GIS-Based Multi-Criteria Decision Analysis (MCDA) and Analytical Hierarchy Process (AHP) Techniques to Derive Flood Risks Management on Rice Productivity in Gishari Marshland

Floods are phenomenon with significant socio-economic implications mainly for human loss, agriculture, livestock, soil loss and land degradation, for which many researchers try to identify the most appropriate methodologies by analyzing their temporal and spatial development. This study therefore attempts to employ the GIS-based multi-criteria decision analysis and analytical hierarchy process techniques to derive the flood risks management on rice productivity in the Gishari Agricultural Marshland in Rwamagana district, Rwanda. Here, six influencing potential factors to flooding, including river slope, soil texture, Land Use Land Cover through Land Sat 8, rainfall, river distance and Digital Elevation Model are considered for the delineation of flood risk zones. Data acquisition like Landsat 8 images, DEM, land use land cover, slope, and soil class in the study area were considered. Results showed that if the DEM is outdated or inaccurate due to changes in the terrain, such as construction, excavation, or erosion, the predicted flood patterns might not reflect the actual water flow. This could result unexpected flood extents and depths, potentially inundating rice fields that were not previously at risk and this, expectedly explained that the increase 1 m in elevation would reduce the rice productivity by 0.17% due to unplanned flood risks in marshland. It was found that the change in rainfall distribution in Gishari agricultural marshland would also decrease the rice productivity by 0.0018%, which is a sign that rainfall is a major factor of flooding in rice scheme. Rainfall distribution plays a crucial role in flooding analysis and can directly impact rice productivity. Oppositely, another causal factor was Land Use Land Cover (LULC), where the Multivariate Logistic Regression Model Analysis findings showed that the increase of one unit in Land Use Land Cover would increase rice productivity by 0.17% of the total rice productivity from the Gishari Agricultural Marshland. Based on findings from these techniques, the Gishari Agricultural Marshlands having steeped land with grassland is classified into five classes of flooding namely very low, low, moderate, high, and very high which include 430%, 361%, 292%, 223%, and 154%. Government of Rwanda and other implementing agencies and major key actors have to contribute on soil and water conservation strategies to reduce the runoff and soil erosion as major contributors of flooding.

Monitoring and Early Warning of Paddy Rice Low Temperature Cold Damage in Ningxia with the Support of GIS and RS

The low temperature cold damage of paddy rice is the major agricultural meteorological disaster in Ningxia.The real-time monitoring and early warning of low temperature cold damage are very important to develop the advantages,avoid the disadvantages and reduce the disaster losses.Based on the prior researches on the low temperature cold damage indexes of paddy rice,we improved the small grid reckoning method of temperature and the reckoning precision with the support of GIS.By using the multitemporal remote sensing data,the paddy rice planting zone was picked.The calculation results of low temperature cold damage monitoring indexes were combined with the paddy rice planting zone,which judged the grade distribution and zone of low temperature cold damage in real time.Meanwhile,the low temperature cold damage of paddy rice was done the early warning,and the automatic monitoring early warning system was developed by using the weather forecast data.This method and system were applied to the business works,and the monitoring and early warning products of paddy rice low temperature cold damage business were made.The monitoring results basically corresponded with the actual situation,and the better monitoring service effect was gained.

Study on the Ecosystem Services Value of Fei County Based on RS and GIS

[Objective] With the background of dramatic changes in land use patterns,the aim was to explore the ecosystem services value of Fei County based on RS and GIS.[Method] Ecological changes in the environment can bring changes in economic value expressed quantitatively by ecosystem service value （ESV）.According to modified ESV equivalency factor tables and three periods of interpreted TM remote sensing images in 1990,2000 and 2009,this paper calculated the total ESV in Fei County,Shandong Province,China and analyzed the relationship between ESV and the land-use changes at last.[Result] The results showed that the total ESV of the study area decreased from 2.144×109 yuan in 1990,2.139×109 yuan in 2000,and at last to 2.098×109 yuan in 2009 as the overall study area land use pattern changed dramatically,in which the built-up land increased by 23％,while the cropland and forest were constantly on the decrease.[Conclusion] The research provides theoretical support for the construction of high efficient ecological economic zone and sustainable development of the region.

