Changes in version 0.1.0 (2026-04-16)                  

First CRAN release

New functions (16 exported)

  - calc_bcr() -- Benefit-cost ratio with discounting, benefit lag,
    residual value.
  - calc_npv() -- Net present value with annual cash-flow table.
  - calc_irr() -- Internal rate of return via bisection (Brent 1973).
  - calc_pbp() -- Simple and discounted payback period.
  - calc_mrr() -- Marginal rate of return (CIMMYT 1988).
  - calc_mbcr() -- Modified benefit-cost ratio (Gittinger 1982).
  - calc_soil_loss_cost() -- USLE-based soil loss economic valuation.
  - calc_nutrient_cost() -- NPK replacement cost from erosion.
  - calc_water_value() -- Groundwater recharge and runoff harvesting
    value.
  - calc_irrigation_benefit() -- Additional crop income from SWC-enabled
    irrigation.
  - calc_employment() -- Employment generation ratio with MGNREGS norm
    check.
  - sensitivity_analysis() -- One-at-a-time sensitivity analysis (8
    scenarios).
  - calc_switching_value() -- Switching value for cost and benefit.
  - monte_carlo_swc() -- Stochastic BCR/NPV simulation (Pouliquen 1970).
  - run_swc_pipeline() -- Full appraisal pipeline in one call.
  - generate_swc_report() -- Self-contained HTML economic appraisal
    report.

Datasets (6)

  - swc_benchmarks -- Real: NABARD WDF Reports 2010-2022; PMKSY-WDC
    (GoI).
  - usle_india_soils -- Real: NBSS and LUP Technical Bulletin 132
    (ICAR).
  - rainfall_erosivity_india -- Real: IMD + Bhattacharyya et al. (2010).
  - swc_cost_norms -- Real: PMKSY-WDC Common Guidelines (GoI 2015).
  - watershed_projects -- Hypothetical: set.seed(2025), 50 projects.
  - farmer_adoption -- Hypothetical: set.seed(2025), 120 households.

Technical notes

  - All source files are pure ASCII -- CRAN portable.
  - Dataset documentation uses NULL sentinel pattern for roxygen2
    compatibility.
  - Zero runtime dependencies beyond base R (stats, graphics, grDevices,
    utils).
  - markdown = FALSE in DESCRIPTION -- plain Rd syntax throughout.