Site Suitability analysis for arti � cial groundwater recharge potential zone using a GIS approach in Basaltic terrain , Buldhana District , Maharashtra , India


 We have selected the site suitability for artificial groundwater recharge in basaltic terrain in India. The overarching aim of this research is to identify appropriate locations for artificial groundwater recharge in the Godavari river basin in the semi-arid zone of Buldhana district, Maharashtra, India. The research involves the selection of an appropriate location with an artificial recharge, the use of weighted values in a (GIS) environment, and the development of thematic layers. The precise type of artificial recharge system, such as a check dam, nullah bund, drainage ditch trying to plug, or percolation ponds, is chosen. Water harvesting considers the availability of land, conventionally, while on the local conditions depends the suitability of a particular artificial recharge technique and the area which is to get benefited. As a result, decisions on the site for water conservation and structure construction could only be undertaken after detailed field research. In stipulated time, the GIS modelling approach provides an excellent tool for the identification of recharge zones with suitable structures. The integrated study helps in designing a suitable groundwater management plan for the areas such as the basaltic terrain.


Introduction
Groundwater stands as a very important natural resource and also a reliable one for different purposes are including irrigation, drinking, and other basic needs in several states of India. Upwards of 90% of the rural population and nearly 30% of the rapid urbanization depend on this for drinking water (NRSA.,2008).
Unsustainable use, as well as ongoing poor management of this vital resource, have led to the world's already availability of water, increasing waste, degraded habitats, and biodiversity degradation of many species in general, and India in particular (Tsakiris 2004;Jha et al 2007;Aggarwal et al 2009b;Rodell et al 2009;Chawla et al 2010, Anand J., 2020. The principle of using advanced methods such as remote sensing (RS) and the Geographic Information System (GIS) in groundwater management studies is comparatively modern. The groundwater is diverse and interdisciplinary, an integrative approach to RS and GIS technologies is quite essential in different groundwater management studies. Remote sensing offers a range of datasets over a wide, inaccessible region that can be easily controlled and evaluated within the GIS system.
The combination of groundwater and hydrogeology information such as topography, rainfall, water density, geology, and hydraulic properties relies on the measurement methodology used and the assessment of groundwater recharge (Alley., 1999;Carver 1991;Thomas., 1999). The GIS and RS Techniques have been useful in identifying prospective groundwater areas. These maps have been used to indicate groundwater recharge activity and groundwater development. A comparatively modern, effective method for excellent quanti cation of groundwater aquifers in basaltic hard rock terrain has been recognized as the geographic information system (Cherkauer., 2004;Baker., 2003). Geographic modeling framework estimated using the application of RS and GIS systems by groundwater potential zones (Corwin., 1996;Minor., 2007;Murray., 2003: Das B., 2020. A few research studies have been reported for groundwater potential zone in both India as well as abroad (Jaiswal., 2003;Solomon., 2006;Singh., 2011;Mukherjee.,2012). Previous research has also shown that work on an integrative approach to remote sensing and GIS for the delineation of arti cial recharge zones and sustainable groundwater management is minimal in the world and India in general (Saraf., 1998;Anbazhagan., 2005;Ravi Shankar., 2005;Ghayoumian., 2005;Chenini., 2010;Chowdhury., 2010: Sharama.,2021. In comparison, except for Saraf., 1998) andChowdhury., 2010), the remaining studies have been on the rocky terrains of southern India and not in the district of Buldhana, Maharashtra.
Besides, minimal research in the Indian subcontinent's large basins is published. Consequently, a few of these experiments have to be conducted in various hydrogeological regimes to devise an effective groundwater management scheme.
The major purpose of this research is to study the identi cation of suitable sites for arti cial recharging of Groundwater using GIS and Remote Sensing techniques. Previous studies have shown that we cannot nd the exact and appropriate region only by the weighted value method. The principle aims and purposes of this analysis are to establish possible locations for identifying groundwater recharge systems using Geospatial Techniques and GIS technologies. Which can be noted as follows:

Materials And Methods
We have obtained for the analysis of Indian research satellite (IRS) LIII Image, Cartosat DEM (http://bhuvan.gov.in), Survey of India (SOI) topographic data from 47J/2 on a 1: 50,000. Water level uctuation data , Rainfall-Runoff data (2008-2017 of Sindkhed Raja village. Remote Sensing (RS) and Arc GIS are advanced technologies that are very useful methods for the groundwater studies of this research. The primary and secondary data were combined in the GIS network, and "thematic" maps have been generated utilizing data obtained from different sources such as satellite and topographic data. To make thematic data accessible, thematic maps provide a variety of detail about any physical substance or theme. To get the spatial component referenced, the spatial data is assembled in digital format and properly registered. Comparatively more reliable information is provided by the namely sensed data on various themes. Different thematic maps were generated for this research using a visual representation of the SOI Topo sheet and satellite imagery. With the aid of the numerous data gathered, thematic maps at scales ranging from 1:140,000 to 1:150,000 have been developed.
Modeling Methods based on GIS Geographic data's volume being high, the analysis becomes very complex and time-consuming. Maps could be generated using GIS factors of complexity in fuzzy terms, and hence the different inconsistencies that occur due to classi cation in GIS can be reduced. Using this type of overlay analysis, new composite maps have been generated which include various features, which can be noticed in the thematic maps and a nal composite map for arti cial groundwater recharge zones have been created.
We have followed the steps are given: 1. Spatial database building 2. Spatial database analysis 3. Data integration through GIS