Integrating multisource RS data and GIS techniques to assist the evaluation of resource-environment carrying capacity in karst mountainous area

The karst mountainous area is an ecologically fragile region with prominent humanland contradictions.The resource-environment carrying capacity(RECC)of this region needs to be further clarified.The development of remote sensing(RS)and geographic information system(GIS)provides data sources and processing platform for RECC monitoring.This study analyzed and established the evaluation index system of RECC by considering particularity in the karst mountainous area of Southwest China;processed multisource RS data(Sentinel-2,Aster-DEM and Landsat-8)to extract the spatial distributions of nine key indexes by GIS techniques(information classification,overlay analysis and raster calculation);proposed the methods of index integration and fuzzy comprehensive evaluation of the RECC by GIS;and took a typical area,Guangnan County in Yunnan Province of China,as an experimental area to explore the effectiveness of the indexes and methods.The results showed that:(1)The important indexes affecting the RECC of karst mountainous area are water resources,tourism resources,position resources,geographical environment and soil erosion environment.(2)Data on cultivated land,construction land,minerals,transportation,water conservancy,ecosystem services,topography,soil erosion and rocky desertification can be obtained from RS data.GIS techniques integrate the information into the RECC results.The data extraction and processing methods are feasible on evaluating RECC.(3)The RECC of Guangnan County was in the mid-carrying level in 2018.The midcarrying and low-carrying levels were the main types,accounting for more than 80.00%of the total study area.The areas with high carrying capacity were mainly distributed in the northern regions of the northwest-southeast line of the county,and other areas have a low carrying capacity comparatively.The coordination between regional resource-environment status and socioeconomic development is the key to improve RECC.This study explores the evaluation index system of RECC in karst mountainous area and the application of multisource RS data and GIS techniques in the comprehensive evaluation.The methods can be applied in related fields to provide suggestions for data/information extraction and integration,and sustainable development.

Exploring the Feasibility of Winter Wheat Freeze Injury by Integrating Grey System Model with RS and GIS

Winter wheat freeze injury is one of the main agro-meteorological disasters affecting wheat production. In order to evaluate the severity of freeze injury on winter wheat systematically, we proposed a grey-system model （GSM） to monitor the degree and the distribution of the winter wheat freeze injury. The model combines remote sensing （RS） and geographic information system （GIS） technology. It gave examples of wheat freeze injury monitoring applications in Gaocheng and Jinzhou of Hebei Province, China. We carried out a quantitative evaluation method study on the severity of winter wheat freeze injury. First, a grey relational analysis （GRA） was conducted. At the same time, the weights of the stressful factors were determined. Then a wheat freezing injury stress multiple factor spatial matrix was constructed using spatial interpolation technology. Finally, a winter wheat freeze damage evaluation model was established through grey clustering algorithm （GCA）, and classifying the study area into three sub-areas, affected by severe, medium or light disasters. The evaluation model were verified by the Kappa model, the overall accuracy reached 78.82% and the Kappa coefficient was 0.6754. Therefore, through integration of GSM with RS images as well as GIS analysis, quantitative evaluation and study of winter wheat freeze disasters can be conducted objectively and accurately, making the evaluation model more scientific.

Study on the oasis corridor landscape in the arid regions based on RS and GIS methods—application of Jinta Oasis, China

The study on the oasis corridor landscape is a new hotspot in the ecological environment research in the arid regions. In oasis, main corridor landscape types include river, ditch, shelterbelt and road. This paper introduces the basic ecological effects of the corridor landscape on the transporting mass and energy and obstructing desert landscape expansion and incursion. Using Geographic Information System(GIS), we have researched the corridor distribution and its spatial relationship with other landscape types in the Jinta Oasis. Based on the dynamically monitoring on the landscape pattern change of the Jinta Oasis during the latter 10 years by using Remote Sensing(RS) and GIS,the driving functions of the corridors on this change have been analyzed in detail. The analysis results showed that all kinds of corridors' characteristics can be quantified by the indexes such as length and width, ratio of perimeter and area, density and non-heterogeneity. The total corridor length of Jinta Oasis is 1838.5 km and its density is 2.1 km/km 2. The corridor density of the irrigation land, forest and resident area is maximal, which shows that affection degree of the oasis corridors on them is the most. The improvement of the corridors quality is one of the important driving factors on the irrigation land and so on. The organic combination of the RS and GIS technologies and landscape research methods would be an effective means for the corridor landscape research on arid region oasis.

