RUSLE2 Model Application for Soil Erosion Assessment Using Remote Sensing and GIS

The study is focused on the estimation of rate of soil erosion, using Revised Universal Soil Loss Eq. 2 (RUSLE2), in the Veppanapalli subwatershed of Krishnagiri catchment located in Tamil Nadu, India. The soil erosion is estimated for each of the hillslope units in the study area. The factors considered are intensity of rainfall, type of soil, land use classification and the existing soil conservation practices. Detailed analysis of soil samples were done to assess the texture, structure, permeability and organic matter content of the soil samples of each hillslope unit. The required data for the other parameters were estimated by carrying out intense field investigations and by the analysis of the satellite imagery of 5.6 m resolution. A data base was created with all the subfactor values for the hillslope units. Incorporation of remote sensing technique and Geographic Information System (GIS) made the spatial analysis of the study more reliable and accurate. The annual average soil erosion rate is estimated as 25 t/ha/year, which is on a higher range. This indicates the immediate need for the adoption of proper conservation strategies in this area to control the eutrophication in the Krishnagiri reservoir and to prevent further watershed degradation.     

Water Balance Approach for Rainwater Harvesting using Remote Sensing and GIS Techniques, Jammu Himalaya, India

Judicious use of the limited fresh water resources is the need of the hour. If sufficient measures are not taken up immediately, we will face a crisis which will be detrimental to the very survival of mankind. The Kandi region of Jammu district in Jammu Himalaya is facing a similar problem of acute shortage of drinking water. One of the most logical steps towards this goal would be acknowledging the importance of rainwater harvesting. The Central Ground Water Board (CGWB), North Western Himalayan Region, Jammu, has already initiated few schemes to recharge and conserve the water resources. The water resources in this study area have been estimated by water balance assessment approach. The water balance study using the Thornthwaite and Mather (TM) models with the help of remote sensing and GIS is very helpful in finding out the moisture deficit and moisture surplus for an entire watershed. The water balance calculation shows that the maximum annual runoff results from the built-up areas/water body followed by agricultural land, dense forest and minimum for the barren land and open forest. The annual deficit in the Devak–Rui watershed is 0.38 mm and the annual surplus is 1,251.34 mm. GIS software’s have been used for spatial analysis for generation of various thematic layers and integration to produce the final runoff map. The total runoff of Devak–Rui watershed was calculated as 1,160.48 mm from the total precipitation of 1,429.26 mm. It was found that suitable sites for rainwater harvesting structures in the Devak–Rui watershed covers an area of nearly 11% of the watershed area whereas the rest of the watershed area was assumed as unsuitable site for rainwater harvesting.     

Estimation the Physical Variables of Rainwater Harvesting System Using Integrated GIS-Based Remote Sensing Approach

Water Resources Management - Geographic Information System (GIS) are an intelligence technique skilled to extract, store, manage and display the spatial information for various applications of...     

Integrated Water Resource Development Plan for Sustainable Management of Mayurakshi Watershed, India using Remote Sensing and GIS

Integrated watershed management requires a host of inter-related information to be generated and studied in relation to each other. Remote sensing technique provides valuable and up-to-date spatial information on natural resources and physical terrain parameters. Geographical Information System (GIS) with its capability of integration and analysis of spatial, aspatial, multi-layered information obtained in a wide variety of formats both from remote sensing and other conventional sources has proved to be an effective tool in planning for watershed development. In this study, area and locale specific watershed development plans were generated for Mayurakshi watershed, India using remote sensing and GIS techniques. Adopting Integrated Mission for Sustainable Development (IMSD) guidelines, decision rules were framed. Using the overlay and decision tree concepts water resource development plan was generated. Indian Remote Sensing Satellite (IRS-1C), Linear Imaging Self Scanner (LISS-III) satellite data along with other field and collateral data on lithology, soil, slope, well inventory, fracture have been utilized for generating land use/land cover and hydro geomorphology of the study area, which are an essential prerequisites for water resources planning and development. Spatial data integration and analyses are carried out in GIS environment.     