Digital Elevation Model (DEM) and Thematic Maps
For the percentage slope map, DEM data has been used. The DEM data was acquired from 'ASTGTM2 N18E073 &74' using ArcGIS 10.1. Various mosaic techniques were used to create Aster DEM data in the ArcGIS framework. Using the spatial analyst tools in ArcGIS 10.1, topographic and gradient maps have been developed, and then the sample locations were clipping out as per its coordinate system, and the imageries were obtained. For the zoning of Arti cial Groundwater Recharge, the data is converted into a raster image and overlaid using the weighted overlay process for the thematic map. (Weightage-wise thematic maps).

Slope Type and percentages:
We used a DEM map with a scale of 1:145000 to estimate the slope percentage here. Weightage values are assigned to various slopes based on their recharge priorities. The potential for groundwater recharge decreases as the slope elongates. When the degree of slope is on the higher side, the highest weightage value is assigned (0 to 4). In the study area, ve categories of slopes were discovered: slightly leveled slope, gentle slope, moderate slope, strong slope, and steep slope.

Soil
According to the data obtained, the research region includes 3 types of soils. i.e. alluvium, loamy, and mountain. On the one side, alluvium soil is relatively more favorable than loamy soil since its penetration rate is greater than the other 2 types of soil. On the other hand, we noticed that the penetration rate of mountain soil is quite low attributed to the prevalence of mountains and hard rock formations, and therefore groundwater recharge is very low in this region. In the Alluvial area, the construction of 9 EW, 4 OW, and 8 Piezometers (Pz) was done. The wells' depth ranges between 61.50 to 311.20 m bgl, while the thickness of alluvium was found to be more than 300 m. The discharge which led from these wells was between traces to 10 lps. Static water levels were found between 3.57 to 16.65 m bgl. Down to the depth of 302 m, aquifer zones were encountered in the wells thus establishing that the groundwater can be seen to be occurring under the con ned conditions even up to the depth of 300 m underneath. However, in the deeper zones below 80 m, the yields are restricted as they occur in the older Alluvium, being more clayey.
The younger Alluvium is more productive than the older alluvium as the younger mask is found to be occurring down to the depth of 70 -80 m bgl. This zone of younger Alluvium can also be used for agricultural purposes using the shallow tube wells which were constructed deep inside to the depth of about 65-70 m and yielding up to 10 lps for a 30 m lift. In structural hill provinces, where the denudation rate is high, valleys are found to be normal. Valleys are active basins or troughs for receiving degraded sedimentary rocks, also including valley ll, which contains poorly consolidated material. This could retain a large amount of water and therefore sustain a large amount of vegetation. While studying the satellite images, we found that the drainages were found all along the valley region originating from the north. The map has a reddish color appearance owing to the combination of vegetation in an erratic pattern.

Plateau and Denudational Hills
Plateaus can be noticed as the areas which have a plain area with a gentle slope towards a direction. The denudational hills are seen to be formed due to the resistive part of hills in the plateau area which facilitates some in ltration and mostly acts as runoff areas.

Land Use Land Cover
The study area enclosed agricultural land (130 Km 2 ), some built-up areas (0.83 Km 2 ), and the rest leftover is wasteland (61.56 Km 2 ). Water bodies have also been observed in the study area. Rest another area of the watershed has been mostly altered due to extension in the cultivation land. The built-up area, the elevated portion, and the region that have been identi ed as wasteland are inappropriate for an arti cial recharge system. Still, the plain land which remains uncovered under any construction or vegetation, like the agricultural land and the land occupied by the water bodies can become the most suitable locations for it. As a result, weightage must be assigned to the different regions in the GIS area where the land used and covering section is visible.