Temporal and Spatial Conversion Analysis of Soil Erosion in the Three Gorges Region Based on RS and GIS Technique——A Case Study in Kaixian County

In this paper, Kaixian County, situated in the hinterland of the Three Gorges Reservoir Region, was selected for the case study. Factors of soil erosion were obtained based on the technique of remote sensing （RS） and geographic information system （GIS）. Combining with field survey, soil erosion data in the years of 1988, 2000 and 2004 which covered the period from the beginning of the Three Gorges Reservoir Project to nowadays were investigated through the judgment model established on soil erosion intensity. With the function of spatial analysis in the geographic information system, the analysis and appraisal of dynamic soil erosion changes were carried out, and the spatial characteristics of the vicious change were highlighted, and the main causes of the vicious change of soil erosion were explored.

Effects of the Land Use Change on Ecosystem Service Value Based on RS & GIS

Assessing the effect of land use change on ecosystem service value(ESV) can provide reference for sustainable land use and ecological environment protection. The land use information was extracted and analyzed based on Landsat TM images in Shuangliu County, Sichuan Province from 1992 to 2008, following remote sensing(RS) and GIS. The ESV of the land use change in study area was evaluated by adopting the service value method within Chinese terrestrial ecosystem. The results showed that:(1) the area of paddy field and forest land reduced in the 16 years, total area of construction land expanded fast on the basis of occupying paddy field and forest land.(2) The regional ESV increased by 4,508.859×104 RMB, but there is different change trend at different times, such as the ESV fell by 10.59% in 1992–2000, increased by 16.024% in 2000–2008.(3) The conversion from forest land and cultivated land to construction land caused a decline and negative flow in ESV, the total value was 2,197.233×104 RMB and 5,317.460×104 RMB.(4) All land use types showed that change of the ESV coefficient was less elastic, the relative sensitivity: forest land > cultivated land > water area. In terms of variability of ESV, water area change had greater influence on the change of ESV in the study area, and cultivated land and forest land had relatively smaller impact.

Hypsometric Analysis of Wadi Mujib-Wala Watershed (Southern Jordan) Using Remote Sensing and GIS Techniques

Hypsometric analysis is considered an effective tool for understanding the stages of geomorphic evolution and geological development of river catchment, and for the delineation of erosional proneness of watershed. In the present study, twenty eight fourth order sub-basins of W. Mujib-Wala (Southern Jordan) were selected, and hypsometric analysis was carried out using 30 m ASTER DEM. Elevation-relief ratio method was employed to calculate the hypsometric integral values within GIS environment. The hypsometric integral values range from 0.71 to 0.88, whereas, the hypsometric curves exhibit remarkably upward convex shapes which indicate that all sub-basins and the W. Mujib-Wala watershed are at the youth-age stage of geomorphic development. Thus, they are of high susceptibility to erosion, incised channel erosion and mass movement activity. Marginal differences exist in mass removal from the watershed and the 28 sub-basins are attributed to variation in tectonic effect, lithology and rejuvenation processes. The relation between basin area and hypsometric integral was examined using regression analysis. Results reveal that negative and weak relationships dominate, where r2 ranges from 0.05 to 0.478 which confirm with other results reported elsewhere. Indirect assessment of erosion status based on hypsometric integral values was validated using estimated sediment yield information related to wadi Mujib and wadi Wala watersheds separately. The recorded sediment yields were in affirmation with high hypsometric integrals values, where higher values of hypsometric integrals and sediment yields occurred in the western part of the W. Mujib-Wala watershed. These findings would help in the construction of appropriate soil and water conservation measures across the watershed and its sub-basins to control soil erosion, to conserve water, and to reduce sediment discharge into the W. Mujib and W. Wala reservoirs.

