青海天然草地属性及适宜性利用对策的探讨

天然草地在青海经济可持续发展和环境保护中占有重要地位,文章分析讨论了青海天然草地的属性及利用 现状,根据利用中存在的主要问题,有针对性地提出了青海天然草地适宜性利用对策,为永续利用草地资源提供参考。

Ecological Suitability Evaluation on Agricultural Land in Western Jilin Province Based on Fuzzy Mathematics

[Objective] This study was to evaluate the ecological suitability of agricultural land in western Jilin Province, with the aim to provide basis for the effective application of agricultural resources and the structural adjustment of land use. [Method] The evaluation index system was constructed based on fuzzy mathematic method according to the principles of systematic, dominant, effectiveness and feasibility; based on law of tolerance, reasonable evaluation criteria were determined according to the ecological amplitude of crops; based on GIS processing, the initial data completed the mathematical operation by using the VBA program in Excel. [Result] The area of agricultural land grade I was 5 512 km2, grade II of 25 985 km2, grade Ill of 7 907 km2, and area of land not suitable for agriculture was 6 312 km2. According to the evaluation results, the key areas for land use adjustment were Zhenlai County, Da＇an County, Tongyu County and western Changling County. The directions of land use adjustment included improving irrigation and drainage conditions, governing land salinization and conversion of cropland to forest and grassland. [Conclusion] This study provided basis for the effective application of agricultural resources and ecological environment construction in western Jilin Province.

Agricultural Land Use Optimal Allocation System in Developing Area:Application to Yili Watershed, Xinjiang Region

In developing countries, land productivity involves little market, where the agricultural land use is mainly determined by the food demands as well as the land suitability. The land use pattern will not ensure everywhere enough land for certain cropping if spatial allocation just according to land use suitability. To solve this problem, a subzone and a pre-allocation for each land use are added in spatial allocation module, and land use suitability and area optimi- zation module are incorporated to constitute a whole agricultural land use optimal allocation （ALUOA） system. The system is developed on the platform .Net 2005 using ArcGIS Engine （version 9.2） and C# language, and is tested and validated in Yili watershed of Xinjiang Region on the newly reclaimed area. In the case study, with the help of soil data obtained from 69 points sampled in the fieldwork in 2008, main river data supplied by the Department of Water Resources of Xinjiang Uygur Autonomous Region in China, and temperature data provided by Data Center for Resources and Environmental Sciences, Chinese Academy of Sciences, land use suitability on eight common crops are evaluated one by one using linear weighted summation method in the land use suitability model. The linear pro- gramming （LP） model in area optimization model succeeds to give out land area target of each crop under three scenarios. At last, the land use targets are allotted in space both with a six subzone file and without a subzone file. The resuits show that the land use maps with a subzone not only ensure every part has enough land for every crop, but also gives a more fragmental land use pattern, with about 87.99% and 135.92% more patches than the one without, while at the expense of loss between 15.30% and 19.53% in the overall suitability at the same time.

Land Suitability Assessment and Landuse Planning： A Prerequisite for Food Security and Climate Change Adaptation

Though Ghana＇s crop yield growth rate was at 17%, 5% of every 1.2 million Ghanaians have insufficient and limited access to nutritious food. Climate change and climate variability have enormously affected the state of agricultural productivity and hence could result in food insecurity. As many ongoing projects use Boolean suitability analysis, land use planning, management recommendations sores, it still remains inadequate to support rural resource poor farmers. This then, is affecting livelihood and agricultural productivity. In this paper, a geostatistical quantitative method to support a geographic information system （GIS） based on multi-criteria decision support system （GMCDSS） for an enhanced land suitability assessment （LSA） and landuse planning （LP） was devised. Project findings indicated that, recommended farm inputs could be estimated and applied accordingly at farm plot levels Soil amendment indicators （e.g., 1.0 t/ha lime ＋ 1.0 t/ha gypsum was estimated for liming） was quantified and currently, farmers can save money in soil fertility management. It has shown that, instead of applying 5.0 t/ha poultry manure （PM） or five bags of N-P-K fertilizer （rate of 15： 15： 15 N-P2O5-K2O/ha） ＋ two bags of sulphate of ammonia （SA）, a farmer may apply 2.0 t/ha PM ＋ two bags 15：15：15 N-P2O5-K2O/ha ＋ one bag of SA. GMCDSS assessment has proved to be fundamental in： （1） urban planning; （2） ensuring food security; （3） poverty reduction and interventions to the effects of climate change and climate variability.

Suitability Evaluation for the Construction of Decentralized Wastewater Reclamation Facilities in Beijing

水资源的缺乏使越来越多的城市和城区开始使用中水作为额外的经济合理的供水水源,并为此制定相应政策。然而,不适宜的中水利用政策往往对用水户使用再生水产生不利影响。本研究目的在于评价中水设施建设适宜性并分析不同行业的中水利用适宜情况,为制定或修订中水利用政策提供参考。本研究以北京市为研究区,在中水生产成本影响因素分析基础上,得到了中水设施建设限制因素和中水设施建设适宜条件,并对北京市机关、高校、饭店的用水户进行了适宜性评价。本研究结果表明,运行水量对中水生产成本有决定性影响。有效原水量对应的给水量、有效中水需求量、建筑面积适合作为中水设施建设影响因素,它们的下限可作为中水设施建设适宜条件。本研究通过分析北京市部分机关、高校、饭店用水户的用水情况,得到这些行业的中水设施建设适宜条件,并用于适宜性评价。评价结果表明,大部分机关用水户和大部分一、二星级饭店不适宜建设中水设施,而大部分高校和大部分三星级以上饭店适宜建设中水设施。

Competitive Learning Approach to GIS Based Land Use Suitability Analysis

This paper uses the expected utility under risk hypothesis to develop a new approach to GIS modeling for land use suitability analysis with competitive learning algorithms （CLG-LUSA）. It uses Kohonen＇s Self Organ- ized Maps （SOM） and Linear Vector Quantization （LVQ） among other tools to create comprehensive ordering of high number of options. The model uses decision makers preferred locations and environmental data to construct a manifold of the decision＇s attribute space. Then, decision and uncertainty maps are derived from this manifold. An application example is provided using the selection of suitable environments for coconut development in a mu- nicipality of Cuba. CLG-LUSA model was able to provide accurate visual feedback of key aspects of the decision process, making the methodology suitable for personal or group decision making.