Micro-Watershed Data Analysis Report

Landscape Overview

The micro-watershed 12_308006 is in Tehsil Godda, which lies in district Godda in Jharkhand, which has towns and cities of Godda.

Fig: Tehsil map with MWS highlighted. MWS id: 12_308006

Hydrology and Land Use Land Cover in this Microwatershed

BASIN SHAPE

DRAINAGE NETWORK

GROUNDWATER & AQUIFER CHARACTERISTICS

TERRAIN AND LAND USE LAND COVER

SEASONAL WATER AVAILABILITY AND CROPPING AREA

Land Use Land Cover

Terrain

The microwatershed relief is 49.68m and the mean elevation is 124.59m.

The micro-watershed is spread across 935.35 hectares. The micro-watershed mainly consists of flat plains covering 91.26 % micro-watershed area. Cropping areas on plains may benefit from checkdams on gentle slopes and farm ponds and bunds on plain cropped areas to improve drought protection during Kharif and soil moisture for Rabi cropping.

Note: Data used for land use land cover classification is remotely sensed from satellites including LandSat-7, LandSat-8, Sentinel-2, Sentinel-1, MODIS and Dynamic World.

Cropping Intensity

The cropping intensity of this area has stayed steady at 1.33. It might be possible to improve cropping intensity through more strategic placement, while keeping equity in mind, of rainwater harvesting or groundwater recharge structures.

Note: We use annual land use land cover (LULC), to identify areas under single cropping, double cropping and triple cropping using pixels which are classified as single kharif, single non-kharif, double and triple classes of LULC classifier to determine cropping intensity. The data used is from 2017 to 2024.

Note: NDVI (Normalized Difference Vegetation Index) is computed over cropped areas in this microwatershed at ~14-day intervals using satellite imagery, and reflects the vigour of vegetation/crop growth over time. Green dots are the raw NDVI values; the blue line is a Whittaker-smoothed trend fitted through them. Whittaker smoothing balances two goals at once — staying close to the raw values while penalizing sharp changes in the curve's slope (its second derivative) — solved as a single linear system rather than a moving average, so it smooths out cloud/noise-driven spikes while preserving the underlying seasonal growth pattern.

Soil Health

Soil health is a foundational indicator for agricultural resilience, land degradation assessment, and precision farming interventions. Nitrogen, phosphorus, and potassium (NPK) concentrations in a microwatershed indicate soil fertility, guide targeted fertilizer use, and help prevent water pollution. Nitrogen concentration in this microwatershed is 254.56 kg/ha, Phosphorus concentration is 26.82 kg/ha and Potassium concentration is 181.02 kg/ha. Organic carbon, which is an indicator of soil's capacity to hold other nitrogen, phosphorus, and potassium, helps retain soil moisture and reduce soil erosion, and drives nutrient cycling, has a concentration of 0.56% in this microwatershed. The soil is Moderately well drained, has a Sandy clay loam texture and has a pH of 6.43.

Note: Ground truth sampling data from Government of India’s Soil Health Card portal was integrated with satellite derived features to compute all parameters. A cropland LULC mask was applied prior to prediction to restrict outputs to active agricultural land. Final rasters are generated at 30 m spatial resolution.

Cropping degradation

There has been a considerate level of degradation of farmlands in this micro watershed over the years 2017-2024. As compared to average degraded land area of 35.22 hectares for the entire block, the degraded land area in this micro-watershed is close to 65.7 hectares.

Note: The degradation in cropping is computed using the IndiaSAT Land Use Land Cover outputs. Transitions from farmland to barren land, shrubs, human settlements (built-up) are computed

Reduction and degradation of tree cover

In about 22.41 hectares of area, there has been a total loss of tree cover, while reduction in canopy density and/or height of tree cover has been noted at about 0.68 hectares during 2017-24. The organic carbon concentration across tree cover in this microwatershed is 1%.

Note: NDVI (Normalized Difference Vegetation Index) is computed over tree-covered areas in this microwatershed at ~14-day intervals using satellite imagery, and reflects the vigour of tree/forest growth over time. Green dots are the raw NDVI values; the blue line is a Whittaker-smoothed trend fitted through them (see the Cropping Intensity section for how the smoothing is computed).