Assessment of Urban Sprawl on Agricultural Soil of Northern Nile Delta of Egypt Using RS and GIS

Urban sprawl is threatening the limited highly fertile land in the Nile delta of Egypt. Landsat TM satellite images of 1984, 1992 and ETM+ of 2006 have been used to study the impact of urban sprawl on agricultural land of the Northern Nile delta, Egypt. Visual interpretation using on screen digitizing and change detection techniques were applied for monitoring the urban sprawl. Combining the land capability map and the urban thematic layer using GIS made it possible to point out the risk of urban expansion on the expense of the highly capable soil class. The results show that a total expansion of urban area amounted to 689.20 km2(6.3% of total area) during the study period 1984–2006. The urban expansion during the 1984–2006 was on the expense of the most fertile soils where, the high capable soils(Class I) lost 247.14 km2(2.26 % of total area) and the moderate capable soils lost 32.73 km2(0.3% of total area), while the low capable soils lost only 57.39 km2(0.53% of total area). The urban encroachment over the non capable soils was very limited during the study period 1984–1992, where 7.33 km2 only was lost. The pattern of urban sprawl has been changed during the 1992 to 2006 whereas much larger area(50.64 km2) of the non capable soils was converted to urban. It can be concluded that the urban sprawl is one of the dominant degradation process on the land of Nile Delta.

DATABASE STRUCTURE FOR THE INTEGRATION OF RS WITH GIS BASED ON SEMANTIC NETWORK

The integration of remote sensing (RS) with geographical information system (GIS) is a hotspot in geographical information science.A good database structure is important to the integration of RS with GIS,which should be beneficial to the complete integration of RS with GIS,able to deal with the disagreement between the resolution of remote sensing images and the precision of GIS data,and also helpful to the knowledge discovery and exploitation.In this paper,the database structure storing the spatial data based on semantic network is presented.This database structure has several advantages.Firstly,the spatial data is stored as raster data with space index,so the image processing can be done directly on the GIS data that is stored hierarchically according to the distinguishing precision.Secondly,the simple objects are aggregated into complex ones.Thirdly,because we use the indexing tree to depict the relationship of aggregation and the indexing pictures expressed by 2_D strings to describe the topology structure of the objects,the concepts of surrounding and region are expressed clearly and the semantic content of the landscape can be illustrated well.All the factors that affect the recognition of the objects are depicted in the factor space,which provides a uniform mathematical frame for the fusion of the semantic and non_semantic information.Lastly,the object node,knowledge node and the indexing node are integrated into one node.This feature enhances the ability of system in knowledge expressing,intelligent inference and association.The application shows that this database structure can benefit the interpretation of remote sensing image with the information of GIS.

Study on Coastline Change of Guangxi in the Last 20 Years Based on RS and GIS

By using three different satellite remote sensing images, Guangxi coastline was extracted on the platforms of RS and GIS, and its change characteristics from 1990 to 2010 were studied. The results showed that the length of Guangxi coastline generally decreased in the last 20 years; the total reduction length was 118.50 km, and the reduction range of coastline from 2000 to 2010 was significantly more than that from 1990 to 2000. With the development of coastal madculture and the construction of port terminals, the changes of coastline length in Fangchenggang and Qinzhou were larger. The total newly added land area was 136.81 km2, and the newly added land area in the last 10 years was greater than that in the first 10 years. The total fractal dimension of coastline presented decreasing trend; the curvature of coastline gradually decreased; the coastline will be straighter.

Study on the Landcover Changes Based on GIS and RS Technologies: A Case Study of the Sanjiangyuan National Nature Reserve in the Hinterland Tibet Plateau, China

With global warming and increased human activity, more and more ground surface areas have been affected, which leads to the creation of many problems. To understand the ecological environment changes in a typical alpine region, information on landcovers changes in the study area from 2000 to 2020 was obtained by combining remote sensing, geographic information system, and traditional statistical analysis for the Sanjiangyuan National Nature Reserve on the Qinghai-Tibet Plateau, China. The results show that the changes of surface cover in Sanjiangyuan National Nature Reserve are relatively concentrated, mainly distributed in the sections of south, northwest, central, and northeast, with the area of the changed regions and the unchanged regions being 31,127.45 km2 and 271,941.37 km2, respectively. The transformation between the various types of ground landcover is mainly characterized by a shift from other types to grassland and from grassland to bare land. And the regions of change are mostly concentrated between 3500 - 4600 m in elevation.

Evaluation on Livability of Urban Residence Based on RS and GIS——A Case Study of Shihezi City of Xinjiang Province

By selecting environmental amenity,living convenience,and living health as the primary indexes as well as park,school,supermarket,main urban traffic road and industrial district as secondary indexes,the livability of urban residence in Shihezhi City was evaluated based on spatial analysis method of RS and GIS technology and the most suitable sites for residence was located,so as to provide references for future planning and construction of Shihezi City. The study showed that:in accordance with the benefits and harms of residential environment to residents,the livability of urban residence in Shihezi City could be graded into seven degrees;the most suitable site could be found in the area between Beiyi Road and Beiwu Road to the east of Xihuan Road,which was close to school,supermarket and park,and was the most ideal residential area in Shihezi City.

