-allocation schemes for local sustainable development that the prerequisite water demand can be guaranteed when the available water resource is scarce.