Innovative watershed management is intense to unravelling watershed related problems on a sustainable manner. Planning and managing developmental practices in the watershed on a sustainable basis usually integrate water or land and both in the present in such a way to attain its goal in the future also (Said et al. 2006) 1. It includes the land and water resources development plan for enhancing the existing resource to a sustainable and resource action plan for the maintaining the resources from deterioration for the economic expansion in a watershed. The environmental constraints feasible through the implementation of integrated watershed planning and management in an innovative scientific approach (Said et al. 2006; Chowdary et al. 2009) 1, 2. The water-related problems in rain-fed agriculture are often related to high intensity and short duration rainfall, with large spatial and temporal variability, rather than to the low cumulative amount of rainfall (Ibrahim-Bathis and Ahmed, 2016a) 3. It has been increasingly recognised that in areas where agriculture is constrained by poor rainfall distribution in time and space, innovations that increase rainwater use efficiency and water management strategies have great potential to improve food security and livelihoods (Ibrahim-Bathis and Ahmed, 2016b) 4. For the innovative planning and Management in the watershed, analysing land degradation through the prioritisation watersheds, assessing the surface runoff, evaluating the Spatio-temporal distribution of the hydrological constraints, groundwater potential zone delineations and the suitable sites for the Rainwater Harvesting (RWH) are considered by spatial multi-criteria evaluation from the several thematic layers that are determined from the remote sensing and GIS technologies (Ibrahim-Bathis and Ahmed, 2014) 5. Geospatial science including the Remote sensing technique affords treasured and reliable spatial information on land and water resources (Chowdary et al. 2009; Ibrahim-Bathis and Ahmed, 2016a) 2, 3. Geographical Information System (GIS) with its proficiency of integrating and analysing the multi-layered spatial information to be an effective tool in the innovative planning for watershed development (Ibrahim-Bathis and Ahmed, 2016b) 4. These innovative spatial technologies contribute to reducing vulnerability to climate change and help minimise or even reverse land degradation.

The planning and management programs for sustainable development in the watershed, inventory on quantitative soil erosion loss and the priority classification of sub-watershed are essential (Ibrahim-Bathis and Ahmed, 2013) 6. The priority classification of the watershed can help in taking up soil conservation measures on a priority basis. The morphometric parameters which influence the soil erodibility are considered to prioritise the sub-watershed (Biswas et al.1999) 7. It includes the linear parameters such as mean bifurcation ratio (Rbm), drainage density (Dd), texture ratio (T), length of overland flow (Lo), stream frequency (Fs), and the shape factors are compactness constant (Cc), circularity ratio (Rc), elongation ratio (Re) and form factor (Ff). CartoDEM (1 arc second) was used to extract the drainages and delineate the watershed using Arc hydro Tool in the ArcGIS domain. The morphometric parameters were calculated using the standard formula from the literature (Ahmed et al. 2010; Ibrahim-Bathis and Ahmed, 2014) 8, 5]. The higher the drainage density (Dd), the more possibilities of erosion there are (Figure 1). Form factor (Ff) describes the shape of the watershed. The shape of the watershed is also responsible for the movement of silt. The more elongated the watershed, the lower the possibility of silt load reaching to the outlet. The ranking of the watersheds has been carried out for giving the highest priority/rank based on highest value for linear parameters and lowest value for shape parameters (Ibrahim-Bathis and Ahmed, 2013) 6. After the rating has been assigned based on every single parameter, the rating value for all the 24 sub-watersheds was averaged so as to arrive at a compound value (Table 1 and Figure 2). Compound value for sub-watersheds was used to prioritise on the basis of their severity for soil erosion; the lowest compound value has been given very high priority, and highest value has been given low priority (Ibrahim-Bathis and Ahmed, 2013) 6. The morphometric analysis can be used for prioritisation of sub-watershed even without the availability of reliable soil maps of the study area (Biswas et al. 1999) 7. The measurement and the implementation of the action plan to conserve and regulate the land from the soil degradation can be assessed on a priority basis.

The present research investigated the hydrogeological determinants to assess the sensitivity of each factor to the infiltration pattern in the Doddahalla watershed. Infiltration is the water penetration into the soil and subsurface layer from the precipitation or by snowfall. Infiltration are soil hydraulic properties that direct the access of water to the soil and its successive vertical movement or storage in the subsurface (Omuto and Gumbe 2009; Zhao et al. 2013) 10, 11. Infiltration is a key important in agriculture and water research because of its necessary role agricultural irrigation, land-surface and subsurface hydrology (Zouheira et al. 2015) 12, 13. Designing the efficient irrigation systems for the sustainable agriculture in the arid and semi-arid region requires the prior knowledge of the infiltration characteristics of soil (Machiwal et al. 2006; Pedretti et al. 2011; Ibrahim-bathis and Ahmed, 2016a) 14, 15, 3 is varied spatially and temporally. Dry soils infiltrate more rapidly, and eventually it reaches a steady rate when all the air pores in the soil layer are filled with the water. Quantitative measurement of the rate of soil infiltration in a watershed is difficult because it depends on many factors such as soil texture, surface topography, the intensity of rainfall and vegetation cover (Brouwer et al. 1988; Zouheira et al. 2015) 13 also get flourished (Ma et al. 2010; Nampak et al; Zouheira et al. 2015) 12, 16, 13.