Development and Application of the GIS-Based Water Mass Analysis Integrated System

The research on water masses is always one important facet of Oceanography. I adopt the method of Fuzzy Density Clustering to analyse water masses. Meanwhile, I use Visual Basic 6.0 as developing platform and utilize the MapX components to develop the platform of GIS. By integrating the Water Masses Model compiled by FORTRAN language, and GIS using Tight Coupling, I develop an Integrated System. That makes all phases are finished in one condition, including the gain of computing grid, the pick-up and analysis of data, the choice of parameters and resetting, the computing of model, and the result＇s visualization. It improves the efficiency of the data analysis and decision-making Finally, this system is applied in the Zhoushan fishing ground and adjacent region. The results are satisfying.

基于GIS与RS的文山州石漠化程度变化图谱分析

以云南省文山壮族苗族自治州为研究区,以2009年、2014年、2019年共3期遥感影像及DEM为基础数据,基于GIS和RS技术分别提取了研究区的植被覆盖度、基岩裸露率和坡度信息,建立石漠化程度等级图谱数据库,研究2009—2019年研究区石漠化程度时空变化。研究结果表明:2009—2019年文山州石漠化面积以无明显石漠化、潜在石漠化和强度石漠化为主,无明显石漠化、潜在石漠化面积有所减少,轻度、中度、强度石漠化面积有所增加;丘北县、砚山县中西部、广南县中南部及文山市北部石漠化程度最为严重;整体来说石漠化等级主要由低等级向高等级转移,石漠化状况呈恶化趋势。

利用GIS与RS技术对植被–气候相关性研究综述

植被是陆地生态系统中最主要的组成成分,它与气候有着紧密的联系。植被–气候之间的相互影响是当前全球变化研究的热点,也是当前国际上的热点问题。本文对全球气候变化、植被变化、遥感与地理信息系统在生态研究中的运用等方面的研究进展进行了总结,并对植被与气候关系在未来的发展进行了展望。

GIS和RS技术在耕地保护信息化建设中的应用

本文详细介绍了GIS和RS技术优势功能,通过专业的研究与分析,将GIS和RS技术应用到耕地保护信息化建设中,建设内容包含搭建耕地保护信息化平台、明确耕地保护数据来源、规范耕地保护信息编辑过程、遥感影像处理设计及科学设置平台数据接口等,并在完成信息化建设后进行平台展示,全面展现区域耕地保护的具体状态,满足耕地数量、质量、生态“三位一体”建设基础需求。

GIS和RS技术在城市规划设计中的应用探讨

在国家经济建设中,合理规划和科学设计城市布局是城市建设有效落实的重要基础,严格落实该项工作,可以强化城市宏观调控。在开展实践工作时,需要深入研究当地发展现状,以此调整城市建设,可以科学改进城市整体规划,使现代城市建设需求得到充分满足。而在现代科技发展中具体设计城市规划时,需要科学引RS技术和GIS技术,在关注规划决策和规划方法时,还需要明确公众需求,保障城市规划设计的公众参与度,确保城市规划建设能够高度符合城市建设需求,为城市居民创造更为舒适的生活环境。本文首先分析城市规划设计过程中GIS和RS技术的应用要求,然后分析可能会对城市规划设计造成影响的各项因素,最后,综合探究如何将RS技术与GIS技术融入城市规划设计,保证其规划设计效果。

GIS、RS技术在国道G345线地质灾害评估中的应用

使用GIS、RS技术能够快速地获取遥感影像中的地形和地质灾害等情况。通过GIS、RS技术,采用多种图像处理方法对遥感影像进行综合处理,再结合西藏自治区那曲市地质灾害的发育特点和遥感影像的基本特征,对国道G345线青藏界至聂荣县段公路走廊带内的地质背景条件、地质灾害进行遥感解译。根据遥感解译结果,并结合野外现场验证,准确地查明了公路走廊带内的不良地质条件和地质灾害的发育特征,为公路的改扩建以及地质灾害的防治提供了科学依据。