基于MapX的遥测水雨情信息查询系统的设计与实现

以宁波市为例,结合水利业务应用需求,详细讨论了基于MapX的遥测水雨情信息查询系统的设计与实现,并就水雨情信息查询系统的主要功能和为防汛防旱工作提供辅助支持等作了介绍。     

基于DEM与遥感影像的水库库容快速估算

遥感技术周期性、宏观性、实时性等优点,使其在监测库容具有无可比拟的优势。为了给水库管理提供一种快速估算库容的方法,利用DEM建立新丰江水库"库面积-库容"模型,并从不同时相的中巴影像中提取库面积,再利用模型计算库容;继而获取每一时相的水库水位观测值,利用水库固有的"库容曲线"计算库容。最后将两个结果进行比较分析,发现前者与后者的相对误差最小只有0.47%,大部分不超过10%,且具有很好的相关性。模型估算精度虽达不到传统测量计算方法,但其快速性、周期性、低成本是传统方法无法比拟的。实验结论表明,利用DEM与遥感技术监测库容,具有较好的实用价值。     

Soil Erosion Assessment in a Hilly Catchment of North Eastern India Using USLE, GIS and Remote Sensing

In the present study, soil erosion assessment of Dikrong river basin of Arunachal Pradesh (India) was carried out. The river basin was divided into 200 × 200 m grid cells. The Arc Info 7.2 GIS software and RS (ERDAS IMAGINE 8.4 image processing software) provided spatial input data and the USLE was used to predict the spatial distribution of the average annual soil loss on grid basis. The average rainfall erositivity factor (R) for Dikrong river basin was found to be 1,894.6 MJ mm ha⁻¹ h⁻¹ year⁻¹. The soil erodibility factor (K) with a magnitude of 0.055 t ha h ha⁻¹ MJ⁻¹ mm⁻¹ is the highest, with 0.039 t ha h ha⁻¹ MJ⁻¹ mm⁻¹ is the least for the watershed. The highest and lowest value of slope length factor (LS) is 53.5 and 5.39 respectively for the watershed. The highest and lowest values of crop management factor (C) were found out to be 0.004 and 1.0 respectively for the watershed. The highest and lowest value of conservation factor (P) were found to be 1 and 0.28 respectively for the watershed. The average annual soil loss of the Dikrong river basin is 51 t ha⁻¹ year⁻¹. About 25.61% of the watershed area is found out to be under slight erosion class. Areas covered by moderate, high, very high, severe and very severe erosion potential zones are 26.51%, 17.87%, 13.74%, 2.39% and 13.88% respectively. Therefore, these areas need immediate attention from soil conservation point of view.     

土壤干旱遥感监测的最新研究进展

近年来土壤干旱的研究已经基于有限站点实测数据扩展到了大尺度多源遥感监测.本文在介绍了陆面过程参数的最新研究进展基础上,概括了土壤水分的多时空动态研究进展,详细介绍了多种土壤干旱指标的计算方法和应用情况,评述了土壤干旱遥感监测方面的国内外进展,对今后土壤干旱的重要研究方向进行了展望.不同土壤干旱监测指标的适用性与地面水文...     

Estimation of Sediment Yield and Areas of Soil Erosion and Deposition for Watershed Prioritization using GIS and Remote Sensing

A Geographical Information System (GIS) based method is proposed and demonstrated for the identification of sediment source and sink areas and the prediction of sediment yield from watersheds. Data from the Haharo sub-catchment having an area of 565 km² in the Upper Damodar Valley in Jharkhand State in India was taken up for the present study due to availability of gauged data at multiple locations within watershed area. The watershed was discretized into hydrologically homogeneous grid cells to capture the watershed heterogeneity. The cells thus formed were then differentiated into cells of overland flow regions and cells of channel flow regions based on the magnitude of their flow accumulation areas. The gross soil erosion in each cell was calculated using the Universal Soil Loss Equation (USLE). The parameters of the USLE were evaluated using digital elevation model, soil and landuse information on cell basis. The concept of transport limited sediment delivery (TLSD) was formulated and used in ArcGIS for generating the transport capacity maps. An empirical relation is proposed and demonstrated for its usefulness for computation of land vegetation dependent transport capacity factor used in TLSD approach by linking it with normalized difference vegetation index (NDVI) derived from satellite data. Using these maps, the gross soil erosion was routed to the watershed outlet using hydrological drainage paths, for derivation of transport capacity limited sediment outflow maps. These maps depict the amount of sediment rate from a particular grid in spatial domain and the pixel value of the outlet grid indicates the sediment yield at the outlet of the watershed. Up on testing, the proposed method simulated the annual sediment yield with less than ±40% error.     

