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 Results showed that if the DEM is outdated or inaccurate due to changes in the terrain, such as construction, excavation, or erosion, the predicted flood patterns might not reflect the actual water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.

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、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。

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.

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.

Dynamic analysis of mainstream area and vegetation coverage degree of Songhua River based on RS and GIS techniques

Based on remote sensing technique,using 1990's Landsat TM data and 2000's Landsat ETM data,the authors conducts the comparative study of mainstream area of Songhua River by means of human-computer inter-action method.The results show that the area of Songhua River mainstream was 738 102 km 2 in 1990,and was 810.451 km 2 in 2000.From 1990 to 2000,the increased area of river mainstream is up to 72.349 km2 due to soil erosion and water loss.Meanwhile,the dynamic changes of surrounding vegetation cover are also studied.It is estimated that the trend of surrounding soil erosion and water loss of Songhua River mainstream becomes worse in Jilin Province.

基于RS和GIS的朝阳县矿区生态环境评价

利用Landsat 8 OLI遥感影像、ASTER卫星DEM数据,提取了朝阳县地形坡度、植被覆盖度信息,运用层次分析法确定了地质安全隐患、区域重要程度、土地损毁程度等12个评价指标权重,根据相关规范确定评价指标等级,建立矿区生态环境评价模型。运用网格法将研究区分为若干个评价单元,将评价指标进行赋值、叠加,确定各个矿区评价分值,依据评分将研究区分为影响严重区、较重区、较轻区与无影响区4个区域。研究表明:1)矿区生态环境影响严重区主要分布在朝阳县北部铁矿区和西南部锰矿区,该区域地质灾害隐患较严重,矿区地质环境复杂,开采破坏程度严重,生态环境影响严重。2)朝阳县生态环境影响最为集中区域为朝阳县北部矿区,该区域为群采区,开发强度高,开采时间长,形成严重的生态环境问题。3)矿山开采导致的土地损毁问题较为突出,不同土地类型的损毁面积占全县采矿用地面积的41.6%,矿区生态修复潜力较大。识别与分析朝阳县矿区生态环境问题,为朝阳县生态修复规划提供理论支撑,对后续矿山生态修复措施研究,绿色矿山建设工作的开展有着重要的意义。

基于GIS的广州市生态敏感性分析研究

城市生态环境是居民生存和发展的物质基础,生态敏感性对城市生态环境保护和可持续发展具有主要意义。文章以广州市为例,进行生态敏感性分析,将研究区分为不敏感、低敏感、中度敏感和高度敏感4个敏感区域。基于GIS和RS技术,采用层次分析法(AHP)建立评价因子体系,选取高程、坡度等9个因子,确定各指标权重并进行GIS加权叠加,综合分析。结果表明,广州市综合生态敏感性较高,以中度敏感和低敏感为主,两者占比为63.37%,广泛分布在广州市全域,多为山区及水系周边地区;高敏感占比为21.12%,分布在东北部山区及水系;不敏感占比为15.51%,主要分布在中部和西南部城镇中心。

基于GIS的空间TOPSIS模型的安徽省休宁县滑坡易发性评价

文章在常规TOPSIS(technique for order preference by similarity to ideal solution)模型的基础上提出空间TOPSIS模型,以安徽省休宁县为例,采用地理信息系统(geographic information system,GIS)技术对安徽省休宁县的滑坡易发性进行评价。研究表明:基于GIS的空间TOPSIS模型的滑坡易发性评价,能够处理和分析滑坡评价因子以及滑坡易发性的空间变化特征;评价结果与休宁县境内已经发生滑坡的空间分布较为吻合,评价结果较好。基于GIS的空间TOPSIS模型在滑坡易发性评价中具有较好的适用性。

基于RS与GIS的福州新区热环境空间分布特征研究

采用2014—2021年福州新区的地表温度、归一化差值植被指数(NDVI)和土地利用类型等数据,从乡镇单元尺度分析热环境的空间分布情况,并探究植被和土地利用对热环境空间分布的影响。结果表明:2014—2021年福州新区地表温度在空间上有明显的空间自相关性,空间集聚特征显著,新区热岛比例指数(URI)呈现出下降趋势,表明在此期间热岛效应状况总体有所缓解;植被覆盖率(FVC)影响热环境的空间分布,可将福州新区的“热点”划分为FVC、NDVI均较低的乡镇和FVC较高、NDVI较低的乡镇两类;土地利用类型、土地利用程度及周边环境亦影响热环境的空间分布。