Groundwater, or subsurface water, is a term used to denote all the waters found beneath the ground surface. It is one of the most significant natural resources worldwide serving as a primary source of water for communities for domestic purpose, industries, agricultural productions (Pradhan, 2009; Ayazi et al. 2010; Manap et al. 2012; Ibrahim-bathis and Ahmed, 2016a) 18, 19, 20, 3, and for tourist developments (Jaturon Konkul et al. 2014) 21. Groundwater is naturally replenished by rain or snow melts which seep down through the soil and/or through pore spaces of underlying rocks (Nampak et al. 2014) 16. Hence, its occurrence and distribution depend on the climate and regional setting of the region, surface and subsurface characteristics such as fractures in the underlying rock, land use type, geomorphic features, structural features and their interrelationships with the hydrological characteristics (Jaturon Konkul et al. 2014) 21. Groundwater demand is drastically increasing due to the immense pressure on population and urbanisation, global impact due to climate and weather change, repetitive drought condition and lack of rainfall. Over exploitation of the groundwater resource caused a sudden decline in the groundwater table and an excess in the sustainability of groundwater resources (Jaturon Konkul et al. 2014; Ibrahim-bathis and Ahmed, 2016a) 21, 3. Especially the agrarian states like Karnataka, the groundwater dependence is high. Recent studies indicate that 26 % of the area of Karnataka state is under over exploited category and numbers of villages are under the critical category (Central Ground Water Board, 2013) 22. The complexity of conventional exploration methods such as field-based hydrogeological, geophysical resistivity surveys, exploratory drilling which is more time-consuming and very expensive, supports the application of satellite-based Geospatial Science. Hydrologists have utilised the Geospatial technology for the groundwater mapping by integrating thematic maps such as geomorphology, drainage pattern, lineament, soil, rainfall intensity and soil texture, resistivity, aquifer thickness, or fault maps (Chowdary et al. 2009; Nampak et al. 2014) 2, 16. The groundwater prospective zone mapping was carried out by integrating the thematic maps such Land use land cover, Geomorphology, Soil texture and depth, Slope, Lineament, Drainage and Rainfall maps in a spatial domain of GIS environment. Cartosat-1 DEM (30m), Landsat 8 Operational Land Imager (OLI -30m), Survey of India (SOI) toposheets (57 B/7, 57 B/8, 57 B/11, 57 B/12, 57 B/15 and57 B/16) and High resolution satellite images from Google Earth (Digital Globe, Astrium and SPOT) were used for preparation of thematic maps.

The water is the most limiting resource in the arid and semi-arid region where the rainfall is low and highly variable in the inter- and intra-season and often inadequate for the economic progress in agricultural and crop production (Barron et al. 2003; Ziadat et al. 2012; Glendenning et al. 2015) 25, 26, 27. In order to prevent the excess runoff of the storm water that is often lost during the rainy season, rainwater harvesting (RWH) is an efficient approach in the semi-arid and arid regions. The rapid urbanisation and drastic growth in the population density in the developing countries like India RWH and conservation is increasingly recognized as critical effort to attainment the economic and financial sustainability, to overcome the uneven water supplies and avoiding the drinking and irrigation water scarcity (Shah, 1998; Sekar and Randhir, 2007; Ziadat et al. 2012; Yousif et al. 2015) 28, 29, 26. The RWH imply the watershed to retain the rainwater and consent delay in the transfer of surface runoff into groundwater, evaporation and transpiration. This process of transfer of blue water (rivers and aquifers) into green water (soil water and plant water use) impact and change the hydrological balance of a watershed by the potential increase in the available surface and groundwater resources (Glendenning et al. 2015) 27. This sustainability would improve the socio-economic and financial status through agricultural crop production and other domestic practices engaged in the watershed. Though the RWH is beneficial to the developmental purpose of the watershed, the poor selection of suitable sites and efficient structure causes the major reason for the failure of RWH projects and the slow adoption of rainwater harvesting techniques in many parts of the world (Oweis et al. 1998; Ziadat et al. 2012; Yousif et al. 2015; Glendenning et al. 2015) 30, 26, 31, 27. Hence, the RWH technology is worthwhile when it is approached through the Geospatial science. The advance and modern space sensor derived satellite images could afford the best selection of the RWH sites and the Geographical Information System (GIS) oriented Decision support system (DSS) enhances the convenient structure for the RWH in the watershed. Several aspects of the terrain and climatic variable, as well as socio-economic facet, have to investigate prior to the implementation of any RWH projects. This includes the land use and land cover feature, topography, rainfall and distance to the human settlement and the utility systems (Glendenning et al. 2015) 27. The amount and the intensity of the rainfall is a key criterion for the RWH. Soil depth and texture govern the amount of water can store in the soil profile. Green vegetation and stoniness are indicators of the potentiality of land to sustenance rainwater harvesting. The RWH has multiple benefits to agriculture and other domestic uses and merely is a challenge in many regions because of the variability in precipitation in semi-arid regions (Ziadat et al. 2012; Yousif et al. 2015) 26, 31. The RWH is essential for the water resources sustainability and to overcome the inadequacy of waters demands, to increase infiltration and enhance groundwater quality in the water scarce region. To increase agriculture production and to improve the ecology of the area by an increase in vegetation cover RWH is ultimate choice in the watershed. The RWH has also reduced flood hazards and mitigates the effects of drought. The RWH reduces soil erosion and storm runoff in a terrain and steep topography.