Drainage
The study area includes the watershed areas, that have been thoroughly depleted to Godavari river with the presence of many streams from source to mouth by dendritic drainage having several 1st order, 2nd order, 3rd order, and 4th order according to Strahler's method. As we know according to the same, 3rd and 4th order drainage carries more runoff water. We have used the order of the stream and followed in Strahler's System (1952): The order of the stream is 1 if a stream has no contributing tributaries.
If more than one tributary is seen to be present, in i and j orders then: if i = j then the order of the resulting stream will be i +1 or j +1 else if i < j then the order of the resulting stream will be j else if i > j then the order of the resulting stream will be i Two streams of the same order merge to create a new stream of order i+1, and if streams of different orders combine, the new stream preserves the order of the highest order stream, as seen in gure 6. Weighted Indexing Table and water level every raster value was modi ed into shape les of the available data and thus assigned weightage values, as seen in Table 1, and these values were then converted back into raster data. The percentage of the areas has been determined based on the speci ed weightage. The values in this report were drawn from the knowledge of other professionals based on their prior ndings and statistics obtained. For the selection of appropriate zones or arti cial groundwater recharge locations, it would be critical to investigate the water level in groundwater. Database collected for this watershed study has been derived from 3 observation wells which were located in the study area, they represented the three basic morpho zones i.e. runoff zone, recharge zone, and storage zone. These observation wells indicated the periodic and routine monitoring of the depth of the water level. After performing the careful study of different meteorological parameters and the static groundwater levels of the study area, the study of two seasons has been carried out.

Availability of Rainfall-Water
Rainfall data is collected from the last 10 years to analyze the trend and pattern. It has revealed that in the monsoon year of 2016, the study area received a very high amount of rainfall i.e. 1190 mm while in the year 2012 received a low amount of rainfall i.e. 496 mm. Rainfall occurs in the peninsula of India, where the study area is located, as a result of the southwest monsoon winds that pass through this area (June-October). The total annual precipitation in this area ranges between 400 and 600 mm (according to IMD, Pune). The nal overlay map indicates the chosen appropriate location for the arti cial groundwater recharge owing to the accessibility of water as runoff and the variations present in the groundwater level during the pre and post-monsoon season.

Discussions
Arti cial Recharge Site Selection A few arti cial recharge techniques are used to supplement the normal ow of surface water into underground formations. Such as building the percolation ponds, recharge Pitts, cement Nullah bunds, creating arti cial oods to induce recharging procedures, and construction of other water impounding and in ltration structures have been practiced successfully everywhere in the world but this process can also be applied in the study area to increase the yielding capacity of the groundwater in this place. Various other types of water conservation methods that have been adopted by other countries commonly can also be accepted in this study area such as contour trenching; terracing, Nulla bunding, etc. These procedures can be adopted and various problems of inadequate rainfall and errant water supply can be sorted. Selecting suitable locations for the implementation of adequate arti cial-recharge techniques is a crucial situation for successful recharge, and this is dependent on many criteria that have been studied together in a GIS context. The penetration capability of the unsaturated zone above the aquifer determines the recharge potential of a terrain area. It also depends on the geological and hydrogeomorphological parameters present in the area alongside, the slopes present in the terrain region, the land used or the land cover i.e. the vegetation present or construction in the location, and the density of the drainage available.
Using the weightage index the groundwater recharge zone is prepared (Table. 1). It provides the necessary data for the map preparation. All of the thematic layers and weight tables required for the weighted model were generated using Arc GIS version 10.1 software. Finally, using the procedures mentioned earlier, we were able to create the most favorable recharge zone diagram. The yellow part of the nal diagram or plot, Figure 7, has a weighted value of 1, which is appropriate for groundwater recharge. The dark blue section (14.1 percent) is quite inadequate for arti cial recharge because the penetration rate was low due to the presence of hard rock and mountain form or rocky soil supply in that area. Because of the high velocity of rainwater ow, the in ltration rate decreases and thereby affecting the amount of groundwater recharge. The following recharge structures which have been suggested would be very helpful, to increase the speci c yield of the soil in this area, increasing the level of the water table, and thus the following recharge structures have been suggested to be constructed in the area under study.

Arti cial Recharge Structures and Percolation Tanks/ Farm ponds
The open water impounding bodies, such as percolation or in ltration tanks, should be excavated in a region of land enclosed by a riverbank and should not exceed 15,000 m3. These can store rainwater, but their primary purpose is to penetrate the water and transfer it to deep aquifers, where it could have been extracted utilizing boreholes, tube wells, and dug wells. These tanks should be constructed in locations where the tank or pond's base is permeable and the aquifer that requires to be recharged is close to the ground surface. Sites of low-potential areas and frequent medium-to-high water table variations are appropriate for these types of systems.