Delineation of groundwater potential zones using remote sensing and Geographic Information Systems(GIS)in Kadaladi region,Southern India

The primary objective of this research is to delineate potential groundwater recharge zones in the Kadaladi taluk of Ramanathapuram,Tamil Nadu,India,using a combination of remote sensing and Geographic Information Systems(GIS)with the Analytical Hierarchical Process(AHP).Various factors such as geology,geomorphology,soil,drainage,density,lineament density,slope,rainfall were analyzed at a specific scale.Thematic layers were evaluated for quality and relevance using Saaty's scale,and then inte-grated using the weighted linear combination technique.The weights assigned to each layer and features were standardized using AHP and the Eigen vector technique,resulting in the final groundwater potential zone map.The AHP method was used to normalize the scores following the assignment of weights to each criterion or factor based on Saaty's 9-point scale.Pair-wise matrix analysis was utilized to calculate the geometric mean and normalized weight for various parameters.The groundwater recharge potential zone map was created by mathematically overlaying the normalized weighted layers.Thematic layers indicating major elements influencing groundwater occurrence and recharge were derived from satellite images.2 Results indicate that approximately 21.8 km of the total area exhibits high potential for groundwater recharge.Groundwater recharge is viable in areas with moderate slopes,particularly in the central and southeastern regions.

基于GIS和RS的北海市生态敏感性分析

利用GIS和RS技术,选取北海市陆域地区的土地利用/覆盖变化(LUCC)、归一化植被指数(NDVI)、高程、坡向及水域缓冲5个生态敏感性影响因子,运用生态因子评分法进行了研究区的单因子生态敏感性评价。采用加权叠加法综合评价生态敏感性,将研究区划分为非敏感区、低敏感区、中敏感区及高敏感区4类敏感区。结果表明:研究区的生态敏感性由东向西、由北向南呈递减趋势;非敏感区和低敏感区面积占比之和为64.30%,主要分布在西南部,高程以30 m以下为主,且河网相对不发达;中敏感区面积占比为29.88%,主要分布在合浦县境内;高敏感区面积占比为5.82%,主要分布在东北部山区。研究成果可为北海市的城市生态环境保护、城市绿色发展以及土地利用合理规划提供一定的理论依据。

基于RS和GIS的生态环境监测评估应用系统

随着城市经济水平的不断提升,生态环境污染逐渐成为人们关注的一个重点,该污染不仅会对人们的生活产生影响,也会在一定程度上影响到城市的发展进程。为了解决生态环境污染的问题,生态环境监测评估系统的应用可以发挥较大作用,通过这个系统的结合,可以对生态环境的质量进行监测,也可以对生态环境进行定量评估,从而使生态环境污染的情况得到有效控制与改善。就生态环境监测评估系统来讲,传统系统的检测结果存在较大问题,如准确性不高、监测时间过长、监测效率低下等,对此RS与GIS技术的联合使用是一个创新点,也是一个优化系统监测的方向。本文主要是针对RS与GIS技术下生态环境监测评估系统的设计与实现进行分析与探讨。

基于GIS和RS的土地利用变化及影响因素分析——以合肥市为例

以2000、2010、2020年三期地表覆盖数据为基础,本文运用地理信息系统(GIS)技术定量分析土地利用变化情况。以土地利用动态度为指标,反映合肥市土地利用变化的速度和幅度,利用地理探测器模型分析合肥市土地利用影响因素。结果显示:近20年来,研究区增幅和降幅最大的地表覆盖类型分别为人造地表和耕地,面积分别为390.17 km^(2)和567.99 km^(2),耕地减少的主要原因为建设用地扩张;2010-2020年,合肥市城市扩张速度相对放缓,湿地、林地、草地较前十年逐步恢复,城市生态环境逐渐向好;研究区地表覆盖类型的最大和最小影响因素分别为地区生产总值(GDP)和年降水量,GDP和人口与其他影响因素的交互作用明显增强。