基于SCS和GIS的不同降雨情景城市内涝过程模拟方法

针对城市暴雨内涝灾害频发的现状,基于城市暴雨强度公式、芝加哥降雨过程线模型、SCS(Soil Conservation Service)产流模型以及基于地理信息系统软件ArcGIS的局部等体积法,提出一种关于城市暴雨内涝过程的模拟方法。选取武汉市内涝灾害严重的汤逊湖流域作为研究对象,使用该方法对流域内多种重现期暴雨内涝量的积水高程和积水淹没范围进行模拟。结果表明:汤逊湖流域内产生的内涝较为严重,10 a一遇的暴雨即可对低洼地区造成轻微内涝;不同重现期暴雨产生的积水区域基本是一致的,但重现期越长的暴雨产生的积水高程越深,淹没范围越广,对周边造成的影响越大。该研究成果对城市暴雨内涝的预防与治理具有借鉴和参考价值。     

Assessment of Waterlogging in Sriram Sagar Command Area,India, by Remote Sensing

Waterlogging is becoming a serious problem in irrigated command areas of India. The study area is the Sriram Sagar command, which is about 120 km north of Hyderabad. An attempt has been made to make an assessment of the waterlogged area and those areas sensitive to waterlogging during the pre and post monsoon periods in the Sriram Sagar command using remorely sensed and field data. Indian Remote Sensing Satellite (IRS-1A-LISS-II) digital data (Computer Compatible Tapes) of 12 April and 6 October 1989, were analysed to assess the areas affected by waterlogging and those areas sensitive to waterlogging. The validation of the IRS-derived waterlogged areas, was done using available water table depth data and other field information. The results obtained from this study indicate that in April and October 1989, areas of some 388 and 540 km2 were waterlogged and about 698 and 802 km2, respectively, were sensitive to waterlogging (where the water table lies between 1 to 2 m, respectively, below the ground surface. It is suggested that periodic assessment of waterlogging, using remotely sensed data, should be carried out in the Sriram Sagar command. The IRS data have been proved to be very succesful for the assessment of waterlogging. Density slicing and principal component analysis are useful techniques in making an assessment of waterlogged areas in irrigated command areas.     

黄河凌情遥感监测信息服务系统设计与实现

针对目前黄河凌情遥感监测解译成果信息传输、存储等存在的问题,建设了黄河凌情遥感监测信息服务系统.介绍黄河凌情遥感监测信息服务系统的总体设计思路,对系统主要功能进行详细分析,提出将凌情遥感监测成果数据存储到关系型数据库中,并发布成Web服务,在客户端叠加地理底图,实现地图服务聚合的设计思路,开发实现实时凌情分析,历史凌情查看,凌情对比、动态和典型凌情事件等功能模块,重点对系统的设计思路和关键技术进行探讨     

An Integrated DSS for Groundwater Management Based on Remote Sensing. The Case of a Semi-arid Aquifer in Morocco

A Decision Support System has been set up as the result of a fruitful cooperation between several public and research institutions in the framework of a large cooperation program. The DSS aims to compare spatially and temporally sectorial water demands of the Haouz-Mejjate plain (Morocco) in regard to available surface and groundwater resources. It is composed of a tool for satellite estimation of Agricultural Water Demand (SAMIR), a tool for integrated water resources planning (WEAP) and a groundwater model (MODFLOW) each of them relying on a common Geographical Information System not described here. The DSS is operating on a monthly time scale. Agricultural water demand accounts for about 80?% of the total demand. In areas where groundwater abstraction is difficult to quantify by direct methods, multitemporal remote sensing associated to the FAO methodology is a simple and efficient alternative to estimate Evapotranspiration (ET). In this work, a monthly estimate of ET from irrigated areas is derived from freely available MODIS NDVI for the 2001?C2009 period. An important part of the paper deals with the validation of these estimates with eddy covariance flux measurements installed on different irrigated crops of the region. Results are satisfactory with a minus 6.5?% error per year on the monthly time scale. This preprocessing allows to dichotomize irrigated versus non-irrigated areas, and then, to estimate groundwater abstraction in subareas distinguishing by their operating modes: traditional, dam or privately irrigated. A dynamic linkage between MODFLOW and WEAP transfers the results of one model as input data to the other. The model restitutes both spatial and temporal variations in head charges and allows the calculation of the ground water balance. After calibration, piezometric validation is acceptable for the majority of the 21 head control points.     