Most of the developed and developing countries in the world follow the strict laws and rules for the RWH to minimise the water crises. In India, RWH is dates backs to the pioneer civilisation. The tank system is traditionally the backbone of agricultural production in arid and semi-arid areas of India (Glendenning et al. 2015) 27. The importance of harvesting and conservation is earnestly coated in the all the religion, and they treated as the sacred place. The present decade the roof top RWH method was made compulsory for every new building to avoid groundwater depletion in the country. Tamil Nadu state took it as role model and given excellent results in its implementation and recorded the rise in water level and significantly improved the water quality. The Doddahalla watershed is water scarce semi-arid region with frequent drought. The rain is variant and records very little amount in the peak season. The RWH is the vital choice for surface and groundwater sustenance of water resource in the watershed. The agriculture and other allied activities predominantly depend on the rain. Most of the crops grown here is rainfed. There are many success stories in the Thar Desert and especially in the Sub-Saharan Africa (SSA) countries which employed the most advanced RWH technologies for the drought mitigation and over the water scarcity problem. Some of the widespread and important land and water harvesting technology are expressed to implement in the water scarce Doddahalla watershed to over in the water scarce related issues. The best fit water harvesting structures are selected by considering the terrain and climatic favourability of the study area and their implementation sites are suggested through the spatial multi-criteria process using the Geospatial technology (Figure 7).

The sustainable management of the natural resources in a region is only possible when the available resources are well planned and managed. The executing the ideal and most suitable cropping pattern in an area is an indication of the sustainability planning in the region. The selecting the ideal crop means the crop water requirements has to fulfill with available water through irrigation. This requires the estimation of crop water require and the amount of available water resources. The crop water requirements depend on the type of crop i.e., a fully developed maize crop needs more water per day than a fully developed crop of onions (Ibrahim-Bathis et al. 2021) 32. The duration of the growing period also influences the water need of particular crops i.e. short duration crops require less water than the long duration crops. The daily water need of melons is less than the daily water need of peas, but the seasonal water need of melons is might higher than the beans. The Groundnut, Maize, Ragi, Jowar, Sunflower and Onion are the major crops cultivated in the Doddahalla watershed. The crops require the fertile soil and water. The amount of the water needs and the types of soil is differing from the crops to crop (Ibrahim-Bathis et al. 2021) 32.

Groundnut is an important oilseed crop in the study area. The crop can be grown in places receiving a minimum rainfall of 500 mm and a maximum rainfall of 1,250 mm. Groundnut is a rain-fed Kharif crop, being sown from May to June, depending on the monsoon rains. Sandy loam and loamy soils and also black soils are good for this crop. Ragi also known as finger millet is an important cereal, grown in areas with rainfall ranging from 500­1000 mm and in the irrigated areas of the watershed. The Ragi crop is well suited in red loams, black and sandy loams. The rain fed crop is cultivated both as a Kharif and Rabi crop. Maize is a short duration warm weather crop and grown in any type of soil ranging from well-drained deep heavy clays to light sandy soils. Maize is highly susceptible to salinity and water logging during seedling stage. The soil with high water holding capacity and good drainage is ideally suited for maize cultivation. Jowar is the most important food and fodder crop of dryland agriculture. The Rabi Jowar are wholly confined to black cotton soils, and the Kharif Jowar are grown on light soils. Sunflower is another important oilseed crop requires a cool climate and thrives well in deep and well-drained light soils (Ibrahim-Bathis et al. 2021) 32. It performs well in the black cotton soils Deccan plateau. The multi-layer thematic integration is processed to the select the ideal crops in the watershed considering the soil, rainfall and cropping pattern in the region (Figure 8).

The multi criteria analysis provides indigenous knowledge to identify and locate the suitable areas for RWH. The sustainable RWH will improve the surface and ground water level, this in turn improve the economy of the watershed. Sensitivity analysis was conducted prior to assigning weights to influencing factors and locating the suitable areas for RWH in the study. Due to the scarcity of the water resources and poor distribution of rains, the RWH is considered an alternative and viable water supply system, particularly during the dry periods in the Doddahalla watershed.