基于RS与GIS的金寨县土地利用变化研究

土地利用变化是导致全球环境变化的重要影响因素之一,土地利用及相关方向研究是当今社会研究的一个热点领域。本文的研究区为金寨县,金寨县拥有众多水资源和森林资源,是我国重要的自然保护区。通过分析研究金寨县土地利用变化特征、景观格局及变化主要影响原因,为我国农村中的土地利用存在的问题、生态环境破坏和制定合理的土地利用总体规划提供参考,以期改善区域内土地可持续利用,维护环境质量,促进社会协调发展。

基于RS与GIS技术的土地利用空间优化方法研究

针对国内城镇存在的用地布局分散、土地过度开发的等问题,通过RS和GIS技术,采用多目标遗传算法优化土地利用配置。首先以邻域同化处理原始土地数据,再以遗传算法优化改进种群初始化,最后对比分析了传统的遗传算法和优化后的遗传算法计算结果,从经济效益和生态景观指数入手评估了区域功能的优化结果。结果表明:优化后经济效益提高21.59亿元,生态效益提高0.17亿元;在景观格局上,空间集聚程度更高。优化后的区域用地布局更加集中,可使城镇用地分散等问题得到有效改善,在后续设计中有一定的借鉴意义。

探析RS和GIS在矿山地质勘测中的应用

矿产资源作为国民经济发展的基础资源,对整个社会经济产生重大作用。从具体层面而言,矿产资源在开采中都是需要制定符合实际情况的开采方案,但是开采方案的科学合理性需要借助地质勘测数据资料作为依据,如果勘测资料存在问题,基本上整个开采过程都会受到很大影响,甚至会造成安全事故出现。在以往矿山地质勘测中,主要使用人工开展勘测活动,但是现阶段矿山地质环境异常复杂,使用人工勘测方式往往无法获取到确切的地质环境信息,最终会影响到开采方案的合理性。在科学技术发展中,遥感技术和GIS技术产生,对地质勘测产生非常重大的影响。通过对这两种技术的使用,能够提升矿山地质勘测的精确性,为矿山开采方案制定奠定良好的基础。因此,在矿山地质勘测工作中,应当加强遥感技术和GIS技术的应用,结合具体情况对这两种技术进行使用,从而保障开采工作顺利落实。本文通过对RS和GIS在矿山地质勘测中的应用优势阐述,分析了RS和GIS在矿山地质勘测中的应用。

A STUDY ON DESERTIFICATION OF WEST JILIN PROVINCE BASED ON REMOTE SENSING AND GIS TECHNIQUES

West Jilin Province" in this paper means Zhenlai, Baicheng, Taonan, Da′an, Tongyu, Fuyu, Songyuan, Qian′an, Changling, also includes Gongzhuling, Shuangliao, Lishu, Siping and Nong′an which have been suffered from desertification. In west Jilin Province there are three sand zones passing through, they are Xiang(Xianghai) Wu(Ulan Tug) sand zone, Hai Feng sand zone, and Tao′er River right bank sand zone. The desertification area of west Jilin Province is 819 100 ha, making up 12.5% of the total land area. Among desertification types, in Jilin Province light desertification is the major, then is medium dersertification, hevey desertification is the least.According to the comparison of the interpretation results of the Landsat images of the 1980s and the 1990s by remote sensing and GIS techniques, it can be seen that the desertification area in west Jilin Province basically didn′t change on the whole, only increased 6130 ha, making up 0.8% of the desertification area, change scale is less than 1%. Evidently, desertification is controlled mostly, but some areas are continuing deterioration.The desertification process of China can be divided into three types according to origin nature, they are sandy steppe desertification, fixed sand area(sand land) activation and dunes transfer invasion.Reasons of desertification of West Jilin Province are analyzed, they include natural factors(such as material source factors, chimate factors) and artificial factors(such as destroying grass to reclaim, steppe decreasing greatly, illegally feeling shelter forest stands, constructing reservoir to influence eco environment etc.). Some suggestions are put forward as follows: establishing the social project for ecological reconstruction of degenerated land; intensifying planning and management of land use, reverting farmland into forestland or pasture in a planned way. The key desertification control is to depend mainly on policy and management, then control techniques.