区域土壤含水率遥感监测分析方法研究进展

土壤水分是陆地表面参数化的一个关键变量。遥感技术为大面积动态监测土壤水分提供了可能。简述了热惯量法、作物缺水指数法、植被指数距平法、微波遥感法、高光谱法五种目前为止比较成熟和广泛应用的土壤水分遥感监测方法和模型,并进行了优缺点分析。     

遥感技术应用于水土保持监测

利用遥感技术对流域或区域进行水土保持生态环境监测,是实现流域水土流失及水土保持效益全面准确的实时、动态监测和预报的重要手段.可以帮助决策部门掌握主要监测区内水土流失分布、面积与流失量的逐年变化情况、植被结构变化情况等,水土保持生物、耕作、工程措施的总体效益的演变情况及生态环境的动态变化过程.通过监测最终对流域水土流失面积、分布状况和流失强度,水土流失造成危害及发展趋势,水土流失防治情况及其效益有一个全面的掌握,并定期向社会进行公告.     

Assessment of Groundwater Potential in a Semi-Arid Region of India Using Remote Sensing,GIS and MCDM Techniques

Remote sensing (RS) and geographic information system (GIS) are promising tools for efficient planning and management of vital groundwater resources, especially in data-scarce developing nations. In this study, a standard methodology is proposed to delineate groundwater potential zones using integrated RS, GIS and multi-criteria decision making (MCDM) techniques. The developed methodology is demonstrated by a case study in Udaipur district of Rajasthan, western India. Initially, ten thematic layers, viz., topographic elevation, land slope, geomorphology, geology, soil, pre- and post-monsoon groundwater depths, annual net recharge, annual rainfall, and proximity to surface water bodies were considered in this study. These thematic layers were scrutinized by principal component analysis technique to select influential layers for groundwater prospecting. Selected seven thematic layers and their features were assigned suitable weights on the Saaty’s scale according to their relative importance in groundwater occurrence. The assigned weights of the thematic layers and their features were then normalized by using AHP (analytic hierarchy process) MCDM technique and eigenvector method. Finally, the selected thematic maps were integrated by weighted linear combination method in a GIS environment to generate a groundwater potential map. Thus, four groundwater potential zones were identified and demarcated in the study area, viz., ‘good’, ‘moderate’, ‘poor’ and ‘very poor’ based on groundwater potential index values. The area falling in the ‘good’ zone is about 2,113 km² (17% of the total study area), which encompasses major portions of Sarada, Salumber, Girwa, Dhariawad, and Mavli blocks of the study area. The northeast and southwest portions along with some scattered patches fall in the ‘moderate’ zone, which encompasses an area of 3,710 km² (about 29%). The ‘poor’ zone is dominant in the study area which covers an area of 4,599 km² (36% of the total area). The western portion and parts of eastern and southeast portions of the study area are characterized as having ‘very poor’ groundwater potential, and this zone covers an area of 2,273 km² (18%). Moreover, in the ‘good’ zone, the mean annually exploitable groundwater reserve is estimated at 0.026 million cubic metres per km² (MCM/km²), whereas it is 0.024 MCM/km² in the ‘moderate’ zone, 0.018 MCM/km² in the ‘poor’ zone, and 0.013 MCM/km² in the ‘very poor’ zone. The groundwater potential map was finally verified using the well yield data of 39 pumping wells, and the result was found satisfactory.     

采用MiniUI框架的综合管理信息系统的设计与实现

为了应对复杂多变的办公环境和业务需求,解决现有办公自动化(Office Automation,OA)系统遇到的开发任务重、前台脚本繁琐、系统兼容性差等问题,提出了一种采用MiniUI作为前端框架的办公系统设计方法。基于MiniUI提供的丰富的控件库,系统实现了“配置”代替“编码”的方式设计前台脚本,极大地减少了代码量、缩短了开发周期。在应用中,综合管理信息系统不仅实现了快速开发,而且具有良好的兼容性。     

Remote Sensing and GIS Based Approach for Identification of Artificial Recharge Sites

The main aim of this paper is to demonstrate the capabilities of Remote Sensing (RS) and Geographic Information System (GIS) techniques for the demarcation of suitable sites for artificial recharge of groundwater aquifers, in the Loni watershed, located in Unnao and Raebareli districts, Uttar Pradesh, India. In this study, the SCS-CN model, groundwater depth data and morphological parameters (bifurcation ratio, elongation ratio, drainage density, ruggedness number, relief ratio, and circulatory ratio) have been used to delineate the recharge sites for undertaking water conservation measures. Augmentation of water resource is proposed in the watershed by constructing runoff storage structures, like check dam, percolation tank and nala bund. The site suitability for these water harvesting structures is determined by considering spatially varying parameters, like runoff potential, slope, groundwater fluctuation data and morphometric information of the watershed. GIS has been used as an effective tool to store, analyse and integrate spatial and attribute information pertaining to runoff, slope, drainage, groundwater fluctuation and morphometric characteristics for such studies.