Check Dam /Cement Nala bund and Continuous Contour Trenching (CCT)
A check dam is a dam, which is comparatively quite smaller than the normal large dam projects. These can be either temporarily built as per the need of the season or else can be set permanently. These may be constructed across a minor canal or a drainage ditch, depending on which is more desirable, to avoid water leakage during rains and thereby retain the groundwater to increase penetration into the subsurface. Check dams have been strongly suggested in runoff recharge areas with low to moderate slopes along with 3rd and 4th order streams.
CCT is a famous agricultural method that could be effectively applied in dry and arid areas to preserve water and soil while also reducing soil erosion. In the study eld, a trench 10 m long, 1 m wide, and 1 m deep can be very successful in increasing water availability. Water must be slowed uniformly around the whole slope on the hillside, so a stagger of the same design must be constructed to carry the water along.
This technique is very useful, but it can only be used in areas where trench may not complicate eld use.
Arti cial recharge zones and groundwater conditions in basaltic terrain: In hard rock (basaltic) terrain the groundwater conditions are multivariate due to the nature of the aquifer being heterogeneous because of the various composition, compaction, and density of weathering. The various direct bene ts and space technologies have demonstrated their usefulness in understanding the factors which can be responsible for maintaining the hydrological cycle. It can be noted that the vegetal cover, surface water bodies, lithotypes, and landform. The various groundwater prospecting maps become a very good database and these also help us in identifying the various favorable zones (prospective zones) around the study area where the problems have been detected, thereby narrowing down the targeted areas. Hence, after conducting the detailed ground hydro-geological and geophysical surveys within these zones, the most appropriate sites can be selected for arti cial recharge. Hence it can be seen that many times we have to consult the geophysical and drilling data for acquiring subsurface information, and decisions le shall be created through overlay by GIS technique if satellites alone cannot provide information regarding con ned aquifers. The groundwater prospecting methods can serve in two ways and bene t eld geologists by helping them to 1) identify quickly the prospective groundwater zones for conducting the site-speci c investigations. 2) Selecting suitable sites for the planning of arti cial recharge structures for the improvement of the sustainability of drinking water sources, wherever it is required. The current map displays that about 23% of the area is most appropriate, where runoff water from the hill enters the eld through different drainage lines and ows directly into the main Nullah. Natural groundwater recharge happens in every catchment area during the monsoon season as a result of precipitation, but this rate is quite low, and the water is dispatched by drains according to the slopes present in the area. To overcome this, a recharge structure is needed to mitigate water depletion. Some of it is evaporated by the heat, while the rest is evapo-transpirated by crops or plants. This water should be collected and then arti cially recharged to keep the water level constant. More physical dimensions, such as holding capacity, possible evapotranspiration, and soil eld capacity, are also taken into consideration. While conventional water harvesting approaches consider land availability, soil structure for groundwater capacity, potential groundwater zone inquiry, and the region bene ted, the new multiparametric approach utilizes GIS and remote sensing to establish a holistic process. It may also minimize the cost and expense taken for the entire procedure, especially for determining suitable site-speci c recharge systems on a regional and local scale, leading to more e cient water management decision-making. The identi cation of any arti cial recharge site is based on a variety of parameters such as geomorphology, lithology, lineament density, slope, soil, and so on. Thematic data may be incorporated for the measurement of groundwater potential zones in the research area using remote sensing technologies. The number of parameters loaded, such as 4, 3, 2, and 1, in the studied region, was used to identify arti cial recharge sites. Based on the number of parameters loaded using GIS integration, the research area has been divided into priority I, II, and III suggested for arti cial recharge sites. The studied zones have been compared with the Land use and Landcover maps for adopting the suitable technique in the arti cial recharge zones.

Conclusions
From this research, an innovative method for determining groundwater recharge characteristics using GIS technology has been suggested for the Basaltic terrain of India. This research provided a map of the basaltic terrain's groundwater recharge potential. This research is critical for the long-term usage of groundwater resources, thus improving groundwater recharge through careful management. The ndings suggest that the use of GIS techniques assists groundwater research by expanding the areas of focus for comprehensive hydrogeological surveys on the site. According to the conclusions, the most e cient groundwater recharge potential region is situated in basaltic terrain. This research explores the complex relationships among groundwater recharge potential variables and groundwater recharge potential scores dependent on India's general hydrology characteristics. The maps generated by this approach could be used as a basic guide by government and water policy decision-makers when choosing appropriate locations for groundwater management practices.     concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. This map has been provided by the authors. Geomorphology Map. Note: The designations employed and the presentation of the material on this map do not imply the expression of any opinion whatsoever on the part of Research Square concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. This map has been provided by the authors.

Figure 5
Land Use Land Cover (LuLc) Map. Note: The designations employed and the presentation of the material on this map do not imply the expression of any opinion whatsoever on the part of Research Square concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. This map has been provided by the authors. Drainage Map. Note: The designations employed and the presentation of the material on this map do not imply the expression of any opinion whatsoever on the part of Research Square concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. This map has been provided by the authors.

Figure 7
Final Site Suitability Map. Note: The designations employed and the presentation of the material on this map do not imply the expression of any opinion whatsoever on the part of Research Square concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. This map has been provided by the authors.