Using geospatial technologies to delineate Ground Water Potential Zones(GWPZ)in Mberengwa and Zvishavane District,Zimbabwe

The main objective of the study was to delineate Ground Water Potential Zones(GWPZ)in Mberengwa and Zvishavane districts,Zimbabwe,utilizing geospatial technologies and thematic mapping.Various factors,including geology,soil,rainfall,land use/land cover,drainage density,lineament density,slope,Terrain Ruggedness Index(TRI),and Terrain Wetness Index(TWI),were incorporated as thematic layers.The Multi Influencing Factor(MIF)and Analytical Hierarchical Process(AHP)techniques were employed to assign appropriate weights to these layers based on their relative significance,prioritizing GWPZ mapping.The integration of these weighted layers resulted in the generation of five GWPZ classes:Very high,high,moderate,low,and very low.The MIF method identified 3%of the area as having very high GWPZ,19%as having high GWPZ,40%as having moderate GWPZ,24%as having low GWPZ,and 14%as having very low GWPZ.The AHP method yielded 2%for very high GWPZ,14%for high GWPZ,37%for moderate GWPZ,37%for low GWPZ,and 10%for very low GWPZ.A strong correlation(ρof 0.91)was observed between the MIF results and groundwater yield.The study successfully identified regions with abundant groundwater,providing valuable target areas for groundwater exploitation and highvolume water harvesting initiatives.Accurate identification of these crucial regions is essential for effective decision-making,planning,and management of groundwater resources to alleviate water shortages.

Exploratory Precipitation in North-Central China during the Past Four Centuries

Two robust precipitation reconstructions were conducted by combining tree-ring chronologies, dryness/wetness indices from historical documents, and climate data from the global grid. It was found that the recurrent drought history of a region can help us understand the variability of precipitation. Several dry/wet periods during the past four centuries and potential cycles of precipitation variation were determined. Furthermore, the reconstructions are not only consistent well with each other in North-central China, but also in good agreement with variations of precipitation in northeastern Mongolia, the Longxi area in Gangsu Province and the Dulan area of Qinghai Province, and the snow accumulation of the Guliya glacier. These synchronous variations indicate that it is valuable to study various climate records, find common information and determine the driving force of climate change.

Relationship between ponding and topographic factors along the China-Russia Crude Oil Pipeline in permafrost regions

The original landform along the China Russia Crude Oil Pipeline(CRCOP,line 2)was disturbed during installation of pavement for the pipeline.Forest and vegetation coverage is dense,and runoff develops along the pipe.Since the opera tion of the CRCOP(line 2)began in 2018,ponding has appeared on both sides of the pipeline.If there is no drainage,ponding can hardly dissipate,due to the low permeability of the permafrost layer.With the supply of surface flow and the transportation of oil at positive temperatures,ponding promotes an increase in temperature and changes the boundary ther mal conditions of the pipeline.Meanwhile,when the ponding freezes and thaws,frost heave threatens operational safety of the pipeline.Furthermore,the ponding can affect the thermal condition of line 1.In this paper,the distribution of pond ing along the CRCOP was obtained by field investigation.The type and cause of ponding were summarized,and the catch ment and stream order were extracted by the Digital Elevation Model(DEM).According to the statistical results in attri butes for topographic factors,it is known that ponding along the pipeline is relative to elevation,slope,aspect,and the Topographic Wetness Index(TWI).Water easily accumulates at altitudes of 300450 m,slopes within 3°5°,aspect in the northeast or south,TWI within 1316,flow direction in north east south,and flow length within 90150 km.This paper proposes a theoretical basis for the cause and characteristics of ponding along the pipeline.

Analysis on the Evolution of Dry and Wet Degree in Benxi Area in Recent 57 Years

[Objective] The research aimed to analyze the evolution situation of dry and wet degree in Benxi area in recent 57 years.[Method] By using the annual,quarterly and monthly temperature and precipitation data in Benxi area during 1953-2009,the interdecadal variations of temperature,precipitation,dry and wet index were analyzed.[Result] The annual average temperature in Benxi area displayed the obvious increase trend,and the linear trend rate was 0.29 ℃/10 a.But the precipitation showed the obvious decrease trend,and the linear trend rate was-29.01 mm/10 a.The dry and wet index showed the decrease trend,and the linear trend rate was-33.61 mm/10 a,which closely related to the rise of temperature and the decrease of precipitation after the 1980s.[Conclusion] It showed the warming-drying development trend in Benxi area.