Note: The reduction in tree cover is computed using the IndiaSAT Land Use Land Cover outputs. Transitions from tree cover to barren land, shrubs, human settlements (built-up) or farmland are computed.

4.82 hectares of this microwatershed has less than 40% canopy density and requires wide scale restoration interventions.

Increase in Tree Cover

There has been a considerate increase in tree cover in this micro watershed over the years 2017-2024, with about 35.36 hectares of new tree cover gained, as compared to 52.75 hectares per micro watershed in the entire block.

Note: The increase in tree cover is computed using the IndiaSAT Land Use Land Cover outputs. Transitions from barren land, human settlements (built-up), farmland or shrubs to tree cover are computed.

Water availability in this microwatershed

The waterbodies in this microwatershed span a total area of 0.39 hectares, covering about 0.04% of the microwatershed. 10.0% of water bodies have a declining trend of surface water availability over the years 2017 to 2024. The drainage density in this micro-watershed is 1.99. 1 river are present.

The surface water presence has remained steady during 2017 to 2024.

In non-drought years, surface water in kharif typically decreases by 10.28% in rabi.

The average surface water availability in this micro watershed during the Rabi season is 0.04%, while during the Zaid season, it is 0.02%.

Note: We use Sentinel-1 (SAR data) VV band for water pixel detection in Kharif season and Dynamic World to detect water pixels in Rabi and Zaid seasons.

Water Balance

Note: Precipitation data is calculated from the Global Satellite Mapping of Precipitation (GSMaP) dataset available on Google Earth Engine's data catalogue. GSMaP provides a global precipitation in mm/hr at spatial resolution of approximately 11km. Runoff is calculated using precipitation data (GSMaP at 11 km resolution), soil type (HYSOGs250m dataset), slope (NASA SRTM DEM dataset at 30 m resolution) and land cover (Dynamic World dataset at 10m resolution). For further information on the computation, refer our technical manual.

Note: Computed by subtracting outgoing fluxes (runoff and evaporatranspiration) from incoming water (precipitation).

A water balance study of the microwatershed indicates whether it is helping conserve water or deplete water from the underlying aquifer. Incoming water into a microwatershed is predominantly through rainfall. Some of this is lost as runoff while the rest percolates into the ground. Crops pull some of this groundwater, and borewells for irrigation may pull groundwater from deeper aquifers too. A positive water balance indicates that less of the incoming water is lost, while a negative water balance indicates that the microwatershed takes away more water.

The water balance is positive and indicates that the groundwater situation in this microwatershed may be stable. Year on year, the groundwater situation seems to be improving.

In the micro-watershed, 2017, 2018, 2019, 2020, 2021, 2022, 2023 and 2024 were good rainfall years,bringing an average annual rainfall of approximately 1019.25 mm with monsoon onset between [05-28, 05-29].This rainfall pattern resulted in positive groundwater recharge, with average groundwater change of 211.2 mm, indicating replenishment of groundwater resources. During these years, around 18.16 % of the rainfall became surface runoff, offering potential for water harvesting, although this should be evaluated carefully so as to not impact downstream micro-watersheds.

Do note that currently we only consider the vertical flux in the microwatershed. We are working on how to model incoming runoff into the microwatershed, as well as sub-surface flow from adjacent areas.

Drought Analysis

Refer to the following graph and see how the intensity of drought has changed in this microwatershed over the years

A Drought year is declared if the total number of weeks under severe intensity drought and moderate intensity drought equal or exceeds 5, which means that the rainfall deficit was more than 25% for more than 5 weeks during the monsoon of that year.

The occurrence of dry spell is defined across four consecutive weeks with each week of these four weeks incurring a rainfall deviation of less than 50%. Prolonged dry spells can lead to significant reduction in crop sown area.

Note: Drought is defined as per the Government of India's Drought Manual and considered moderate or severe if the number of weeks of drought is five or more. Drought weeks are identified based on whether meteorological drought occurred in that week (i.e. the rains were less than usual in that week as compared to previous years, possibly intensified by dry spells defined as consecutive weeks of low rainfall) and/or agricultural drought occurred in that week (i.e. cropped area or crop health were lower than usual in that week as compared to previous years). Severe drought weeks are those when meteorological and agricultural drought are both coincident.