Understanding the spatial distribution of hydrologic sensitive areas in the landscape using soil topographic index approach

Maintaining healthy watershed is pivotal to ensure sustainability in water resources thereby improving the carrying capacity of the earth.Understanding and identifying the spatial variability of hydrologically sensitive areas(HSAs)in a watershed is an important step to prioritizing the landscape to maintain water sustainability with limited resources.A spatial technique known as Soil Topographic Index(STI)was used to identify HSAs in the landscape.This study was conducted in Clinton and Tewksbury Townships in New Jersey,United States.Three different scenarios(STI>=9,STI>=10,and STI>=11)were conducted to understand the spatial distribution of HSAs in the watershed.The following conclusions were derived from this study.Firstly,a more detail representation of HSAs in the watershed was observed when applying the STI technique with a fine scale light detection and ranging(LiDAR)digitial elevation model.Secondly,all three scenarios consistently identified perennial stream corridors as HSAs;therefore,it is important to protect perennial stream corridors through implementation of various land use controls.Thirdly,this study analyzes the land use pattern of HSAs under the three scenarios and identifies the HSAs for high intensity land uses such as agriculture and urban to be the high priority locations for implementing best management practices for water quality improvements.The procedures developed in this study can be applied to watersheds in other parts of the world with similar physiographic characteristics.

Scale-location specific relations between soil nutrients and topographic factors in the Fen River Basin, Chinese Loess Plateau

Understanding scale-and location-specific variations of soil nutrients in cultivated land is a crucial consideration for managing agriculture and natural resources effectively. In the present study, wavelet coherency was used to reveal the scale-location specific correlations between soil nutrients, including soil organic matter （SOM）, total nitrogen （TN）, available phosphorus （AP）, and available potassium （AK）, as well as topo- graphic factors （elevation, slope, aspect, and wetness index） in the cultivated land of the Fen River Basin in Shanxi Province, China. The results showed that SOM, TN, AP, and AK were significantly inter-correlated, and that the scales at which soil nutrients were correlated differed in different landscapes, and were generally smaller in topographically rougher terrain. All soil nutrients but TN were significantly influenced by the wetness index at relatively large scales （32-72 km） and AK was significantly affected by the aspect at large scales at partial locations, showing localized features. The results of this study imply that the wetness index should be taken into account during farming practices to improve the soil nutrients of cultivated land in the Fen River Basin at large scales.

Applicability of SRTM data for landform characterisation and geomorphometry: a comparison with contour-derived parameters

Geomorphologic and hydrologic research heavily depends on digital elevation models(DEM)which are currently being prepared from digital contours.The present study examines the use and applicability of freely available global elevation data source(3 arc seconds finished Shuttle Radar Topography Mission(SRTM))in landform characterisation,geomorphometry,river basin studies and other allied scientific applications in comparison with contour elevation data derived from the surveyed topographical sheets.The relief data extracted from a conventionally digitised geo-information science dataset of topographic contours(1:50,000)are compared with the SRTM-DEM and the variations are analysed.The automated geomorphometric and landform parameters derived from the contour DEM and the computed statistical properties of those parameters have substantial agreement with the same parameters derived from the SRTM-DEM.At the same time,localised variations also exist in some spatial domains.Derivative landscape analysis outputs from the SRTM-DEM suggest the wide acceptability and applicability of the freely available SRTM data source,especially in the regional scale applications related to hydrological modelling,terrain characterisation,disaster management and land degradation studies.

Insights on pretreatment of Indian hematite fines in grate-kiln pelletizing process： the choice of grinding processes

Indian hematite fines are normally characterized by high iron grade and minor impurities, which are usually used for sinter fines. With macroscale operations technology of blast furnace in Indian, pellets, as a kind of high-quality materials, attract more and more attention. However, the hematite fines possess the coarse size. Hence, they inevitably need to be further finely ground for pelletizing before balling. The grinding behavior of Indian hematite fines was revealed by conducting the ball milling tests and determining the Bond ball mill work index （Wi）. The results show that Indian hematite fines have an excellent grindability with Wi of only 7.40-7.73 kWh/t, indicating that ball milling is an economically viable way to pretreat Indian hematite fines. Nonetheless, due to poor sedimentation and filtering properties of wet ground products, the dry ball milling is more appropriate to process Indian hematite fines. In addition, the superior quality green balls can be manufactured with dry ground products under the conditions of 0.5% bentonite dosage, 7.5% moisture and balling for 12 min, which further confirmed that the recommended pellet feed preparation technique is reasonable.